Bypass air

[Dik]

Phil,

I'm have been thinking about what you have said about bypass air when using small hoses.  I also saw what you posted today about adding an extension to the inboard side of the inlet.  Would a small bypass inlet to the inboard of the inlet, facing at a slight angle to the incoming air stream to help force it toward the outside help?  I'll see if I can draw up what I'm considering and post it later.  I see the bypass being made of a 1" PVC el and ball valve.

Okay, I've attached my idea...

Have fun...

Dik

[phil (admin)]

Hi Dik.

It would certainly help with separation.  But it would probably reduce suction substantially at the small hose.  The small hose requires a great deal of static pressure to overcome the small cross section.  So it may be a too great a compromise.

But I don't know for sure, I haven't tried it.

[Dik]

Since I'm going to need some bypass air, where would be the most effective location?

[phil (admin)]

Since I'm going to need some bypass air, where would be the most effective location?

The best location would probably be in the hose near the tool.  But bypass is going to reduce suction no matter what.  Unfortunately you are probably in for some trial and error to determine if you can live with the reduction in suction.

[Dik]

I guess I'll give my original idea a try.  Hopefully, I can adjust the amount of bypass air enough with the ball valve to be able to eliminate the buckling of teh can but not so much as to reduce the vacuum at the business end.  I'll keep you posted.

Later:
Well, I tried it, and it does elimnate the can buckling without harming the vacuum at the business end.  I used a .75" elbow, extension and ball valve, and can close the valve about half way and still not get buckling.

It didn't eliminate fines getting to the filter.  I didn't test enough to see if it reduced the amount.  I think  I'll try your plastic piece to the inside of the inlet.  I'll just angle the bypass air elbow so that the air stream passes along the plastic before getting to the main stream.

Have fun...

Dik

[Hobkirk]

Dik -

Isn't this baffle great? Hello, from a fellow Eureka Zone regular.

Your SketchIt skills are very, very impressive.

Doug

[Dik]

Doug,

Isn't it ever!  I learned of it from a post on SMC.

Thanks for the complement.

Have fun...

Dik