Dust Collector baffle question

[JimmyC]

I know, I know, I should know better than to ask a question about dust collection, but here it goes. This will be my set up so don't tell me that I need a cyclone, it's not in the stars at the moment.

I have a Grizzly 2hp DC, I will be using 6" HVAC pipe ( got it free ) and a Phil Thien seperator (also 6" inlet/outlet), but here's the catch, I want to blow it outside of my shop instead of using a bag/filter set up. The closest neighbor in the direction of the outlet will be about 1/4 mile away, but I still have people near me in the front so I am worried a little about the noise.

Here are my questions:

1) Is there a limitation on the length of the outlet pipe ? I would probably use 10' in length.

2) Is there any plans out there for baffles, and do they work well for knocking down the decibels, also would a baffle cause a back pressure problem ?

3) Has anyone here done anything like this with their set up, and how does it work ?

Thanks in advance.

[AndyBarnhart]

I thought "real" DCs used induction motors and were not very loud. I have a noise issue with my ShopVac and have one of those nearly worthless mufflers for it, but it is that universal motor that makes the racket.

EDIT - Out of curiosity, I looked it up. Sealed bearings TFEC induction motor. Have you tried turning it on and seeing how far you have to walk away before it can barely be heard?

[woodrat]

Jimmy,

I think, from seeing your shop, that you could safely vent to towards
the creek without disturbing anyone. Or back towards the horse pasture.
As far as the shop is from the neighbors in front, I don't think there would
be a noise problem.

Are you thinking of putting the DC outside or just venting it?

[Partman]

Jimmy, do you have heat or ac in the shop. If you vent outside all of your heat or ac goes with the dust, and where does the air come back into the shop.


Danny

[Bas]

Originally Posted by JimmyC

1) Is there a limitation on the length of the outlet pipe ? I would probably use 10' in length.

The longer the pipe, the more difficult it is for the motor & impeller to move the air (more pipe = more resistance to overcome). But 10ft of straight pipe is not going to have a significant impact (not compared to flex and corners).

Originally Posted by JimmyC

2) Is there any plans out there for baffles, and do they work well for knocking down the decibels, also would a baffle cause a back pressure problem ?

I assume that by baffle, you mean a muffler, not a Phil Thien separator baffle. I wouldn't worry about noise too much. DCs are pretty quiet to begin with, it's not like you're running a jet engine. Bill Pentz has a muffler design on his web site I believe. A muffler will add some resistance, but if you build it right not very much. So I wouldn't worry about back pressure.

Originally Posted by JimmyC

3) Has anyone here done anything like this with their set up, and how does it work ?

Not me, this is just my opinionated opinion But I think venting outside is the way to go. With a good separator, you'll have very little dust going outside, most of it invisible. Certainly not enough to be noticeable. You lose some heat/ ac if your have a conditioned shop, but here in NC, the climate is pretty mild, so it's not as big a deal as in say, Arizona or Vermont.

[FredP]

see partman's post. he's right on the money! noise shouldnt be an issue.... ummm.... why bother with a separator if your gonna blow it outside anyway? turn the pipe toward the ground and set a barrel under it. most of the chips will stay in the barrel [I think].

[ptt49er]

If I was going to vent it outside, I certainly wouldn't use a seperator. That's one of the benefits to blowing it all outside. (Atleast in my eyes it is).

[McRabbet]

If you (or anyone) find you need a muffler on the exhaust side of your DC system, here are some pictures from the ClearVue Cyclones Photo Gallery. First is the overall view of the muffler:


Next is a view of the interior and ends between the two layers of pipe:



Here is a description of the construction by John Randle, the guy who designed and built it:

Muffler construction is 1/2" hardware cloth wrapped with fiberglass window screen then wrapped with about a three inch thick blanket of fiberglass insulation. All of this was then wrapped with 6 mil polyethelene and pulled into the outer pipe. The end nozzles are 8" flue pipe fastened to the hardware cloth core pipe. The end caps are 3/4" MDF. The core pipe is 8" and the outer jacket is 12". The muffler is 60" long.

You can view all of Randle's photo gallery at http://www.gallery2.clearvuecyclones...VMax/rand4723/

Hope this helps.

[JimmyC]

Rob,

That is impressive, I might want to make one just because it looks cool.

Any sound muffle will help, and as far as blowing it straight outside that's not much of an option because I don't want to clean up the mess.

I think the muffler should work out well, unless anybody has better ideas, but I still have to figure out the air replacement thing.

Thank you everyone so far.

Originally Posted by McRabbet

If you (or anyone) find you need a muffler on the exhaust side of your DC system, here are some pictures from the ClearVue Cyclones Photo Gallery. First is the overall view of the muffler:


Next is a view of the interior and ends between the two layers of pipe:



Here is a description of the construction by John Randle, the guy who designed and built it:

You can view all of Randle's photo gallery at http://www.gallery2.clearvuecyclones...VMax/rand4723/

Hope this helps.

[Bigdog72]

Jimmy,

I wasn't too far off, was I?

[Alan in Little Washington]

I would discuss the exhaust pipe, shop temperature, and mufflers, (and baffle) but I fear, based on recent history, that the DC police will report me and thread police will edit or delete my post.

See post later on in this thread.

[JimmyC]

Originally Posted by Alan in Little Washington

I would discuss the exhaust pipe, shop temperature, and mufflers, (and baffle) but I fear, based on recent history, that the DC police will report me and thread police will edit or delete my post.

Don't be that way Alan, I look forward to your input. My main concern at the moment is getting make up air if in vents outside.

[Bigdog72]

"My main concern at the moment is getting make up air if in vents outside."

Crack a window or a door on the side opposite the exhaust.

[Tarhead]

Jimmy,
I would be concerned about any gas fired appliance (Hot water heater, HVAC heater, etc) sucking carbon monoxide back into your shop if you exhaust your DC to the outside. Just make sure you have adequate make-up air coming in. Also second Partman's concern about heating/cooling the outdoors. Other than that I wouldn't hesitate to blow it outside. Shortest run possible but with 6" pipe you would have to run it a loooooong way before resistance would be a concern. I would turn it on when I walked into the shop and not turn it off until I was finished and not worry about the muffler. Much less disturbing if you only turn it on and off once.

Mark (a slide rule guy in a Matlab world)

[JimmyC]

Originally Posted by Tarhead

Mark (a slide rule guy in a Matlab world)

Mark,
I love the mention of a slide rule, I too am a child of the slide rule and it changed over fast, my late brother who was two years younger than me was using a calculator in school.