Round to Rectangular Duct Evolution complete

[RonS]

Here are instructions for making a round to rectangular Duct Evolution.
I downloaded these instructions from the following Web Site:

http://joe.emenaker.com/DuctEvolution/index.html

I used joe's EXCEL and PDF instructions to create a drawing file using "DoubleCAD XT" which is a very good and free drafting package from this Web Site.

http://www.doublecad.com/ 

The drawing file is attached below.

The first image is showing the full scale print out of the drawing taped to a 12" X 24" X 24Gauge sheetmetal I used the full 12" height to capture a 2" section of round & Rectangular overlay outside of the fold requirements.



The second Image shows the sheetmetal being marked as the paper is cut away at the cut lines. The fold lines are marked at the ends and scaled later with a steel rule & knife.



The third Image shows the sheetmetal marked complete.



The forth Image shows sheetmetal cutout and ready to bend. I used 2 pieces of angle iron clamped to the bench to do the bending. The bottom section is the 2" Rectangular portion and the top section past the bend marks are for attaching the round inlet port with a finshed edge.



I got carried away during the bending and assembly process and forgot to take any pictures. The bending is an easy process since you only need to make very small 15 deg. bends. I used a "hook" joint and a 5" round insert too attach the transition together at the seam, then I hammered the seam closed and filled it with solder. The rectangular end I just rivited (Hammer & anvel not pop rivits) the ends together. I then attached (rivits) a 5" finished section from a 4" to 5" transition then taped up all the rivited joints.

The following pictures are the finished product and how it inserted into the tophat. I was lucky to get a press fit, when I installed the top the Evolution can't be removed.







I haven't used the tophat yet since I am still working on my duct work. I will post some more pictures on my top hat build and what I am doing with my duct work and 50-760 DC.

I ordered my duct work parts from KenCraft.com on Jan 4 and They shipped it Today 1/5. Good service...

Here is the DoubleCAD XT file:

ftp://

Ron

[Bulldog8]

Nothing to add, but "Nice Work." I also like the support for the hardboard baffle.

Steve.

[phil (admin)]

Beautiful work.  Looking forward to hearing your report after you've used it a bit.

[retired2]

Ron,

Congratulations on a really nice build.  It looks a lot like one I've seen somewhere!!

I'll thank you for all the people that might take advantage of your directions for an affordable home-built round to rectangular transition.  I could never find a way to prove the rectangular inlet works better, but intuitively, instinctively, and watching it work was enough to convince me.

I'm sure with the quality of your build, you are planning something clever for attaching and disconnecting the waste drum.  Are you planning to use and air straightener too?

Did you take construction photos of the separator during the build?  I'd sure be interested in seeing them if you have.

Regards,
Retired2

[Peter]

Okay, enough lurking.  :)

I'm designing a top hat separator for a HF DC unit. I'm gonna turn the impeller/motor unit on its side and abbreviate the run to the filter. Same old, same old.

I have already built a top hat thing for my shop vac, which I used 2" PVC inlet/outlet. It works. But it isn't a DC.

Originally, I had designed the thing for 4" duct, but enough pundits have complained (we all know their names) that 4" isn't big enough to move dust adequately, so I'm reconfiguring everything to 6". This despite the Woodcraft Supply class room I visited over the holidays that used 4" duct throughout and the claims by the staff that it "works great."

So my top hat design for 4" duct is 6" high from baffle to top plate, and the 4" to rectangular devolvement makes a nice narrow entrance into the separator, forcing the dust-laden air against the circumference wall. Well, I said to myself, I will just enlarge the opening to accommodate the 6" pipe.

My assumption is that the area of the pipe must be maintained regardless of the cross sectional shape. I didn't change the internal height (6") but just divided that into the 28+ square inches of the 6" pipe to arrive at a rectangle about 6" x 4.5". (My math was more precise, but that isn't the issue here.) What happens is that the edge of the rectangle nearest the center of the separator cylinder is REALLY close to tangent to the outlet (5" --  HF unit, remember?). I want to put in a bell mouth exit because the comments about that elsewhere here in these forums are compelling.

So my question is this:

What is more important? Concentrating dust-laden air near the outer circumference or maintaining a shallow internal height between the baffle and top plate?

[retired2]

Okay, enough lurking.  :)

I'm designing a top hat separator for a HF DC unit. I'm gonna turn the impeller/motor unit on its side and abbreviate the run to the filter. Same old, same old.

I have already built a top hat thing for my shop vac, which I used 2" PVC inlet/outlet. It works. But it isn't a DC.

Originally, I had designed the thing for 4" duct, but enough pundits have complained (we all know their names) that 4" isn't big enough to move dust adequately, so I'm reconfiguring everything to 6". This despite the Woodcraft Supply class room I visited over the holidays that used 4" duct throughout and the claims by the staff that it "works great."

So my top hat design for 4" duct is 6" high from baffle to top plate, and the 4" to rectangular devolvement makes a nice narrow entrance into the separator, forcing the dust-laden air against the circumference wall. Well, I said to myself, I will just enlarge the opening to accommodate the 6" pipe.

My assumption is that the area of the pipe must be maintained regardless of the cross sectional shape. I didn't change the internal height (6") but just divided that into the 28+ square inches of the 6" pipe to arrive at a rectangle about 6" x 4.5". (My math was more precise, but that isn't the issue here.) What happens is that the edge of the rectangle nearest the center of the separator cylinder is REALLY close to tangent to the outlet (5" --  HF unit, remember?). I want to put in a bell mouth exit because the comments about that elsewhere here in these forums are compelling.

So my question is this:

What is more important? Concentrating dust-laden air near the outer circumference or maintaining a shallow internal height between the baffle and top plate?

Peter,

Here's an oblique answer to your question.  You system is limited to the cfm's carried by your 5" separator outlet pipe, so the area of your inlet does not have to match the area of the 6" pipe coming to the separator.  You could reduce the 6" pipe just ahead of the separator to 5" without really incurring any measurable line losses.  That would increase the entry velocity (a good thing), and it would push the entry stream a little further from the outlet pipe (also a good thing). 

Regards

[phil (admin)]

So my question is this:

What is more important? Concentrating dust-laden air near the outer circumference or maintaining a shallow internal height between the baffle and top plate?

Simple enough question, here is a simple answer:  Keeping the incoming airstream near the outer circumference is more important than the height between the baffle and top plate.

[galerdude]

Here are instructions for making a round to rectangular Duct Evolution.
I downloaded these instructions from the following Web Site:

http://joe.emenaker.com/DuctEvolution/index.html

I used joe's EXCEL and PDF instructions to create a drawing file using "DoubleCAD XT" which is a very good and free drafting package from this Web Site.

http://www.doublecad.com/ 

The drawing file is attached below.

The first image is showing the full scale print out of the drawing taped to a 12" X 24" X 24Gauge sheetmetal I used the full 12" height to capture a 2" section of round & Rectangular overlay outside of the fold requirements.



The second Image shows the sheetmetal being marked as the paper is cut away at the cut lines. The fold lines are marked at the ends and scaled later with a steel rule & knife.



The third Image shows the sheetmetal marked complete.



The forth Image shows sheetmetal cutout and ready to bend. I used 2 pieces of angle iron clamped to the bench to do the bending. The bottom section is the 2" Rectangular portion and the top section past the bend marks are for attaching the round inlet port with a finshed edge.



I got carried away during the bending and assembly process and forgot to take any pictures. The bending is an easy process since you only need to make very small 15 deg. bends. I used a "hook" joint and a 5" round insert too attach the transition together at the seam, then I hammered the seam closed and filled it with solder. The rectangular end I just rivited (Hammer & anvel not pop rivits) the ends together. I then attached (rivits) a 5" finished section from a 4" to 5" transition then taped up all the rivited joints.

The following pictures are the finished product and how it inserted into the tophat. I was lucky to get a press fit, when I installed the top the Evolution can't be removed.







I haven't used the tophat yet since I am still working on my duct work. I will post some more pictures on my top hat build and what I am doing with my duct work and 50-760 DC.

I ordered my duct work parts from KenCraft.com on Jan 4 and They shipped it Today 1/5. Good service...

Here is the DoubleCAD XT file:

ftp://

Ron

Ron,
Nice job, nice photos, excellent execution. Thanks for sharing  8).

Gale