I This A Good Idea? Has Anyone Tried This?

[WoodCzar]

As I slowly and meticulously build my Thien Seperator and try to find out the relationship of the height of the top lid down to the baffle, in relationship to the size of the duct work of the inlet, what about creating a radius`d wall from the inlet duct to the drop slot of the baffle? So if I`m using a 4" inlet, create a full height wall using 20ga flat stock metal.

I ask this as it appears the height distance of this opening varies from one builder to another? Mr. Thien appears to have little or no extra clearance from the height of the inlet, and I`ve seen others state great success with what appears to have double or triple the height of the inlet duct.

But the wall might give better cyclone action and divert more solids to the drop slot? Maybe, even a 1 or 2" high wall?

Know of anyone to try this?

[alan m]

im not sure I follow exactly what you mean. are you saying that the inlet should be flattened so its entering all along the wall of the separator . a 4" pipe is 12.56 square inchs. if you make it 1" x 12 and a half inchs you will increase the resistance  and losses from the transition.
I don't think it would be a good idea

[WoodCzar]

Hello Alan,

Guess it`s hard to explain but picture exactly the separator Mr. Thien has pictured here (http://www.jpthien.com/cy.htm). He pictures using 2.5" inlet elbow going down into the `plenum`. The inlet is placed over the 1/3rd section of baffle that is not notched. Also, it appears the inlet is positioned tight to the outboard side of the plenum (baffle chamber). Or, against the metal garbage can he has pictured.

From the pictures, the distance from the bottom of the lid to the top of the baffle is the same height of the 2.5 inlet fitting. Making the height of the plenum a little over 2.5".

My thinking is creating a full height vertical wall (full height of plenum), or even possibly a shorter 1" or 2" knee wall (thin material, metal flat stock)? Starting at the inboard side of his inlet, and follow the radius of that point, several inches away to the drop slot.

This vertical wall might help channel more material (fines) over the drop slot? And at the same time, depending on the height of the wall and positioning it, allowing the circular movement inside the plenum.

As I`m using 4" ducting, my numbers will obviously be scaled.

Hope this explains better.

[alan m]

I think I would need to see a pic of your plan

[WoodCzar]

Allrighty then, let me try this,

Topographical view of the baffle (not to scale):

- 240 degree Drop Slot as described.
- 4" inlet and outlet as described.
- 3 point mounts to the top lid not shown.
- Proposed `Wall` as I have been trying to describe, shown as dotted line.

Apologize for the confusion

[alan m]

that makes a lot more sense. that should work to stop the dust being sucked into the outlet before it has time to spin round. I wouldn't di this on a single height separator because the dust coming around from behind will end up hitting it and creating disturbance or just forces to the inside of it. its one of those things that you would have to test out and see if the benefits (if any) out weigh the negatives ( a few) .

I don't have much experience with this type of separator, I prefer the top hat design with a side inlet. its way better

[WoodCzar]

..................................... I wouldn't di this on a single height separator because the dust coming around from behind will end up hitting it and creating disturbance or just forces to the inside of it. .........................................

What is a single height separator?

[alan m]

if you build a seperater where the height from the baffle to the top is the same as the inlet dia (or height of rectangular transition) . that's single height .
over the year we have started to build with a higher separator . often 1.5 or 2 times the height are used. it gives the dust more time to spin round and drop out.

[WoodCzar]

Is there a reason Phil`s design shows the outlet, using a 45 degree fitting entering the top/center of the separator?

Seems most people go strait down. Coming in on a 45 would have some affect whether good or bad?

[alan m]

every bend you put in a dc system reduces its efficiency and increases resistance , and reduces air flow. be angling the inlet it means the change in angle of the dust is only 45 degrees ang not 90.. so it should be better

[WoodCzar]

every bend you put in a dc system reduces its efficiency and increases resistance , and reduces air flow. be angling the inlet it means the change in angle of the dust is only 45 degrees ang not 90.. so it should be better

I was thinking about the direction the outlet was sucking up. Instead of pulling the air strait up, it appears the 45 elbow would be drawing the air from the path of the incoming inlet? Maybe I`m splitting hairs here?

Also is the placement, or spacing of the three baffle supports at all critical? Looks like Phil`s design has the first one right after the inlet. Seems to be the best spot?

[alan m]

I agree. the 45 on the outlet is weird. while it would be better on the good side it would be worse on the bad side.