Thread: Impeller Help

You best bet is either purchase a s/hand dusty for parts or contact the distributors of brands like JET, etc., and enquire about buying replacement impellers. Of course you will need to be sure to match the shaft diameters up.

When I built my cyclone I used the Motor and impellor off my old Carbatec dust collector.

Im sure you would be able to buy one separately from somewhere. As Histring says, try some of the distributers. One place that might be worth a phone call is "Gregory Machinery", in Brisbane .

Built a dusty off Bill Pentz plans.

I have a 1450rpm 5.5hp motor driving a 610mm diameter airfoil type fan that has been running for the last 2 years with no issues at all.

Used a furnace blower fan/motor from a demolition site. All the motors I have come across (cheap) are all 1450rpm industrial jobs, not the 2800 ones that most of the dustys have. 5.5hp, 3hp motors and blower $50.


copied the original blower casing as it was rusted out and needed widening to accomodate the widened fan and reverse the rotation of the fan to lessen noise.

Trying to attach photo for the last 15min, no go!

Stringy
Could you please elaborate on how reversing the fan lowered the noise?
Thanks BobT

You cant reverse the rotation of the fan/impeller and expect it to move the same amount of air... The direction of the fins on the impeller will set the correct rotation of the impeller for correct opperation... Even a simple paddle impeller needs to be spun the correct way in relation to the direction of the snail for it to be efficient. But the governing factor with moveing the air, is horsepower.

Stringy, thats not an airfoil they are a cage shape same as the old swampy aircons had.(barrel fan)

Wrinkels, prob be cheaper to buy a secondhand one or a new 2hp unit and butcher it. At least then there's no problems with PITA shaft bushings and the casing is already made for you.

Harry, you are correct, this is not a true airfoil, as they have curved blades that are thicker in the centre and thinner at the edges like a wing (airfoil), they also have a cap over the top of the blades to prevent air spilling over them. Have some plans for one but the blades are difficult to profile.

The air con / electric motor blower types are also like this but also not true airfoils, we call them squirrel cages or HVAC at work, any way, I have been told that they are no good as dusty blowers, high volume but no suction.

Reversing the rotation of the fan - the blades were curved, originally toward the exhaust, this orientation moves the most air but creates more noise. Making the housing opposite hand and spinning the motor in the opposite direction curves the blades away from the exhaust decreasing efficiency slightly but lowering noise levels significantly. The motor is a 3phase job with forward/reverse switch fitted.

Also had a big win on the noise front by cutting a "V" into the leading edge of the exhaust and profiling to keep a consistent clearance to the fan.

Picture shows housing and fan in an unfinished state, fan attachment now has propper securing and has not loosened in 2 years, housing now has the "V" cut into exhaust.

I agree that it would be easier to modify an existing blower/fan unit onto a cyclone, but depending on the amount of air movement required, availability of resources and ability to build one, I think it is good to know what options are available.

Attachment 41787 Attachment 41788

Found, photo of Proper airfoil for 3200rpm dusty.

Attachment 41790

Thanks Guys, will keep searching.

Hey wrinkles
Have you looked at the blower used in a clothes tumble dryer. It's just a thought and I figure you could pick one up second hand and cheap (especially if it is not working) then change the motor and/or pulley setup to suit.
Good luck with it
Pete