Selection of single-screw pumps

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Determination of the pressure of single-screw pumps: The maximum output pressure of a single-screw pump is determined by the number of sleeve stages, that is, the number of lead distances of the sleeves. For 1 stage, the maximum operating pressure is 0.6 MPa； Level 2: Maximum operating pressure of 1.2 MPa ； Grade 4: Maximum operating pressure of 2.4 MPa ； Due to differences in the conveying medium, for media with high abrasiveness, please refer to Table 1 to select the bushing grade. Table 1: Selection of bushing grade based on the weariness of the medium. Wear level: Low, Medium. 0.6 MPa, 1.2 MPa; Medium: 0.4 MPa, 0.8 MPa; High: 0.2 MPa, 0.4 MPa. 2. Selection of the speed of single-screw pumps: Due to their structural characteristics, single-screw pumps are mainly used for transporting liquids with high viscosity or those containing particles; therefore, the choice of rotation speed is very important. Based on experience, Tables 2 and 3 are provided, which can be used as a reference for making decisions based on specific circumstances. Table 2: Selection of pump speed based on the weariness of the medium. Name of abrasive medium, Speed (rpm): Fresh water, coagulants, oil, pulp, minced meat, paint, soapy water, blood, glycerin – 400–1000; Ordinary mud, suspensions, industrial wastewater, paint pigments, waste silk water (sugar), mortar, fish, wheat bran, rapeseed oil, filtered sediments – 200–400; Highly abrasive media such as lime slurry, clay, plaster, clay – 50–200. *The table shows specific examples of the media to be transported and their corresponding wear characteristics. Note that the properties of these media change depending on their concentration and temperature. *When the pump has large specifications, the speed should be set lower. Table 3: Selection of pump speed based on medium viscosityMedium viscosity (cst): 1-1000, 1000-10000, 10000-100000, 100000-1000000Pump speed (rpm): 400-1000, 200-400