Self-priming pump, self priming sewage pumps, industrial self suction pumps, it is widely used in many fields, I plant, production after many years of experience in the manufacturing and design that directly affect the self-priming pump performance of six factors:
1. Determination of the height . Reservoir fluid volume and the liquid storage: storage liquid volume refers to after stopping the pump, pump body can store the volume of the liquid part, is the pump suction mouth below the lowest point of the pump body volume, this part of the volume is mainly part of the extrusion chamber and the gas-liquid separation. Liquid storage volume shall be not less than in seconds the meter pump design flow of half [for example, the design flow of the pump, liquid storage volume is not less than, liquid storage volume is too small is stored in the pump liquid too little], the self-priming time growth, even can not be self-priming; in, making bulky pumps. In addition to adequate storage capacity, but also must have a certain degree of reservoir height, the height of the pump suction is the lowest point to the height of the center of the impeller, usually taken as an approximation is equal to the radius of the impeller.
2. Self suction pump type extruding chamber liquid flow rate: centrifugal pump self suction flow rate of the liquid in the pump chamber is lower than general centrifugal pump, equal to about general centrifugal pump chamber in the liquid flow rate of 80-90%.
3. Self suction pump impeller back shroud turning: for mixed centrifugal self-priming pump, when impeller cylindrical velocity is less than, self absorption effect is poor, the turning impeller back shroud method to improve self absorption capacity, the reason is to facilitate the self suction mixing of liquid and gas in the process. Turning quantity can not be too large, otherwise it will significantly reduce the pump head and efficiency. At that time, cutting impeller back shroud diameter; at that time, and in every tongue reinforced, so as not to bring the liquid bubbles at the rear of the cutting off the cycle, the impact of self priming effects.
4.The height of the center line of the body outside the export volume 4. The gas-liquid separation chamber and the pump body height: gas-liquid separation refers to the pump body extruding chamber, the volume is large, gas and liquid separation effect is better, the separation of the faster, but the gas-liquid separation chamber volume to a certain extent, and increase the effect is not significant, the opposite will be the pump body is bulky, so the gas-liquid separation chamber is one of the most tolerant product value, according to the existing experience and its value is equal to or slightly larger than the liquid storage volume, in order to ensure the gas-liquid separation chamber, the pump outlet to the impeller according to the liquid storage volume and gas-liquid separation chamber volume in the drawing to determine the height.
5. Self suction pump chamber across the tongue and the impeller clearance: for the centrifugal self-priming pump, vibration of the tongue and the impeller clearance of self-priming performance has a great influence, upper extruding chamber of across the tongue and the impeller clearance, the more small, self-priming time is shorter, the gap is usually mixed; mixing. If the design for the double volute chamber is lower extruding chamber across the tongue and the impeller clearance, usually by general centrifugal pump chamber across the tongue and the impeller clearance determination method to determine.
6. Self-priming pump type backflow hole area: for mixed centrifugal self-priming pump, reflux hole area of self absorption effect on the performance of large, large area, the reflux hole back to the impeller inlet liquid, so short time of self - priming, but self ceiling and the maximum vacuum degree is reduced; reflux hole surface product hours of self-priming time long, self absorption maximum vacuum high. Integrated above, to determine the return hole area, to consider the requirements of the self absorption time and self suction height.
