ESFR and ANTIFREEZE 1

[johnbelg]

I can't find an available solution to protect our refrigarated frozen food building. We have rack storage protected by ESFR K14, filled with 45m³ water+polyprop.glycol for use until -35°C. Since we know from NFPA13 or FM2-2 that this is not a good solution, we are looking for other solutions, covered by NFPA13 or FM2-2. I heard last december(2003) that FM took away all his appovals for anti-freeze solutions. Does anybody knows the real reason ? Other technics to protect frozen food buildings ?

 

[scotty409]

First, there has only been one antifreeze solution with successful test results for use in an ESFR system. It is called "lactate" and was developed by TYCO. After beta testing in a few facilities they discovered small leaks in the piping. It was no fault of the piping. It was attributed to the small molecule size of the antifreeze. The small molecules would find their way through the fitting threads. In a large food warehouse a small leak can cause big problems from a health inspection standpoint. So, TYCO pulled the product and is continuing R&D.

If the solution in your system is not "lactate", beware. Prop and ethylene glycol solutions actually increase the heat release rate of a fire just after system activation. For a control mode sprinkler system like spray or large drop sprinklers, its not that big of a deal but with ESFR its a different story. ESFR is suppression mode technology and must have early knock-down of the fire to be successfull.

I would look at large drop sprinklers.

J. Scott Mitchell
Fire Protection Engineer

 

[pierrepaul]

Hi Johnbelg, I fully agree with J. Scott Mitchell, large drop is THE solution in that case.

Regards

B Franc
SPK Engineering

http://www.spk.fr/index.htm?referrer=securite_incendie

 

[johnbelg]

Thank you Scotty and Pierrepaul for the reply. I don't fully agree with your statements of Large Drop as a solution for my problem. Why ?
You have to know that we engineered the building in 1998. It was a 12m high building. First, we wanted to make a compartmentation around the freezer (+/- 5000m²). We used a lot of ESFR for the rest of the site (12m high, storage 10,3m, racks).
A dry system was not a solution for us (f.e. dry Large Drop),not because the max. storage height is less, but for the next reason.
I know a lot of frozen food-manufacturers are using this (in combination with in-rack-sprinkling) for the moment.
I think the negative results of sprinkling water in a building of -22°C are underestimated: the floor will come up, sprinkling piping is gone and you have to unfreeze the building. The most risk for this case is an accidental damage of a bulb.
Then, we heard about antifreeze-solutions for ESFR. The few tests and experiences were a (false) argument to go for this solution. In a surpression scenario we had a good chance to surpress a beginning rack-fire with max 4 sprinklers and 45000 l of water-glycol-solution.
At this moment I know this was not a good choice. As a matter of fact it's difficult to find other solutions.