Regarding the speed of centrifugal pumps
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I would like to ask the experts: if the rotational speed of a centrifugal pump is designed to be higher, can the cylinder of the pump be designed to be smaller? Recently, I observed the two multi-stage centrifugal pumps in our installation: one is of domestic manufacture with a rotational speed of 2980; it has a large pump body and is heavy. The other is of Japanese origin, with a rotational speed of 4800, and it is smaller in size compared to the domestic pump. I’m not sure if my view is correct; I hope those who are more knowledgeable can share their opinions.
Your opinion is valid, but from what I remember, there don’t seem to be motors with such high rotational speeds So is a gearbox still needed? Won’t that result in high costs for investment and maintenance?
The higher the rotational speed, the greater the flow rate and head. Head is related to the square of the fluid velocity (rotation speed). The relationship between flow rate and rotational speed is not clear; please explain it downstairs.
Calculations can be carried out using the proportional law and the cutting law for centrifugal pumps
Is there a direct relationship between flow rate and rotational speed? It seems to be related to back pressure, right?
The original poster observed well; it should be like that. Since the flow rate of a centrifugal pump is proportional to its rotational speed, at the rated flow rate, the higher the speed, the smaller the diameter of the impeller can be – and consequently, the pump casing also becomes narrower!
With the diameter of the impeller remaining constant, the flow rate is proportional to the rotational speed; this is the qualitative analysis
It’s like this: the speed of the high-speed pump in our company is over 10,000, but the volute is very small. A comparison with pumps at low speeds makes it clear.
Reply to 1# zhg20051007: The pump’s speed, flow rate, head, and NPSHR are all related to each other, with relationships of the first power, second power, and third power respectively. Pumps with a higher speed have a smaller volume under the same parameters.