Grain auger for cleaning out dust cyclone

trim4u2nv · December 17, 2008, 12:24:01 AM

Due to open machine time and an auction deal, I picked up a larger cyclone with 16" inlet with 20hp pull through blower. Looking at purchasing a 10" x 61' agricultural auger to convey shavings. What kind of HP would an auger this size take to move sawdust at 440 gallons per hour. I do have gear reducer motors available. I could probably shorten the auger as it just needs to fill a dump trailer instead of a tall silo.

Gary_C · December 17, 2008, 01:34:32 AM

That auger is overkill as you would only be moving 23.5 bushels per hour thru an auger that could handle 1000-2000 bushels per hour at 200 RPM.

Your problem is going to be feeding that material without it hanging up in the inlet. A belt conveyor would work better.

trim4u2nv · December 17, 2008, 02:31:58 AM

Bridging is a real problem. I also want to avoid a rotary airlock if possible. If the auger is smaller than 8" diameter, maybe a small chain or wire rotating in the cyclone will help keep the auger feeding. I only have clearance for a 55 gal drum or 2 below the cyclone due too ceiling clearances above. Also considering building an auger with pvc pipe and a screw. The 10" is priced around $1200.00 and jacknife style with PTO and would have to be converted to AC motor. I like the conveyor idea but not the airlock maintenance.

Gary_C · December 17, 2008, 02:50:27 AM

Quote from: trim4u2nv on December 17, 2008, 02:31:58 AM
The 10" is priced around $1200.00 and jacknife style with PTO and would have to be converted to AC motor.

Wow! A 10" x 61' auger would cost way more than $1200 around here as that's a big auger. At least if it was in good shape. Better check and see if you can use the flights to shave.

I doubt you can get by without a rotary airlock. Even if you sealed the auger to the bottom of that hopper, it would suck a lot of air thru the tube.

trim4u2nv · December 17, 2008, 03:17:22 AM

The flighting on the first stage is worn some but the second stage looks better. Very large and very small augers go cheap around here. 6"-8" get the highest prices. I am considering a paddle or bucket conveyor with a steep incline to keep the whole thing indoors. Missed a good deal on airlocks at a large commercial bakery closing down. Koger and torit seem to be the most popular for sawdust.

trim4u2nv · December 17, 2008, 09:51:53 AM

Also considering a double dump valve (double flapgate) with air control and a belt conveyor. Anyone had any luck with these dump valves instead of a rotary airlock?

trim4u2nv · December 19, 2008, 12:20:42 AM

Final layout should look like this

beenthere · December 19, 2008, 01:46:00 AM

pics/sketchs are great.

Is it to scale?

Gary_C · December 19, 2008, 02:23:17 AM

Even though that belt conveyor will be better than an auger, there are a couple of things to consider.

Belt conveyors do not do well with steep inclines and light materials. The stuff may roll back even with ribbed belts.

You will most likely need a cover on that conveyor or it will all blow away.

If you want to see a good low cost conveyor check this out:

http://www.usagnet.com/loyal-roth/Feed_Handling2.html

They make both belt and chain conveyors.

trim4u2nv · December 19, 2008, 02:44:48 AM

Very close to scale as I have to fit this under a 18' ceiling and this is 17' tall + weighs over a ton but does come apart in sections that are manageable. May be able to find a bucket conveyor or chip conveyor. I guess the conveyor can be dry tested at the slope I hope to get while keeping the whole deal indoors to conserve heat. Can currently dump into 4x4x8 plywood boxes which the horse people pickup. Did the layout in google sketchup, a lot easier than maneuvering large bulky components to clear the rafters ect.

Ianab · December 19, 2008, 02:48:06 AM

What about just extending the 16" inlet and mounting the whole cyclone assembly on top of the bin?

While the shavings are suspended in the air flow it's no big problem to suck / blow them a few more feet.

A site I work at sometimes has a couple of big moulder/planers in a big shed. The blower is mounted on the roof and blows the waste over the office, car park and driveway to the cyclone mounted on top of another shed where the shavings collect, probably 100 feet away.

A extra run of pipe seems a lot simpler.

Ian

trim4u2nv · December 19, 2008, 03:16:07 AM

Our old system had 2 smaller cyclones dumping into an airtight box. But the objective is to lower power consumption on the new system. We considered the idea to blow out across the parking lot but this would require an addional 50hp to blow to a remote building and lose the heat through the pipe. Outdoor temps are around 7 degrees fahrenheit today. Maybe I need one of those woodmizer boilers to burn the sawdust. The current project is all contained within 1 building to limit heat loss.

Ianab · December 19, 2008, 05:25:45 AM

Ahh.. the cold climate thing :(

Yes, sucking air out of the nice warm shop at that rate isn't so good if the outside air is below freezing.

Back to the auger or conveyer idea then.

Ian

StorminN · December 20, 2008, 10:38:56 PM

Quote from: trim4u2nv on December 17, 2008, 02:31:58 AMI like the conveyor idea but not the airlock maintenance.

trim,

We have two rotary airlocks and the maintenance is not bad at all... just keep the gear motors lubed and you're ok. It wouldn't deter me from buying one, that's for sure.

Our system is has a 40hp blower that sucks the dust through a cyclone first... the big stuff falls out, through a rotary airlock and into the back of a specially-built box on the back of a pickup truck with dump bed. Then the small stuff goes into a bag house and falls from that through an airlock and into a special-built box that we can pick up and dump with the fork truck. We empty the pickup truck about three times a day, and the forktruck box much less often, maybe once every couple of weeks?

-N.

trim4u2nv · December 21, 2008, 11:44:45 AM

Does your airlock use vane seals or is it metal to metal. I have seen some of the new airlocks have a slideout vane assembly (bearings and cover together) to make for easy cleaning. But the $8000. pricetage is hard to swallow. Missed some new old stock for sale last month, went for around $800 at auction. Still on the fence whether to use rotary airlock or double dump valve.

ksu_chainsaw · December 22, 2008, 11:49:23 AM

I have never seen the airlock that you are talking about, but for grain bins we have used just a slide gate to stop the flow of grain into an auger. You could put a small drum- roughly the size of what you would produce in shavings and dust for one day with a slide gate at the bottom. Then at the end of the day, start the auger, open the slide gate, and empty the drum out. An auger will work fine, as long as you don't have large pieces in there- a 6" auger has only about 2" of clearance on each side of the shaft and 3-5" of clearance between each flight.

Just my 2 cents- I still try to make do with the lowest cost solution out there.

Charles

trim4u2nv · December 22, 2008, 05:35:23 PM

Here are double dump valves. Just 2 check valves in series timed to only open 1 valve at a time. The rotary air lock works like a water wheel type pump but is enclosed airtight.

These for my purpose are to run continuously without having to empty bins and stop the moulder.

StorminN · December 23, 2008, 01:53:06 AM

Quote from: trim4u2nv on December 21, 2008, 11:44:45 AMDoes your airlock use vane seals or is it metal to metal. I have seen some of the new airlocks have a slideout vane assembly (bearings and cover together) to make for easy cleaning. But the $8000. pricetage is hard to swallow. Missed some new old stock for sale last month, went for around $800 at auction. Still on the fence whether to use rotary airlock or double dump valve.

trim, I tried to get out there today to take a couple of pictures, but it didn't happen in daylight. I believe both of our airlocks are rubber seals. The airlock on our last baghouse was rubber seals, I know that for a fact. If memory serves me correctly, we bought the whole baghouse (it's about 25-30ft tall?) and blower (40hp) along with all the electronics... big control panel, soft start, etc. for $6,500... at an auction for a cabinet shop that had gone under... so look around, I'm sure you could find an airlock for much less. I'll try and get some pics tomorrow.

-N.

StorminN · December 24, 2008, 07:01:29 PM

trim, here's the pictures...

The yellow cyclone on the right (ductwork leaving the building is behind the cyclone) is the first stage collector, and the large particles fall out there, into the box on the truck... the truck has a dump bed kit on it. The smaller dust continues on out of the cyclone, to the white bag house on the left, where it's filtered out and falls into the box at the bottom, which has large casters and is fork-liftable. The bag house is purged with compressed air. The whole thing is powered by the 40hp blower at the center. (ignore the extra ductwork in the foreground, that's for a different project.)

Both airlocks are rubber seal, the airlock on the cyclone is maybe 36" in diameter, and the airlock on the bag house is maybe 12" in diameter...

Again, we bought the entire white bag house tower... with the 40hp blower at the center and a large control panel (fridge-sized, not pictured) with soft-start, interlocks, etc. for $6,500 at auction. It cost us more than that to move the bag house to our location and get the ductwork hooked up.

-Norm.

trim4u2nv · December 25, 2008, 12:43:22 AM

Here is the model dust collector I am reassembling. It's 36 inch diameter by 16 foot tall weighs 2300 lb. Got this for $250 at auction but had to rig it out myself. Was installed in a soundproof room (built after installation) and had to be lowered by chainfall and dismantled section by section. Took 2 days to dismantle hanging off the ceiling like a spider. All the components fit on 4x4 pallets fortunately. Right now it looks like a box of bolts on pallets. It has 4 x 3 dust bag array to blow back directly into the building. Not nearly as nice as an automated baghouse.

Your bag house is impressive. I bet you don't miss cleaning out those bags manually. You got a heck of a deal for $6500 with the baghouse and airlocks included.

StorminN · January 02, 2009, 03:07:38 PM

trim,

That looks like a good system... and for $250... WOW!! We've had good luck with Torit systems.

Our last big bag house was automated as well... but the bags inside the bag house hung from a frame that was vibrated by a shaker motor... maybe 2hp? I forget. Anyway, one day a year and a half ago, the bag house went "boom" and then we had flames shooting out the exhaust duct... got shut it off and got the fire department out here and long story short, we're not sure, but picking through the pieces afterwards, it looked like the vibrator motor (which was a TEFC) overheated, sparked or something and caused the explosion / fire... that baghouse was pretty old, so after the fire it was a complete loss... hence the new (used) one that we bought at auction and have now, in the pictures above. With the air purging that this one has, there's no motor inside the bag house to spark or overheat and cause a fire.

-N.