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

　　What is a multistage centrifugal pump? What is a single-stage centrifugal pump? What is the difference between a multistage centrifugal pump and a single-stage centrifugal pump? This is what everyone wants to know about centrifugal pumps as water pumps.

　　Single-stage centrifugal pump is definitely the basis of multi-stage centrifugal pump, both are centrifugal pumps, the same size of the impeller connected in series, and installed in the same pump, the formation of multi-stage centrifugal pump.

　　Single-stage centrifugal pumps are flowing bodies and liquids, or perhaps a mixture of suspended particles and gases or liquids, vane rotor shaft root of the inlet to enter, relying on the rotation of the vane to obtain a centrifugal force, and subsequently generate high pressure, from the outlet of the pressure relief, outflow of these media conveying device.

　　Multi-stage centrifugal pump is to have two of the same function of a number of pumps together, the structure of the fluid channel, its performance in the first level of the media pressure relief port and the entrance of the latter level can be mutually channeled, so that layers of grades at the entrance, the pressure relief port and the entrance are communicated, so that the composition of the series, the formation of a multi-stage centrifugal pump. The purpose of setting up a multi-stage centrifugal pump is to increase the set pressure.

　　Single-stage centrifugal pumps include pump body, pump cover, motor unit with output shaft, pump shaft installed in the pump body, bearing housing, impeller, mechanical seal and seal gland structural components, the key feature is that it is contained between the output shaft of the motor and the pump shaft there is a device called the clamp coupling, or mounted in the bearing housing is called a device to help support the pump shaft guide bearing.

　　What is the difference between a multistage centrifugal pump and a single-stage centrifugal pump?

　　The difference focuses on the number of impellers, multi-stage centrifugal pumps are characterized by high pressure and low flow, single-stage centrifugal pumps are only one level of impeller, characterized by low pressure and high flow.

　　First, single-stage pump refers to only one impeller pump, the highest head is only 125 meters.

　　Second, multi-stage pumps with two or more than two impellers pump, the highest head can exceed the single-stage centrifugal pump head; multi-stage pumps in the single-stage pump head, the need to must be added to the state of the two-stage motor, can be increased by increasing the number of impellers to be equipped with four-stage motors, which can improve the pump life and reduce the unit noise, but the multi-stage pump maintenance relative to a single-stage pumps to be a little bit more difficult.

　　Third, in the pump the actual need for the head does not exceed 125 meters, according to the pump studio area and the price of the pump, multi-stage pumps are generally more expensive, but also a combination of reasons to consider, the choice of single-stage pumps or multi-stage pumps.

　　Fourth, because the single-stage centrifugal pump pump shaft only an impeller, and multi-stage centrifugal pump pump shaft series has a lot of impellers, multi-stage centrifugal pumps are more than two levels of impellers in the same shaft above the installation of the common rotating work, the front of the impeller's output, and then into the back of the impeller input, each layer of the installation of the impeller blades, is called a level.

　　Multi-stage pumps and single-stage pumps in the balance disk what is the difference?

　　The difference between multi-stage pumps and single-stage pumps in the balancing device. Multi-stage pump balance device: segmented multi-stage centrifugal pump axial force is the superposition of all levels of the axial force of the impeller, the value is very large, it is impossible to bear completely by the bearings, must take effective balance measures.

　　① impeller symmetrical arrangement will centrifugal pump every two impellers in the opposite direction symmetrically mounted on the same pump shaft, so that the axial force generated by every two impellers cancel each other out. This program flow channel complex, high cost. When the number of stages, due to different levels of leakage and different levels of impeller wheel diameter is not the same, the axial force can not be completely balanced, often also need to use auxiliary balance device.

　　② balance disk device because of segmented multi-stage centrifugal pump impeller mounted on the shaft in one direction, the total axial force is very large, often in the last stage of the impeller behind the balance disk to balance the axial force. Balance disk device is mounted on the shaft by the balance disk and fixed in the pump casing balance ring composition, in the balance disk 5 and balance ring 4 between an axial clearance b, in the balance disk 5 and balance between the sleeve 3 there is a radial clearance b0, balance disk 5 behind the balance chamber and pump suction population with a pipe connected, so that the pressure before the radial clearance is the pressure of the back of the last stage impeller P2, the balance of the disk after the pressure is close to the suction port of pressure Pl. Pl. After the pump is started the high-pressure liquid from the final impeller of the multistage pump flows through the radial clearance b0 and the pressure drops to P‵, and since the pressure P‵>Pl, there is a pressure P‵ a Pl acting on the balancing disk 5, which is the balancing force, in the opposite direction to the axial force acting on the impeller. When the centrifugal pump is in operation, when the axial force on the impeller is greater than the balancing force on the balance disk 5, the pump rotor will run in the suction direction, reducing the axial clearance b0 of the balance disk 5, increasing the fluid resistance of the liquid, and therefore reducing the amount of leakage. After the leakage is reduced, the pressure of the liquid flowing through the radial clearance b0