It is believed that the centrifugal pump water filling is an important part of the operation and management of the pump. With the purpose of convenience, practicality and efficiency, the water filling method will be more and more, and the water filling effect will be better and better, so as to make a positive contribution to the development of electromechanical drainage and irrigation.
The centrifugal pump (except the self-priming pump) is filled with water before starting the pump and the water inlet pipe. There are two main methods of filling water before the centrifugal pump is started: one is to fill the water with the assembly bottom valve. Otherwise, the pump is unable to pump water, the centrifugal pump will not be discharged after the start, often because the air in the pump is not discharged, the water is not filled.
The bottom valve is a one-way valve, which is installed in the inlet pipe. The disadvantage of this method is that the water head loss of the bottom valve is larger, which affects the efficiency of the pump. Another is without bottom valve filling water, energy saving, the biggest advantage of this method is compared with the bottom valve pump station can be energy-saving 10% 10% below several centrifugal pump water filling method, for user choice when running the pump. Stainless steel self-priming pump.
The inlet pipe is usually equipped with a bottom valve, and the artificial water filling method is less than 300mm small pump station. In general, the artificial water filling method is used, namely, the water filled with water from the special filling vent in the upper part of the pump casing. For small pumping stations with a diameter of less than 300mm, the inlet pipe is usually equipped with a bottom valve and can be filled with water from the outlet pipe of the pump (the short pump station of the outlet pipeline). Because of the need not to purchase other water filling equipment, this water filling method is more common in rural small pump stations.
It can also be used to start small pump stations with no bottom valve, reverse check valve and short line. One side of the water from the outlet pipe to the water pump, so that the pump and the air in the pipeline gradually take out, after a few minutes of continuous water filling, the pump can be normal pumping work.
It can be filled with vacuum water tank. The vacuum water tank is a closed type water tank which is made of sheet metal, and the vacuum water tank filling method is used for the small pump station without the bottom valve. Its capacity is at least three times the volume of the inlet pipe, the position of the water tank should be as close as possible to the pump, and the bottom height of the tank 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.
Fill the tank with water to seal. After the pump starts, the pump starts. Water pump from the water inlet chamber, because the water tank water level drop tank to form a certain vacuum, into the water in the pool will be under the action of atmospheric pressure, the pressure pipe into the tank, thus forming the water cycle, make the normal operation of pump start. This water filling method has the following advantages: small hydraulic loss, high efficiency of pump station, low labor intensity of technical personnel, simple start-up, and conducive to the realization of automatic control of pump unit.
The exhaust gas from the diesel engine can be connected to the jet stream at the top of the pump, and the jet pump is used to pump the pump with the diesel engine. The pump is drained and the bottom valve is removed. When the pump starts, the valve cover connected to the handle is closed, and the exhaust gas is expelled from the efflux, and the air in the pump is sucked out through the pipe. Open the cover after filling and close the control valve. The advantage of this method is to make full use of the engine, and the second is to improve the efficiency of the pumping station.
The manual pump is widely used in the countryside, and the manual pump is a kind of reciprocating volume pump. The farmers can use their own manual pump as a vacuum pump, the centrifugal pump to fill the water, both convenient and economical.
The most common use of pumping water is to install the manual pump on the suction hole of the centrifugal pump or on the inlet pipe of the pump. It makes it a tool to fill water when the centrifugal pump is turned on, thereby saving the bottom valve of the water pump inlet pipe, reducing the energy loss and improving the efficiency of the water pump device.
Pump unit elevation at the same time, reduce the water filling water itself for the half submerged pump (pressure pipe and pump on the top of the elevation of pump in pump station) into the pool below the surface water can introduce without artificial irrigation water diversion in the pump. The disadvantage of this pumping station is that it does not fully utilize the water absorption capacity of the pump. It not only enlarges the foundation excavation quantity, but also the operation management is more inconvenient; But the advantage is also obvious, namely easy to realize the pump station automation, the timeliness is stronger.
This method can remove the bottom valve of the water pump through the principle of water vapor displacement. The self-suspension water filling method is the fault tolerance of water and gas.
Design an appropriate container for the tank, first. The exchange tank is generally made of plastic products, or thin sheet metal parts, the interest is only one half of the valve. Then, the gas tank is placed in the inlet of the pump, forming a connecting body with the pump and pipeline. At the same time, a ventilation control valve is installed on the gas flow channel between the gas tank and the pump. When filling, fill the tank with water in advance, then seal it and open the air valve. After the ventilation is completed, the valve will be closed, and a part of the water will be suspended in the inlet pipe. According to this method repeated several times, the air will be completely drained, and the inlet pipe is filled with water at this time, can start the pump for pumping water. Before the shutdown, just close the gate valve and then stop, and the water will not return. The advantage of this water filling method is that the price of the replacement tank is lower, easier to manufacture, lower labor intensity and energy saving.
Or the pump station with higher level of automation, the vacuum pump filling method is larger than 300mm in diameter and medium pump station. Vacuum pumping unit is a commonly used water filling equipment. It is assembled by vacuum pump and other equipment. The vacuum pump used in the filling station is mostly water ring vacuum pump.
In vacuum, the cylindrical pump of the water ring vacuum pump has an eccentric toothed impeller. The pump shell is filled with circulating water. The impeller rotation, centrifugal force, the circulating water in the pump shell is dumped around the impeller, the inner wall of the pump is formed a rotating water ring. Because the impeller is eccentric device in the pump case, the space between the water ring and the tooth shape is different. Impeller rotate clockwise, the right local demand is gradually increasing the space between the two blades, airtight conditions, with the increase of air volume, pressure decreases, the formation of a vacuum, water pumps and air through the suction pipe in the pipeline, into the vacuum pump on the right side of the pump shell crescent-shaped inspiratory mouth drawn into a vacuum pump, vacuum pump impeller left half the space between the two blades is gradually reduced so that the air is compressed, pressure subsequently heighten, finally through the vacuum pump on the left side of the pump shell crescent-shaped exhaust discharge vacuum pump, enter the water separation tank, that is out of the circulating water reuse again after separation. The impeller continuously rotates, the vacuum pump intermittently inhales and exhausts, and finally fills the water pump.
For small pump stations, the number of vacuum pumps. When the unit has less than 3 units, the general election is 1, when the unit is more than 4, the general election is 2; For medium and large pumping stations, it is advisable to choose two units, and when the unit is large, one should be considered. The advantages of vacuum pump filling are short filling time, high efficiency of pump station, low labor intensity and easy to realize automatic pumping station. The disadvantage is that the investment is large.