When we encountered a situation like this we would ask the equipment mfgr to provide a 4"-6" piece of pipe about 6-8" long with a 1" threaded coupling on it be welded to a flange and bolted to the body of the piece of equipment at the locations where we needed to place the nozzles. The assembly kind of looked like a Top Hat. This is a deluge type system so there is no bulb that needs to be in the airstream to worry about.
At that "hat" we could thread the on pipe and then thread the head, reducer (if necessary) and a short nipple from the inside with the deflector at or near the inside edge of the vessel. This put the head out of the airstream but cleared the deflector enough not to interfere with the discharge into the vessel. There were a few variations on this type of installation based on the equipment, internal access for inspection and cleaning of the heads etc. I suggest putting a union on the outside to make removal of the head from the vessel easier (if you can bolt the flange of the hat to the vessel). Craig L. Prahl, CET Fire Protection Specialist Mechanical Department CH2MHILL Lockwood Greene 1500 International Drive PO Box 491, Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 [email protected] http://www.ch2m.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ryan Hinson Sent: Monday, February 02, 2009 6:22 PM To: [email protected] Subject: sprinklers inside trommels Is there anyone out there with any input on sprinkl.ering trommels? The only thing I can find is NFPA 850 (2005) section 9.4.4.2 which states, "Classifiers/trommels, such as rotating screens, should be provided with water spray protection to prevent fire from propagating downstream through the screen. Systems should be designed for a minimum of .25 gpm/sq ft of the entire screen area with nozzles no more than 10 ft on center. Consideration should be given to avoiding physical damage from mobile equipment operation in the area and from material being processed." Having never done one before, it seems that there is nowhere inside the trommel container to put heads where they are not exposed to flying debris. This particular trommel is elevated off the floor >10' and there is sprinkler protection below designed at .25 density with the overhead system designed at .25/3000 per NFPA 850 section 9.4.4.4. Also, is there any significance to the phrase 'water spray protection' and 'nozzles' as this seems to allude to a deluge system. A wet system designed per above will already be in place protecting everything outside the trommel. Is a design as indicated adequate, or should I go to the booth for a review as should have been done last night? Thank you in advance for any input, Ryan L. Hinson, EIT, CET, Nicet III FP Design Manager Fire Construction Design Services, LLC #C124 A Division of Fire Construction Services, Inc. 6950-43rd Avenue SE St. Cloud, MN 56304 Direct: 320-250-5404 Fax: 320-358-3495 email: <mailto:[email protected]> [email protected] CONFIDENTIALITY NOTICE: The information contained in this message, including any files transmitted within, is confidential, may be legally privileged, and is intended only for the use of the individual(s) named above. The use of any confidential or personal information may be restricted by state and federal privacy laws. If this message was received in error, please notify the sender and then delete this message. _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
