Shavings Collection: Hopper Receiver or Rotary Air Lock?

Shop owners discuss alternative ways to outfeed shavings and sawdust from their dust collection systems. November 8, 2007

I am looking at two different Torit model 30 cyclones. One has a 100 cu. ft. hopper with slide gate; the other has a rotary air lock. The cyclone will be located outside, and I am either going to pay for dumpster pickup once a week, or get someone to park a trailer underneath, or give away the chips and dust.

I am wondering which setup would make the most sense. I generate about 1/2 yard a day from planer, jointer, saws, shapers, sanders. Seems like with a RAL, you might have to shut down the DC when the garbage truck shows up to avoid dumping into the parking lot? But with a hopper plus slide gate, someone has to open/close it every night. A hopper could also dispense into a truck bed if someone wanted to take a load.

This will be a big investment for us, and I want to get a system that is easy. I'm sick of dealing with 55-gal drums.

From the original questioner:
Just realized the hopper receiver model is 3.5 Cu. Yds. That would mean I could go for at least a week without opening the slide gate. I could always put a RAL on the hopper if I needed, but couldn't easily add a receiver later, as this would mean changing the ductwork, and redoing the steel stand. Does this info change anything?

Forum Responses
(Dust Collection Forum)
From contributor R:
I have a RAL, no receiver. I have a farmer with two wagons. One wagon is always under the RAL.

From contributor K:

We have a small hopper under our Torrit cyclone (approximately 3 yards), and a RAL under the hopper. Generally, the RAL runs whenever the system is on, and the hopper is constantly unloaded. We turn the RAL off when changing the roll-off dumpster, and the hopper serves to collect the dust during the changeover period.

From contributor D:
Wood shavings/sawdust are worth $10 per cubic yard for me. Thought about using sawdust as fuel, but on my scale the boiler cost isn't justified. The sales of sawdust more than offset the money spent on oil. Why spend money on the system and give money away that could be in your pocket? Or even pay for the removal of money from your pocket?

From the original questioner:
Who do you sell your sawdust to? Around me there are lots of wood products people generating it, so I haven't found anyone yet who is even willing to pick it up for free.

From contributor D:
I sell mine to a dairy farm, and they are glad to pay for it! Look for horse owners too, but they tend to be very picky about what exactly is in the mix. Try calling a feed store or veterinarian - they may be of help finding animal owners/farmers in need. There is always the option of using as mulch, but I've found it to be a poor option. Here in the Northeast there used to be plenty of businesses making shavings/sawdust, but now the big operations are getting thinned out (thanks China and Mexico), so the market is no longer flooded with wood waste... therefore the demand is outstripping the supply, and I'm paying for my heating oil. Oh yeah, I also ran an ad in the local paper, and got no less than 12 calls...

From contributor W:
People with horses seem to love my shavings, but I work a lot with walnut, which is known to be harmful, if not fatal, to horses. Be very careful about what you send out!

From the original questioner:
Thanks everyone. I decided to go with the hopper system for now. Once I have a better feel for what I'll do with the waste, I will either get a RAL as well or just stick to the slide gate.