Idea for Room Fire Sprinkler Comments?

vanity | 10/4/03 | Ken Roberts

[Chummy]

Would this involve having 75 gallon water heater tanks, etc. for each individual room? How does one safeguard the common areas, eg, dining halls, hallways, restrooms, support facilities for the building?

[Old Professer]

It opened the valve and held it open against water pressure.

I think I misstated the volume of the room; it is, of course 800 cubic feet.

[supercat]

Sorry; the dip tube would be removed prior to using the tank for this purpose. The hot water pipe picks up from the bottom in my proposal and no heating elements need be incorporated.

What he's referring to as the "dip tube" I think is the cold water pipe. You need to take water from the bottom of the tank, since gas will accumulate at the top. If you remove the pipe that goes to the bottom, you'll get nothing but gas out.

This is basically an oversized version of the old-fashioned water-filled hand-held fire extinguishers Class A.

Have you considered other substances besides water? An 80 cubic foot room measures 10 feet on a side and 8 feet high; an inch of water on the floor is about 63.5 gallons.

How effectively can you make sure that water will get to or stay at places other than the floor? Would detergent or some other such substance help?

[supercat]

It opened the valve and held it open against water pressure.

That requires a 120CUFT N2 bottle? Why not use a pilot-valve arrangement like that used in electropneumatic pipe organs (in a pipe organ, a small valve allows pressurized air into a bellows which then operates the main valve; for water, I'd sugget having a small valve let water into a piston to do likewise).

[Old Professer]

Indeed, it is one such unit for each room; the hallways and the rest are generally low-risk ignition areas and not necessarily protected in many buildings.

Actually, I started with the idea of using a bladder-fitted tank with the bladder enclosed inside the tank and chargeable from an outside source with air at normal ASME air tank pressures of 120-200PSI but this would require a special construction and would cost more but would be far simpler.

In any case, I figure the device would need to dump (rain) at least one inch of water in less than 5 minutes to be effective, which is why I said it would take at least 63 gallons for a 10 foot by 10 foot floor area.

[Old Professer]

This is a nursing home; people are immobile. Any gas that will smother the fire will smother the people.

This whole thing relies on a single fire sprinkler head of an industry standard design that is capable of delivering 25 GPM and will cover the entire enclosed area, floor-to-ceiling thereby smothering the fire.

If the fire has a secondary source of fuel and air, all is lost.

[Chummy]

Kitchens? Mechanical areas? Storage areas?

[Old Professer]

I didn't design it, I just made the rounds with the fire inspector testing the units. I arranged to have all the bottles hydrostated and they all passed - even the one stamped 1937 as its first hydrostat date. This was in 1991.

[Old Professer]

Kitchens have their own fire-suppression already by code; mechanical areas are generally manned or policed apart from the quarters areas; storage areas are supposed to be isolated from ignition sources by code.

[Chummy]

I recognized immediately and share in your concern with this problem: it's a choice between protecting the vulnerable and the massive expense of retrofitting existing buildings to a new code.

I'm just wondering if there is not a more efficient means of solving the problem.

Where would all of these water heaters and support apparatus be placed?

[supercat]

Any gas that will smother the fire will smother the people.

I wasn't intending the CO2 as a primary fire suppression agent; I was suggesting its use as a propellent (though having large quantities of it dissolved in water may not be too good, limitting the time that water is exposed to CO2 under pressure would keep that down). The quantity of gas needed as a propellent is small enough that asphyxiation should not be a problem.