Differing blower options

H

hastingr

New member
First, kind of a hello and an introduction....

I just got my garage back for use as a shop...

I have a 3 car garage, and I get 1/3 of it... I tried for 2/3, but I didn't get very far with the boss... :huh:

The three car design is 20' wide for the first 20 feet, and 10' wide for the next 18 feet.
So, I get a 18' X 10' shop size...
The good news is that I have a 13-14' ceiling. I plan on placing a floor (or is that an attic?) above much of the shop maybe about 11'X10' of storage there.
So, I have a lot of vertical room to work with as well...

I'd like to build my dust system so that I can place this floor between me and the motor to reduce noise.

This space could have access to the outside to vent air out the side wall, (and that could vent at the height well above the ground..)


When I started the process of looking at dust collection, I told my wife that it might run a couple hundred. Obviously, after reading up on all this, I may have missed the mark by a factor of 4 or 5....

I had run across Lee Styron's site where he built his own dust collection system, which certainly doesn't collect the smallest of the dust (He pipes his air to the outside as well, so it would appear) but I like his impeller design for two reasons.

http://www.leestyron.com/dustcollector2.php

1. It uses a 19" impeller
2. uses a 1 HP motor with a 1725 RPM.

Advantage of this design would be that the impeller would cost $20 to make, and it would be far quieter as well. I can also imagine that it would be slightly more efficient than having a faster but smaller throw design.

He says that he gets 1375 CFM at 4.75" of water column, which would be just fabulous for a cyclone like the clearvue. Has Bill or anyone else for that matter, looked into using a larger impeller with a slower motor?

Thanks to Bill for his over the top discourses on dust and collecting it. Thanks Ed for making such a cool cyclone. I hope to budget one in this spring as I start to work on my shop.

Richard
 
In terms of that impeller, it is similar to the Cincinnati Fan 18.5" diameter unit. At 1766 RPM the Cincinnati Fan impeller, according to the maker's engineering specifications, draws 1.93 hp and moves 1400 CFM at 4". The 19" is a bigger diameter fan but turning just a little slower, so should be very similar.

I would like to see the amp rating on that 1 hp motor and see what is actually being drawn because it is more likely than not the motor is being over taxed.

In general, the slower moving impellers make less noise and can still move quite a bit of air, but you need a big diamenter impeller and a tiny shop. Most lack enough pressure at these speeds to take care of any but the smallest shop. 4" is a lot of resistance when you give 3" away to your cyclone filter and only 10' of smooth walled flex. Adding much ducting and you get most small 1-car garage sized shops at about 5" of resistance, a 2-car sized garage up to 2" more and a 3-car sized shop up 4" more.

Finally, I still recommend considerable caution in making your own impeller. Yes, they are less expensive but even at 1750 RPM you can be dealing with over ten tons of force, so if something goes bad, it can be terrible. I've now blown up three impellers. One was a plastic airfoil I tried and the plastic destroyed the metal walls of my blower. The second was a large leaf blower impeller that let go when hit with a small block of wood. That fiberglass plastic went every which way. The finally was a steel impeller sent to me for performance testing. The welding was bad and a blade let loose. I have not hit the ground so hard or fast since Vietnam. Please be careful in making your own impellers, they are not something to fool with at all.

bill
 
Thanks Bill for the reply...

You give me much to contemplate:)

Richard
 
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