Centrifugal pumps have the characteristics of high speed, direct motor drive, convenient and small size, wide range of flow applications, high efficiency, simple structure, convenient maintenance, low cut-off pressure, simple pipeline equipment, etc., so they are widely used in various industries, then centrifugal pumps How does it work? Let's simply analyze it in graphic form.
① The definition of a centrifugal pump is "a machine that gives energy to liquid by rotating the impeller in the pump body." Then, how can water be sent from a low place to a high place? When the umbrella is rotating, the water droplets fly outwards. The faster the rotation, the farther the water will fly. This force is called "centrifugal force."
When the pump is filled with water and rotates the impeller, the water will fly outwards at high speed due to the centrifugal force. The scattered water is collected by a container called a pump body and led to the outlet. In this process, the kinetic energy of the water is converted into pressure energy and then pushed to a high place.
②So, why can the water from the lower place be pumped up again?
The earth is surrounded by air, and the air also has weight, which acts on all objects in the form of "atmospheric pressure". (In Figure 1-3, when the impeller rotates, the water flies out due to centrifugal force, just like pumping with a piston, the pressure at the center of the impeller drops, thus forming a "low pressure area". In this way, despite the suction surface It is located under the pump, but due to the higher atmospheric pressure, the water is pushed upwards, and the water is pumped up.
The pressure of atmospheric pressure on the water column is about 10m. Therefore, in theory, it should be possible to pump water to a height of 10 meters. However, due to various factors, the actual height is about 6 meters.
When the water temperature is high or for liquids that are easy to evaporate, the height is still lower, and sometimes it may not be able to be pumped up.
③It can be seen that the centrifugal pump generates low-pressure area and centrifugal force through the rotation of the impeller, and sends the water from the low place to the high place through the simultaneous continuous suction and discharge action.
