Analyze which six major components of the foam fire truck

The foam fire truck can be seen literally to deal with all kinds of fires. On the way to and from work every day, you may see several fire trucks screaming at the sirens, you may also aim at the two eyes. I thought that the fire truck is not the case! In fact, it is not what you think. The internal structure and working principle of the fire truck are extremely complicated. Today, I will take a look at the composition and working principle of the foam fire truck.

First, the fire extinguishing mechanism of foam

The relative density of the foam is small, the fluidity is good, the durability and the anti-burning property are strong, the thermal conductivity is low, and the adhesion is large. These physical properties allow it to quickly cover the surface of the combustion fluid, to isolate the transfer of flammable vapors, air, heat, and the cooling effect, which acts as a fire extinguisher.

Second, the structure and working principle of the foam fire truck

The foam fire truck consists of a special device for the chassis of the car and its upper part. Foam fire trucks produced at home and abroad mostly use the second-class GM chassis provided by the whole vehicle manufacturer. Its special equipment mainly includes power take-off, water foam liquid tank, equipment box, pump room, fire pump, vacuum pump, foam proportion mixing device and so on.

The working principle is as follows: the power output of the automobile chassis engine is driven by the power take-off device, and the fire pump is driven by a set of transmission devices, and the water and the foam are mixed according to a certain ratio through the fire pump and the foam proportion mixing device, and then the fire cannon is fired. Fire with a foam fire extinguisher. Therefore, the vehicle chassis must meet certain load mass and engine power. At present, the national standard has been formulated. The chassis is selected according to the national standard of “General-purpose chassis series, type, basic parameters and technical requirements of fire engines”. The power of the engine must be selected according to the requirements of Appendix A of the industry standard “General Technical Conditions for Foam Fire Trucks”. Meet their requirements.

1. Power output device

Domestic foam fire trucks mostly adopt the main vehicle engine power take-off mode. The power take-off arrangement can take many forms. At present, the medium and heavy-duty foam fire trucks adopt the sandwich force force between the main clutch and the transmission. (transmission front) and drive shaft take-off (transmission rear). The sandwich type power take-off is used to take the power of the main engine out to the water pump through the transmission system, and drive the water pump to operate, which can realize the double action function. Most of this form is currently used.

2, water-foam tank

The water-foam tank is the main container for fire extinguishing agent on foam fire trucks. It can be made of various materials according to the development of the fire protection industry. In the 1980s and 1990s, polyester fiberglass materials were used, and now it is gradually developed to use high quality carbon. Made of steel and stainless steel.