[LyX GSoC/tex4htTesting] Added the tex file for the previous commit. Run "mk4ht ooxelatex PS_Report_Final.tex imageconv.cfg" for the conversion

[Prannoy Pilligundla]

The branch, tex4htTesting, has been updated.

- Log -----------------------------------------------------------------

commit 32bb3609197b3422fb987980536e2020e3439521
Author: Prannoy Pilligundla <prannoy.b...@gmail.com>
Date:   Tue Aug 5 00:17:59 2014 +0530

    Added the tex file for the previous commit. Run "mk4ht ooxelatex 
PS_Report_Final.tex imageconv.cfg" for the conversion

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+%% LyX 2.1.0dev created this file.  For more info, see http://www.lyx.org/.
+%% Do not edit unless you really know what you are doing.
+\documentclass[english]{report}
+\usepackage[T1]{fontenc}
+\setcounter{secnumdepth}{3}
+\setcounter{tocdepth}{3}
+\usepackage{graphicx}
+\usepackage{subscript}
+\usepackage{babel}
+\begin{document}
+
+\title{Implementing PLC based system in Upgrading Plant}
+
+
+\author{Prannoy Pilligundla 2012A8PS264P\\
+Siddarth Singh 2012AAPS823P\\
+Vineet Cherian 2012A3PS015P}
+
+\maketitle
+\tableofcontents
+\begin{abstract}
+Heavy water which is used a moderator in a PHWR is often contaminated
+with some chemical impurities and Light water. The chemical impurities
+like corrosion products, oil, dirt etc are removed from the downgraded
+Heavy water in the cleanup system before sending it to Upgrading plant
+for further processing. Basis of seperation of Heavy water and Light
+water is the difference in Boiling point of 1.41\textsuperscript{o}C.
+Upgrading is done by the continuous distillation under sub-atmospheric
+condition. The downgraded heavy water is boiled in a reboiler and
+made to ascend through the packed distillation column. It is condensed
+at the top in the reflux condensor and the condensed liquid is putback
+at the top of the tower as reflux. The vapour ascending and liquid
+descending will come in intimate contact in tower section. Due to
+this mass transfer takes place. Ligher component H\textsubscript{2}O
+is transferred to the vapour phase from liquid phase. The mass transfer
+taking place in the tower sets up a concentration gradient throughout
+the tower section. Thus at the bottom of the tower it will be pure
+heavy water and at the top of the column it will be light water. The
+process instrumentation logic is based on the philosophy of simple
+and safe operation. Interlocks have been provided with process parameters
+to trip the plant whenever unsafe conditions are developed.
+
+Our main objective here is to upgrade an existing relay based control
+system with a Programmable Logic Controller(PLC) in this Heavy Water
+Upgradation Plant
+\end{abstract}
+Heavy water which is used a moderator in a PHWR is often contaminated
+with some chemical impurities and Light water. The chemical impurities
+like corrosion products, oil, dirt etc are removed from the downgraded
+Heavy water in the cleanup system before sending it to Upgrading plant
+for further processing. Basis of seperation of Heavy water and Light
+water is the difference in Boiling point of 1.41\textsuperscript{o}C.
+Upgrading is done by the continuous distillation under sub-atmospheric
+condition. The downgraded heavy water is boiled in a reboiler and
+made to ascend through the packed distillation column. It is condensed
+at the top in the reflux condensor and the condensed liquid is putback
+at the top of the tower as reflux. The vapour ascending and liquid
+descending will come in intimate contact in tower section. Due to
+this mass transfer takes place. Ligher component H\textsubscript{2}O
+is transferred to the vapour phase from liquid phase. The mass transfer
+taking place in the tower sets up a concentration gradient throughout
+the tower section. Thus at the bottom of the tower it will be pure
+heavy water and at the top of the column it will be light water. The
+process instrumentation logic is based on the philosophy of simple
+and safe operation. Interlocks have been provided with process parameters
+to trip the plant whenever unsafe conditions are developed.
+
+
+\chapter{Upgrading Plant}
+
+
+\section{Introduction}
+
+The Madras Atomic Power Station is designed of the CANDU type,almost
+similar to the Rajasthan Atomic Power Station. The Nuclear reactor
+is of natural Uranium, Heavy water moderated and cooled. This Heavy
+Water gets depleted due to leakages in the system. These leakages
+are mainly collected from fuelling machine vault, Primary heat transfer
+system and boiler room. In the ``PHWR'' type of reactors heavy water
+is used both as moderator and as heat transport fluid. Downgrading
+of high quality water occurs through two mechanisms:
+\begin{enumerate}
+\item Light water leakage into the heavy water system.
+\item Heavy water escape from PHT and Moderator systems where it comes in
+contact with light water
+\end{enumerate}
+Downgraded D\textsubscript{2}O is a mixture of light water, D\textsubscript{2}O
+and other solid and chemical impurities. The downgraded heavy water
+containing various chemical impurities render the heavy water unfit
+for use without further processing. The chemical impurities like corrosion
+products, oil, dirt etc are removed from the downgraded heavy water
+in the clean up system before sending it to the upgrading plant for
+further processing. The chemical purity should be strictly followed
+before processing the downgraded heavy water in the distillation plant. 
+
+\emph{Design Capacity of Distillation Columns}: The distillation plant
+has been designed to process 36 litres/hr of 60\%(w/w) and 36 litres/hr
+of 30\%(w/w) for bottom product at 99.8\% D\textsubscript{2}O(w/w)
+with top reject of 0.5\% D\textsubscript{2}O(w/w). Based on the above
+performance data at 7800 operating hours oer year the annual plant
+capacity is expected to be 250 tonnes of reactor grade Heavy Water.
+
+
+\section{Distillation Processs}
+
+
+\subsection{Principle of Operation}
+
+Heavy Water(D\textsubscript{2}O) and Light Water(H\textsubscript{2}O)
+are alike in their chemical properties but differ in their physical
+properties. At atmospheric pressure the boiling point of H\textsubscript{2}O
+is 100\textsuperscript{o}C and boiling point of D\textsubscript{2}O
+is 101.42\textsuperscript{o}C. Thus relative volatility ( Boiling
+point difference i.e 1.42\textsuperscript{o}C) is basis for seperation
+of D\textsubscript{2}O and H\textsubscript{2}O in the distillation
+column.
+
+Upgrading is done by continuous distillation under sub atmospheric
+condition. The downgraded heavy water is boiled in a reboiler and
+made to ascend through the packed distillation column. It is condensed
+at top in the reflux condenser and the condensed liquid is put back
+at the top of the tower as reflux. The vapour ascending and liquid
+descending will come in intimate contact in the tower section. Due
+to this mass transfer takes place. Lighter component(H\textsubscript{2}O)
+is transferred to the vapour phase from liquid phase. The mass tranfer
+taking place in the tower sets up a concentration gradient throughout
+the tower section. Thus at the bottom of the tower,it will be pure
+heavy water and at the top of column it will be light water.
+
+Part of the reboiler vapour is taken as product and part of the condensed
+liquid from the reflux condenser is collected as reject (IP ≤0.25\%w/w).
+Depending on the feed concentration, feed is put into the tower at
+some point along the height of the tower where the feed concentration
+matches with the local concentration of the tower.
+
+
+\subsection{Process}
+
+The principle of the distillation and equilibrium condition are mentioned
+above. It takes nearly three days i.e 72 hours to achieve this equilibrium
+condition. Feed in the form of vapour will be added at a point in
+the column where its Isotopic Purity (I.P) matches with the column
+section I.P. Reject is removed from the top as a liquid and product
+is taken from the bottom. One important thing to be noticed is, the
+equilibrium should not be disturbed at any condition. This is possible
+if the feed rate is equal to the reject rate plus product rate. This
+is given below as the material balance equation.
+
+\begin{equation}
+F=P+R
+\end{equation}
+
+
+\[
+F=\mathrm{Feed}\: Rate\: in\: lit/hr
+\]
+
+
+\[
+P=Product\: Rate\; in\: lit/hr
+\]
+
+
+\[
+R=Reject\: rate\: in\: lit/hr
+\]
+
+
+Mole fraction or Component(D\textsubscript{2}O) balance is given
+by
+
+\begin{equation}
+FX_{F}=PX_{P}+RX_{R}
+\end{equation}
+
+
+\[
+X_{F}=D_{2}O\: fraction\: of\: feed
+\]
+
+
+\[
+X_{P}=D_{2}O\: fraction\: of\: feed
+\]
+
+
+\[
+X_{R}=D_{2}O\: fraction\: of\: Reject
+\]
+
+
+As per design, for a specified feed I.P the feed rate should not exceed
+above a certain value. This is given in the table and also in the
+graph. Product and Reject I.P's are as oer our requirements i.e reject
+I.P<0.25\% and Product I.P>99.97\% for moderator grade and >99.4\%
+for PHT grade liquid. Hence 
X\textsubscript{F},X\textsubscript{P},X\textsubscript{R}
+and F are fixed. To find out the product and reject rates the above
+two equations can be solved to get
+
+\begin{equation}
+P=\frac{F(X_{F}-X_{R})}{(X_{P}-X_{R})}
+\end{equation}
+
+
+\begin{equation}
+R=F-P
+\end{equation}
+
+
+For a distillation column the seperation factor achieved is 1.05.
+Seperation factor is defined as follows:
+
+\[
+Seperation\: Factor=\frac{\frac{atom\: fraction\: of\: H_{2}}{atom\: 
fraction\: of\: D_{2}}\: in\: gas}{\quad\frac{atom\: fraction\: of\: 
H_{2}}{atom\: fraction\: of\: D_{2}}\: in\: liquid}
+\]
+
+
+The maximum attainable seperation factor is 1.05 as per design. To
+achieve this the column pressure should be reduced. This pressure
+cannot be reduced beyond a certain value because of the increase in
+the specific volume of vapour which inturn leads to very high column
+dimensions and inturn increases the column cost. Since the process
+water temperature is limited around 33\textsuperscript{o}C, there
+is always a lower limit on the temperature of the vapour which is
+required to be cooled, so that efficient condensation can take place.
+(This inturn means a low pressure restriction inside the column top,
+which is 120mm of Hg absolute). Column sump pressure is around 230mm
+of Hg.abs.
+
+
+\subsection{Definitions}
+
+
+\paragraph{Total Reflux}
+
+Total Reflux implies that there is no feed, no product, and reject
+take off i.e 3493 CV-53, 3493 CV-272, 3493 CV-73 and 3493 CV-134 are
+closed.
+
+
+\paragraph{Shut down of the distillation column}
+
+In addition to the total reflux state, the reboiler steam control
+CV-266 is also closed in this state.
+
+
+\subsection{Specification of feed D\protect\textsubscript{2}O}
+\begin{enumerate}
+\item K ≤ 5 micromho/cm or microsiemens/cm
+\item PH 6.5 to 8
+\item Chloride ≤ 0.5ppm
+\item Nitrate ≤ 1ppm
+\item Oil Free
+\item Particulate matter free
+\item Organic materials ≤ 10ppm ammonia and amines
+\end{enumerate}
+
+\section{Equipment Description}
+
+
+\subsection{Distillation Column}
+
+Distillation column consists of 14 identical sections with sump at
+the bottom. At the top of the column reflux condenser CD-4 and a vent
+condenser CD-5 are present to condense the vapours. Operating temperature
+and pressure varies from 74\textsuperscript{o}C and 230mm Hg(abs)-at
+column sump to 56\textsuperscript{o}C and 120mm Hg(abs) at the top.
+Outside diameter and height of each column section is ∓2.5mm and 3200∓3mm
+respectively. Each column section is packed with corrugated phosphor
+bronze wire mesh packing with a coating of copper oxide for surface
+activation which increases wet surface. This packing is supported
+by means of a bottom ring. The top support ring supports the liquid
+distributor, which distributes the liquid evenly on the packing. Liquid
+collector collects the downcoming liquid and puts it onto the distribution
+without hindering the vapour flow. For the fourteenth section liquid
+collector is not required
+
+
+\subsection{Column Sump}
+
+Column sump at the bottom of the column holds the downcoming reflux
+liquid from the distillation column and provides flooded suction to
+the reboiler circulating pump. Capacity of the sump is decided on
+the initial hold up required for flooding the distillation column.
+This requirement is around 3 tonnes.
+
+
+\subsection{Reboiler EV-2}
+
+A falling film type reboiler is provided for reboiling the reflux
+liquid of the distillation tower. It is a shell and tube type 1-1Hx.
+Liquid is pumped to the top of the tubesheet of the reboiler and falls
+thorugh the tubes in the form of a film and is vapourised. The vapour
+along with the liquid comes down from the bottom side and enters the
+column sump. For getting a good heat transfer coefficient a 4.5:1
+circulation ratio is to be used.
+
+Special features of falling film reboiler are:
+\begin{itemize}
+\item High heat tranfer coefficient due to the turbulent film flowin tubes.
+\item Low hold up because tubes are not completely filled.
+\end{itemize}
+
+\subsection{Reflux Condenser(CD-4)}
+
+This is a 2-2 shell and tube Hx, cooled by process water, used to
+condense the ascending vapours and to provide reflux to distillation
+column. In the vapour hood portion an annular space serves as the
+reflux drum, where condensate gets collected and overflows into the
+distillation column. This reduces the reflux holdup considerably.
+The temperature of the column at the reflux end is 55.3\textsuperscript{o}C.
+
+
+\subsection{Feed Evaporator(EV-1)}
+
+It is a jacketed vessel with a surface area of 1.2Sq.m. Feed heavy
+water is boiled in this vessel and is fed to the column in the vapour
+form. Steam condenses in the jacket and goes to steam condensate collection
+tank TK-15.
+
+
+\subsection{Product Condenser(CD-2)}
+
+This is a 1:2 shell and tube type of Hx with a surface are of 
5.5M\textsuperscript{2}
+used to condensate the vapour form the collection sump which goes
+down to the product tank TK-10.
+
+
+\subsection{Vent Condenser(CD-5)}
+
+This is a 1:2 shell and tube condenser with a surface are of 
3.6M\textsuperscript{2}which
+condenses any vapour that escapes uncondensed from the reflux condenser.
+Chilled water is used as the cooling media in this condenser.
+
+
+\subsection{Exhaust Cooler(CD-1)}
+
+It is a 1:2 shell and tube type condenser used to trap any vapour
+escaping from vacuum pump exhaust, feed tank and feed overflow tank
+vent line.
+
+
+\subsection{Product vent condenser CD-6 and Product tank vent cold trap CD-3}
+
+Both are of similar geometry and construction. CD-6 condenses the
+escaping vapours from product condenser whereas CD-3 acts as a trap
+for product tank TK-10
+
+
+\subsection{Water circulating tank TK-4 vacuum pump and cyclone seperators(TK-2
+\& TK-3)}
+
+To create and maintain vacuum at the distillation column two 100\%
+capacity vacuum pumps are used. To provide cooling two 100\% capacity
+vacuum pumps are used. To provide cooling water for these pumps at
+the rate of 14lpm in a closed loop circulation arrangement, a water
+circulating tank and two 100\% capacity pumps are provided. A chilled
+water cooling arrangement is provided for cooling the seal liquid
+TK-4. A cyclone separator is provided at the exhaust of each vacuum
+pump to separate the seal water from the exhaust vapours going to
+exhaust cooler thereby reducing the load on the exhaust cooler, 
\textsubscript{1}H\textsuperscript{3 }affinity
+towards water is more and so it gets diluted with water and 
\textsubscript{1}H\textsuperscript{3}
+free air which further cooled in CD-1 is sent out to atmosphere.
+
+
+\subsection{Feed tank TK-5 \& TK-13}
+
+This tank stores the depleted D\textsubscript{2}O from the evaporation
+clean up section. Capacity of these tanks are 3170 litres eac. This
+is based on holding 48 hours feed at a time for the distillation tower.
+The second tank is used to prepare feed stock when the first one is
+in stream.
+
+
+\subsection{Product storage tank TK-10}
+
+Reactor grade D\textsubscript{2}O is collected in this tank from
+the distillation process. This is intermittently pump to drums and
+sent to station whenever required.
+
+
+\subsection{Reject storage tank TK-10}
+
+Reject containing ≤ 0.25\% I.P liquid is collected in this tank and
+then it is sent out to liquid effluent management plant(LEMP).
+
+
+\subsection{Feed Overflow tank TK-6}
+
+This tank provides feed flow to the feed evaporator at constant head
+which can be further controlled by a flow control loop arrangement
+controlling CV-53.
+
+
+\subsection{Buffer tank TK-1}
+
+This tank acts as a buffer in the vacuum system.
+
+
+\subsection{Steam Condensate tank TK-15}
+
+This tank collects the steam condensate from evaporator EV-1 \& EV-2
+and puts back the condensates to deaerator for steam generation in
+the boilers with the help of steam condensate pumps 4321-P-16 \& P-17.
+
+
+\subsection{Product \& Reject overflow vessels TK-8 \& TK-9}
+
+These two graduated vessels have the following functions
+\begin{enumerate}
+\item To keep sufficient holdup of liquid to provide barometer head
+\item To calibrate the product and reject flow through orifices. They are
+provided with integral visual level gauges.
+\end{enumerate}
+
+\subsection{Pumps}
+
+All pumps are used in the upgrading plant for D\textsubscript{2}O
+service are canned motor pumps to attain zero leakage.
+
+
+\subsection{Reboiler circulating pumps}
+
+These pumps provide circulation for falling film type reboiler EV-2.
+Only one pump is operated at a time. The other pump will be standby.
+
+
+\subsection{Feed, Product and Reject transfer pumps}
+
+These are $2\times100\%$ capacity. These are required for pumping
+liquid from feed tanks to feed overflow tank TK-6. Product transfer
+pump is used to transfer the reactor grade D\textsubscript{2}O from
+product tank TK-10 to drums and reject transfer pump is used to pump
+the water in reject tank TK-11 to LEMP.
+
+
+\subsection{Cooling water pumps 7131-P9, P10, P-11}
+
+These are $2\times100\%$ capacity pumps used for boosting the pressure
+of the cooling water to 9Kg/cm\textsuperscript{2} which is required
+at the reflux condenser as per design. During plant startup both the
+pumps can be run.
+
+
+\subsection{Chilled water booster pumps 7192-P-5, P-6 \& P-7}
+
+These are 100\% capacity pumps. These pumps boost the chilled water
+pressure required for the vent condenser and cold traps.
+
+
+\section{Inter connection with other system}
+
+
+\subsection{Steam Requirement}
+
+Approximately 5000Kg/hr of dry saturated steam at a pressure of 
1.8Kg/cm\textsuperscript{2}is
+required during the startup of distillation for flooding operation.
+After some 3 to 4 hours during normal operation the requirement is
+3400Kg/hr at a pressure of 1.8Kg/cm\textsuperscript{2}.
+
+
+\subsection{Cooling Water Requirement}
+
+Cooling water requirement of 250M\textsuperscript{3}/hr at 
9Kg/cm\textsuperscript{2}and
+33\textsuperscript{o}C is required during normal operation for reflux
+condenser and product condenser of both the distillation columns.
+During flooding 400M\textsuperscript{3}/hr of process water will
+be required for both the distillation columns.
+
+
+\subsection{Chilled Water}
+
+Chilled water is required for vent condensers, vacuum pump assembly
+and also for vent cold traps. 15M\textsuperscript{3}/hr of chilled
+water at 9Kg/cm\textsuperscript{2}is required for the above chilled
+water loads.
+
+
+\subsection{Electrical Power}
+
+Power supply required for this plant is 400/400 volts, 3Ø HZ A.C 180
+KW. Installed capacity is 400KW.
+
+
+\subsection{Instrument Air}
+
+Oil free, moisture free air at a pressure of 5.3Kg/cm\textsuperscript{2}is
+required for pneumatic instruments.
+
+
+\section{Interlocks \& Logics}
+
+
+\subsection{Safety Interlocks}
+
+There are two conditions which can shutdown the plant. They are
+\begin{itemize}
+\item High temperature in vacuum line $50-G-93$ in CD-5 exit
+\item Failure of vacuum which results in very high pressure alarm of vacuum
+line $50-G-93$
+\end{itemize}
+The following are the interlocks provided for pytting the column under
+total reflux
+\begin{itemize}
+\item Low $\triangle P$
+\item Low flow in reboiler EV-2 i.e < 7M\textsuperscript{3}/hr
+\item High temperature in CD-6(product vent condenser) i.e 
>25\textsuperscript{o}C
+\end{itemize}
+Hand switches, Indicators, Controllers for most of the equipments
+covered in distillation process are in upgrading plant control room
+located in first floor of upgrading plant.
+
+
+\subsection{Feed Pump Hand Switch}
+
+Feed pump starts if there is no overload and emergency push button
+is not pressed and HS is in ON position or HS is in auto 1 position
+and low level in TK-5 is not existing or HS is in auto 2 position
+and low level in TK-13 is not existing. Running feed pump stops if
+overload exists or emergency push button is pressed or HS is kept
+in auto 2 position and low level exists in TK-13
+
+
+\subsection{Feed Flow Control}
+
+Feed flow from feed overflow tank to feed evaporator is measured by
+FE-12147 and this signal is fed through a FRC-12202 to control CV-53
+(Presently in MAPS, the feed flow is set and controlled by a rotameter)
+
+
+\subsection{Feed Overflow tank level}
+
+Low level in this TK-6 will close CV-53. Alarm ``low level in TK-6''
+also comes in UGP control room. This TK-6 inventory is sufficient
+to continue the operation of the distillation column for approximately
+1 hour with the inflow to TK-6 is stopped
+
+
+\subsection{Feed Evaporator (EV-1) level control loop}
+
+LT-12072 measures the EV-1 level and controls steam CV-272 through
+a controller LIC-12005 so that the evaporator level is maintained.
+This implies that whatever is the inflow to EV-1 from TK-6 will be
+evaporated and fed to distillation column.
+
+
+\subsection{Differential pressure control loop for the column}
+
+The performance of the distillation tower is very much dependent on
+the pressure drop across the tower and on the boil up rate from reboiler.
+A variation in boil up rate can vary the pressure drop across the
+column. Hence, control on $\triangle P$ which is cascaded with the
+steam pressure control in reboiler is used to control $\triangle P$
+across the column and boilup from reboiler. A larms are provided for
+high and low $\triangle P$ in the column. A low $\triangle P$ will
+put the column under total reflux.
+
+
+\subsection{Vacuum Control Loop}
+
+PT-12045 senses the pressure at the buffer tank and controls CV-159
+such that 120mm of Hg absolute is maintained at the top of the column.
+A bleed air facility with a 2 way solenoid valve is provided so that
+CV-159 will operate well in its control range, if the air leak to
+the process system is very small. Presetting of the bleed air is done
+by a needle valve, which is in series with the solenoid valve
+
+
+\subsection{Water circulating tank TK-4 level control}
+
+High level in TK-4 closes SV-12325 and stops DM water addition and
+also it gives an alarm. Low level in TK-4 annunciates and also it
+closes CV-159, stops bleed air flow, stop vacuum pumps and seal water
+circulating pumps. LC-12007 level control provided keeps steady level
+in TK-4 by supply make up water through SV-12325
+
+
+\subsection{Product and Reject withdrawal system}
+
+
+\subsubsection{Column sump (TK-7) level control}
+
+This controls product (reject) flow through CV-73 (CV-134), if the
+feed IP >50\% and HS-12327 is in High (Low) position. The lesser of
+these two flow (Product \& Reject flows) is controlled by timer and
+the larger of these two flows is controlled by column sump level control
+
+Flow restriction orifices in the product and reject lines which limit
+the flow to 100Kg/hr
+
+Low sump level will stop product and reject withdrawal. High sump
+level will cut off steam supply to feed evaporator
+
+
+\subsubsection{Timer Circuit Control}
+
+The lower of the two product and reject withdrawal rate is controlled
+by a timer circuit. If feed IP is less(more) than HS-12327 will be
+low(high) and timer will control CV-73(CV-134). First timer gets energized
+and opens the CV-73 (CV-134) for a certain period as determined in
+the setting. When the first timer is timed out the second timer is
+energized and this closes the CV-73 (CV-134). This continues in a
+cyclic manner and hence maintains the rate of withdrawal of product
+(Reject)
+
+
+\subsection{Reboiler Circulation}
+
+High heat transfer is achieved if there is a turbulent to the film
+flow in the tubes. If low flow is existing then running reboiler pump
+trips and the plant will run under total reflux. Auto starting of
+standby pump works only on over-load tripping of running pump if reboiler
+circulation is less than 7M\textsuperscript{3}/hr. Then CV-266 will
+be closed to safeguard EV-2
+
+
+\subsection{Steam Condensate tank TK-15 level control}
+
+Steam condensate pumps (2x100\% capacity) can be started/stopped manually.
+In auto condition, these pumps start if tank level is high and stop
+when TK-12 level is low.
+
+
+\subsection{Instrument Air Pressure}
+
+Air supply pressure is 10Kg/sq.cm. If it is 100psi then air pressure
+low alarm comes in UGP control room.
+
+
+\subsection{Product and Reject Tank Level Control}
+
+Low level in these tanks trips the corresponding pumps low and high
+level alarms are provided in upgrading plant control room
+
+
+\chapter{Experimental Details and Concepts Involved}
+
+
+\section{Programmable Logic Controller (PLC)}
+
+
+\subsection{Introduction}
+
+A PLC (Programmable Logic Controller) is defined as a user-friendly,
+microprocessor based specialized computer that carries out control
+functions of many types and levels of complexity. The first PLC systems
+evolved from conventional computers in the late 1960s and early 1970s.
+These first PLCs were installed primarily in automotive plants. What
+has taken months back then takes few days today. Many companies like
+Allen-Bradley, Mitsubishi, and Siemens manufacture PLCs. In conventional
+controllers the functions are determined by their physical wiring,
+whereas the functions of PLCs are defined by a program. They are also
+connected to other parts with cable , but the content of their program
+memory can be changed at any time to adapt their programs to different
+control tasks.
+
+
+\subsection{Advantages of using PLC}
+\begin{itemize}
+\item Flexible
+\item Faster response time
+\item Simpler Wiring
+\item Modular Design- easy to repair and expand
+\item Handles much more complicated systems
+\item Sophisticated instruction set available
+\item Allows for diagnostics and easy to troubleshoot
+\end{itemize}
+
+\subsection{Component description}
+
+Programmable controllers have grown throughout industrial control
+applications because of the ease they bring to creating a controller:
+ease of programming, ease of wiring, ease of installation, and ease
+of changing. PLCs span a wide range of sizes, but all contain six
+basic components
+\begin{itemize}
+\item Processor or central processing unit (CPU)
+\item Rack or Mounting
+\item Input assembly
+\item Output assembly
+\item Power supply
+\item Programming unit, device or PC
+\end{itemize}
+
+\subsubsection{Rack Assembly}
+
+Most medium to large PLC systems are assembled such that the individual
+components - CPU, Input/Output, Power Supply - are modules that are
+held together within a rack. In smaller PLC systems - all of these
+components may be contained in a single housing or 
\textquotedbl{}Brick\textquotedbl{}
+- these smaller systems are sometimes referred to as 
\textquotedbl{}bricks\textquotedbl{}
+or \textquotedbl{}shoebox\textquotedbl{} PLCs.
+
+
+\subsubsection{Power Supply}
+
+The power supply provides power for the PLC system. The power supply
+provides internal DC current to operate the processor logic circuitry
+and input/output assemblies. Common power levels used are 24V DC or
+120 VAC.
+
+
+\subsubsection{Processor (CPU)}
+
+The processor, central processing unit, or CPU is the 
\textquotedbl{}brain\textquotedbl{}
+of the PLC. The size and type of CPU will determine things like: the
+programming functions available, size of the application logic available,
+amount of memory available, and processing speed. Understanding the
+CPU can be a complex subject and we will tackle that in other articles.
+
+
+\subsubsection{Programming Device}
+
+The PLC is programmed using a specialty programmer or software on
+a computer that can load and change the logic inside. Most modern
+PLCs are programmed using software on a PC or laptop computer. Older
+systems used a custom programming device.
+
+
+\subsubsection{Input/Output Assembly}
+
+Many types of inputs and outputs can be connected to a PLC, and they
+can all be divided into two large groups - analog and digital. Digital
+inputs and outputs are those that operate due to a discrete or binary
+change - on/off, yes/no. Analog inputs and outputs change continuously
+over a variable range - pressure, temperature, potentiometer.
+
+\includegraphics[scale=0.8]{pasted1}
+
+
+\paragraph{Configurations}
+
+PLCs are available in various configurations, which are chosen according
+to the necessity of the work. Basic PLCs which are available on a
+single PCB are called open-frame or single board PLCs; these are totally
+self-sustained (except power supply) and can be directly mounted inside
+the controls cabinet on threaded standoffs. They are inexpensive,
+small, consume less power, easy to program but do not have large number
+on inputs and outputs; their instruction set is also small. PLCs are
+also available housed in a single case, with all inputs, outputs and
+power supply points located in a single unit. This type is generally
+chosen according to available program memory, required number and
+voltage of inputs and outputs to suit the application. These systems
+also have an expansion port which allows addition of specialized units.
+More sophisticated units with wider array of options are modularized
+PLCs.
+
+
+\paragraph{Operation of a PLC}
+
+A PLC retains its operating system, user programs, and some data in
+retentive (nonvolatile) memory. It executes an initialization step
+when placed in run mode, and then repeatedly executes a scan cycle
+sequence. The total time for one complete program scan is a function
+of processor speed, I/O modules used, and length of user program (Ladder
+Logic).
+
+The basic PLC scan cycle consists of three steps:
+\begin{itemize}
+\item An input scan: Data is taken from all input modules in the system
+and placed into an area of PLC memory referred to as the input image
+area
+\item A user program scan: Data in the input image area is applied to the
+user program, the user program is executed and the output image area
+is updated
+\item An output scan: data is taken from the output image area and sent
+to all output modules in the system.
+\end{itemize}
+For the Allen-Bradley PLCs and the simulator used, the input and output
+image areas (in addition and counters. Programs are written as Ladder
+Logic for PLCs. It is written in rungs, which are individual structures
+consisting of basic elements like NC/NO contacts, timers, counters,
+etc.
+
+
+\subsection{Basic Elements and Instructions}
+
+
+\paragraph{Contacts}
+
+There are 2 types of contacts, normally open (NC) and normally open
+(NO). When an NC contact is energized it opens and vice-versa. XIO
+is used for an NC contact and XIO for an NO contact.
+
+
+\paragraph{Outputs/Coil}
+
+The output for a rung is denoted by the instruction OTE. It is energized
+when all the logics preceding it are true (1). The output can also
+be latched and unlatched by OTL \& OTU respectively.
+
+
+\paragraph{Timers}
+
+The most commonly used process control device after coils and contacts
+is the timer. A timer is simply a control block that takes an input
+and changes an output based on time. A PLC timer’s time may be a programmable
+variable time as well as a fixed time. Many kinds of timers like Non-Retentive,
+Timer Delay Off, Retentive, etc. are available. For our project we
+have used NRT timers which get reset as and when the input is off.
+
+\includegraphics[scale=0.8]{pasted3}
+
+
+\section{Instrument and Control Loops in Upgrading Plant}
+
+\begin{figure}
+
+
+\protect\caption{\protect\includegraphics[scale=0.1]{WP_20140710_001}}
+
+
+\end{figure}
+
+
+
+\subsection{Feed System}
+
+Feed tank level TK-5 and TK-13 are provided with level indicating
+alarms LIA-12053 and LIA-12055 with a range of 0-2900 litres. They
+have a high and low level adjustable set points and give high and
+low level alarms. They receive signal from differential pressure transmitters
+LT-12071 and LT-12076 respectively. Pressure switches are provided
+for alarms and associated interlock circuits. Low levels in feed tank
+also trips feed pump P-1 and P-2.
+
+Feed pumps P-1 and P-2 are provided with hand switches HS-12317 and
+HS-12318 respectively. These hand switches have ON, AUTO-1, AUTO-2
+and OFF positions. AUTO-1 is connected to TK-5 low level alarm circuit
+and AUTO-2 is connected to TK-13 low level alarm circuit. Depending
+on the on line feed tank, HS of both feed pumps should be put in corresponding
+AUTO position so that they trip when level in the tank goes down to
+the trip level.
+
+
+\subsubsection{Feed Flow Control Loop}
+
+Flow control loop measures, controls and records pre-set D2O feed
+flow to the feed evaporator EV-1 from feed overflow tank TK-6. The
+flow element FE-12147 and pneumatic recording controller FRC-12002
+have a range of 0-110 litres/hour(i.e. 0-1.833 lpm). The setting of
+the flow has to be done manually depending on the feed concentration.
+
+
+\subsubsection{Level of TK-6 Feed Overflow Tank}
+
+Low level alarm LA-10257 provided in TK-6 will caution failure of
+feed pump. There will be sufficient hold up still to continue feed
+for approximately one hour. Very low level alarm LA-12058 shuts off
+the feed flow control valve CV-53.
+
+
+\subsubsection{Feed Evaporator (EV-1) Level Control Loop}
+
+This controls steam flow into the evaporator EV-1. The control loop
+has LOC-12005 with a range of 0-420 Litres (non-linear scale) and
+receives signal from differential pressure transmitter LT-12072 and
+gives signal to CV-272.
+
+The control loop maintains constant level in EV-1, so that controlled
+feed flow from the flow control loop is completely evaporated and
+fed into the column.
+
+
+\subsection{Differential Pressure Control Loop for the Column}
+
+The performance of the distillation tower is very much dependent on
+the pressure drop across the tower and on the boil up rate from the
+reboiler. A variation in the boil up rate can vary the pressure drop
+across the column. Hence, a control on $\triangle P$ which is cascaded
+with the steam pressure control in reboiler is used to control simultaneously
+$\triangle P$ across column and boil up from reboiler. The $\triangle P$
+control from FRC-12001 has a range of 0 to 300mm of Hg. (abs) (linear
+scale) and can be set at required $\triangle P$ manually. $\triangle P$
+across the column is the primary variable. This receives signal from
+$\triangle P$ transmitter DPT-12004 and gives signals to PIC-12008,
+which is the pressure indicating controller for the steam line to
+reboiler 150-S-1416. Signal from DPT-12044 adjusts the set point of
+PIC-12008. PIC-12008 gets signal from absolute pressure transmitter
+PT-12046 which senses and transmits steam pressure for line 150-S-146
+and gives signal to CV-266. Reboiler steam pressure is expected to
+go below atmospheric pressure at times during operation and hence
+an absolute pressure transmitter is used PT-12046.
+
+Also alarms for high pressure DPA-12004 drop across column and low
+pressure drop DPA-12003 across column are provided on $\triangle P$
+control loop. Low  will bring the column under total reflux.
+
+
+\subsection{Vacuum Control Loop}
+
+The absolute pressure in the system is measured at the buffer tank
+TK-1 by an absolute pressure transmitter PT-12045 and controlled by
+a recording control on panel PRC-12005. This has a range of 0-200mm
+of Hg. abs pressure. Control valve CV-159 is provided between TK-1
+and vacuum pump assembly.
+
+A bleed air facility with a 2 way solenoid valve SV-12322 is provided
+at the inlet line of buffer tank (line 50-G-93). This is for enabling
+the vacuum control valve CV-159 to function within its control range,
+if the air leak to the process system is very small. Presetting the
+bleed air is done by a fine needle valve. SV-12322 opens or shuts
+off instrument air bleed into the system.
+
+Pressure switched for high pressure alarm is provided. PA-12021 very
+high pressure in vacuum system will close CV-272, CV-73, CV-134, CV-266
+and shut down the plant.
+
+
+\subsection{Water Circulating Tank (TK-4) Level and Temperature}
+
+Seal Water required for vacuum pump is taken from this tank(TK-4).
+An ON-OFF type level control is provided to control level in this
+tank. Level switches LA-12055(HIGH) and LA-12056(LOW) are also provided.
+High level gives an alarm and cuts off make up water to the tank by
+closing SV-202. Low Level will give an alarm and trip level will cut
+off bleed air to vacuum system; close CV-159 and puts off water circulating
+pumps P-16/P-17 and vacuum pumps P-7/P-8. LC-12007 level control provided
+keeps steady level in TK-4 by supplying make up water through SV-202.
+
+
+\subsection{Product and Reject Withdrawal System Column Sump (TK-7) Level 
Control}
+
+This is controlled either by product take off or reject take off depending
+on the feed concentration. The high-low change over hand switch HS-12327
+connects this loop either to product CV-73 or reject CV-134 control
+valve. This change over is at around a feed concentration of 60\%
+or as per operational needs.
+
+Of the product and reject withdrawal, the lesser flow is controlled
+by a timer loop and the larger flow of the two through the sump level
+control loop. Flow limiter orifices FE-12150 (product) and FE-12151
+(reject) are provided on both the take-off lines with flow limit at
+100kg/hr.
+
+Sump (TK-7) has differential pressure transmitters LT-12073 which
+transmits signal to LIC-12073. Range if this is 0 to 1260 litres (non
+linear scale) and has low (LA-12053) and high (LA-12054) alarms, which
+are adjustable.
+
+The high level alarm will cut off steam supply to feed evaporator
+and low level stops product and reject withdrawal.
+
+
+\subsection{Reboiler Circulation}
+
+FE-12184 senses the flow. Flow indicating alarm FIA-12017 has adjustable
+high and low positions and has a range of 0 to 333.3 lpm. It receives
+signal from FT-12122.
+
+Low flow of circulation will give an alarm through a time delay relay
+and will stop the recirculation pump and put the column under total
+reflux. In this condition, standby pump will not start automatically.
+Auto start of standby pump works only on over load tripping of running
+pump.
+
+
+\subsection{Steam System}
+
+Pressure control PIC-12008 controls steam pressure in EV-2 and in
+cascade with $\triangle P$ control . Steam flow in reboiler EV-2
+is monitored by FT-12123 and FT-12105 which have a range of 0 to 4000
+kg/hr. Orifice FE-12149 senses the steam flow.
+
+
+\subsection{Steam Condensate Tank Level}
+
+LA-12062 and LA-12061 with high and low level switches respectively
+are provided on TK-12 which respectively starts and stops the pump
+P-13/P-14 and pumps condensate back to boiler house/reactor source.
+
+Since both pumps are given hand switches with ON,AUTO,OFF positions,
+both pumps will start at the tank high level and stop at tank low
+level, if hand switches are placed in AUTO. Hence at a time only one
+pump need to be placed on AUTO and the other may be placed on 'OFF'.
+
+
+\subsection{Instrument Air}
+
+Instrument air supply pressure is expected at 10 kg/cm2. This is being
+reduced by differential PRV's to 0.35 kg/cm2 for vacuum system bleed
+air and 1.4 kg/cm2 for instruments. Pressure switch PS-12089 gives
+low pressure alarm of the instrument air supply system.
+
+
+\subsection{Product and Reject Tank Levels}
+
+These tanks are provided with visual level gauges and have low and
+high level alarms. Low level alarms trip the product and reject pump.
+\begin{itemize}
+\item LIA-12056 and LT-12074 for product tank
+\item LIA-12054 and LT-12075 for reject tank
+\end{itemize}
+Both have range of 0-1516 litres with adjustable high and low positons.
+
+
+\subsection{Temperature Measurement and Alarms}
+
+Total six point R.T.D type temperature recorder (range 0-100oC) are
+provided for temperature recording. The temperature points are as
+follows
+\begin{itemize}
+\item Feed evaporator vapour outlet TR-12067
+\item Column sump TR-12065
+\item Column top TR-12066
+\item Reflux condenser cooling water out TR-12069
+\item Vent condenser exit TR-12068
+\end{itemize}
+Three temperature alarms having a range of 0-60oC are provided at
+the following points
+\begin{itemize}
+\item Water circulating tank TA-12033: gives alarm only
+\item Vent Condenser exit TA-12031: will shut down the plant closing feed,
+product and reject, and steam to EV-1 control valves
+\item Product vent condenser exit TA-12032 will bring the column under total
+reflux closing feed, product and reject control valves
+\end{itemize}
+
+\chapter{Results and Discussion}
+
+The Programming of PLC is done by Ladder Logic for which we used Logix
+Pro Software. Various steps followed for drawing a ladder diagram
+\begin{enumerate}
+\item Find the inputs and outputs
+\item Familiarising with control logics
+\item Making a Flow diagram of the process
+\end{enumerate}
+There of 32 inputs and outputs available in a I/O simulator in Logix
+Pro which we used for simulation.
+
+\includegraphics{pasted4}
+
+
+\section{Flow Diagrams}
+
+\includegraphics[scale=0.8]{FEED_PUMP_FLOW_CHART}
+
+\includegraphics[scale=0.3]{maps_feed_flow_diag}
+
+
+\section{Ladder Logic}
+
+
+\section{Explanation of Ladder Logic Diagram}
+
+
+\chapter{Conclusion}
+
+The Project entitled “Implementation of PLC based system in Upgrading
+Plant” was pursued to complete the objective of learning about the
+present relay system in MAPS and replacing it with PLC. From our work
+under the guidance of our mentor we concluded the following things
+\begin{itemize}
+\item The hardwired electromagnetic based relays should be replaced with
+PLC (Programmable Logic Controller) because of their advantages over
+relays in flexibility and they are easy to maintain
+\item Upgrading plant being one of the most oldest parts of MAPS, it needs
+to be upgraded quickly to be able to use it smoothly for many years
+to come. There may be some difficulties for upgradation but there
+are many benefits to ripe in the future
+\end{itemize}
+
+\chapter{Future Work}
+
+
+\section{Implementing Microprocessor based System}
+
+
+\subsection{Microprocessor}
+
+A microprocessor incorporates the functions of a computer's central
+processing unit (CPU) on a single integrated circuit (IC), or at most
+a few integrated circuits. All modern CPUs are microprocessors making
+the micro- prefix redundant. The microprocessor is a multipurpose,
+programmable device that accepts digital data as input, processes
+it according to instructions stored in its memory, and provides results
+as output. It is an example of sequential digital logic, as it has
+internal memory. Microprocessors operate on numbers and symbols represented
+in the binary numeral system.
+
+The integration of a whole CPU onto a single chip or on a few chips
+greatly reduced the cost of processing power. The integrated circuit
+processor was produced in large numbers by highly automated processes,
+so unit cost was low. Single-chip processors increase reliability
+as there are many fewer electrical connections to fail. As microprocessor
+designs get faster, the cost of manufacturing a chip (with smaller
+components built on a semiconductor chip the same size) generally
+stays the same.
+
+Before microprocessors, small computers had been implemented using
+racks of circuit boards with many medium- and small-scale integrated
+circuits. Microprocessors integrated this into one or a few large-scale
+ICs. Continued increases in microprocessor capacity have since rendered
+other forms of computers almost completely obsolete (see history of
+computing hardware), with one or more microprocessors used in everything
+from the smallest embedded systems and handheld devices to the largest
+mainframes and supercomputers.
+
+
+\subsection{Using Microprocessor for Alarm Circuits}
+
+To start with we have used an 8086 Microprocessor and simulated the
+Tank Level Alarm system which displays the level of water if everything
+is normal and raises an alarm if the level exceeds the threshold level.
+Threshold level has been directly set via the code. Keypad interface
+can be added to set the threshold level.
+
+\includegraphics[scale=0.3]{Screenshot_from_2014-07-10_22:21:32}
+
+
+\end{document}

commit 4ad173670372218bf7800cf518a54fdb89d620a5
Author: Prannoy Pilligundla <prannoy.b...@gmail.com>
Date:   Tue Aug 5 00:15:01 2014 +0530

    Added a general LyX test file
    
    Run "mk4ht ooxelatex PS_Report_Final.tex imageconfig.cfg" for the 
conversion. All the images in the lyx file have not been committed. One of each 
type i.e one normal image and an another in a float has been added.

diff --git a/tests/PS_Report_Final.lyx b/tests/PS_Report_Final.lyx
new file mode 100644
index 0000000..56a1ba0
--- /dev/null
+++ b/tests/PS_Report_Final.lyx
@@ -0,0 +1,2384 @@
+#LyX 2.1 created this file. For more info see http://www.lyx.org/
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+\end_header
+
+\begin_body
+
+\begin_layout Title
+Implementing PLC based system in Upgrading Plant
+\end_layout
+
+\begin_layout Author
+Prannoy Pilligundla 2012A8PS264P
+\begin_inset Newline newline
+\end_inset
+
+Siddarth Singh 2012AAPS823P
+\begin_inset Newline newline
+\end_inset
+
+Vineet Cherian 2012A3PS015P
+\end_layout
+
+\begin_layout Standard
+\begin_inset ERT
+status open
+
+\begin_layout Plain Layout
+
+
+\backslash
+tableofcontents
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Abstract
+Heavy water which is used a moderator in a PHWR is often contaminated with
+ some chemical impurities and Light water.
+ The chemical impurities like corrosion products, oil, dirt etc are removed
+ from the downgraded Heavy water in the cleanup system before sending it
+ to Upgrading plant for further processing.
+ Basis of seperation of Heavy water and Light water is the difference in
+ Boiling point of 1.41
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C.
+ Upgrading is done by the continuous distillation under sub-atmospheric
+ condition.
+ The downgraded heavy water is boiled in a reboiler and made to ascend through
+ the packed distillation column.
+ It is condensed at the top in the reflux condensor and the condensed liquid
+ is putback at the top of the tower as reflux.
+ The vapour ascending and liquid descending will come in intimate contact
+ in tower section.
+ Due to this mass transfer takes place.
+ Ligher component H
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O is transferred to the vapour phase from liquid phase.
+ The mass transfer taking place in the tower sets up a concentration gradient
+ throughout the tower section.
+ Thus at the bottom of the tower it will be pure heavy water and at the
+ top of the column it will be light water.
+ The process instrumentation logic is based on the philosophy of simple
+ and safe operation.
+ Interlocks have been provided with process parameters to trip the plant
+ whenever unsafe conditions are developed.
+\end_layout
+
+\begin_layout Abstract
+Our main objective here is to upgrade an existing relay based control system
+ with a Programmable Logic Controller(PLC) in this Heavy Water Upgradation
+ Plant
+\end_layout
+
+\begin_layout Standard
+Heavy water which is used a moderator in a PHWR is often contaminated with
+ some chemical impurities and Light water.
+ The chemical impurities like corrosion products, oil, dirt etc are removed
+ from the downgraded Heavy water in the cleanup system before sending it
+ to Upgrading plant for further processing.
+ Basis of seperation of Heavy water and Light water is the difference in
+ Boiling point of 1.41
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C.
+ Upgrading is done by the continuous distillation under sub-atmospheric
+ condition.
+ The downgraded heavy water is boiled in a reboiler and made to ascend through
+ the packed distillation column.
+ It is condensed at the top in the reflux condensor and the condensed liquid
+ is putback at the top of the tower as reflux.
+ The vapour ascending and liquid descending will come in intimate contact
+ in tower section.
+ Due to this mass transfer takes place.
+ Ligher component H
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O is transferred to the vapour phase from liquid phase.
+ The mass transfer taking place in the tower sets up a concentration gradient
+ throughout the tower section.
+ Thus at the bottom of the tower it will be pure heavy water and at the
+ top of the column it will be light water.
+ The process instrumentation logic is based on the philosophy of simple
+ and safe operation.
+ Interlocks have been provided with process parameters to trip the plant
+ whenever unsafe conditions are developed.
+\end_layout
+
+\begin_layout Chapter
+Upgrading Plant
+\end_layout
+
+\begin_layout Section
+Introduction
+\end_layout
+
+\begin_layout Standard
+The Madras Atomic Power Station is designed of the CANDU type,almost similar
+ to the Rajasthan Atomic Power Station.
+ The Nuclear reactor is of natural Uranium, Heavy water moderated and cooled.
+ This Heavy Water gets depleted due to leakages in the system.
+ These leakages are mainly collected from fuelling machine vault, Primary
+ heat transfer system and boiler room.
+ In the 
+\begin_inset Quotes eld
+\end_inset
+
+PHWR
+\begin_inset Quotes erd
+\end_inset
+
+ type of reactors heavy water is used both as moderator and as heat transport
+ fluid.
+ Downgrading of high quality water occurs through two mechanisms:
+\end_layout
+
+\begin_layout Enumerate
+Light water leakage into the heavy water system.
+\end_layout
+
+\begin_layout Enumerate
+Heavy water escape from PHT and Moderator systems where it comes in contact
+ with light water
+\end_layout
+
+\begin_layout Standard
+Downgraded D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O is a mixture of light water, D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O and other solid and chemical impurities.
+ The downgraded heavy water containing various chemical impurities render
+ the heavy water unfit for use without further processing.
+ The chemical impurities like corrosion products, oil, dirt etc are removed
+ from the downgraded heavy water in the clean up system before sending it
+ to the upgrading plant for further processing.
+ The chemical purity should be strictly followed before processing the 
downgrade
+d heavy water in the distillation plant.
+ 
+\end_layout
+
+\begin_layout Standard
+
+\emph on
+Design Capacity of Distillation Columns
+\emph default
+: The distillation plant has been designed to process 36 litres/hr of 60%(w/w)
+ and 36 litres/hr of 30%(w/w) for bottom product at 99.8% D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O(w/w) with top reject of 0.5% D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O(w/w).
+ Based on the above performance data at 7800 operating hours oer year the
+ annual plant capacity is expected to be 250 tonnes of reactor grade Heavy
+ Water.
+\end_layout
+
+\begin_layout Section
+Distillation Processs
+\end_layout
+
+\begin_layout Subsection
+Principle of Operation
+\end_layout
+
+\begin_layout Standard
+Heavy Water(D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O) and Light Water(H
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O) are alike in their chemical properties but differ in their physical 
propertie
+s.
+ At atmospheric pressure the boiling point of H
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O is 100
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C and boiling point of D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O is 101.42
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C.
+ Thus relative volatility ( Boiling point difference i.e 1.42
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C) is basis for seperation of D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O and H
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O in the distillation column.
+\end_layout
+
+\begin_layout Standard
+Upgrading is done by continuous distillation under sub atmospheric condition.
+ The downgraded heavy water is boiled in a reboiler and made to ascend through
+ the packed distillation column.
+ It is condensed at top in the reflux condenser and the condensed liquid
+ is put back at the top of the tower as reflux.
+ The vapour ascending and liquid descending will come in intimate contact
+ in the tower section.
+ Due to this mass transfer takes place.
+ Lighter component(H
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O) is transferred to the vapour phase from liquid phase.
+ The mass tranfer taking place in the tower sets up a concentration gradient
+ throughout the tower section.
+ Thus at the bottom of the tower,it will be pure heavy water and at the
+ top of column it will be light water.
+\end_layout
+
+\begin_layout Standard
+Part of the reboiler vapour is taken as product and part of the condensed
+ liquid from the reflux condenser is collected as reject (IP ≤0.25%w/w).
+ Depending on the feed concentration, feed is put into the tower at some
+ point along the height of the tower where the feed concentration matches
+ with the local concentration of the tower.
+\end_layout
+
+\begin_layout Subsection
+Process
+\end_layout
+
+\begin_layout Standard
+The principle of the distillation and equilibrium condition are mentioned
+ above.
+ It takes nearly three days i.e 72 hours to achieve this equilibrium condition.
+ Feed in the form of vapour will be added at a point in the column where
+ its Isotopic Purity (I.P) matches with the column section I.P.
+ Reject is removed from the top as a liquid and product is taken from the
+ bottom.
+ One important thing to be noticed is, the equilibrium should not be disturbed
+ at any condition.
+ This is possible if the feed rate is equal to the reject rate plus product
+ rate.
+ This is given below as the material balance equation.
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\begin{equation}
+F=P+R
+\end{equation}
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\[
+F=\mathrm{Feed}\: Rate\: in\: lit/hr
+\]
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\[
+P=Product\: Rate\; in\: lit/hr
+\]
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\[
+R=Reject\: rate\: in\: lit/hr
+\]
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+Mole fraction or Component(D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O) balance is given by
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\begin{equation}
+FX_{F}=PX_{P}+RX_{R}
+\end{equation}
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\[
+X_{F}=D_{2}O\: fraction\: of\: feed
+\]
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\[
+X_{P}=D_{2}O\: fraction\: of\: feed
+\]
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\[
+X_{R}=D_{2}O\: fraction\: of\: Reject
+\]
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+As per design, for a specified feed I.P the feed rate should not exceed above
+ a certain value.
+ This is given in the table and also in the graph.
+ Product and Reject I.P's are as oer our requirements i.e reject I.P<0.25% and
+ Product I.P>99.97% for moderator grade and >99.4% for PHT grade liquid.
+ Hence X
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+F
+\end_layout
+
+\end_inset
+
+,X
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+P
+\end_layout
+
+\end_inset
+
+,X
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+R
+\end_layout
+
+\end_inset
+
+ and F are fixed.
+ To find out the product and reject rates the above two equations can be
+ solved to get
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\begin{equation}
+P=\frac{F(X_{F}-X_{R})}{(X_{P}-X_{R})}
+\end{equation}
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\begin{equation}
+R=F-P
+\end{equation}
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+For a distillation column the seperation factor achieved is 1.05.
+ Seperation factor is defined as follows:
+\end_layout
+
+\begin_layout Standard
+\begin_inset Formula 
+\[
+Seperation\: Factor=\frac{\frac{atom\: fraction\: of\: H_{2}}{atom\: 
fraction\: of\: D_{2}}\: in\: gas}{\quad\frac{atom\: fraction\: of\: 
H_{2}}{atom\: fraction\: of\: D_{2}}\: in\: liquid}
+\]
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+The maximum attainable seperation factor is 1.05 as per design.
+ To achieve this the column pressure should be reduced.
+ This pressure cannot be reduced beyond a certain value because of the increase
+ in the specific volume of vapour which inturn leads to very high column
+ dimensions and inturn increases the column cost.
+ Since the process water temperature is limited around 33
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C, there is always a lower limit on the temperature of the vapour which
+ is required to be cooled, so that efficient condensation can take place.
+ (This inturn means a low pressure restriction inside the column top, which
+ is 120mm of Hg absolute).
+ Column sump pressure is around 230mm of Hg.abs.
+\end_layout
+
+\begin_layout Subsection
+Definitions
+\end_layout
+
+\begin_layout Paragraph
+Total Reflux
+\end_layout
+
+\begin_layout Standard
+Total Reflux implies that there is no feed, no product, and reject take
+ off i.e 3493 CV-53, 3493 CV-272, 3493 CV-73 and 3493 CV-134 are closed.
+\end_layout
+
+\begin_layout Paragraph
+Shut down of the distillation column
+\end_layout
+
+\begin_layout Standard
+In addition to the total reflux state, the reboiler steam control CV-266
+ is also closed in this state.
+\end_layout
+
+\begin_layout Subsection
+Specification of feed D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O
+\end_layout
+
+\begin_layout Enumerate
+K ≤ 5 micromho/cm or microsiemens/cm
+\end_layout
+
+\begin_layout Enumerate
+PH 6.5 to 8
+\end_layout
+
+\begin_layout Enumerate
+Chloride ≤ 0.5ppm
+\end_layout
+
+\begin_layout Enumerate
+Nitrate ≤ 1ppm
+\end_layout
+
+\begin_layout Enumerate
+Oil Free
+\end_layout
+
+\begin_layout Enumerate
+Particulate matter free
+\end_layout
+
+\begin_layout Enumerate
+Organic materials ≤ 10ppm ammonia and amines
+\end_layout
+
+\begin_layout Section
+Equipment Description
+\end_layout
+
+\begin_layout Subsection
+Distillation Column
+\end_layout
+
+\begin_layout Standard
+Distillation column consists of 14 identical sections with sump at the bottom.
+ At the top of the column reflux condenser CD-4 and a vent condenser CD-5
+ are present to condense the vapours.
+ Operating temperature and pressure varies from 74
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C and 230mm Hg(abs)-at column sump to 56
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C and 120mm Hg(abs) at the top.
+ Outside diameter and height of each column section is ∓2.5mm and 3200∓3mm
+ respectively.
+ Each column section is packed with corrugated phosphor bronze wire mesh
+ packing with a coating of copper oxide for surface activation which increases
+ wet surface.
+ This packing is supported by means of a bottom ring.
+ The top support ring supports the liquid distributor, which distributes
+ the liquid evenly on the packing.
+ Liquid collector collects the downcoming liquid and puts it onto the 
distributi
+on without hindering the vapour flow.
+ For the fourteenth section liquid collector is not required
+\end_layout
+
+\begin_layout Subsection
+Column Sump
+\end_layout
+
+\begin_layout Standard
+Column sump at the bottom of the column holds the downcoming reflux liquid
+ from the distillation column and provides flooded suction to the reboiler
+ circulating pump.
+ Capacity of the sump is decided on the initial hold up required for flooding
+ the distillation column.
+ This requirement is around 3 tonnes.
+\end_layout
+
+\begin_layout Subsection
+Reboiler EV-2
+\end_layout
+
+\begin_layout Standard
+A falling film type reboiler is provided for reboiling the reflux liquid
+ of the distillation tower.
+ It is a shell and tube type 1-1Hx.
+ Liquid is pumped to the top of the tubesheet of the reboiler and falls
+ thorugh the tubes in the form of a film and is vapourised.
+ The vapour along with the liquid comes down from the bottom side and enters
+ the column sump.
+ For getting a good heat transfer coefficient a 4.5:1 circulation ratio is
+ to be used.
+\end_layout
+
+\begin_layout Standard
+Special features of falling film reboiler are:
+\end_layout
+
+\begin_layout Itemize
+High heat tranfer coefficient due to the turbulent film flowin tubes.
+\end_layout
+
+\begin_layout Itemize
+Low hold up because tubes are not completely filled.
+\end_layout
+
+\begin_layout Subsection
+Reflux Condenser(CD-4)
+\end_layout
+
+\begin_layout Standard
+This is a 2-2 shell and tube Hx, cooled by process water, used to condense
+ the ascending vapours and to provide reflux to distillation column.
+ In the vapour hood portion an annular space serves as the reflux drum,
+ where condensate gets collected and overflows into the distillation column.
+ This reduces the reflux holdup considerably.
+ The temperature of the column at the reflux end is 55.3
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C.
+\end_layout
+
+\begin_layout Subsection
+Feed Evaporator(EV-1)
+\end_layout
+
+\begin_layout Standard
+It is a jacketed vessel with a surface area of 1.2Sq.m.
+ Feed heavy water is boiled in this vessel and is fed to the column in the
+ vapour form.
+ Steam condenses in the jacket and goes to steam condensate collection tank
+ TK-15.
+\end_layout
+
+\begin_layout Subsection
+Product Condenser(CD-2)
+\end_layout
+
+\begin_layout Standard
+This is a 1:2 shell and tube type of Hx with a surface are of 5.5M
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+ used to condensate the vapour form the collection sump which goes down
+ to the product tank TK-10.
+\end_layout
+
+\begin_layout Subsection
+Vent Condenser(CD-5)
+\end_layout
+
+\begin_layout Standard
+This is a 1:2 shell and tube condenser with a surface are of 3.6M
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+which condenses any vapour that escapes uncondensed from the reflux condenser.
+ Chilled water is used as the cooling media in this condenser.
+\end_layout
+
+\begin_layout Subsection
+Exhaust Cooler(CD-1)
+\end_layout
+
+\begin_layout Standard
+It is a 1:2 shell and tube type condenser used to trap any vapour escaping
+ from vacuum pump exhaust, feed tank and feed overflow tank vent line.
+\end_layout
+
+\begin_layout Subsection
+Product vent condenser CD-6 and Product tank vent cold trap CD-3
+\end_layout
+
+\begin_layout Standard
+Both are of similar geometry and construction.
+ CD-6 condenses the escaping vapours from product condenser whereas CD-3
+ acts as a trap for product tank TK-10
+\end_layout
+
+\begin_layout Subsection
+Water circulating tank TK-4 vacuum pump and cyclone seperators(TK-2 & TK-3)
+\end_layout
+
+\begin_layout Standard
+To create and maintain vacuum at the distillation column two 100% capacity
+ vacuum pumps are used.
+ To provide cooling two 100% capacity vacuum pumps are used.
+ To provide cooling water for these pumps at the rate of 14lpm in a closed
+ loop circulation arrangement, a water circulating tank and two 100% capacity
+ pumps are provided.
+ A chilled water cooling arrangement is provided for cooling the seal liquid
+ TK-4.
+ A cyclone separator is provided at the exhaust of each vacuum pump to separate
+ the seal water from the exhaust vapours going to exhaust cooler thereby
+ reducing the load on the exhaust cooler, 
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+1
+\end_layout
+
+\end_inset
+
+H
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+3 
+\end_layout
+
+\end_inset
+
+affinity towards water is more and so it gets diluted with water and 
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+1
+\end_layout
+
+\end_inset
+
+H
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+3
+\end_layout
+
+\end_inset
+
+ free air which further cooled in CD-1 is sent out to atmosphere.
+\end_layout
+
+\begin_layout Subsection
+Feed tank TK-5 & TK-13
+\end_layout
+
+\begin_layout Standard
+This tank stores the depleted D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O from the evaporation clean up section.
+ Capacity of these tanks are 3170 litres eac.
+ This is based on holding 48 hours feed at a time for the distillation tower.
+ The second tank is used to prepare feed stock when the first one is in
+ stream.
+\end_layout
+
+\begin_layout Subsection
+Product storage tank TK-10
+\end_layout
+
+\begin_layout Standard
+Reactor grade D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O is collected in this tank from the distillation process.
+ This is intermittently pump to drums and sent to station whenever required.
+\end_layout
+
+\begin_layout Subsection
+Reject storage tank TK-10
+\end_layout
+
+\begin_layout Standard
+Reject containing ≤ 0.25% I.P liquid is collected in this tank and then it
+ is sent out to liquid effluent management plant(LEMP).
+\end_layout
+
+\begin_layout Subsection
+Feed Overflow tank TK-6
+\end_layout
+
+\begin_layout Standard
+This tank provides feed flow to the feed evaporator at constant head which
+ can be further controlled by a flow control loop arrangement controlling
+ CV-53.
+\end_layout
+
+\begin_layout Subsection
+Buffer tank TK-1
+\end_layout
+
+\begin_layout Standard
+This tank acts as a buffer in the vacuum system.
+\end_layout
+
+\begin_layout Subsection
+Steam Condensate tank TK-15
+\end_layout
+
+\begin_layout Standard
+This tank collects the steam condensate from evaporator EV-1 & EV-2 and
+ puts back the condensates to deaerator for steam generation in the boilers
+ with the help of steam condensate pumps 4321-P-16 & P-17.
+\end_layout
+
+\begin_layout Subsection
+Product & Reject overflow vessels TK-8 & TK-9
+\end_layout
+
+\begin_layout Standard
+These two graduated vessels have the following functions
+\end_layout
+
+\begin_layout Enumerate
+To keep sufficient holdup of liquid to provide barometer head
+\end_layout
+
+\begin_layout Enumerate
+To calibrate the product and reject flow through orifices.
+ They are provided with integral visual level gauges.
+\end_layout
+
+\begin_layout Subsection
+Pumps
+\end_layout
+
+\begin_layout Standard
+All pumps are used in the upgrading plant for 
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\strikeout off
+\uuline off
+\uwave off
+\noun off
+\color none
+D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\strikeout off
+\uuline off
+\uwave off
+\noun off
+\color none
+2
+\end_layout
+
+\end_inset
+
+O service are canned motor pumps to attain zero leakage.
+\end_layout
+
+\begin_layout Subsection
+Reboiler circulating pumps
+\end_layout
+
+\begin_layout Standard
+These pumps provide circulation for falling film type reboiler EV-2.
+ Only one pump is operated at a time.
+ The other pump will be standby.
+\end_layout
+
+\begin_layout Subsection
+Feed, Product and Reject transfer pumps
+\end_layout
+
+\begin_layout Standard
+These are 
+\begin_inset Formula $2\times100\%$
+\end_inset
+
+ capacity.
+ These are required for pumping liquid from feed tanks to feed overflow
+ tank TK-6.
+ Product transfer pump is used to transfer the reactor grade D
+\begin_inset script subscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+O from product tank TK-10 to drums and reject transfer pump is used to pump
+ the water in reject tank TK-11 to LEMP.
+\end_layout
+
+\begin_layout Subsection
+Cooling water pumps 7131-P9, P10, P-11
+\end_layout
+
+\begin_layout Standard
+These are 
+\begin_inset Formula $2\times100\%$
+\end_inset
+
+ capacity pumps used for boosting the pressure of the cooling water to 9Kg/cm
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+ which is required at the reflux condenser as per design.
+ During plant startup both the pumps can be run.
+\end_layout
+
+\begin_layout Subsection
+Chilled water booster pumps 7192-P-5, P-6 & P-7
+\end_layout
+
+\begin_layout Standard
+These are 100% capacity pumps.
+ These pumps boost the chilled water pressure required for the vent condenser
+ and cold traps.
+\end_layout
+
+\begin_layout Section
+Inter connection with other system
+\end_layout
+
+\begin_layout Subsection
+Steam Requirement
+\end_layout
+
+\begin_layout Standard
+Approximately 5000Kg/hr of dry saturated steam at a pressure of 1.8Kg/cm
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+is required during the startup of distillation for flooding operation.
+ After some 3 to 4 hours during normal operation the requirement is 3400Kg/hr
+ at a pressure of 1.8Kg/cm
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+.
+\end_layout
+
+\begin_layout Subsection
+Cooling Water Requirement
+\end_layout
+
+\begin_layout Standard
+Cooling water requirement of 250M
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+3
+\end_layout
+
+\end_inset
+
+/hr at 9Kg/cm
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+and 33
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C is required during normal operation for reflux condenser and product 
condenser
+ of both the distillation columns.
+ During flooding 400M
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+3
+\end_layout
+
+\end_inset
+
+/hr of process water will be required for both the distillation columns.
+\end_layout
+
+\begin_layout Subsection
+Chilled Water
+\end_layout
+
+\begin_layout Standard
+Chilled water is required for vent condensers, vacuum pump assembly and
+ also for vent cold traps.
+ 15M
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+3
+\end_layout
+
+\end_inset
+
+/hr of chilled water at 9Kg/cm
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+is required for the above chilled water loads.
+\end_layout
+
+\begin_layout Subsection
+Electrical Power
+\end_layout
+
+\begin_layout Standard
+Power supply required for this plant is 400/400 volts, 3Ø HZ A.C 180 KW.
+ Installed capacity is 400KW.
+\end_layout
+
+\begin_layout Subsection
+Instrument Air
+\end_layout
+
+\begin_layout Standard
+Oil free, moisture free air at a pressure of 5.3Kg/cm
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+2
+\end_layout
+
+\end_inset
+
+is required for pneumatic instruments.
+\end_layout
+
+\begin_layout Section
+Interlocks & Logics
+\end_layout
+
+\begin_layout Subsection
+Safety Interlocks
+\end_layout
+
+\begin_layout Standard
+There are two conditions which can shutdown the plant.
+ They are
+\end_layout
+
+\begin_layout Itemize
+High temperature in vacuum line 
+\begin_inset Formula $50-G-93$
+\end_inset
+
+ in CD-5 exit
+\end_layout
+
+\begin_layout Itemize
+Failure of vacuum which results in very high pressure alarm of vacuum line
+ 
+\begin_inset Formula $50-G-93$
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+The following are the interlocks provided for pytting the column under total
+ reflux
+\end_layout
+
+\begin_layout Itemize
+Low 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+
+\end_layout
+
+\begin_layout Itemize
+Low flow in reboiler EV-2 i.e < 7M
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+3
+\end_layout
+
+\end_inset
+
+/hr
+\end_layout
+
+\begin_layout Itemize
+High temperature in CD-6(product vent condenser) i.e >25
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+o
+\end_layout
+
+\end_inset
+
+C
+\end_layout
+
+\begin_layout Standard
+Hand switches, Indicators, Controllers for most of the equipments covered
+ in distillation process are in upgrading plant control room located in
+ first floor of upgrading plant.
+\end_layout
+
+\begin_layout Subsection
+Feed Pump Hand Switch
+\end_layout
+
+\begin_layout Standard
+Feed pump starts if there is no overload and emergency push button is not
+ pressed and HS is in ON position or HS is in auto 1 position and low level
+ in TK-5 is not existing or HS is in auto 2 position and low level in TK-13
+ is not existing.
+ Running feed pump stops if overload exists or emergency push button is
+ pressed or HS is kept in auto 2 position and low level exists in TK-13
+\end_layout
+
+\begin_layout Subsection
+Feed Flow Control
+\end_layout
+
+\begin_layout Standard
+Feed flow from feed overflow tank to feed evaporator is measured by FE-12147
+ and this signal is fed through a FRC-12202 to control CV-53 (Presently
+ in MAPS, the feed flow is set and controlled by a rotameter)
+\end_layout
+
+\begin_layout Subsection
+Feed Overflow tank level
+\end_layout
+
+\begin_layout Standard
+Low level in this TK-6 will close CV-53.
+ Alarm 
+\begin_inset Quotes eld
+\end_inset
+
+low level in TK-6
+\begin_inset Quotes erd
+\end_inset
+
+ also comes in UGP control room.
+ This TK-6 inventory is sufficient to continue the operation of the 
distillation
+ column for approximately 1 hour with the inflow to TK-6 is stopped
+\end_layout
+
+\begin_layout Subsection
+Feed Evaporator (EV-1) level control loop
+\end_layout
+
+\begin_layout Standard
+LT-12072 measures the EV-1 level and controls steam CV-272 through a controller
+ LIC-12005 so that the evaporator level is maintained.
+ This implies that whatever is the inflow to EV-1 from TK-6 will be evaporated
+ and fed to distillation column.
+\end_layout
+
+\begin_layout Subsection
+Differential pressure control loop for the column
+\end_layout
+
+\begin_layout Standard
+The performance of the distillation tower is very much dependent on the
+ pressure drop across the tower and on the boil up rate from reboiler.
+ A variation in boil up rate can vary the pressure drop across the column.
+ Hence, control on 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ which is cascaded with the steam pressure control in reboiler is used to
+ control 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ across the column and boilup from reboiler.
+ A larms are provided for high and low 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ in the column.
+ A low 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ will put the column under total reflux.
+\end_layout
+
+\begin_layout Subsection
+Vacuum Control Loop
+\end_layout
+
+\begin_layout Standard
+PT-12045 senses the pressure at the buffer tank and controls CV-159 such
+ that 120mm of Hg absolute is maintained at the top of the column.
+ A bleed air facility with a 2 way solenoid valve is provided so that CV-159
+ will operate well in its control range, if the air leak to the process
+ system is very small.
+ Presetting of the bleed air is done by a needle valve, which is in series
+ with the solenoid valve
+\end_layout
+
+\begin_layout Subsection
+Water circulating tank TK-4 level control
+\end_layout
+
+\begin_layout Standard
+High level in TK-4 closes SV-12325 and stops DM water addition and also
+ it gives an alarm.
+ Low level in TK-4 annunciates and also it closes CV-159, stops bleed air
+ flow, stop vacuum pumps and seal water circulating pumps.
+ LC-12007 level control provided keeps steady level in TK-4 by supply make
+ up water through SV-12325
+\end_layout
+
+\begin_layout Subsection
+Product and Reject withdrawal system
+\end_layout
+
+\begin_layout Subsubsection
+Column sump (TK-7) level control
+\end_layout
+
+\begin_layout Standard
+This controls product (reject) flow through CV-73 (CV-134), if the feed
+ IP >50% and HS-12327 is in High (Low) position.
+ The lesser of these two flow (Product & Reject flows) is controlled by
+ timer and the larger of these two flows is controlled by column sump level
+ control
+\end_layout
+
+\begin_layout Standard
+Flow restriction orifices in the product and reject lines which limit the
+ flow to 100Kg/hr
+\end_layout
+
+\begin_layout Standard
+Low sump level will stop product and reject withdrawal.
+ High sump level will cut off steam supply to feed evaporator
+\end_layout
+
+\begin_layout Subsubsection
+Timer Circuit Control
+\end_layout
+
+\begin_layout Standard
+The lower of the two product and reject withdrawal rate is controlled by
+ a timer circuit.
+ If feed IP is less(more) than HS-12327 will be low(high) and timer will
+ control CV-73(CV-134).
+ First timer gets energized and opens the CV-73 (CV-134) for a certain period
+ as determined in the setting.
+ When the first timer is timed out the second timer is energized and this
+ closes the CV-73 (CV-134).
+ This continues in a cyclic manner and hence maintains the rate of withdrawal
+ of product (Reject)
+\end_layout
+
+\begin_layout Subsection
+Reboiler Circulation
+\end_layout
+
+\begin_layout Standard
+High heat transfer is achieved if there is a turbulent to the film flow
+ in the tubes.
+ If low flow is existing then running reboiler pump trips and the plant
+ will run under total reflux.
+ Auto starting of standby pump works only on over-load tripping of running
+ pump if reboiler circulation is less than 7M
+\begin_inset script superscript
+
+\begin_layout Plain Layout
+3
+\end_layout
+
+\end_inset
+
+/hr.
+ Then CV-266 will be closed to safeguard EV-2
+\end_layout
+
+\begin_layout Subsection
+Steam Condensate tank TK-15 level control
+\end_layout
+
+\begin_layout Standard
+Steam condensate pumps (2x100% capacity) can be started/stopped manually.
+ In auto condition, these pumps start if tank level is high and stop when
+ TK-12 level is low.
+\end_layout
+
+\begin_layout Subsection
+Instrument Air Pressure
+\end_layout
+
+\begin_layout Standard
+Air supply pressure is 10Kg/sq.cm.
+ If it is 100psi then air pressure low alarm comes in UGP control room.
+\end_layout
+
+\begin_layout Subsection
+Product and Reject Tank Level Control
+\end_layout
+
+\begin_layout Standard
+Low level in these tanks trips the corresponding pumps low and high level
+ alarms are provided in upgrading plant control room
+\end_layout
+
+\begin_layout Chapter
+Experimental Details and Concepts Involved
+\end_layout
+
+\begin_layout Section
+Programmable Logic Controller (PLC)
+\end_layout
+
+\begin_layout Subsection
+Introduction
+\end_layout
+
+\begin_layout Standard
+A PLC (Programmable Logic Controller) is defined as a user-friendly, 
microproces
+sor based specialized computer that carries out control functions of many
+ types and levels of complexity.
+ The first PLC systems evolved from conventional computers in the late 1960s
+ and early 1970s.
+ These first PLCs were installed primarily in automotive plants.
+ What has taken months back then takes few days today.
+ Many companies like Allen-Bradley, Mitsubishi, and Siemens manufacture
+ PLCs.
+ In conventional controllers the functions are determined by their physical
+ wiring, whereas the functions of PLCs are defined by a program.
+ They are also connected to other parts with cable , but the content of
+ their program memory can be changed at any time to adapt their programs
+ to different control tasks.
+\end_layout
+
+\begin_layout Subsection
+Advantages of using PLC
+\end_layout
+
+\begin_layout Itemize
+Flexible
+\end_layout
+
+\begin_layout Itemize
+Faster response time
+\end_layout
+
+\begin_layout Itemize
+Simpler Wiring
+\end_layout
+
+\begin_layout Itemize
+Modular Design- easy to repair and expand
+\end_layout
+
+\begin_layout Itemize
+Handles much more complicated systems
+\end_layout
+
+\begin_layout Itemize
+Sophisticated instruction set available
+\end_layout
+
+\begin_layout Itemize
+Allows for diagnostics and easy to troubleshoot
+\end_layout
+
+\begin_layout Subsection
+Component description
+\end_layout
+
+\begin_layout Standard
+Programmable controllers have grown throughout industrial control applications
+ because of the ease they bring to creating a controller: ease of programming,
+ ease of wiring, ease of installation, and ease of changing.
+ PLCs span a wide range of sizes, but all contain six basic components
+\end_layout
+
+\begin_layout Itemize
+Processor or central processing unit (CPU)
+\end_layout
+
+\begin_layout Itemize
+Rack or Mounting
+\end_layout
+
+\begin_layout Itemize
+Input assembly
+\end_layout
+
+\begin_layout Itemize
+Output assembly
+\end_layout
+
+\begin_layout Itemize
+Power supply
+\end_layout
+
+\begin_layout Itemize
+Programming unit, device or PC
+\end_layout
+
+\begin_layout Subsubsection
+Rack Assembly
+\end_layout
+
+\begin_layout Standard
+Most medium to large PLC systems are assembled such that the individual
+ components - CPU, Input/Output, Power Supply - are modules that are held
+ together within a rack.
+ In smaller PLC systems - all of these components may be contained in a
+ single housing or "Brick" - these smaller systems are sometimes referred
+ to as "bricks" or "shoebox" PLCs.
+\end_layout
+
+\begin_layout Subsubsection
+Power Supply
+\end_layout
+
+\begin_layout Standard
+The power supply provides power for the PLC system.
+ The power supply provides internal DC current to operate the processor
+ logic circuitry and input/output assemblies.
+ Common power levels used are 24V DC or 120 VAC.
+\end_layout
+
+\begin_layout Subsubsection
+Processor (CPU)
+\end_layout
+
+\begin_layout Standard
+The processor, central processing unit, or CPU is the "brain" of the PLC.
+ The size and type of CPU will determine things like: the programming functions
+ available, size of the application logic available, amount of memory 
available,
+ and processing speed.
+ Understanding the CPU can be a complex subject and we will tackle that
+ in other articles.
+\end_layout
+
+\begin_layout Subsubsection
+Programming Device
+\end_layout
+
+\begin_layout Standard
+The PLC is programmed using a specialty programmer or software on a computer
+ that can load and change the logic inside.
+ Most modern PLCs are programmed using software on a PC or laptop computer.
+ Older systems used a custom programming device.
+\end_layout
+
+\begin_layout Subsubsection
+Input/Output Assembly
+\end_layout
+
+\begin_layout Standard
+Many types of inputs and outputs can be connected to a PLC, and they can
+ all be divided into two large groups - analog and digital.
+ Digital inputs and outputs are those that operate due to a discrete or
+ binary change - on/off, yes/no.
+ Analog inputs and outputs change continuously over a variable range - 
pressure,
+ temperature, potentiometer.
+\end_layout
+
+\begin_layout Standard
+\begin_inset Graphics
+       filename pasted1.png
+       scale 80
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Paragraph
+Configurations
+\end_layout
+
+\begin_layout Standard
+PLCs are available in various configurations, which are chosen according
+ to the necessity of the work.
+ Basic PLCs which are available on a single PCB are called open-frame or
+ single board PLCs; these are totally self-sustained (except power supply)
+ and can be directly mounted inside the controls cabinet on threaded standoffs.
+ They are inexpensive, small, consume less power, easy to program but do
+ not have large number on inputs and outputs; their instruction set is also
+ small.
+ PLCs are also available housed in a single case, with all inputs, outputs
+ and power supply points located in a single unit.
+ This type is generally chosen according to available program memory, required
+ number and voltage of inputs and outputs to suit the application.
+ These systems also have an expansion port which allows addition of specialized
+ units.
+ More sophisticated units with wider array of options are modularized PLCs.
+\end_layout
+
+\begin_layout Paragraph
+Operation of a PLC
+\end_layout
+
+\begin_layout Standard
+A PLC retains its operating system, user programs, and some data in retentive
+ (nonvolatile) memory.
+ It executes an initialization step when placed in run mode, and then 
repeatedly
+ executes a scan cycle sequence.
+ The total time for one complete program scan is a function of processor
+ speed, I/O modules used, and length of user program (Ladder Logic).
+\end_layout
+
+\begin_layout Standard
+The basic PLC scan cycle consists of three steps:
+\end_layout
+
+\begin_layout Itemize
+An input scan: Data is taken from all input modules in the system and placed
+ into an area of PLC memory referred to as the input image area
+\end_layout
+
+\begin_layout Itemize
+A user program scan: Data in the input image area is applied to the user
+ program, the user program is executed and the output image area is updated
+\end_layout
+
+\begin_layout Itemize
+An output scan: data is taken from the output image area and sent to all
+ output modules in the system.
+\end_layout
+
+\begin_layout Standard
+For the Allen-Bradley PLCs and the simulator used, the input and output
+ image areas (in addition and counters.
+ Programs are written as Ladder Logic for PLCs.
+ It is written in rungs, which are individual structures consisting of basic
+ elements like NC/NO contacts, timers, counters, etc.
+\end_layout
+
+\begin_layout Subsection
+Basic Elements and Instructions
+\end_layout
+
+\begin_layout Paragraph
+Contacts
+\end_layout
+
+\begin_layout Standard
+There are 2 types of contacts, normally open (NC) and normally open (NO).
+ When an NC contact is energized it opens and vice-versa.
+ XIO is used for an NC contact and XIO for an NO contact.
+\end_layout
+
+\begin_layout Paragraph
+Outputs/Coil
+\end_layout
+
+\begin_layout Standard
+The output for a rung is denoted by the instruction OTE.
+ It is energized when all the logics preceding it are true (1).
+ The output can also be latched and unlatched by OTL & OTU respectively.
+\end_layout
+
+\begin_layout Paragraph
+Timers
+\end_layout
+
+\begin_layout Standard
+The most commonly used process control device after coils and contacts is
+ the timer.
+ A timer is simply a control block that takes an input and changes an output
+ based on time.
+ A PLC timer’s time may be a programmable variable time as well as a fixed
+ time.
+ Many kinds of timers like Non-Retentive, Timer Delay Off, Retentive, etc.
+ are available.
+ For our project we have used NRT timers which get reset as and when the
+ input is off.
+\end_layout
+
+\begin_layout Standard
+\begin_inset Graphics
+       filename pasted3.png
+       lyxscale 50
+       scale 80
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Section
+Instrument and Control Loops in Upgrading Plant
+\end_layout
+
+\begin_layout Standard
+\begin_inset Float figure
+wide false
+sideways false
+status open
+
+\begin_layout Plain Layout
+
+\end_layout
+
+\begin_layout Plain Layout
+\begin_inset Caption Standard
+
+\begin_layout Plain Layout
+\begin_inset Graphics
+       filename WP_20140710_001.jpg
+       lyxscale 20
+       scale 10
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Plain Layout
+
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Subsection
+Feed System
+\end_layout
+
+\begin_layout Standard
+Feed tank level TK-5 and TK-13 are provided with level indicating alarms
+ LIA-12053 and LIA-12055 with a range of 0-2900 litres.
+ They have a high and low level adjustable set points and give high and
+ low level alarms.
+ They receive signal from differential pressure transmitters LT-12071 and
+ LT-12076 respectively.
+ Pressure switches are provided for alarms and associated interlock circuits.
+ Low levels in feed tank also trips feed pump P-1 and P-2.
+\end_layout
+
+\begin_layout Standard
+Feed pumps P-1 and P-2 are provided with hand switches HS-12317 and HS-12318
+ respectively.
+ These hand switches have ON, AUTO-1, AUTO-2 and OFF positions.
+ AUTO-1 is connected to TK-5 low level alarm circuit and AUTO-2 is connected
+ to TK-13 low level alarm circuit.
+ Depending on the on line feed tank, HS of both feed pumps should be put
+ in corresponding AUTO position so that they trip when level in the tank
+ goes down to the trip level.
+\end_layout
+
+\begin_layout Subsubsection
+Feed Flow Control Loop
+\end_layout
+
+\begin_layout Standard
+Flow control loop measures, controls and records pre-set D2O feed flow to
+ the feed evaporator EV-1 from feed overflow tank TK-6.
+ The flow element FE-12147 and pneumatic recording controller FRC-12002
+ have a range of 0-110 litres/hour(i.e.
+ 0-1.833 lpm).
+ The setting of the flow has to be done manually depending on the feed 
concentra
+tion.
+\end_layout
+
+\begin_layout Subsubsection
+Level of TK-6 Feed Overflow Tank
+\end_layout
+
+\begin_layout Standard
+Low level alarm LA-10257 provided in TK-6 will caution failure of feed pump.
+ There will be sufficient hold up still to continue feed for approximately
+ one hour.
+ Very low level alarm LA-12058 shuts off the feed flow control valve CV-53.
+\end_layout
+
+\begin_layout Subsubsection
+Feed Evaporator (EV-1) Level Control Loop
+\end_layout
+
+\begin_layout Standard
+This controls steam flow into the evaporator EV-1.
+ The control loop has LOC-12005 with a range of 0-420 Litres (non-linear
+ scale) and receives signal from differential pressure transmitter LT-12072
+ and gives signal to CV-272.
+\end_layout
+
+\begin_layout Standard
+The control loop maintains constant level in EV-1, so that controlled feed
+ flow from the flow control loop is completely evaporated and fed into the
+ column.
+\end_layout
+
+\begin_layout Subsection
+Differential Pressure Control Loop for the Column
+\end_layout
+
+\begin_layout Standard
+The performance of the distillation tower is very much dependent on the
+ pressure drop across the tower and on the boil up rate from the reboiler.
+ A variation in the boil up rate can vary the pressure drop across the column.
+ Hence, a control on 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ which is cascaded with the steam pressure control in reboiler is used to
+ control simultaneously 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ across column and boil up from reboiler.
+ The 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ control from FRC-12001 has a range of 0 to 300mm of Hg.
+ (abs) (linear scale) and can be set at required 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ manually.
+ 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ across the column is the primary variable.
+ This receives signal from 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ transmitter DPT-12004 and gives signals to PIC-12008, which is the pressure
+ indicating controller for the steam line to reboiler 150-S-1416.
+ Signal from DPT-12044 adjusts the set point of PIC-12008.
+ PIC-12008 gets signal from absolute pressure transmitter PT-12046 which
+ senses and transmits steam pressure for line 150-S-146 and gives signal
+ to CV-266.
+ Reboiler steam pressure is expected to go below atmospheric pressure at
+ times during operation and hence an absolute pressure transmitter is used
+ PT-12046.
+\end_layout
+
+\begin_layout Standard
+Also alarms for high pressure DPA-12004 drop across column and low pressure
+ drop DPA-12003 across column are provided on 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ control loop.
+ Low  will bring the column under total reflux.
+\end_layout
+
+\begin_layout Subsection
+Vacuum Control Loop
+\end_layout
+
+\begin_layout Standard
+The absolute pressure in the system is measured at the buffer tank TK-1
+ by an absolute pressure transmitter PT-12045 and controlled by a recording
+ control on panel PRC-12005.
+ This has a range of 0-200mm of Hg.
+ abs pressure.
+ Control valve CV-159 is provided between TK-1 and vacuum pump assembly.
+\end_layout
+
+\begin_layout Standard
+A bleed air facility with a 2 way solenoid valve SV-12322 is provided at
+ the inlet line of buffer tank (line 50-G-93).
+ This is for enabling the vacuum control valve CV-159 to function within
+ its control range, if the air leak to the process system is very small.
+ Presetting the bleed air is done by a fine needle valve.
+ SV-12322 opens or shuts off instrument air bleed into the system.
+\end_layout
+
+\begin_layout Standard
+Pressure switched for high pressure alarm is provided.
+ PA-12021 very high pressure in vacuum system will close CV-272, CV-73,
+ CV-134, CV-266 and shut down the plant.
+\end_layout
+
+\begin_layout Subsection
+Water Circulating Tank (TK-4) Level and Temperature
+\end_layout
+
+\begin_layout Standard
+Seal Water required for vacuum pump is taken from this tank(TK-4).
+ An ON-OFF type level control is provided to control level in this tank.
+ Level switches LA-12055(HIGH) and LA-12056(LOW) are also provided.
+ High level gives an alarm and cuts off make up water to the tank by closing
+ SV-202.
+ Low Level will give an alarm and trip level will cut off bleed air to vacuum
+ system; close CV-159 and puts off water circulating pumps P-16/P-17 and
+ vacuum pumps P-7/P-8.
+ LC-12007 level control provided keeps steady level in TK-4 by supplying
+ make up water through SV-202.
+\end_layout
+
+\begin_layout Subsection
+Product and Reject Withdrawal System Column Sump (TK-7) Level Control
+\end_layout
+
+\begin_layout Standard
+This is controlled either by product take off or reject take off depending
+ on the feed concentration.
+ The high-low change over hand switch HS-12327 connects this loop either
+ to product CV-73 or reject CV-134 control valve.
+ This change over is at around a feed concentration of 60% or as per 
operational
+ needs.
+\end_layout
+
+\begin_layout Standard
+Of the product and reject withdrawal, the lesser flow is controlled by a
+ timer loop and the larger flow of the two through the sump level control
+ loop.
+ Flow limiter orifices FE-12150 (product) and FE-12151 (reject) are provided
+ on both the take-off lines with flow limit at 100kg/hr.
+\end_layout
+
+\begin_layout Standard
+Sump (TK-7) has differential pressure transmitters LT-12073 which transmits
+ signal to LIC-12073.
+ Range if this is 0 to 1260 litres (non linear scale) and has low (LA-12053)
+ and high (LA-12054) alarms, which are adjustable.
+\end_layout
+
+\begin_layout Standard
+The high level alarm will cut off steam supply to feed evaporator and low
+ level stops product and reject withdrawal.
+\end_layout
+
+\begin_layout Subsection
+Reboiler Circulation
+\end_layout
+
+\begin_layout Standard
+FE-12184 senses the flow.
+ Flow indicating alarm FIA-12017 has adjustable high and low positions and
+ has a range of 0 to 333.3 lpm.
+ It receives signal from FT-12122.
+\end_layout
+
+\begin_layout Standard
+Low flow of circulation will give an alarm through a time delay relay and
+ will stop the recirculation pump and put the column under total reflux.
+ In this condition, standby pump will not start automatically.
+ Auto start of standby pump works only on over load tripping of running
+ pump.
+\end_layout
+
+\begin_layout Subsection
+Steam System
+\end_layout
+
+\begin_layout Standard
+Pressure control PIC-12008 controls steam pressure in EV-2 and in cascade
+ with 
+\begin_inset Formula $\triangle P$
+\end_inset
+
+ control .
+ Steam flow in reboiler EV-2 is monitored by FT-12123 and FT-12105 which
+ have a range of 0 to 4000 kg/hr.
+ Orifice FE-12149 senses the steam flow.
+\end_layout
+
+\begin_layout Subsection
+Steam Condensate Tank Level
+\end_layout
+
+\begin_layout Standard
+LA-12062 and LA-12061 with high and low level switches respectively are
+ provided on TK-12 which respectively starts and stops the pump P-13/P-14
+ and pumps condensate back to boiler house/reactor source.
+\end_layout
+
+\begin_layout Standard
+Since both pumps are given hand switches with ON,AUTO,OFF positions, both
+ pumps will start at the tank high level and stop at tank low level, if
+ hand switches are placed in AUTO.
+ Hence at a time only one pump need to be placed on AUTO and the other may
+ be placed on 'OFF'.
+\end_layout
+
+\begin_layout Subsection
+Instrument Air
+\end_layout
+
+\begin_layout Standard
+Instrument air supply pressure is expected at 10 kg/cm2.
+ This is being reduced by differential PRV's to 0.35 kg/cm2 for vacuum system
+ bleed air and 1.4 kg/cm2 for instruments.
+ Pressure switch PS-12089 gives low pressure alarm of the instrument air
+ supply system.
+\end_layout
+
+\begin_layout Subsection
+Product and Reject Tank Levels
+\end_layout
+
+\begin_layout Standard
+These tanks are provided with visual level gauges and have low and high
+ level alarms.
+ Low level alarms trip the product and reject pump.
+\end_layout
+
+\begin_layout Itemize
+LIA-12056 and LT-12074 for product tank
+\end_layout
+
+\begin_layout Itemize
+LIA-12054 and LT-12075 for reject tank
+\end_layout
+
+\begin_layout Standard
+Both have range of 0-1516 litres with adjustable high and low positons.
+\end_layout
+
+\begin_layout Subsection
+Temperature Measurement and Alarms
+\end_layout
+
+\begin_layout Standard
+Total six point R.T.D type temperature recorder (range 0-100oC) are provided
+ for temperature recording.
+ The temperature points are as follows
+\end_layout
+
+\begin_layout Itemize
+Feed evaporator vapour outlet TR-12067
+\end_layout
+
+\begin_layout Itemize
+Column sump TR-12065
+\end_layout
+
+\begin_layout Itemize
+Column top TR-12066
+\end_layout
+
+\begin_layout Itemize
+Reflux condenser cooling water out TR-12069
+\end_layout
+
+\begin_layout Itemize
+Vent condenser exit TR-12068
+\end_layout
+
+\begin_layout Standard
+Three temperature alarms having a range of 0-60oC are provided at the following
+ points
+\end_layout
+
+\begin_layout Itemize
+Water circulating tank TA-12033: gives alarm only
+\end_layout
+
+\begin_layout Itemize
+Vent Condenser exit TA-12031: will shut down the plant closing feed, product
+ and reject, and steam to EV-1 control valves
+\end_layout
+
+\begin_layout Itemize
+Product vent condenser exit TA-12032 will bring the column under total reflux
+ closing feed, product and reject control valves
+\end_layout
+
+\begin_layout Chapter
+Results and Discussion
+\end_layout
+
+\begin_layout Standard
+The Programming of PLC is done by Ladder Logic for which we used Logix Pro
+ Software.
+ Various steps followed for drawing a ladder diagram
+\end_layout
+
+\begin_layout Enumerate
+Find the inputs and outputs
+\end_layout
+
+\begin_layout Enumerate
+Familiarising with control logics
+\end_layout
+
+\begin_layout Enumerate
+Making a Flow diagram of the process
+\end_layout
+
+\begin_layout Standard
+There of 32 inputs and outputs available in a I/O simulator in Logix Pro
+ which we used for simulation.
+\end_layout
+
+\begin_layout Standard
+\begin_inset Graphics
+       filename pasted4.png
+       lyxscale 80
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Section
+Flow Diagrams
+\end_layout
+
+\begin_layout Standard
+\begin_inset Graphics
+       filename FEED_PUMP_FLOW_CHART.jpg
+       lyxscale 60
+       scale 80
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Graphics
+       filename maps_feed_flow_diag.jpg
+       lyxscale 30
+       scale 30
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Section
+Ladder Logic
+\end_layout
+
+\begin_layout Section
+Explanation of Ladder Logic Diagram
+\end_layout
+
+\begin_layout Chapter
+Conclusion
+\end_layout
+
+\begin_layout Standard
+The Project entitled “Implementation of PLC based system in Upgrading 
Plant”
+ was pursued to complete the objective of learning about the present relay
+ system in MAPS and replacing it with PLC.
+ From our work under the guidance of our mentor we concluded the following
+ things
+\end_layout
+
+\begin_layout Itemize
+The hardwired electromagnetic based relays should be replaced with PLC 
(Programm
+able Logic Controller) because of their advantages over relays in flexibility
+ and they are easy to maintain
+\end_layout
+
+\begin_layout Itemize
+Upgrading plant being one of the most oldest parts of MAPS, it needs to
+ be upgraded quickly to be able to use it smoothly for many years to come.
+ There may be some difficulties for upgradation but there are many benefits
+ to ripe in the future
+\end_layout
+
+\begin_layout Chapter
+Future Work
+\end_layout
+
+\begin_layout Section
+Implementing Microprocessor based System
+\end_layout
+
+\begin_layout Subsection
+Microprocessor
+\end_layout
+
+\begin_layout Standard
+A microprocessor incorporates the functions of a computer's central processing
+ unit (CPU) on a single integrated circuit (IC), or at most a few integrated
+ circuits.
+ All modern CPUs are microprocessors making the micro- prefix redundant.
+ The microprocessor is a multipurpose, programmable device that accepts
+ digital data as input, processes it according to instructions stored in
+ its memory, and provides results as output.
+ It is an example of sequential digital logic, as it has internal memory.
+ Microprocessors operate on numbers and symbols represented in the binary
+ numeral system.
+\end_layout
+
+\begin_layout Standard
+The integration of a whole CPU onto a single chip or on a few chips greatly
+ reduced the cost of processing power.
+ The integrated circuit processor was produced in large numbers by highly
+ automated processes, so unit cost was low.
+ Single-chip processors increase reliability as there are many fewer electrical
+ connections to fail.
+ As microprocessor designs get faster, the cost of manufacturing a chip
+ (with smaller components built on a semiconductor chip the same size) 
generally
+ stays the same.
+\end_layout
+
+\begin_layout Standard
+Before microprocessors, small computers had been implemented using racks
+ of circuit boards with many medium- and small-scale integrated circuits.
+ Microprocessors integrated this into one or a few large-scale ICs.
+ Continued increases in microprocessor capacity have since rendered other
+ forms of computers almost completely obsolete (see history of computing
+ hardware), with one or more microprocessors used in everything from the
+ smallest embedded systems and handheld devices to the largest mainframes
+ and supercomputers.
+\end_layout
+
+\begin_layout Subsection
+Using Microprocessor for Alarm Circuits
+\end_layout
+
+\begin_layout Standard
+To start with we have used an 8086 Microprocessor and simulated the Tank
+ Level Alarm system which displays the level of water if everything is normal
+ and raises an alarm if the level exceeds the threshold level.
+ Threshold level has been directly set via the code.
+ Keypad interface can be added to set the threshold level.
+\end_layout
+
+\begin_layout Standard
+\begin_inset Graphics
+       filename Screenshot_from_2014-07-10_22:21:32.png
+       lyxscale 50
+       scale 30
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+
+\end_layout
+
+\end_body
+\end_document
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Summary of changes:
 tests/PS_Report_Final.lyx                     | 2384 +++++++++++++++++++++++++
 tests/PS_Report_Final.odt                     |  Bin 0 -> 315263 bytes
 tests/PS_Report_Final.tex                     | 1111 ++++++++++++
 tests/Screenshot_from_2014-07-10_22:21:32.png |  Bin 0 -> 168659 bytes
 tests/WP_20140710_001.jpg                     |  Bin 0 -> 1555822 bytes
 tests/parselyx.py                             |   43 +
 6 files changed, 3538 insertions(+), 0 deletions(-)
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 create mode 100644 tests/Screenshot_from_2014-07-10_22:21:32.png
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 create mode 100644 tests/parselyx.py


hooks/post-receive
-- 
Repositories for GSOC work