It’s not common, but every so often, perhaps even despite best efforts, a fire — or even explosion — happens in the oven. That’s why planning is just as important as prevention.
Today, a few different types of fire extinguishing systems are available, depending on the product, plant and, of course, equipment supplier. Before choosing a system, it’s important to see how it all fits together.
For example, the CO2 system that Reading Bakery Systems (R.B.S.) offers with its ovens is designed using piping that runs the length of the baking or drying chamber and has nozzles at the end of each pipe.
“This system is meant to be used when the fire has the potential to get out of control and cause damage to the plant,” said Tremaine Hartranft, director of engineering, R.B.S. “The CO2 fills the entire baking chamber and starves the flames.”
Water, of course is also a great enemy of fire, and many bakeries employ mist or steam systems for fire suppression. Steam uses water vapor to take on the flames.
“Steam is 10 times the volume of air, so it expands very quickly and pushes out the oxygen,” said Kevin Knott, technical sales manager, Franz Haas Machinery of America. “Pushing out the oxygen snuffs the fire.”
The added benefit to steam suppression is that water is readily available, and a bakery is not likely to run out of it.
Separate suppression systems aside, some ovens are designed to mitigate a fire or explosion and its potential damage. Topos Mondial Corp.’s J4 ovens are designed with explosion hatches in the oven chamber. In the event of an explosion in the chamber, the hinged hatches blow straight upward to allow for the rapid expansion of gas to be released from the chamber upward as well.
“Explosions are not instantaneous. It takes time for the pressure to build up once a flame begins to propagate in the fire chamber,” said Ondrej Nikel, director of engineering, Topos. “As an ignition and subsequent explosion begins to expand and pressure builds, the relief hatches open up and let out the pressure upward in a safe way before the fire/explosion gets to the point where it will create any serious damage.”
Without these hatches, Damian Morabito, Topos president and chief executive officer, added, an oven has the potential to transform into a sort of bomb and send pieces flying outward and into the bakery. It can not only can take an oven down for months, but it can also damage other equipment or, worse, seriously injure someone.
For Auto-Bake, part of the Middleby Bakery Group, controlling a fire starts with discovery. Its ovens come with optional integrated fire detection system and includes an auto shutoff for the machine.
“Using redundant UV/IR sensors, the system will respond to a fire or even a spark in less than three seconds,” said Scott McCally, president, Auto-Bake.
Outside the machine, four manual fire alarm stations and four siren/strobe stations are attached.
“Should a sensor or pull station activate, the fuel source and all power along the line is cut off immediately,” Mr. McCally added.
No one is comfortable anticipating a fire in the bakery. But nobody wants to be the example of what not to do, either. A little fear is healthy. As long as bakers treat ovens — and their power — with a bit of reverence, they can keep the quality of their baked goods high and the risk of fire low.