How can i make my own venturi vaccum?

Question

From what ive seen it just consist of three different holes, input, output and air compression in, what else is needed in the design of it. Any help on the subject greatly appreciated, I need a high purity ss one.

Answer 1

These are known as ejectors or eductors. THe difference is what is used for the powering medium. Ejectors use gas like air or steam while eductors use liquid.  Either may be used to move liquids, gases or both.    

You need a nozzle to direct high pressure air into an outlet. The outlet has to be large enough so as to not cause back pressure in the chamber .

You can fabricate one using plumbing fittings   use a 1 inch Tee and place a 1x 1/2 bushing and 1/2 nipple for the suction on the branch of the tee.   Attach a 1 x 1/4 bushing on one end of the run on the tee. On this 1x1/4 bushing you will attach a 1/4 nipple on the wron side of the bushing so that it directs air into the opposite side opening of the tee.   By wrong side I mean that this nipple will be mounted on teh inside of the Tee.   A 1/4 inch air connection is made to the  1x1/4 bushing and supplay compressed air to it. The discharge  will have just a 1 inch nipple .   When you supply air  to this you will have to adjust the air pressure(flow) so as to not overwhelm the outlet and cause back pressure. Also you will have to play around with the internal nipple lenght.  

You know when this demo is working as you will feel a suction on the 1/2 inch nipple attached to the tee branch.