Multi-stage pumps are composed of multiple levels of impellers and shells, each of which can further increase the pressure of the liquid. This pump is usually used to handle fluids that require high pressure, such as water supply systems, chemical processes, and the energy industry. Multi-stage pumps can be designed into different types according to specific needs, such as centrifugal multi-stage pumps and axial flow multi-stage pumps. Centrifugal multistage pumps use a rotating impeller to push the liquid to the next level by centrifugal force, thereby increasing the pressure. The axial flow multistage pump uses the principle that the direction of the liquid flow is parallel to the axis, so that the liquid is continuously stressed on the impeller to achieve the effect of increasing the pressure.

These different types of multistage pumps are suitable for different working conditions and liquid characteristics. The operation of multi-stage pumps requires attention to reasonable lubrication and cooling to ensure stable operation and long life of the pump. When choosing a multi-stage pump, it is necessary to consider factors such as liquid flow, pressure requirements, and working environment to ensure the performance and safety of the pump. All in all, the multi-stage pump is a very important industrial equipment, which is widely used in various fields and provides a reliable solution for industrial production and domestic water supply. Below Hunan Sanchang Pump Co., Ltd. will introduce the structure and working principle of the multi-stage pump.

What is the difference between a 1. multi-stage pump and a single-stage pump?

Single-stage pump refers to a pump with only one impeller, with a maximum lift of only 125 meters.

Multi-stage pump refers to a pump with two or more impellers, and the maximum lift can exceed 125 meters. Under the condition that the lift of a single-stage pump needs to be equipped with two-stage motors, multi-stage pumps can be equipped with four-stage motors by increasing the number of impellers, thus improving the service life of the pump and reducing the noise of the unit. However, maintenance of multi-stage pumps is a little more difficult than that of single-stage pumps.

When the actual lift of the pump is less than 125 meters, the selection of single-stage pump or multi-stage pump can be considered according to the pump room area, pump price (multi-stage pump is generally higher than single-stage pump price), and other factors.

With the progress of technology, the pump of single-stage impeller can increase the head of the pump by increasing the speed of the pump, which can replace the multi-stage pump, but the price is a little more expensive.

2. what is a multistage pump?

Multistage pump is a kind of centrifugal pump, is to have the same function of more than two centrifugal pumps together.

Fluid channel structure, performance in the first stage of the medium pressure relief port and the second stage of the inlet, the second stage of the medium pressure relief port and the third stage of the inlet, so the series mechanism formed a multi-stage centrifugal pump.

Single-stage pump refers to a pump with only one impeller, with a maximum head of only 125 meters; while multi-stage pump refers to a pump with two or more impellers, with a maximum head of more than 125 meters.

Structure and working principle of 3. multistage pump

01. The working principle of multi-stage pump

The liquid being transported enters the suction port of the pump under a given pressure. Due to the action of the impeller, the kinetic energy and potential energy of the liquid are increased. After the liquid enters the guide vane, a part of the kinetic energy is converted into potential energy (each impeller is equipped with a guide vane), and the reverse blade of the guide vane conveys the liquid to the inlet of the next impeller under favorable hydraulic characteristics.
Due to the repetition of this process from one stage to another, each stage increases the same pressure. After passing through the final guide vane, the fluid enters the annular chamber of the cylindrical body, and finally enters the discharge pipe through the discharge port.

02. Structure of multi-stage pump

Multistage pump is mainly composed of stator, rotor, bearing, shaft seal four parts.

The rotor part is mainly composed of shaft, impeller, balance disc, shaft sleeve and so on.

The main components are: low-pressure suction section (feed pipe, feed chamber); pump body (volute, guide wing, anti-wear ring); high-pressure device (packing seal, mechanical seal); pump shaft (shaft sleeve, impeller, positioning Key, bearing) composition.

Auxiliary devices: bracket, machine base, coupling, motor, filter, etc.