Grinder specific dust collection

[drysideshooter]

I am starting to get my new Esteem set up. I have read some different threads, here and elsewhere with regard to dust collection for knife grinders. I've read about shop vac fires and looked at some different ways of dealing with the dust. I thought I would ask a couple of questions and see what the current thinking is.

I have dust collection for my wood tools. I want something specifically for just the belt grinder. What I am thinking right now is going with a 5 gallon bucket system I saw posted on these forums. It's a shop vac hooked to the lid of a bucket, and the inlet pipe goes to the bottom of the bucket and is cut away inside the bucket portion to allow suction at the grinder end. The fellow that posted it says he keeps an inch or two of water in the bottom of the bucket. Basically the bucket is a low/zero pressure vessel and the dust is drawn away from the grinder into the bucket. I think I would add some type of baffle between the suction area and the rest of the bucket to prevent any potential hot embers from making it to the actual vacuum. I was even thinking of using something like a humidifier filter as a baffle.

Thinking about that set-up had me wondering if using a wet/dry shop vac with no bag and the reservoir about half full of water would work instead of having the bucket in line? I guess there would still be the chance the filter could possibly catch on fire? For the sake of simplicity I would possibly consider running without the filter, like you do when you use a wet/dry vac for sucking up water. I know without the filter the motor wouldn't probably last as long, but for the simplicity offered maybe shorter motor life would be a worthwhile tradeoff? Any thoughts or advice would be genuinely appreciated.

I wish I could get a look at one of the Jet metal dust collector units. Looking at the pics I can find of it, I don't see how the metal dust is removed from the air stream and deposited in the collection drawer. Overall, it looks like a pretty simple design. A large cabinet with filters built into the end and a collection drawer where the dust gets deposited. For hooking up to a few different metal machines with blast gates and such it looks like it would be pretty cool.

 

[timgunn1962]

Looking at the exploded drawing of the 414700. it looks to me like the dust just drops into the drawer when the dust-laden air leaves the hose and slows down to a speed where it will no longer entrain the dust.

Bear in mind that it is specifically for metal dust and that this is extremely dense when compared to wood dust. It takes a very high air speed to entrain metal dust and it falls out of the airstream relatively quickly/easily when it slows down.

With reasonably thoughtful design, the likelihood of a metal particle with sufficient mass and temperature to be a fire hazard remaining in the airstream all the way to the filter is negligible. A 4" hose has an area of 12 1/2 square inches. The Jet 414700 filter is 19" x 19 1/2" giving an area of 370 square inches. With 2 hose inlets giving 25 square inches, the airspeed at the filter will be 25/370 = .0676 or about one-fifteenth of the airspeed in the hose.

 

[Roadracer_Al]

If you add a Oneida Dust Deputy with the water in the bottom, you should be good to go with a shop vac without ruining the shop vac. Moisture inside is just about the only thing they won't tolerate.

Link to MFG site:

http://www.oneida-air.com/category.asp?Id={CC6B6F2A-E3D7-4F18-A53C-B5C357DFE131}

 

[Lo/Rez]

I made mine out of an old furnace fan and use a filter to trap whatever dust gets there. I have a piece of wood dividing the bottom of the pail and a 90 degree elbow for the pipe to the filter (in the pail). Works OK so far.

 

[drysideshooter]

Thanks guys. Lo/Rez I think I saw that picture in one of the other threads I was reading. Looks like a great set-up.

I hadn't seen the dust deputy. It looks somewhat similar to the Clearvue type system.

I enjoy tinkering and trying things out. I have thought about what timgunn1962 said about the time in a hose diminishing the temp of particles. It makes a lot of sense, especially if there isn't potentially any wood dust in the ducting for the metal embers to catch on fire.

I wonder if a couple of big magnets in the bottom of the bucket would help metal dust fall out of the air stream?

 

[C.I.TR3]

I am curious too as to how the Jet metal dust collector works. Has anyone used one? I have a line on a used Torit model 64 which I think is a similar design and made for metal but am having a hard time finding out any details on the unit Mia's anyone use one of the Torit models?