I recently read somewhere that the geometry of centerline discharge pumps prevent air from being trapped in the volute. Is this true? How does centerline discharge prevent that?
There's a compromise though- not a good idea if you're pumping settling slurries and you can't flush the pump before shutdown (the pump won't drain without an integrated drain in the bowl- which will block up...)
As a chem eng/metallurgist the first part of any answer I give starts with "It Depends"
Neither will any other vertically discharging pump.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
True- I'm used to dealing with pumps that have tangential discharge. You can get some self venting by mounting them with a vertical discharge but they're commonly mounted side discharge for effective drainage (slurry pumps).
As a chem eng/metallurgist the first part of any answer I give starts with "It Depends"
Correct, horizontal under-shot discharge is the only way a centrifugal pump can self-draining - as you said slurry pumps (usually).
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)