Be Careful! How To Use Chemical Centrifugal Pump Before Starting?

Nov 08, 2024

Chemical centrifugal pumps (except for self-priming pumps that require irrigation for the first time) are connected to the inlet pipe of the pump and filled with water before starting, otherwise the pump will not pump.
There are two main research methods for pre start water filling experiments: one is to use different assembled bottom valves for water filling, with the bottom valve being a one-way valve installed at the inlet of an inlet pipe. The disadvantage of this teaching method is that there is a high risk of head pressure loss in the bottom valve; Another method is to fill water without a bottom valve.
1. Siphon bucket: Before starting the water pump, fill the water tank with water and seal it. After the pump is started, water enters through the siphon tube. Due to the decrease in water level in the tank, a certain vacuum is formed inside the tank. The water in the water tank will enter the tank through the inlet pipe under atmospheric pressure, thus forming a water cycle. Start the water pump to operate normally. For small pump stations without bottom valves, vacuum water tank filling method can be used. The siphon bucket is called a vacuum water tank, which is a closed water tank welded with iron sheets. Its volume is at least three times the volume of the inlet pipe. The installation position of the water tank should be as close as possible to the water pump, and the height of the bottom of the water tank should be slightly lower than the axis of the water pump. The height of a vacuum tank is generally twice the diameter of the tank body.
2. Manual filling method: For small pump stations without bottom valves, one-way valves, and short pipes, the method of pouring water from the outlet pipe into the pump during startup can also be used to gradually exhaust the air inside the pump. Generally, the pump can work normally by continuously pouring water for a few minutes. For small pump stations with inlet pipe diameters less than 300 millimeters, there is usually a bottom valve at the inlet of the inlet pipe, which is filled with water from a special filling vent on the upper part of the pump casing through a water funnel (or by removing the inverted bottom with a bottle). For small pump stations with inlet pipe diameters less than 300 millimeters, a bottom valve is usually installed at the inlet of the inlet pipe, and water can be injected into the pump from the outlet (pump stations with shorter outlet pipes). Due to the lack of need to purchase other irrigation equipment, this irrigation method is quite common in small rural pumping stations at present.
3. Due to the use of water and air in the suspended water filling method, the difference in packing density between water is achieved through the principle of "water vapor replacement". This method can remove the bottom valve of the pump. Repeat this method several times, and all the air will be discharged into the water that fills it. At this point, you can start the water pump pumping operation. Before closing, simply close the first valve and then close it, and the water will not sit idly by. Next time, you won't need to activate irrigation water. The design of the variation of the container and the exchange tank is usually made of plastic or thin metal components, and its cost is only half of that of the bottom valve. Then, the changes in the tank are set at the pump inlet, and the pump forms a connected component, the conduit. At the same time, switch the direction between the gas tank and the gas flow pump track, and install a ventilation control valve. Fill the water tank with pre filled changes, then cover it tightly and open the ventilation door. Ventilate, close the gas exchange valve, and suspend a portion of the water in the inlet pipe. The advantages of this method are that the water tank filled with water has a lower exchange price, is easy to manufacture, has low labor intensity, and saves energy.
4. The self guided water filling method is suitable for semi submerged pump rooms used by enterprises (i.e. pump stations where the elevation of the inlet pipe and pump top are both below the water level of the inlet pool), and water can be introduced into the pump by itself without the need for manual water filling. The disadvantage of affecting the pump station is that the suction capacity of the water pump has not been fully developed and utilized. At the same time, installing a water pump at a lower elevation can not only increase the excavation volume of the foundation, but also make it difficult to manage economic operating costs; But the advantages are also quite obvious, that is, it is easy to achieve automation of the pump station and has strong timeliness.