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venturi nozzle instead of sharp edged orifice

Posted: Wed Feb 16, 2011 9:52 am
by Hans Derbe
Hello,

does anyone here have ever used a venturi nozzle to measure flow in a flowbench? I'm thinking of a symmetrical design that could be used for intake and exhaust when used with a roots blower and vfd to reverse the flow. the extra space needed by this design an the limitation to one size wouldn't be a problem for me. Anything else to consider?

Re: venturi nozzle instead of sharp edged orifice

Posted: Wed Feb 16, 2011 5:23 pm
by jfholm
I have a friend with a venturi bench. I works very well but he is a little limited due to number of motors. With a Venturi bench you can have multiple flow ranges with a single venturi just by the placement of the pressure taps on the opening big side of the venturi. I will go into it further when I get home from work.

John

Re: venturi nozzle instead of sharp edged orifice

Posted: Thu Feb 17, 2011 12:24 am
by jfholm
Below are a couple of pictures that may help you visualize how a venturi bench would be set up. My friends bench only flows one direction and you can probably visualize why. To flow the exhaust ports you have to have an adapter that bolts to the exhaust port and you tip the head to set on the opening on the flow bench and suck through the exhaust port. this makes it a little tough to probe velocity in the exhaust ports.

John
venturifixed1.JPG
venturi bench.JPG

Re: venturi nozzle instead of sharp edged orifice

Posted: Thu Feb 17, 2011 12:46 am
by jfholm
Here is a venturi calculator web site if you decide to go that route
http://www.flowmeterdirectory.com/flowm ... _calc.html

John

Re: venturi nozzle instead of sharp edged orifice

Posted: Tue Dec 22, 2015 6:24 am
by SWR
Hmm.. 3 different venturi sizes.... swapping them by use of big Wiggins clamps either end... literally seconds to swap, much less pressure loss than a orifice bench. I think I'll test that sometime... :)