Classification Of Vortex Pumps

1) Closed vortex pump
Closed vortex pump adopts closed impeller and open runner structure. Closed impeller refers to a blade part with a middle partition, the blade is relatively short impeller. The suction and discharge of the pump are separated except in the septal tongue part. Through the flow channel communication. The flow channel directly connected with the suction and discharge is called the open flow channel. Closed vortex pumps must be equipped with open flow channels.
There are many blade and channel forms of closed vortex pump. Generally, the flow rate of rectangular channel is large, but the head and efficiency are low. The semi-circular flow channel has higher head and efficiency, but smaller flow rate. Therefore, the medium and low specific revolution vortex pumps mostly use semicircular cross section flow channels, while the medium and high specific revolution vortex pumps mostly use rectangular cross section flow channels. The most widely used blade shape is the radial straight blade, and the rear corner blade is also used in the low specific revolution vortex pump.
In a closed vortex pump, the liquid flow enters the pump from the outer edge of the impeller with a larger circular velocity. Therefore, the cavitation performance is poor, and the cavitation allowance must be large. And because the discharge of the closed vortex pump is located at the outer edge of the flow channel. When gathered at the root of the gas is not easy to discharge. Therefore, if there is no special measure, the closed vortex pump has no self-priming capacity and cannot pump the aspirated liquid mixture. The efficiency of the closed vortex pump is higher than that of the open vortex pump, which can reach 35% to 45%.
2) Open vortex pump
Open vortex pump adopts open impeller and closed flow channel structure. The open impeller is an impeller with a long blade without a middle partition. Closed runner refers to the runner whose suction and outlet cannot be directly connected. The suction and discharge ports of the open vortex pump are generally opened at the side cover of the pump near the root of the blade, so that on the one hand, the gas is easy to discharge, which is conducive to improving the self-priming and pumping of the gas liquid mixture. On the other hand. The circular speed at the inlet is relatively small, so the cavitation resistance is also better than that of the closed vortex pump. However, the efficiency of the open vortex pump is low, such as the use of the worst efficiency of the closed flow channel, the efficiency is only 20% to 27%, even if the use of less hydraulic loss of the centripetal open flow channel, the efficiency can only be increased to 27% to 35%.
3) Centrifugal vortex pump
Compared with centrifugal pump, vortex pump has higher head, easier to achieve self-priming, but the cavitation performance is poor, while centrifugal pump has low head, but the cavitation performance is relatively good. Centrifugal vortex pump is to combine these two pumps together, that is, the first stage is the centrifugal impeller, in order to reduce the necessary cavitation allowance of the pump; The second stage is the vortex impeller, which increases the lift of the pump. In this way, not only the cavitation performance is good, but also the pump head is higher.