Need help with 5.75" intake Dust Separator

[George Courson]

Hi all. I was given a blower to use to build a dust collection/separator system.
IMG_20161203_212531.jpgIMG_20161203_212451.jpg
The intake has a 5.75" intake collar. The manufacturer states that I can not reduce the intake size without stressing the motor and burning it up, so I'm stick using a 5.75" intake hose for pulling dust into a separator.

I've tried to check the links that I could find, doing a search, but they are out of date. So I'm asking for some help with the math.

What diameter does the separator need to be and how far down does the 5.75" tube need to go into the separator?

I'd like to put a helix in it to direct the dust and shavings down into the cone, but I have no idea how big of a container I need to have around the 5.75" exhaust tube, the distance between the helix and exhaust tube, or how fare the exhaust tube should go into the container, and the length the cone has to be, if any....

I'm going to mount the blower on the wall and use a flexible tube to connect it to the dust collection unit. Between the the collection unit and blower, I plane to install a dust filter, so I can redirect the exhaust air to cool the motor on the blower.

[George Courson]

Note: I live in Lima Peru, so I don't have access to the industrial stuff that ya'll have up there. The import cost to get it down here on my budget, pretty much means I can't get it.

[Jamie Buxton]

I'm confused. "Separator" is somewhat a general term, so maybe I don't know what you mean by it. For instance, a cyclone is a kind of separator.

Questions....
* Do you plan to suck all your dirty air through this separator, and then through the blower? Or will the blower push the dirty air through the separator?
* What happens to the semi-clean air? Will you run it through a filter, and release it into the shop? Or will you just blow it outside?

[Andy Giddings]

George, the collar on the intake looks like its outside diameter is totally different to the actual fan intake (in other words, it looks like there is an abrupt change in diameters that the air has to flow through). Is the fan tube also 5.75 inches or is it a lot smaller (as it looks)? My concern is that you are going to get a lot of debris building up in an abrupt change like that and may even get a blockage.

In terms of the separator, are you talking about a Thein baffle or a cyclone - not clear which type of separator you want to use?

[George Courson]

I was able to find two cardboard barrels today.
IMG_20161204_140712.jpg it's 16' tall 13.5.jpg with a 13-1/2" diameter. the 2nd barrel is
IMG_20161204_140718.jpg 17-1/2" tall 17-.25.jpg and 17-1/2" in diameter.
I'd like to use the smaller 16" barrel as the separator. Either a vortex or baffle separator. Whichever would work best.

The larger 17-1/2” barrel will be where the dust-shaving get dumped.

Question is, will the 16” deep barrel work better as a baffle separator or a vortex?

As a baffle separator, would it work better with a Helix spiral directing the dust/chips downward?

If I have to build a cone to make a spiral vortex separator, I’ll be able to use the smaller barrel to house a semi-truck canister air-filter to separate the fine dust that gets picked up by the exhaust pipe, so the air going into the fan and ported out is clean.

As to the intake:
IMG_20161204_140634.jpg it's 5-3/4". The white collar is the exhaust. I'll be redirecting it to cool the motor, as it's for 50Hz and the power here is 60Hz. I know I'll have to get the motor re-wound sooner or later, but the cooler I can keep it, the longer it will last. Being disable and on a limited budget, you have to use what you can get.

[Bruce Wrenn]

The semi truck filter will QUICKLY clog and become useless. A Thien baffle is a great place to start, but will need something with a larger radius. Construct your baffle using the "Top Hat" design.

[Brian W Smith]

We've used truck filters with VG success.BUT,only because of size.Meaning,on very small portable units...and after the separator,which are inhouse made custom sized cyclones.

Further,they need to be cheap...which if "buying",over the counter,isn't.Next up when space requirements dictate,is long/tall/small diam.high quality bags.Very effective for fines.And easily can have automatic blow down features designed in.But does require a bag "house".Not cheap,very effective,and utilizes "vertical" space.

Work on getting the best separation possible first.Then step up your ductwork,eliminating ALL possible flow and restrictions as possible.I just think these two need attention first.The filters for me at least are then more about "packaging".Good luck with your project.

[George Courson]

I'm actually using the area of my apartment that should be the dinning-room. I'll only have 1 tube for dust collection, so I won’t need to run any duct-work. I can remove the 2 white shelves to put the separator and air-filters there.
IMG_20161205_114707.jpgIMG_20161205_114720.jpg
What I need help with the most is the math…. meaning, with a 5.75” exhaust tube feeding into the intake of the blower (as well as for the suction hose), can someone tell me how deep the separator should be, how big around, and how far into the separator the tube needs to extend-that feeds the intake to the blower…

I drew up a TopHat design in can using the smaller barrel, but the intake for dust overlaps the exhaust tube by about a third. Maybe a little less.
Finding an adapter that transitions a 5-3/4” tube into a rectangle…. None existent here. Having one made-impossible. So, I have to feed the pickup tube as a tube, into the separator.

So, does the fact that it overlaps by about a third break the efficiency? I could use the larger drum if needed and the smaller one for filtering the air for the fine dust.