The earliest fire extinguishing agents used dry powder for F (K) type fires. The fire extinguishing effect is also very good. However, the practical inspection found that the cleaning work after the fire extinguishing was very heavy, and the wet powder chemical agent appeared.
About fat and temperature
In the early commercial kitchens, the main target was animal oil fires. After 1960, health issues attracted the attention of the public, advocating less animal oil and more vegetable oil. At the same time, in order to adapt to the high efficiency and high efficiency of the social development, stoves emerged at the historic moment. The most obvious manifestation is the fast heating and slow cooling, that is, the heat storage performance of the stove is getting stronger and stronger, and more than 70% of kitchens use vegetable oil.
Animal oils contain very high saturated fats, while vegetable oils do not. The burning temperature of animal oil is 550-600F (2880C-3150C), and the burning temperature of vegetable oil is 685F (3620C), which is much higher than the burning point of animal oil.
Kitchen fire extinguisher's medicine is a kind of alkaline chemical agent. When the acidic animal oil meets the alkaline fire extinguishing agent, the saponification reaction will occur to form a foaming liquid, and when the fire extinguishing agent is sprayed on the cooking oil of the high-temperature stove. It will accelerate the saponification reaction process and quickly produce a layer of saponification film. It is this layer of soap film that cuts off the connection between fire and oxygen until the oil is cooled to a condition that cannot be re-ignited automatically.
Vegetable oil and animal oil are very different, especially the saponification reaction is reduced, resulting in lower foaming. Moreover, the higher temperature of vegetable oil coupled with high-efficiency and high-temperature cookers causes the formed soap film to be destroyed, and its fire-extinguishing efficiency is greatly reduced. .
1. When the temperature of the pan on the kitchen stove reaches 360-366 ° C, the oil in the pan starts to ignite spontaneously, and the temperature reaches above 400 ° C within a short time. When the burning flame generates huge heat to increase the temperature in the hood to 183 ° C, the temperature detector is turned off, thereby activating the fire extinguishing device of the kitchen equipment.
2. At the same time when the device starts automatically, the gas in the cylinder is driven through the pressure reducing device to instantly push the agent through the atomizing nozzle into the oil pan and the fume hood, and chemically react with the burning oil to form a thick covering layer to make the oil It is isolated from the air to stop the fire and achieve the purpose of rapid fire suppression. Jiuzhaigou earthquake
3. When the device is started, the gas valve is automatically closed, the gas is completely cut off, and the audible and visual alarm system is started through the micro switch to start the alarm.
4. After the fire extinguishing agent is sprayed, the water flow valve is automatically activated to spray water into the oil pan and the exhaust fume hood to allow it to cool down physically to prevent secondary re-ignition.
5. The automatic fire extinguishing system of the kitchen equipment only needs 3-8 seconds to complete the fire extinguishing process, which cannot be replaced by other fire extinguishing equipment.
Note: Normally, the heat of the cooktop does not reach the temperature at which the temperature detector is blown out, which will not cause a false spray.