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Several Simple Water Filling Methods for Agricultural Centrifugal Pumps
Centrifugal pumps (except for self-priming pumps) should be filled with water before the pump and the inlet pipe, otherwise the pump is unable to pumped work. Centrifugal pump does not start after the water is often due to the pump air is not discharged, the water is not filled due. Centrifugal pump water filling method before there are two main ways: one is the use of bottled water valve assembly, the end valve is a one-way valve, installed in the intake pipe inlet, this method has the drawback of large loss of foot valve head, Affecting the efficiency of the pump device; the other is the bottomless valve filling water, the biggest advantage of this method is energy saving, compared with the bottomed valve pumping station can save 10% to 15%. Here are several centrifugal pump water filling method for users to choose when running the pump. â– Artificial water-filling method For the small pumping station whose inlet pipe diameter is less than 300mm, the bottom valve is usually provided at the inlet of the water inlet pipe. Generally, artificial water-filling method is used mostly, that is, Water funnel (or a bottle of inverted inverted ordinary bottle) water. For small pumping stations with an inlet pipe diameter of less than 300 mm, a foot valve is usually provided at the inlet of the inlet pipe, and the pump can also be filled with water from the outlet port of the pump (pump station with a short outlet pipe). Because there is no need to buy other water-filled equipment, this method of water-filling is common in small rural pumping stations. For a small pump station that does not have a bottom valve, a check valve, and a short pipe, it is also possible to adopt a method of starting water from the water outlet to the water pump to gradually bring out the air in the water pump and the pipe , The general continuous water for a few minutes, the pump can work normally pumping. â– Vacuum tank filling method For small pump stations without a bottom valve, a vacuum tank filling method can be used. Vacuum tank is made of metal welded closed tank, the volume of at least 3 times the volume of the inlet pipe, the tank should be installed as close as possible to the pump, tank bottom height should be slightly lower than the axis of the pump. The height of the vacuum tank is generally 2 times the diameter of the tank. Before starting the pump, the tank is filled with water and sealed. Pump starts, the pump water from the vacuum box, the water tank as the water level decreases causing the tank to form a certain vacuum, the water in the pool will be under the action of atmospheric pressure into the tank through the inlet pipe to form a water cycle, so that The pump started to operate normally. The water filling method has the following advantages: small hydraulic loss, high pumping station efficiency, low labor intensity of technicians, simple start-up, and beneficial realization of automatic control of a water pump unit. â– Jet pump water filling method Diesel engine driven water pump, the exhaust gas can be used to exclude the diesel engine connected to the top of the pump connected to the jet, the suction filling water, eliminating the pump bottom valve. When the pump is started, the bonnet attached to the handle is closed, the exhaust gas is ejected from the ejector, and the air in the pump is drawn out through the connecting pipe. After filling the valve cover open, the control valve closed. One advantage of this method of filling water is to make full use of the power machine, the second is to improve the pumping station efficiency. â– Manual pump water-filling method As a kind of reciprocating positive displacement pump, manual pump is widely used in our country's rural areas. Farmers can use their own manual pump as a vacuum pump to charge the centrifugal pump, which is convenient and economical. The most common usage is: the manual pump installed in the pump suction hole near or close to the pump inlet pipe, pumping suction diversion, making it a centrifugal pump boot water filling tool, thus eliminating the pump inlet pipe The end of the valve, reducing energy loss and improve the efficiency of the pump device. â– Self-priming water-filling method For semi-submerged pump houses (that is, pumping stations and pumping stations whose top elevation is below the water level in the intake basin), water can be introduced into the pump without manual irrigation. The disadvantage of this pump station is that it does not make full use of the water absorption capacity of the pump, meanwhile, the installation elevation of the pump is reduced, which not only increases the foundation excavation capacity but also has inconvenient operation and management. However, the advantage is also obvious that it is easy to realize the pump station Automation, timeliness stronger. â– Self-hanging water flooding method Self-hanging water flooding method is the use of water and gas bulk density difference, through the "water vapor replacement" principle to achieve. This method can remove the bottom valve of the pump. First of all, the design of a suitable container gas exchange tank, gas exchange tank is generally plastic products, but also for thin metal leather, the cost is only one-half of the bottom valve. Then, the gas exchange tank placed in the pump inlet, with the pump, pipe form a connected body. At the same time, a ventilation control valve is installed on the ventilation passage between the ventilation tank and the water pump. Fill water, pre-gas tank filled with water, then stamped seal, and then open the ventilation valve. Ventilation is completed, close the ventilation valve, there will be part of the water hanging in the water pipe. Repeated several times in this way, the air will be completely drained, the inlet pipe will be filled with water. At this point, you can start the pump for pumping operations. Stop before, as long as the first shut down the valve and then shut down, diversion will not sit back. The next time you start without irrigation water. The advantage of this water filling method is the lower price of the gas exchange tank, easy manufacture, low labor intensity and energy saving. â– Vacuum pump water filling method For large and medium-sized pumping stations with inlet diameter greater than 300mm, or pump stations requiring a high degree of automation, a vacuum pumping device is commonly used as a water-filling equipment. It is assembled by vacuum pumps and other equipment. The vacuum pumps often used in irrigation and drainage stations are mostly water ring vacuum pumps. Water ring vacuum pump cylindrical pump housing equipped with an eccentric tooth impeller. Circulating water is injected into the pump housing, and when the pump is evacuated, the impeller rotates. Under the action of centrifugal force, the circulating water in the pump housing is thrown to the periphery of the impeller to form a rotating water ring on the inner wall of the pump housing. Because the impeller is eccentrically installed in the pump housing, so the water ring and the formation of tooth space between the different sizes. As the impeller rotates clockwise, the space between the two blades in the right half of the rotor gradually increases. As the volume of air increases, the pressure decreases, creating a vacuum. The water in the pump and the pipe passes through Suction tube, into the right side of the vacuum pump housing crescent-shaped suction port is sucked into the vacuum pump, vacuum pump impeller left half of the space between the two leaves is gradually reduced, so the air is compressed, the pressure increases, and finally through the vacuum pump The left side of the pump housing crescent-shaped exhaust vent vacuum pump, into the water vapor separation tank, the recycled water is taken out after the re-use. Impeller kept rotating, the vacuum pump on the inspiratory and exhaust, and finally the pump filled with water. For the number of vacuum pumps, for a small pumping station, when the unit is less than 3, generally choose 1, when the unit is more than 4, generally choose 2; for medium and large pumping stations, the best selection of 2 units, when the unit More time, we should consider the reserve one. Vacuum pump has the advantage of water filling time is short, pumping station high efficiency, low labor intensity, easy to pump station automation. The disadvantage is a larger investment. Centrifugal pump water filling is an important part of the pump operation and management, I believe that with the water conservancy researchers on the centrifugal pump filling method of continuous exploration, "convenient, practical and efficient" for the purpose of pump water filling method will be more and more, Water filling effect will be getting better and better, so as to make a positive contribution to the development of electromechanical irrigation and drainage.