will this blower work ok - ring compresser

[jim fuchs]

i picked up 4 of these,1.5 pipe in and out. 98cfm max
79cfm at 20inchs water 1 hp 3 ph
was going to run these with a vfd and use that to slow and speed them up to set inchs of water . would a ball valve work to shut them off and turn them on ok. just pipe them into a main box then to the main tube right. how long does the tube have to be from the main box .jim

[84-1074663779]

An interesting idea to be sure Jim.

If you look at the pressure flow characteristics of ring compressors they behave very much like positive displacement pumps, rather than the more common fans and blowers. They should work particularly well with a VFD to control the airflow, especially at higher test pressures.

A ball valve might not be a good idea to control flow directly, because then the pressure and motor current will go very high if you tried to completely close off the flow with the motor running.

It might be better to all run the units together at similar speeds directly off the VFD and use that to control total flow. Or fit some one way flow valves and then switch in various compressors. One way valves could just be a rubber flap in a box.

I run a VFD on my bench, and it is extremely easy and convenient to use. Running the blower at reduced speed greatly reduces noise and power consumption when operating well below maximum flow.

[jim fuchs]

ok thanks ,so if i pipe the 4 pumps into a main box then comeoff that with say a 4 inch tube up to bench top how long should the tube be or how short could it be . does it have to neck down. or can it go 4 inch up to top . how big should i make my box to dump the 4 pumps into ,eny size or do i need it at all . just put 4 1.5 pipe fittings on my 4 inch tube? jim

[84-1074663779]

I would experiment starting with the simplest and most convenient layout, and see how it goes. Just couple it all up with cheap plastic pipe fittings and take some pressure and flow measurements. Do this before you assemble all the bench outer panels. It will then be very easy to change things around if there are problems. There is no substitute for actually trying out some ideas yourself.

[bruce]

Bringing back an old thread from the past . . . never heard back if this worked or not for an air mover so I picked one up on eBay in the past week for myself to give it a try.

Tony and I have had some good off forum email discussion on this style of blower over the past year and I was waiting and waiting till I ran into a good deal on one to try out. The one I got is 2.5-3hp. I should get it up and running in the next few weeks, its 3 phase so I have to wire it into my shops rotary phase converter.

I'll keep the forum posted on my progress . . .

[84-1074663779]

It sounds like you hit the jackpot there Bruce. I have been looking for a large side channel blower, or ring compressor myself for quite a long time, but without success so far.

Few people even know this unusual type of blower even exists.

They are fairly common in the smaller sizes, and are typically used as spa blowers, the type that really howls. These blowers are often rated at around a hundred inches of pressure at nominal flow.

It should make a wonderful flow bench blower, particularly if you can get yourself a variable frequency drive to control the Rpm.

[dirt-clod]

tony or bruce , i am new to this site , and very interested in this thread. can either of you post a pic of this style motor your talking about ? i live in a very big military surplus area and i think (if its the same ones ) i can get some of these motors pretty cheap . but im not sure if im on the same idea as you guy's......thanx

[bruce]

Here is a small image of a regenerative blower, they come in all sizes.

[84-1074663779]

They all look pretty much exactly like that picture, and easy to distinguish from anything else.

There are always two straight through mufflers mounted below the motor, one silences the intake, the other the discharge.

[gofaster]

You probably could find a variable frequency drive for one of these 3 phase blowers. You could use it to control the motor speed / air output. I installed one on a large liquid pump about 15 years ago, and it allowed the motor to start easy, then ramp up speed gently, and the operator was able to control the flow through the pump (i.e. motor speed) by turning a knob (rheostat).The motor ran cooler, lasted longer, and used a lot less juice. I think you could use this method to eliminate throttling to control depression, and it would keep things cooler. If you use a Flow com / motor controller, or something similar you could eliminate manually adjusting the rheostat and you could run your test faster.
Jim