What is a foam fire extinguisher?

There are many types of fire extinguishers. According to the way it moves can be divided into portable and cart type; according to the power source of driving the extinguishing agent can be divided into storage cylinder type, storage pressure type, chemical reaction type; according to the filled extinguishing agent can be divided into foam, dry powder, halogenated alkane, carbon dioxide, water, etc. We have already introduced the principle and use of dry powder fire extinguishers, and in this article, we will briefly introduce foam fire extinguishers.

Here is the list of contents

• What is a foam fire extinguisher?

• What is the extinguishing principle of foam fire extinguishers?

• The structure of foam fire extinguisher

  
  

What is a foam fire extinguisher?

There are two containers inside the foam fire extinguisher, holding two kinds of liquid, they are aluminum sulfate and sodium bicarbonate solution, in normal times, the two solutions do not touch each other, no chemical reaction occurs. However, when the foam extinguisher is needed, the extinguisher is turned upside down, and the two solutions will be mixed together to produce a large amount of carbon dioxide gas, so the foam extinguisher should not be touched down at ordinary times.

What is the fire extinguishing principle of foam extinguisher?

We know that there are three methods of fire extinguishing, which are cooling method, asphyxiation method and isolation method. Cooling method is the fire extinguishing agent is sprayed directly onto the burning object to reduce the temperature of the burning material to below the ignition point so that the burning stops; or the fire extinguishing agent is sprayed on the material near the source of the fire, so that it does not form a new fire point due to the thermal radiation effect of the flame. Cooling method of fire extinguishing is a major method of fire extinguishing, commonly used water and carbon dioxide as a fire extinguishing agent to cool down the fire. Extinguishing agent in the process of extinguishing the fire does not participate in the chemical reaction in the combustion process, this method belongs to the physical fire extinguishing methods. Isolation fire extinguishing method is the burning material and the surrounding unburned combustible material isolated or removed, interrupting the supply of combustible material so that the combustion due to the lack of combustible material and stop. In the event of a hill fire, we often dig out isolation strips to isolate burning trees and non-burning trees. Asphyxiation method is to prevent the flow of air into the burning area or use non-combustible substances to dilute the air so that the burning material does not get enough oxygen and extinguish the fire.

In addition to the two reactants in the foam fire extinguisher, some foaming agent is also added. Turn on the switch, the foam will be ejected from the fire extinguisher, covering the burning items, isolating the burning material from the air and lowering the temperature for the purpose of extinguishing the fire. This is a typical example of using a combination of cooling and asphyxiation methods to extinguish a fire.

The Structure of foam fire extinguisher

The acid-base fire extinguisher consists of a cylinder, a cylinder cover, a sulfuric acid bottle, a nozzle, etc. The cylinder is filled with aqueous sodium bicarbonate solution, and the sulfuric acid bottle is filled with concentrated sulfuric acid. There is a lead plug at the mouth of the bottle, which is used to seal the mouth of the bottle to prevent the concentrated sulfuric acid in the bottle from absorbing water and diluting or mixing with the liquid outside the bottle. The principle of the acid-base fire extinguisher is the use of two agents mixed chemical reaction, resulting in pressure to make the agent sprayed, so as to extinguish the fire.

Nanjing Jiayi Fire Technology Co., Ltd produces many high quality fire extinguishers and has obtained many international certifications with sufficient quality assurance. If you want to know more information, welcome to send us a message!