material flow through a T'd orfice, can it be done?

[johmue]

Hello, I am attempting to create a vacuum by flowing air through a T joint. With a restriction at the 90 degree line to force the air by the T creating a slight vacuum effect in the 90degree elbow. it is working but I am using gravtiy feed also the help the material into the air flow. any suggestions for pipesize vs air flow, pipe sizes in the T itself, will restricting the air flow create more vacuum or less? Any words of wisdom would be appreciated.
Thanks
J

 

[ve7brz]

Hi johmue,

Essentially what you've created is a venturi. This site might be helpful:

http://flow.netfirms.com/venturiflow/calculator.htm

 

[ve7brz]

I've just realized that the site mentioned above doesn't really answer you questions. The principle of a venturi pump is to create a low pressure zone in the pipe at the inlet for the material being pumped. You'll notice in the diagram at the site mentioned that there is a restriction in the pipe which is very similar in section to an airplane wing. As in an airplane wing a low pressure zone is created by the acceleration of the flow followed by an expansion area.

A common and simple application of this uses a restriction of the 'pumping' flow to accelerate the flow, then releases it into a larger area or chamber connected to the material to be pumped. The combined flow in this area then continues to flow in the original direction of the 'pumping' flow. This is very difficult to describe in words, but I hope it gives you some ideas.

 

[ve7brz]

See:

http://www.lmnoeng.com/venturi.htm

http://www.triflotech.com/venturi.htm

for more ideas.