I have a question regarding the semi-open impeller design. Urgent!
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In practice, there is a selection issue regarding semi-open impellers； Based on past experience, it is usually a front-opening design, that is, the front cover is removed. Now, referring to the impellers produced by a factory in Jiangsu, their semi-open impellers are of a back-opening type, meaning the rear cover is removed. So here’s the problem: with an inlet at the front, it’s possible to add some balancing devices to the rear cover of the impeller, but it’s completely impossible to do so when the inlet is at the back ； An experienced designer told me that the shaft itself already balances the axial forces; no matter how I think about it, it doesn’t make sense
It should be possible to achieve balance as well; it depends on whether the pump’s head is high or not. If it’s high (over 100 meters for a single stage), attention should be paid to the axial force. If it’s not high (under 50 meters), this issue can be ignored, and proper consideration can be given to the design aspects; the residual axial force can then be handled by the bearings.
This post was last edited by 3983596_FPPZ on 2018-10-30 at 10:58. You are indeed worried; you can ask the other party to provide a plan and explanation for achieving axial force balance. At least I think it is possible to achieve balance, but few people do this, I guess it’s due to considerations regarding the strength of the cover plates and blades.
This post was last edited by foam_ZPTK on 2018-10-30 at 11:42; the MARK 3 pump from FLOWSERVE features a rear-mounted impeller
It controls the small gap between the back side of the impeller and the pump cover, and the impeller is equipped with balance holes
If the rear cover is removed, only the force at the front cover pointing toward the drive end remains; what balancing mechanism is used to balance the axial force?
Take a look at the area of the front and rear cover plates; the remaining bearings bear the load
The super version is awesome; even this image can be found
It matches what I thought; the question arose because that technician’s views differed from mine, which led to doubts； Thank you for clarifying it
It’s rare to come across this type of impeller; a picture would be helpful
What is the purpose of such a design? What problems in traditional design cannot be solved or are imperfect, and is this designed to address them?