Side channel pumps are a combination of centrifugal and displacement pumps.
This type of pump was developed in the 1920s from the water ring pump. It combines the numerous advantages of centrifugal pumps with the self-priming capacity of positive displacement pumps.
The advantages of the side channel pump
How the side channel pump works
As with the centrifugal pump, there is an impeller inside the pump casing. This impeller is equipped with blades. A narrow gap remains between the blades and the housing wall. In addition, the housing has one or two side channels that extend over the entire circumference. At one point, however, there is an opening. The rotation of the impeller causes the medium to move back and forth several times between the individual areas of the paddle wheel and the side channel. While the pumped medium rotates in the main channel at the peripheral speed of the impeller, it flows much more slowly in the side channel. Between these two flows, impulses are exchanged and thus energy is transferred. This results in an extremely high delivery head, which can be up to 15 times the delivery head of a comparable simple radial impeller. This effect can be further increased by connecting several of these pumps in series. There are two options for sealing the pumps: a magnetic coupling or a shaft seal. If there is a partition between the primary and secondary parts of this coupling, the pump can be completely sealed with the magnetic coupling. This is not 100% possible with a mechanical seal as a shaft seal. The material used for the pumps ranges from grey cast iron and bronze to stainless steel, depending on the application.
Applications of side channel pumps
This type of pump is very popular for pumping small or medium flow rates and not too high heads. Typical values are a flow rate of up to 35 m³/s and a head of up to 400 m. This pump is used in the food industry as well as in the dairy industry and agriculture. The chemical industry appreciates these pumps for pumping solvents or acids, for example. Refineries use them to produce diesel, oil or heating oil.