Sawdust Collection for Sawmills
You need a fan powerful enough to move sawdust and tough enough to withstand impacts from big chunks. August 30, 2007
I have a squirrel cage furnace blower which I intend to use to remove sawdust from my private sawmill. I intend to power it using the same motor as the mill saw. I have removed every second fan blade from the blower to reduce clogging. How should I position the blower to receive the sawdust and blow it away from the mill?
(Sawing and Drying Forum)
From contributor M:
Using this type of blower may not work. The blower should be capable of withstanding material strikes. A furnace blower may not be able to do this and come apart on you. If you choose to use this blower, consider housing the blower in a steel box to contain it should it come apart while at speed.
From contributor D:
I am no expert on this, but as I understand, a furnace fan will move a lot of air but it doesn't have the static pressure behind it to move sawdust. Even if it could, I would bet the first wood chunk to go through it would destroy it. If you could, take a look at a blower that a commercial sawmill would use. They are made with very heavy steel. The blower at the mill where I buy lumber weighs almost 500 pounds and they have to rebuild it every 1 1/2 to 2 years because of regular wear. I have heard chunks go through it. It sounds like someone hitting it full swing with a hammer.
From contributor B:
What you really need is a material handling impeller. It's made to move lots of air with a high static pressure and deal with solids at the same time. Check out the budget blower at Bill Pentz's page (billpentz.com). This blower is meant to move air for a cyclonic dust collector for woodworkers, but you could just do without the cyclone part, and simply have a hose in and a hose out to a discharge pile. He calls for running it off a 5 hp motor, but that's only if you want to get enough velocity for the cyclone to work. You would be able to definitely get by with a 3hp motor, maybe less, if you set it up with just an in and out hose.
I agree with the earlier post, that the squirrel cage will not hold up. Not only will it be subject to strikes from larger chunks, but the eroding force from just sawdust moving at the velocity you're dealing with is significant. Couple that with the moisture the fan will have to deal with and the fan will be toast in a short amount of time.