Two Spray-Booth Fires
A $300,000 fire and water loss due to the use of lacquer spray booths occurred some time ago at the Luce Furniture Company, Grand Rapids, Michigan. The fire started on the upper floor of the three-story building in a room containing ten spray booths used for applying pyroxylin lacquer to radio cabinets and furniture.
Four of the booths were provided with independent exhaust pipes in which an induced draft was maintained by means of an air-blast supplied through connections front a big blowerpipe. The blower-fan was located on the first floor in a wood-working room, and fine sawdust constantly drawn in by the fan had collected inside the pipe.
Directly beneath this blower-pipe in the top story, a fire started due to spontaneous ignition in a box of waste material, probably containing some of the pyroxylin lacquer residue from the spray booths. Three sprinklers opened and extinguished the lire, whereupon the water was shut off at the outside indicator-post gate. Then it was discovered that a section of the blower-pipe was red hot, evidently due to burning of the accumulated wood dust inside the pipe, ignited by the fire in the waste material.
Before fire extinguishers could be used, a noise was heard like the rushing of wind; and flames hurst out of one of the booths and shot twenty-five feet across the room, blowing the glass out of several of the windows. Mild explosions followed in rapid succession from the adjoining booths which were connected to the same blower-pipe. The rope supports for the gravity-feed lacquer-tanks burned off, and the tanks fell, spreading burning lacquer over the floor and igniting a large stock of furniture in process, some with the finishing coats applied.
Within three minutes after the first burst of flame from the booth the sprinklers were turned on again, supplied with city water from both highand low-pressure mains. The fire pump was also started and run at full speed, pumping directly into the sprinkler system. In addition, two hose lines front a fire-engine, which had come for the original fire, furnished water to the sprinklers through the fire department connections.
In spite of these prompt measures, every one of the 356 sprinklers in the room opened, including 19 in the spray booths. Although the sprinklers system was not modern, and had nine and ten sprinklers on the branch lines, yet the deluge of water from the sprinklers held the fire in check and permitted firemen to enter the room after about ten minutes. Nine hose streams were used intermittently for about an hour before the fire was completely extinguished. Most of the contents of the top story were involved in the fire and the stock on the lower floors was completely wet down.
Brick fire-walls kept the fire out of adjoining sections of the building: At one end of the room, standard sliding firedoors closed automatically and prevented sprinklers openingin the section beyond; but at the opposite end of the room non-standard fire-doors did not all’ close promptly, and the wave of heat opened two sprinklers in the next section, causingconsiderable water damage.
Lessons of This Fire
- Possibility of serious loss in well-protected property during brief interruption of sprinkler protection. Restore protection immediately after fire or accident, keeping hose lines and extinguishers at hand, in the meantime.
- Suddenness of fires in spray booths and vent pipes. Danger of combustible supports for gravity-feed lacquer-tanks.
- Rapidity of spread of fire throughout furniture finishing rooms. Consequent need of cutting off hazardous processes and providing large water supplies. Fire-department connections to sprinklers, valuable.
- Clean spray booths and vent pipes frequently, and remove waste immediately from buildings. Keep spray-booth vents separate from other exhaust, systems.
- Induced-draft fans for spray booths should take suction from out of doors. Provide open sprinklers manually controlled. in long exhaust-pipes for dust or lacquer.
- Value of fire walls between sections of building and need of waterproofing and draining upper floors in rooms containing hazardous occupancies.
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The Second Fire
The second spray-booth fire occurred at the Anthes-Bactz Furniture Company, Kitchener, Ont. I wo booth using pyroxylin lacquer for finishing furniture were located at opposite ends of the top story of a three-story building. The booths were a lx nit 90 feet apart and close to the side walls of the building. They faced away from each other and toward the end walls, which were ten to fifteen feet distant in each case. Both spray booths were of metal about ten feet square and each was ventilated by a large exhaust pipe extending up through the roof.
A wooden partition from floor to ceiling and containing three large windows extended entirely across the room between the booths. On each side of the partition the floor space was used for the storage of furniture in process, although but a few pieces were near the booths. There was also some staining, filling and rubbing of furniture carried on in these rooms.
At about 10:00 a. m. the north booth, which has been idle since the previous day, was discovered to be on fire, apparently due to spontaneous ignition in the accumulation of lacquer on the walls and floor of the booth. I here w’ere no sprinklers in the booths and an employee tried to use a pail of sand on the fire, but the heat and fumes drove him from the room. The flatties from the ventilator set fire to the tar roof-covering which bad been recently laid but not covered with gravel. A strong wind quickly spread the fire over the roof to the other ventilator, igniting the deposit of lacquer inside the pipe. The fire then flashed down into the second booth.
Eleven sprinklers opened around the first booth and twelve around the second. The sprinklers were supplied with city water good for 400 gallons per minute at 50 pounds pressure, and from a 25,000 gallon tank on the roof as a secondary supply. The flames issuing from the booth were not directed toward the stock of goods in the room but toward the end windows. On this account there was no tendency for the fire to flash throughout the room; and the sprinkler water protected the building and contents so well that only a small area of the roof was charred in front of each booth. The only furniture burned was inside the south booth and on a rack just outside.
The city-water pressure was raised to 80 pounds fire pressure soon after the start of the fire. This was sufficient to furnish three good hose streams without the use of fire engines, and also ample water for the sprinklers, so that the water level in the sprinkler tank was lowered only two feet during the fire.
The water from the sprinklers and from the hose streams used by the public fire department damaged veneered goods on all floors. Although the fire loss was less than one thousand dollars, the water loss may reach $25,000.
It is worthy of especial note that in these spray-booth fires the large water loss in each case was due to the location of the spraying process oil the top story of a building containing large values on the floors below.
Lessons of This Fire
- Enclose or detach such hazardous processes; and when in upper stores waterproof and drain floors.
Clean spray booths and ventilating pipes frequently. I tit sprinklers in spray booths. .
Sprinklers with ample water supplies are efficient m hazardous occupancies.
- Tar roofs without gravel or slay covering are hazardous. – Factory Mutual Record.