5", Rectangular Inlet, Bellmouth Outlet with Air Straightener, Top Hat Separator

[dabullseye]

just a thought but try 2 layers of wax paper under your top

[retired2]

just a thought but try 2 layers of wax paper under your top

That might work.  I'll give it a try, but I'm almost to the point where I don't expect to have much need to pull the top off.

Thanks

[phil (admin)]

just a thought but try 2 layers of wax paper under your top

That might work.  I'll give it a try, but I'm almost to the point where I don't expect to have much need to pull the top off.

Thanks

Wait, what is the wax paper for?

[dabullseye]

I was thinking that two layers so that if eighter the top cap or the removable bellmouth cap were to stick to the paper that they would not stick to each other :)

[phil (admin)]

I was thinking that two layers so that if eighter the top cap or the removable bellmouth cap were to stick to the paper that they would not stick to each other :)

Oh!  I get it.  :)

[dabullseye]

ok ive been thinking about a seal for the outlet pipe. im thinking about getting section of old inner-tube and cutting out a 1/2 the diamaller hole it and screw it down with a chunk of mdf or plywood and maybe using a hose clamp on the rubber. mabe if i could find a small inner-tube i could just cut it in half lengthwise and hope the valve stem dont cause to much problems

[retired2]

ok ive been thinking about a seal for the outlet pipe. im thinking about getting section of old inner-tube and cutting out a 1/2 the diamaller hole it and screw it down with a chunk of mdf or plywood and maybe using a hose clamp on the rubber. mabe if i could find a small inner-tube i could just cut it in half lengthwise and hope the valve stem dont cause to much problems

If you are considering the inner-tube and hose clamp seal as a means of keeping the outlet pipe adjustable or removable, it might be worth the trouble.  However, once testing is complete I don't see the need for that flexibility, and at that point I will be making my outlet pipe permanent.  I plan to attach it exactly the same way I did my floor sweep.

Here's a photo of the floor sweep showing a second collar around the outlet pipe to maintain vertical stability.  Before installing the snap-lock pipe I wiped a thin layer of Locktite PL Premium Polyurethane Construction Adhesive on the end of the pipe and the inside surfaces of the floor sweep and collar.  I wiped off the excess and allowed it to dry overnight.  Then I came back the next day and put a heavy bead of caulk around the collar and pipe.  I smoothed it with my finger, and allowed it plenty of time to dry.  Then it was painted (with oil based enamel).


 

[Don_Z]

How did you connect the bellmouth to the pipe?

[retired2]

How did you connect the bellmouth to the pipe?

Don,

My bellmouth tapers slightly at the neck.  That made it very easy to slip a piece of snap lock pipe over the end (see the first photo below).  Then I put a board over the end of the pipe and tapped on it until the pipe was snug enough that I could pick the assembly up without the bellmouth falling off. 

Initially, I planned to just use 3 equally spaced self-tapping duct screws to lock them together.  However when I looked inside the pipe there was an 1/8" gap at the top end of the bellmouth (due to the taper).  So, only the very end of the snaplock pipe was gripping the bellmouth.  I decided the screws would hold it together fine, but I would surely have air leaks unless I applied silicone caulk to either the inside, the outside, or both.

At that point I decided to skip the screws, and the silicone, and use Lab-metal to fill the interior gap.  Lab-metal seems to be a high tech (and high priced) body-filler that I use to smooth the inside of wye joints.  The second photo shows the Lab-metal worked into the gap around the bellmouth neck, and then smoothed with my finger.  The gap was large enough that the Lab-metal filler was sufficient to make it structurally sound and air tight. 

[Don_Z]

That's good enough for me. Thanks :)

[retired2]

WASTE DRUM LIFT TABLE


I am making a little progress on the lift table I am building to eliminate the need for disconecting hoses in order to empty the waste drum.   I considered a number of different mechanisms, but in the end I decided on axle-mounted wooden cam's.

In this first picture you see the four cams sandwiched together.  They are glued together with a paper joint.  One tap with a chisel and they are separated.  You can see the cams are shaped to provide 1" of lift in 270 degrees of rotation.





This is a photo of the lift assembly.  The cams are mounted on axels of 3/8" threaded rod.  Where the axel passes through the wooden frame there is a hub made of 1/2" steel tubing.  The tubing is hidden in the photo by the washers and double nuts.  The cams look a little darker because they have been given a good coat of paste wax.





Here the lift assembly has been installed in the DC stand, and 4 pairs of UHMW Polyethelyne guides have been added to keep the lift table moving in a vertical path.  Notice that the cams have been turned in opposing directions.  That means one axel will have to be turned clockwise while the other is turned counter-clockwise.  The objective is to eliminate lateral forces during the lifting action.





Here's a picture of the top side of the lift table.  The routed out donut matches the bottom of my Brute waste drum.  This depession centers the drum so that it aligns with the separator which will be suspended from above.





The is the bottom side of the lift table.  You can see the male half of the vertical guide strips.  Also, you can see four rub strips of the same material where the cams will contact the table. 





And finally, here's a photo of the table installed in the lift assembly.  I need to build or buy two handles to attach to the end of the axels for operation, but I gave it a quick try with a wrench and it works like a charm (but I didn't try it with a full drum yet).







Well, that is as far as I have progressed.  The next step is to suspend the separator from the DC frame.  It is little more complicated than just hanging it with some threaded rod.  If the separator is fixed with no movement, then the cams would require a locking mechanism to hold the drum up against the fixed position of the separator and to maintain a good seal.  I decided a locking mechanism was a complication I could do without.  So, I designed the cams with a slight amount of overtravel.  When they reach the 270 degree mark the table lands on a flat on the cam.  The flat is wide enough so that the position is maintained without any locking device.

However, with this arrangement, the separator must move up slightly to absorb the cam overtravel.  It must also maintain a slight downward pressure to ensure a good seal with the drum.  So, the threaded suspension rods will have to be spring-loaded at one end.  I don't think it is going to be very complicated.

Keep watching this space for updates and photos.  I will post them as soon as the work is completed.

FINAL PHOTOS

Here's the final photos of the waste drum lift mechanism.  The first photo shows the lift table in the up position and the drum engaged with the separator.  You can also see I have not finished the levers for turning the axles.  The second photo shows the spring-loaded suspension rods.  The springs can be adjusted to increase of decrease the downward loading.







So, how does it work?  Well, a lot better than disconnecting hoses to empty the drum, but not quite as good as I had hoped.  The problem is getting the top rim of the drum to line up with the receiving dado on the bottom of the separator.  There are two issues:

The first is that the top of the drum is not concentric with the bottom (I should have expected that), so my centering donut was centering the bottom, but not the top.  I was able to correct this problem by moving the separator slightly off center, and then marking the drum so that it is always installed in the same rotation.

The second problem is the cams must be rotated equally or the drum will raise with a slight tilt and miss the dado.  This just requires keeping an eye on the top of the drum as the table is being raised. 

Both of these issues could be improved by adding a heavy chamfer to both sides of the receiving dado on the separator.  That would require cutting the dado deeper or adding another ring with chamfers to the existing dado.  Unfortuantely, that extra depth would require replacing the cams with new ones that have a higher lift.

[dabullseye]

humm i thought u said u would never use mdf again

[retired2]

humm i thought u said u would never use mdf again

Actually, what I said was "Remind me never to use MDF again."  No one called! :)

The problem is I still have some of it on hand, so I will probably keep burying myself in silt until it is gone.

[Don_Z]

I used JB weld Putty and was able to connect it to the pipe. I then repositioned the pupe so that the bottom of the bellmouth was 3" from the top. It works fine, but I am still getting just a little bypass.

[retired2]

I used JB weld Putty and was able to connect it to the pipe. I then repositioned the pupe so that the bottom of the bellmouth was 3" from the top. It works fine, but I am still getting just a little bypass.

Don, in all my posts I have been stating the position of the bellmouth as measured from the top inside of the separator.  It just made it easy to mark dimensions on the exit pipe.  However, the distance from the baffle is a much more relevant reference point.  So, for what it is worth, my bellmouth is now 2-1/8" above the baffle.  It was 2-7/8", but I changed it for testing.  I can't see any difference in performance between the two.

As I recall, your build is very similar to mine, but I am getting no by-pass.  Maybe your problem is air velocity?  Got any leaks, even small ones?  Are there any major differences between yours and mine?  Did you use a rectangular inlet?  I'm convinced that is a big plus.  I think round inlets are prone to turbulance where the air streams merge and an upset like that can easily contribute to by-pass. 

I think a round to rectangular transition could be fashioned from wood with no exotic angled cuts and you would get 90% of the benefit I am getting from my fab shop version.