The foam formation mechanism of the compressed air foam system (CAFS) is that a certain proportion of compressed air is injected into the foam mixture to produce foam after hitting the mixture.
Compressed air is air compressed by external forces. Air has compressibility, through the air compressor to do mechanical work to reduce the volume of its own, after the pressure increase of the air is called compressed air. Compressed air is an important source of power. Compared with other energy sources, it has the following obvious characteristics: clear and transparent, easy to convey, no special harmful performance, no fire risk, not afraid of overload, can work in many adverse conditions, air everywhere on the ground, inexhaustible.
Compressed air is the second largest power source after electric power, and it is also a process gas source with multiple USES. Its application range covers petroleum, chemical industry, metallurgy, electric power, machinery, light industry, textile, automobile manufacturing, electronics, food, medicine, biochemistry, national defense, scientific research and other industries and sectors.
The bad news is that compressed air contains a fair amount of impurities, mainly solid particles -- about 140 million particles per cubic meter of air in a typical metropolitan environment, about 80 percent of which are less than 2 m in size, and the compressor's suction filter is powerless to remove them. In addition, the air compressor system will continue to produce dust, rust and oil carbide, they will accelerate the use of gas equipment wear, leading to seal failure; Water -- the relative humidity in the atmosphere is usually as high as 65% or more. After being compressed and condensed, it becomes saturated wet air with a large number of liquid water droplets, which are the root cause of corrosion of equipment, pipes and valves. It is worth noting that even if the pure saturated air is separated, as the temperature decreases, there will still be condensed water precipitation. About every 10℃ reduction, its saturated water content will drop by 50%, that is, half of the water vapor will be converted into liquid water droplets.