A fire at an Iowa feed plant Tuesday demonstrates why firefighters must be cautious and consider the effects of every action when dealing with fires in compartmented areas of manufacturing equipment. Reports stated that a fire occurred within a cooling tower, and upon firefighters opening the tower, the fire flared up.
Fires within pelleting operations are common, especially if a malfunction or power failure causes a disruption in the flow of air or product within the system. Fresh pellets are very hot when they exit the extrusion presses, due to the heat build-up from friction and pressure. If the cooling process is interrupted, the product can rapidly heat up and begin smoldering. Because these systems are designed to direct air flow in a specific manner, a cease of air flow can actually cause airtight pockets to occur within the system. A smoldering fire can then create a backdraft situation within the equipment, and any attempt to open the system can then allow air infiltration to initiate a fire or explosion.
Pellet manufacturing operations and equipment are found in a number of industries, ranging from a feed plant like the one noted here to facilities that produce wood-pellets for fuel. The systems typically involve the drying and grinding of a raw material, an extrusion press, a cooling process, and a holding and packaging area. Pellets may be stored for bulk distribution by truck or rail, or they may be packaged into containers ranging from pallet gaylords to individual bags.
Because of the inherent fire potential within this process, fire protection systems are often installed within these systems which will allow the introduction of fire suppression water in an automatic or manual deluge fashion. Some pelleting systems are designed with power-failure protection that will keep the drying or cooling processes operational, at least long enough to empty the system of in-process materials. The systems may be designed to simply sustain material movement into a purge operation that dumps the superheated material to safe area outside of the system.
If you have any of these systems within your response area, be sure to familiarize yourself with the operation and the equipment, ensure that an emergency response plan is in place for a fire situation, and recommend the addition of protective engineering to prevent or suppress fires with minimal interruption and danger.
Officials at Hubbard Feeds hoped to resume production later Tuesday after an early morning fire in a feed-cooling area.
Sioux City firefighters were called to the scene at about 12:30 a.m. after a passer-by reported smoke coming from the plant at 4520 S. York St. Assistant Fire Chief Brad Robinson said firefighters entered a cooling tower, where some feed was smoldering. Once the door was opened, the feed flared up into flames. Robinson said it took about 15 minutes to put out the fire.
Robinson said the fire was caused by an overheated machine. He said there was no fire damage to the building.
A fire early Tuesday morning had Sioux City Fire Rescue crews out in the cold at a feed plant.
Crews were called to Hubbard Feeds, Inc. on the 4500 block of York Street in Sioux City just before 1 a.m. Someone reported seeing smoke in the area.
Fire officials say that when they arrived, the owners were there, and thought that there was no problem.
Once inside, however, Assistant Fire Chief Brad Robinson says they found the fire.
“We got to investigating, and found a smoldering, small smoldering fire going on in the cooling tower down in the basement, the cooling box,” Robinson said. “It’s a box where the feed goes through the pellets and cools it down before they actually package it.”
Robinson says they immediately got to work extinguishing the fire. Fortunately, he says, the damage was confined to one cooling box of feed pellets.
“We’re emptying the rest of the feed pellets out of the box that are left in there smoldering. Once that’s out, we’ll rinse it out, and we should be good to go,” Robinson said.
Robinson says they’re still investigating what started the fire in the first place.