Testing Vacuum Motor Entry.

[larrycavan]

That SF plate should flow 147 - 148 CFM @10" with the small hole blocked off as shown. What do you get with that setup? Have you tested it and converted the number to 10"?

[1960FL]

Grey,

Please help me understand this test some, you are trying to test the inlet of the vac motor with the affect of radius on the inlet side correct?

You are trying to measure the performance of this by flow though and orifice correct?

I am not sure this is a valid test as the flow through the plate is based on DP and your radius would have to make the motor produce more pressure which is based on impeller tip speed.

I think a more valid test may be to use a piece of 2.5 to 3” PVC as the motor outlet then use a pito to measure the FREE flow air speed.

A simple change to your current setup may be to use an orifice that will crate the very least restriction so the DP would be less than 1” and use a sloping monometer for your measurement.

Last in the photo #1 if I understand your fixture correctly and the flow path the Orifice plate is mounted backwards.

If by chance I do not understand your test setup then just ignore this post.

Rick

[Old Grey]

That SF plate should flow 147 - 148 CFM @10" with the small hole blocked off as shown. What do you get with that setup? Have you tested it and converted the number to 10"?

It's a SF-1020 plate from a bench purchased about a year ago.

Surprisingly it has Lazar cut holes

More Surprisingly the small hole out of round and has a dag in it.

[Old Grey]

Grey,

Please help me understand this test some, you are trying to test the inlet of the vac motor with the affect of radius on the inlet side correct?

You are trying to measure the performance of this by flow though and orifice correct?

I am not sure this is a valid test as the flow through the plate is based on DP and your radius would have to make the motor produce more pressure which is based on impeller tip speed.

I think a more valid test may be to use a piece of 2.5 to 3” PVC as the motor outlet then use a pito to measure the FREE flow air speed.

A simple change to your current setup may be to use an orifice that will crate the very least restriction so the DP would be less than 1” and use a sloping monometer for your measurement.

Last in the photo #1 if I understand your fixture correctly and the flow path the Orifice plate is mounted backwards.

If by chance I do not understand your test setup then just ignore this post.

Rick

It was a vac motor blowing into a box with a orifice restriction exit, and I was measuring the pressure in the box. My logic was that if the motor flowed more it would produce higher internal pressure in the box, but after reading your post I'm not sure now. I was chasing a higher pressure drop so that I had more free flowbench capacity at high lifts.

It's a bit late, as I have finished that part of the bench, but did I make a mistake.

[1960FL]

Ahh, Square edge orifice...

See that now.

Rick

[larrycavan]

That SF plate should flow 147 - 148 CFM @10" with the small hole blocked off as shown. What do you get with that setup? Have you tested it and converted the number to 10"?

It's a SF-1020 plate from a bench purchased about a year ago.

Surprisingly it has Lazar cut holes

More Surprisingly the small hole out of round and has a dag in it.

Crunch the number and it's the same as they ship with the 110 & 600 units. I don't believe mine was laser cut. You got the hot new technology

[Old Grey]

Crunch the number and it's the same as they ship with the 110 & 600 units. I don't believe mine was laser cut. You got the hot new technology

Good one Larry. It's a friends bench and I now remember it was bought new and delivered Jan 2012 - 2 years old -

He also lent me an old SF-110 gold passivated mild steel one - SF-1020 is stainless - that has had the holes punched out. I guess they didn't like the rounding of the hole from the punch so they lazar/plasma cut them now.