Vacuum pumps are widely used in conveying water, wet sludge and flocculant chemicals in sewage treatment plants because of their variable capacity to transport, self-priming capacity, reversible capacity and the ability to transport liquids containing solid particles. The quality of vacuum pump products Now on the market more types of pump products, relatively speaking, the imported pump product design is reasonable, the material is excellent, but the price is higher, the service is not in place, high pump prices It can be used and popularized in different industries, playing an important role and performance, displaying good performance and advantages in the industry, selecting according to certain standards and methods, and ensuring the value and effect in actual use. Long order cycle, may affect the normal operation of production. Most of the domestic production of imported products imitation, product quality varies greatly in the choice of domestically produced products, considering its cost-effective time, the choice of low speed, long lead, transmission parts of good quality, long life rating of the product. Pump selection should follow the economic, reasonable and reliable principles. If the lack of consideration in the design selection will give future use, management, maintenance trouble, so choose a production according to actual needs, reasonable and reliable pump products to ensure the smooth production, but also reduce repair costs . Pump speed selection of vacuum pump products in the selection according to certain standards and methods, can show good performance in the use of advantages and contributions. Will inevitably lead to failure of the screw pump, screw rotor and high-speed fixed rotor length is very short, easy to wear, thus shortening the life of pump products. Through the speed reducer or stepless speed regulating mechanism to reduce the speed, the speed maintained at a reasonable range of three hundred revolutions per minute, and high-speed operation of the screw pump, the service life can be extended several times. Compared with low speed screw pump, high speed pump products can increase the flow and lift, but the power is obviously increased, the high speed accelerates the wear between the rotor and the stator, Third, to ensure that debris does not enter the pump wet sludge mixed with solid impurities will pump the rubber material of the stator damage, so to ensure that debris does not enter the cavity of the pump is very important, many sewage treatment plant in the pump Before the installation of a grinder, and some grille installation or filter, blocking debris into the pump products, the grille should be promptly cleared to avoid clogging.