A pump is a machine that delivers or pressurizes a fluid. It transfers the mechanical energy of the prime mover or other external energy to the liquid, increasing the energy of the liquid. The pump is mainly used to transport liquids such as water, oil, acid and alkali, emulsion, suspoemulsion and liquid metal, as well as liquids, gas mixtures and liquids containing suspended solids.
Pumps can usually be divided into three types according to the working principle: positive displacement pumps, power pumps and other types of pumps. In addition to classification by working principle, they can be classified and named by other methods. For example, according to the driving method, it can be divided into electric pump and water pump, etc.; according to the structure, it can be divided into single-stage pump and multi-stage pump; according to the application, it can be divided into boiler feed water pump and metering pump; Pumps, oil pumps and mud pumps. According to the shaft structure, it can be divided into linear pumps and traditional pumps. The pump can only transport fluid-based streams and cannot transport solids.
The impeller is mounted in the pump casing and fastened to the pump shaft, and the pump shaft is directly driven by the motor. There is a liquid suction pipe in the center of the pump casing. The liquid enters the pump through the bottom and suction lines. The liquid discharge port on the pump casing is connected to the discharge pipe.
Before the pump is started, the pump casing is filled with the liquid to be conveyed; after starting, the impeller is driven by the shaft to rotate at a high speed, and the liquid between the blades must also rotate. Under the action of centrifugal force, the liquid is thrown from the center of the impeller to the outer edge and obtains energy, leaving the outer edge of the impeller at high speed into the volute casing. In the volute, the liquid decelerates due to the gradual expansion of the flow path, and part of the kinetic energy is converted into static pressure energy, and finally flows into the discharge pipe at a relatively high pressure and is sent to a place where it is needed. When the liquid flows from the center of the impeller to the outer edge, a certain vacuum is formed at the center of the impeller. Since the pressure above the liquid level of the tank is greater than the pressure at the inlet of the pump, the liquid is continuously pressed into the impeller. It can be seen that as long as the impeller rotates continuously, the liquid is continuously sucked in and discharged.
The working principle of the linear pump is different from that of any other pump. The principle of magnetic levitation and the hydrodynamic structure of the spiral ring are used to realize the fluid propulsion, that is, the shaft is cancelled, the shaft connection is cancelled, and the shaft sealing structure is cancelled. After starting, the current is converted into a magnetic field, and the magnetic force drives the spiral ring to operate, that is, the spiral ring promotes the advancement of the fluid.