The foam fire truck consists of a chassis and special devices on its upper part. Its special devices mainly include power take-off, water tank, foam tank, equipment box, pump room, fire pump, vacuum pump, foam proportional mixing device and fire monitor, etc. The extinguishing medium loaded is composed of water and foam liquid, which can independently extinguish fire. It is especially suitable for fighting oil fires such as oil, and can also provide a mixture of water and foam to the fire scene. It is a petrochemical enterprise and an oil transportation terminal. Essential equipment for professional firefighting at airports and cities.
The working principle of the foam fire truck is to output the power of the chassis engine through the power take-off, drive the fire pump to work through a set of transmission devices, mix water and foam in a certain proportion through the fire pump and foam proportion mixing device, and then pass the fire monitor and The foam fire extinguisher sprays out to put out the fire.
PTO
Foam fire trucks mostly use the power take-off of the main vehicle engine, and the arrangement of the power take-off can be in various forms. At present, medium and heavy foam fire trucks mostly use sandwich type power take-off (gearbox front-mounted) and drive shaft power take-off (gearbox rear-mounted), and sandwich-type power take-offs are used to take out the power of the main engine and transmit it through the transmission system. The water supply pump drives the water pump to run to realize the double-action function.
Foam tank
The foam water tank is the main container for the foam fire truck to load the fire extinguishing agent. According to the development of the fire protection industry, it can be made of various materials. In the 1980s and 1990s, polyester fiberglass was mostly used, and now it has gradually developed into alternative carbon steel and stainless steel.
Equipment box
Most of the equipment boxes are steel frame welded structures, and the interior is made of all aluminum alloy plates or steel plates. In recent years, the internal layout structure of the equipment box can be divided into four types: fixed partition type, that is, each partition frame type is fixed and cannot be adjusted; movable partition type, that is, the partition frame is made of aluminum alloy profiles, and there are decorative patterns inside. The interval is adjustable; the push-pull drawer type, that is, the push-pull drawer type equipment is easy to take, but the production is more complicated; the rotating frame type, that is, each partition is made into a rotatable small equipment cutting gear, which is commonly used in imported fire trucks.
Fire Pump
At present, the fire pumps deployed on foam fire trucks in China can be roughly divided into three categories: atmospheric pumps (low pressure fire pumps), that is, single-stage centrifugal pumps, such as BS30, BS40, BS60, R100 (imported), etc. Medium and low pressure combined fire pumps, multi-stage centrifugal pumps such as 20.10/20.40, 20.10/30.60, 20.10/35.70, KSP import), etc. High and low pressure pumps, such as NH20. NH30 (import), 40.10/6.30 etc. Both are equipped with middle and rear fire pumps. 2.5 The pump room is the same as the equipment box, and the pump room is mostly a welded structure with a rigid frame. In addition to the fire pump, there is also space for equipment related to the pump, which is convenient for firefighters to operate.
Foam proportional mixing device
The foam proportional mixing device is the main equipment for absorbing and transporting foam liquid in the air foam fire extinguishing system. It can mix water and foam in proportion. Generally, there are three mixing ratios of 3%, 6% and 9%. At present, the foam proportioning mixers produced in China are mainly foam liquid, and the mixing ratio is 6%. The mixers are generally divided into three specifications: PH32, PH48, and PH64. In recent years, most of the imported high and low pressure pumps and medium and low pressure pumps adopt ring pump type air foam proportional mixing device, which is integrated with the pump design. It is an indispensable main equipment for foam fire trucks.
Foam fire extinguishing mechanism: foam has low relative density, good fluidity, strong durability and flame resistance, low thermal conductivity and high adhesion. These physical properties enable it to quickly cover the surface of the burning liquid, isolate the transfer of combustible vapor, air and heat, and have a cooling effect to play the role of fire extinguishing.
Post time: Mar-03-2023