Working principle and application of fully enclosed liquefied petroleum gas pump

1. Fully enclosed liquefied petroleum gas pump Overview With the development of the petroleum industry, household fuel for urban and rural residents in China has gradually replaced by coal liquefied petroleum gas, canned liquefied petroleum gas more and more widely used. In the meantime, liquefied petroleum gas stations have mushroomed. The current application of canned equipment is a single-action vane rotor pump, shaft seal with two single-end mechanical seal, one side as a shaft seal to prevent leakage of liquefied petroleum gas; sealed bearing on one side to ensure that the bearing grease lubrication. From the application situation, the pump mechanical seal there is a problem of wear and tear, the tank area taste great, causing pollution to the environment; Moreover, the seal replacement operation cumbersome, not suitable for overhaul. Based on the principle of permanent magnet drive and the successful application in the field of non-leaking magnetic centrifugal pumps, valves and reactors, the authors extend this technology to the rotor pump and design a fully enclosed liquefied petroleum gas pump to realize the sealless, Fully enclosed, absolutely sealed. The pump in addition to canned liquefied petroleum gas, but also transport liquid hydrocarbons, liquid ammonia, propylene and other similar nature of the volatile liquid and petroleum products. 2. Pump works Fully enclosed liquefied petroleum gas pump is a single-action vane pump, the working principle shown in Figure 1. Mainly by the pump body 1, the inner sleeve 2, the rotor 3, the shaft 4, the slider 5, the side plate 6 (not shown) and other components. The inner sleeve and the rotor eccentric distance e, the vane placed in the rotor slot can slide along the slot, when the rotor rotates, the vane by its own centrifugal force close to the inner wall of the inner sleeve by the inner sleeve inner surface, the outer surface of the rotor , A plurality of closed working chambers are formed between the vane and the end faces of the two side plates. When the rotor rotates counterclockwise, the right vane gradually protrudes and the volume between adjacent vanes gradually increases to form a partial vacuum, and the liquid is inhaled The mouth into the studio, which is the pump inhalation process. The left of the vane is gradually pushed into the tank by the inner sleeve, the adjacent volume between the two vanes closed gradually reduced, the liquid pressure out of the mouth, which is the pump out of the process. Turn the rotor a week to complete a suction pressure. Between the suction and discharge chambers of the pump, there is a sealing zone that separates the suction and discharge chambers. Pump displacement Q and eccentricity e, the pump speed n is proportional to, so you can change the eccentricity and speed of the way to adjust the displacement or a series of products to meet the needs of different conditions. Fully enclosed liquefied petroleum gas pump is a rotary displacement pump, displacement at a constant speed, for the number of vanes greater than 4, the displacement pulse is very small. As the pressure difference increases, the displacement decreases slightly; the fluid viscosity m has little effect on the efficiency η. These two points are obviously better than the centrifugal pump. Figure 2 vane pump performance curve. Table 1 CYQB type pump for the basic parameters. Table 1 CYQB fully enclosed LPG pump basic parameters Model Speed ​​r / min Flow m3 / h Pressure differential MPa Working pressure MPa Motor power kw Operating temperature ℃ CYQB10? 5 580 10 0.5 1.5 4.0 -40 ~ 100 CYQB15? 5 790 15 0.5 1.5 5.5 -40 ~ 100 CYQB25? 5 580 25 0.5 1.5 7.5 -40 ~ 100 CYQB35? 5 790 35 0.5 1.5 11 -40 ~ 100 CYQB45? 5 580 45 0.5 1.5 11 -40 ~ 100 CYQB60? 5 580 60 0.5 1.5 15 -40 ~ 100 3. Transmission and sealing principle Power from the gear motor, flexible coupling 5, outside the magnetic drive rotor 4. The inner wall of the outer magnet rotor is provided with a permanent magnet. The magnetic flux passes through the seal cap 3 to drive the inner magnet rotor 2, and the inner magnet rotor and the pump rotor are arranged on the same axis. The inner and outer magnetic rotors are alternately arranged with permanent magnets of different polarities, and are repelled by the same sex and absorbed by the opposite sex, so as to keep accurate synchronous rotation. In the external torque does not exceed the design of magnetic torque, the inner and outer rotor will not slip off. Sealing cover similar to the end cover, with a static seal connected to the pump body, the pump shaft without extending the casing, the pump fluid is completely enclosed in the pump body and the seal cover, the complete elimination of the mechanical seal leakage problem, change the seal to static Sealed, it is called non-sealed, fully enclosed, absolutely sealed.