The dry powder fire extinguisher is filled with ammonium phosphate dry powder fire extinguishing agent. Dry powder fire extinguishing agent is a dry and easy-flowing fine powder used for fire extinguishing. It consists of inorganic salt with fire extinguishing effect and a small amount of
The additives are dried, crushed, and mixed to form a fine solid powder composition. It is a fire extinguishing agent widely used in fire fighting, and is mainly used in fire extinguishers. In addition to special dry powder chemical fire extinguishing agents for fighting metal fires, dry powder fire extinguishing agents are generally divided into BC dry powder fire extinguishing agents (sodium bicarbonate, etc.) and ABC dry powder (ammonium phosphate, etc.).
One is to rely on the volatile decomposition products of inorganic salts in the dry powder to chemically inhibit and negatively catalyze the free radicals or active groups generated by the fuel during the combustion process, so that the combustion chain reaction is interrupted and the fire is extinguished;
The second is that the dry powder falls on the surface of the combustible, chemical reaction occurs, and forms a glassy coating under the action of high temperature, thereby isolating oxygen, and suffocating fire. In addition, there are some diluting oxygen and cooling effects.
classification
Dry powder fire extinguishers can be divided into two types: ABC and BC.
According to the mode of operation, it is divided into portable dry powder fire extinguishers and cart-type dry powder fire extinguishers.
According to the type of dry powder fire extinguishing agent, it can be divided into ordinary dry powder fire extinguisher and superfine dry powder fire extinguisher.
NaOH+AlCl3+2NaHCO3====Al(OH)3↓+2CO2↑+3NaCl
Dry powder fire extinguishers can be divided into three types: portable type, backpack type and cart type.
When using an external portable fire extinguisher, hold the nozzle with one hand and lift the lifting ring with the other hand, and the dry powder can be sprayed.
Dry powder fire extinguisher
When using a cart-type fire extinguisher, turn the rear of the fire extinguisher toward the fire source (it should be placed in the upwind direction when outdoors), first remove the spray gun, unfold the powder pipe (remember not to twist), and then lift the intake pressure rod to allow carbon dioxide to enter Storage tank, when the gauge pressure rises to 0. When 7 MPa ~ 1 MPa, lower the intake pressure lever to stop the intake. At this time, turn on the switch and spray dry powder to extinguish the fire from near to far. For example, when fighting an oil fire, do not allow the airflow of dry powder to directly impact the oil stain, so as to avoid splashing the oil surface and spreading the fire.
When using a backpack-type fire extinguisher, stand at a distance of 5 to 6 meters from the edge of the flame, and hold the dry powder gun grip firmly with your right hand (if it is powered by nitrogen, you can only hold the wooden handle, otherwise you may be frostbited by the low temperature gas), and your left hand Move the changeover switch to position "3" (spraying sequence is 3, 2, 1), open the safety device, point the spray gun at the fire source, pull the trigger, and the dry powder can be sprayed. If you can't put out the fire after spraying a bottle of dry powder, you can turn the switch to No. 2 or No. 1, and spray continuously until the spray is finished.
Note: If the lithium ion battery warehouse is on fire, the dry powder fire extinguisher cannot effectively extinguish it. When the fire is large, it will be more difficult to extinguish the fire.
Dry powder fire extinguishers can be filled in various types of portable and fixed dry powder fire extinguishing devices. They can be combined with fluoroprotein foam fire extinguishing agents and aqueous film foam fire extinguishing agents to extinguish the initial fire of oil tanks and quickly control the flame Development plays a role of rapid fire extinguishing
Dry powder fire extinguishers are widely used in oil fields, oil depots, refineries, chemical plants, chemical warehouses, ships, airports and industrial and mining enterprises.
