Roots blower is a positive displacement blower, impeller end, fan cover. The principle is the use of two lobe rotor in the cylinder relative motion to compress and transport gas rotary compressor. The blower has the advantages of simple structure, convenient manufacture, widely used in aquaculture wastewater treatment aeration, aeration, cement conveying, transporting gas is more suitable for low pressure applications and pressurization system, but also can be used as vacuum pump etc..