PTO driven fan/blower: Looking for ideas

srjones · Mar 27, 2006

Has anyone built a PTO driven fan or blower? The main thing I'm interested is having a 'wind source' to get big brush/stump piles burning nice and hot, but a leaf blower might be a nice side benefit. It would also come in handy to get air circulating in areas that are otherwise damp.

The two different designs I'm thinking about are as follows:

1. A 'Squirrel cage" blower which would blow perpendicular to the PTO. A simple design but limited in output direction.

2. A "propeller fan" should would blow inline and away from the PTO. Then put a series of baffles (like a swamp boat or a hoovercraft) that would direct the wind. A little more complicated to build but would be more flexable (and thus useful).

Any thoughts on the ideal speed run each type of fan? Also, any design guidance on PTO HP requirements for CFM output? Pictures and other info would be great!

Thanks,

-Steve

Highbeam · Mar 27, 2006

This is great. There are commercial blowers as you describe that you could copy but what fun is that. The logger used a fire fan that was a briggs (thus 3600 rpm) 5 HP engine with a fan and he tells me that when the fan breaks up that they use car fans on the same shaft. So, a steel or plastic engine fan from a large truck would be cheap. You could even use the water pump as a mount for the pulley to get you up from PTO 540 to 3600 rpm. It should be caged, shrouded would be good too but not required. It would blow directly behind you but be cheap enough. Not sure about CW or CCW rotation but you'll want to know.

I used my leaf blower just this Saturday to substantially accelerate the burning of a large heap of logs and slash. It's not just for starting the fire but for keeping it hot, fast, and smoke free.

I also bought a large floor fan from HD that runs on a small amount of electricity that I've used my big generator to run. That worked pretty good but not so much flow and the generator and cord were a hassle.

An eengine fan going full blast should be up near 5000 CFM. Stick it in a barrel as a shroud, maybe put a simple swivel duct on it and you could get some flexibility.

The logger tells me that he has actually set up a series of barrels to put the air from his fire fan right to the core of the baby fire.

Pooh_Bear · Mar 27, 2006

Go to a heating and air business.
They often have the units sitting out back that they replaced in a house.
These units have some big squirrel cage blowers in them.
The blower is powered by a motor via a belt drive.
Get the motor too. Great source of motors and always handy to have around.
You should be able to get this stuff for free since they have to dispose of it or a scrap metal hauler comes and picks them up.

Just mount the blower on a frame with out the motor.
Use a shaft with a pulley on it to drive the motor.
Hook the PTO shaft to the pulley axle shaft.
Use whatever size pulley you need to get the speed you want.
Simple, cheap, effective.

The blower will blow to the side of the tractor but you can add an elbow duct to direct it backwards.

Pooh Bear

jimgerken · Mar 27, 2006

I just saw one in the Farm Show News, built from a sileage blower. These are usually 540 pto implements designed to blow chopped hay or corn into the silo, thru a 8 inch diameter tube up the side of the silo, 50-80 feet high. They move a bunch of air. This guy had rotated the output (they are designed to allow at least some of this rotation) from vertical to horizontal, and put a screen over the inlet for safety. He was using it for leaf blowing for his lawn care or landscaping business. To me, it looked like it would take less than a couple hours to put this together. Plus, you can add stock lengths of 8 inch tube, already equipped with bolt-up flanges, onto the output of the blower and thereby get your tractor further from the fire.
If you can see silos standing in the country wherever you live, chances are you can buy a sileage blower used at a dealer or auction and try it. Maybe you can even try one before you buy it. I know it took 135 horsepower to operate ours on the farm to put corn sileage into out 72 foot silo. But to move only air, I would think it would take much less. Good luck . Another last-minute thought: there are half-size versions of this type of blower on other machines, which could be more like the size you want. A forage harvester, either mounted or pull-type would contain one that blows the chopped hay/corn into the wagon. Also, a Flail chopper has a nice blower on it.
Here's a link to show you what a silo blower looks like:
Shortened Long Link

And here is a link to a forage chopper:
Shortened Long Link

srjones · Mar 27, 2006

Highbeam,

I like the idea of using automotive fans and 55 gal barrels. As a fellow Northwesterner you're well aware of how wet things get (and are this year). BTW, lived in Puyallup for a few years in my youth. /forums/images/graemlins/smile.gif

Pooh_Bear,

Thanks for the source idea. I've got one of these in a scrap heap and I didn't even think of it. /forums/images/graemlins/shocked.gif

Jim,

Again, another good idea for a fan /forums/images/graemlins/smile.gif I can think of two or three places that I might check.

Highbeam · Mar 27, 2006

Yes it is wet here. My slash pile sits on a clay soils so while the surface seems dry, after you drive back and forth on it it turns to spooge. I would have burned aggressively both days but the rains came on Sunday and I know better than to make the mud real bad, it takes longer to heal. The slash I'm burning was piles with a bulldozer by a moron that didn't know how to keep dirt out of the pile, me. So burning is a separation and then stack process. Plus, the logs are wet so the heat needs to first dry the log and then it can burn.

That little 2 stroke leaf blower makes a huge difference.

Taylortractornut · Mar 27, 2006

Ive made a few using a a 3 point and pto as the power unit. I get a 2 foot diameter explosion proof exhaust fan and make weld on a frame that resembles a carry all for it to set in, Its got a shoud thats tapered and places to bolt on screens iff needed. the only thing you have to do is where the belts com in get a 1 3/8 shaft and 2 pillow block bearing s and the appropriate pulley and they you have it. Ive smoked a bunch of piles with them. Im waiting to build another one this spring if I ever get time.

Fredex · Mar 27, 2006

Many of the smaller air blast mist sprayers used by small vineyards and orchards are built around squirrel cage blowers (like furnace blowers). The one I have has about a 10-12" double-V pulley on the pto and about a 3" on the blower. The air can be directed from 20-30 degrees below horizontal on one side all the way around to the same on the other side. Vanes could be put in the output and adjusted to spread the air flow out wider.

RonR · Mar 27, 2006

I'm not sure how feasible this is, but it sure would be cheap.

Take an old rotary mower that runs. Take the blade off weld some flat strap perpendicular to the blade. These will be the vanes. Secure a chunk of steel or plywood over the bottom to "close" the fan cage.

Think you'd need to allow air in, so it would need openings somewhere. I'm thinking near the center would be best. Maybe leave a 12" hole in the bottom shield.

Think you could funnel down the discharge chute to rig it to a tube if you needed to.

So, whaddayathink? I know my snapper with the curved up blades throws a lot of air (grass).

If someone tries this, please let me know how it works. I think you wouldn't even have to destroy your mower to make it work.....

ron

Highbeam · Mar 28, 2006

"I get a 2 foot diameter explosion proof exhaust fan and make weld on a frame that resembles a carry all for it to set in, Its got a shoud thats tapered and places to bolt on screens iff needed."

This sounds like the ticket. Any pics or sources for the fans?