Does anyone have advice as to how one would calculate a "spray booth" for spraying foam insulation that is approximately 90' tall X 25' diameter with five levels of working platforms?
Typically, when I have done paint booths for vehicles (even as large as fire trucks) I have calculated the system as a deluge system because of concerns regarding flames in a vapor cloud opening heads throughout the booth. In this case, there will likely be 8 - 10 sprinklers at each level of the working platforms plus 20 sprinklers at the roof (due to structural obstructions). This totals 60 - 70 sprinklers flowing at Extra Hazard Group 2 densities if the system is treated as a deluge system for hydraulic calculation purposes. NFPA 33:9.6.3 (also NFPA 13:26.4.1.4) "The water supply shall be sufficient to supply all sprinklers likely to open in any one fire incident without depleting the available water for use in hose streams." I am wondering about the likelihood of sprinklers at the roof operating simultaneously with multiple levels of sprinklers below the operating platforms. Or, as the Annex to NFPA 33:9.6.3 puts it, what is a "credible fire scenario" for a spray booth such as this? Is it a reasonable assumption that sprinklers installed 15' AFF will operate while the flame front continues to open sprinklers at different elevations up to and including the roof level at approximately 90' AFF? Conversely, is it reasonable to make the assumption that a fire will not open all of the sprinklers? If I had an unlimited water supply I would simply calculate the system as a deluge system. If I had an unlimited budget, I would make each level a separate deluge system with flame detectors at each level. Unfortunately, we do not operate with unlimited water supplies and unlimited budgets. Any advice would be greatly appreciated. David L. Miller, P.E. Engineered Fire Protection, LLC 11920 Richcroft Avenue Baton Rouge, Louisiana 70814 225-273-5040 _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
