Impeller
This converts the mechanical power transmitted by the drive (motor) via the pump shaft into pumping power.
Tag: Impeller
Side channel pump
They transport the fluid through a star-shaped wheel into a channel next to the impeller. The delivery heads achieved are 5 to 15 times higher than those of radial impellers.
The pumps are self-priming. They are used in particular for the conveyance of liquid-gas mixtures (partial gas conveyance) and for special suction requirements.
The efficiency is comparatively low. Therefore, the power range is only up to about 4 kW.
Due to the narrow gaps, they are generally not suitable for conveying fluids with abrasive components.
Multistage centrifugal pumps
The flow is thus directed from the outlet of the preceding impeller into the inlet of the following one. The high-pressure centrifugal pump is often designed as a ring-section pump.
With the same design, the delivery pressure (delivery head) increases proportionally to the number of impellers for the same flow rate. If the additional losses due to flow diversion in the inlet and outlet are neglected, the hydraulic efficiency is independent of the number of stages. Thus the characteristic curves of multistage centrifugal pumps can be converted as follows as a good approximation:
Hn(Q) = n/m · Hm(Q)
P2,n(Q) = n/m · P2,m(Q)
ηhydr,n(Q) = ηhydr,m(Q)
NPSHn(Q) = NPSHm(Q)
n, m – Number of impellers
Q – Flow
H – Head
P2 – Shaft power
η – efficiency