Air Intake Quantity for efficient conveying in Vacuum Pneumatic Conveyor

Posted in: , on 4. Jul. 2002 - 19:33

Dear Sirs/Madams

I need information about the correct (optimum) quantity of Air at the intake of Vacuum Pneumatic Conveying Systems and the methods (design) for such.

Also do the Intake Nozzles have to be placed at an low angle (inclined). What would be correct design of such intake nozzles ?

Would be glad to recieve your comments and feedback in this regard.

My Email ID is

Thanking you in advance...

Best Regards

Shrinivas Deshpande

(not verified)

Re: Air Intake Quantity For Efficient Conveying In Vacuum Pneum…

Posted on 8. Jul. 2002 - 01:22

Dear Mr. Deshpande,

Thanks for your mail. My paper on Pneumatic Conveying Drying was published

quite early .

Chand, P. (1973) "A theoretical model of the pneumatic conveying- drying

system", Proc. 2nd Int. Conf. on the pneumatic transport of solids in pipes,

BHRA, Guildford,England,pp C2-15 - C2-27

But I consider still the right way to proceed for that kind of problem. My

recent work- expected to be presented at Montreal on 18th July ( ASME

Forum ) is in fact an extension of this work.

Regarding your other problem- feeding material into the piping, I think you

must be having a metering device in the form of a well designed Star Feeder

/ Nozzle/ Screw Feeder at the intake to have smooth flow of material.


Dr. Prem Chand

Re: Air Intake Quantity For Efficient Conveying In Vacuum Pneum…

Posted on 8. Jul. 2002 - 03:27

Air intake quantity must be such that it results in the required pick-up velocity at the solids' feed point. In vacuum systems, this means that the vacuum blower must be sized for providing this velocity.

The orientation of air intake whether inclined or horizontal does not have much effect on the pick-up velocity. This is because the resulting pressure drop is very low.


Amrit Agarwal (Tim)

Pneumatic Conveying Consultants

Re: Air Intake Quantity For Efficient Conveying In Vacuum Pneum…

Posted on 8. Jul. 2002 - 04:45

If I have understood your question correctly, you are referring to the use of inclined pick-up nozzles to entrain the material into the conveying line? If this is indeed the case, then there will be a marked drop off in entrainment performance as the nozzle moves away from the vertical. The design of the inner/outer tube relationship will also be critical in obtaining the required feedrate into the system.

If you e-mail me your full postal contact details, I will put some technical papers that have resulted from our research on this topic in the mail to you.


Richard Farnish

Consulting Engineer

The Wolfson Centre for Bulk Solids Handling Technology

University of Greenwich, London