Fans for High Ambient Pressures

[rjw57]

I have an application where I would like to recirculate ~35000 ACFM of nitrogen in a container pressurized to 20 atmospheres. My boost is ~10 inches of water, putting the power required in the vicinity of 100 HP. I am having trouble finding a source for this fan application and was wondering if anyone had any suggestions based on personal experience. I have gone to my normal supplier and they are not able to fulfill the needs of this application in a standard centrifugal fan & housing design (volute scroll). Thanks for any input.

 

[RossABQ]

When you say 35,000 ActualCFM, do you mean at 10 atmosphere conditions, or at ambient atmospheric conditions? There is a huge difference.

I would assume their problem is the pressure rating of the casing? I think a high pressure centrifugal blower manufacturer might have the casing ratings you need, but not sure if they could produce the CFM. If allowed in your situation, a vane-axial fan with a direct-drive motor would seem like the best bet, since the casing can be (essentially) a big pipe.

 

[rjw57]

@ RossABQ

35,000 ACFM @ 20 ATM = 700,000 SCFM. Casing should not be an issue since I intend to put the casing in the vessel containing the 20 ATM gas. The casing only has to handle the boost and any dynamic forces inherent to the redirection of the gas in the scroll. Vane-axial would be difficult to use in this application, but thanks for the suggestion.

 

[RossABQ]

I assumed the fan would be external, see what happens when you make assumptions?! What restrictions do you have; is a belt drive OK? Any corrosive aspect to this? Without seeing the vessel's construction it is difficult to understand what you are after. If the fan is internal, 10 inches seems high. Where are the losses?

 

[Compositepro]

Contact autoclave manufacturers. This is a standard part of their equipment.