The pneumatic conveying control system is mainly divided into three categories: dense phase pneumatic conveying, dilute phase positive pressure pneumatic conveying and dilute phase negative pressure pneumatic conveying.
Dense phase pneumatic conveying: use the gas pressure with the gauge pressure higher than 1kg/cm2 to push the material through the conveying pipeline. The main features are large conveying capacity, long conveying distance, high gas-solid ratio, low gas flow rate, small pipe wear, and automatic control of the whole working cycle through PLC.
Dilute phase positive pressure pneumatic transmission: Roots blower power source is generally selected, and the transmission distance can be longer, generally 100-300m. It can implement multi-point feeding and multi-point discharging, continuous transmission, good environmental protection performance, no dust leakage, low equipment use cost and maintenance cost.
Dilute phase negative pressure pneumatic conveying: Roots blower, centrifugal blower or vortex pump are generally used as the power source to pump the pipeline and vacuum feed hopper into a certain vacuum state, so that the inlet air forms a two-phase flow of material powder and gas under the action of atmospheric pressure, and then is fed into the vacuum feed hopper through the conveying pipeline. The gas-solid separation is carried out through the positive empty upper hopper.
The application scope of the centralized feeding system: it is widely used for conveying pulverized materials such as fly ash in power plants, cement in cement plants, aluminum oxide powder in alumina plants, and raw meal powder in pneumatic conveying.
