new build questions

[JSP]

Hi,

I have a few questions similar to the one below, but different details.   I'm building a side inlet top hat for a steel drum.  Drum dia. is 17" x 25" high.  6" duct work going in the side and out the top.  3HP motor, blower (Griz.) .

The outlet duct goes straight up to the attic of the shop where the DC is located.   

What is the best size for the top hat?   Using 3/4 plywood material for the top hat bottom and top, with polycarb sidewall.  If I make the top about 22" diameter it will give me about a 2.5" overhang on the top.

Should the unit height be twice the inlet diameter? 

Just looking to get general demensions before I start to lay out the design on the material.   

thanks for your input!

JP

[alan m]

the wall of the seperate will have to line up with the barrel. if there is any kind of step you wont get seperation.

you could put some kind of funnel under the seperater to narrow it down to the barrel size.

the larger the diameter the better,

use inlet diameter x2 if you can. that should give better seperation

[tvman44]

So if the outer diameter of the drop slot (where the wall is) is a little smaller than the inside diameter of the barrel that should not be a problem?  I want the diameter of the bottom of the top hat a little larger than the barrel so I can route a slot in it to sit on the barrel.  Another question, I read that the thinner the the baffle is the better the separator will work, but I want something thicker to route a slot for sitting on the barrel so thinking about making a bottom of 3/4" with a larger drop slot and setting a piece of 1/8" hard board over that with the proper size drop slot.  How do most of you'll handle the bottom of the Top Hat?  8)

[rickc]

So if the outer diameter of the drop slot (where the wall is) is a little smaller than the inside diameter of the barrel that should not be a problem?  I want the diameter of the bottom of the top hat a little larger than the barrel so I can route a slot in it to sit on the barrel.  Another question, I read that the thinner the the baffle is the better the separator will work, but I want something thicker to route a slot for sitting on the barrel so thinking about making a bottom of 3/4" with a larger drop slot and setting a piece of 1/8" hard board over that with the proper size drop slot.  How do most of you'll handle the bottom of the Top Hat?  8)

What I did, and that's where I ran into trouble, was cut a 1/4 inch x thickness of hardboard, counter bore just inside the barrel diameter.  Then cut out the center.  Made a hardboard disc to fit c'bore, then cut drop slot.  then glued it in place.  Now to the trouble, I wound up with a step between drop slot and outer wall of separator, so when vac is turned off, something is left in the top hat, does not empty it's self.  But I can not see any reduction of separation.  Kinda messy when emptying, trash falls out, but separation is great.