Improving airflow in DC with Wynn canister

[David Romano]

I have a Jet DC 1200 with a canister filter from Wynn environmental. The top of the separator ring is beveled such that it is lower in the center where the hole is. See 1st photo.

When the canister sits on this surface, a wedge shaped gap is formed between them. The problem with this is that the air does not exit the separator ring straight up through the hole as you'd first expect. Instead it swirls out at a very shallow angle, and is forced right into that gap.

To cover this gap, I bought a 10" to 8" reducer from the local big box store for about 7 bucks. The hole in the bottom of the canister is 12" but this is not critical to match. The hole in the separator ring is 9.25". Probably a 12" to 9" reducer would be best, bu these are not readily available. I cut the reducer down to length and used some good weather stripping to make a good seal. See 2nd photo

To keep the ring in place, I cut 2 notches to accept a cross bar located on the bottom of the canister, which is part of my flapper. The 1" bar fits in the notches shown in the 3rd photo. The bottom of the canister is shown in the 4th photo.

The canister holds the spacer in place. With the gap eleminated, the air flows easier up into the canister. I experimented briefly with different length spaceers. If the spacer is flush with the hole in the separator ring, the air flows the easiest. If it is longer, then is acting as an extended outlet pipe, and turbulence is increased. You caould speculate that this improves separation, but with Phil Thien's baffle, I don't think I need better separation.

David

[Mike Goetzke]

Looks like another easy mod I can copy. Have you done any type of test to verify increased air flow?


Mike

[Rob Blaustein]

Interesting modification. I also have a DC1200 and Wynn filter combo. Can I ask what type of plastic bags you use for the lower portion? I got some from Wynn, but find that they don't fit--I have to stretch them too much. I wonder if they were made for a DC1100, though I'm not even sure if that DC is a different size. --Rob

[Don Abele]

Interesting modification. I also have a DC1200 and Wynn filter combo. Can I ask what type of plastic bags you use for the lower portion? I got some from Wynn, but find that they don't fit--I have to stretch them too much. I wonder if they were made for a DC1100, though I'm not even sure if that DC is a different size. --Rob

Rob, the DC1100 ring is only 17.25 inches, the dc1200 is 20". The bags I got from Wynn fit my 1100 perfectly.

Be well,

Doc

[Don Abele]

David, I don't understand how you came to this conclusion or exactly what this is doing.

I modified my DC1100 two years ago, but in the exact opposite direction. If you look at my photo, I attached a neutral vane inlet to bring the air stream into the ring at the center of it (to reduce turbulence). This was an idea I got from Bill Pentz that he uses for his cyclone design.

I also added a down draft tube into the lower bag. The tube forces the incoming air to circulate into a circular motion down into the bag. As it rotates around the tube it slows down and the particulates fall out of suspension. I get very little dust up into my filter.

When I tested it, I used a smoke machine (borrowed from work) to get a better idea of what was happening. Without my modifications, the smoke came straight out the top of the separator ring (without the filter installed). When I installed the down draft tube, it came out of that hole in a solid plume straight up (much more consolidated). The other dramatic discovery was that without modifications the smoke just swirled around like a tempest in the lower bag. With the modifications, it swirls in a very organized cyclonic motion. I could not test with the canister installed as I wouldn't be able to see anything.

I'm all about modding to make things work better, and I'll try yours out as well...I just don't understand it. Can you clarify what it's doing and how?

Thanks,

Be well,

Doc

[Mike Goetzke]

Rob, the DC1100 ring is only 17.25 inches, the dc1200 is 20". The bags I got from Wynn fit my 1100 perfectly.

My DC-1100C has a bottom ring ID of over 19" - maybe larger due to the canister.

Be well,

Doc

Without my modifications, the smoke came straight out the top of the separator ring (without the filter installed). When I installed the down draft tube, it came out of that hole in a solid plume straight up (much more consolidated). The other dramatic discovery was that without modifications the smoke just swirled around like a tempest in the lower bag. With the modifications, it swirls in a very organized cyclonic motion. I could not test with the canister installed as I wouldn't be able to see anything.

Don - w/o mods you say the smoke came straight up and w/ mods straight up the pipe. This sounds like the smoke exited in a similar manner. Can you clarify?

Also, smoke particles are heavier than air (I think). So, I almost think your test w/o mods where the smoke stayed in the bag is the best result. Or am I all wrong???

Thanks for your pic. -
Mike

[Jason Beam]

Rob, the DC1100 ring is only 17.25 inches, the dc1200 is 20". The bags I got from Wynn fit my 1100 perfectly.

Be well,

Doc

Not all DC1100 rings are created equal. Mine is 19.5" and the 20" bags are just a little too snug for me. I got my bags from jet and just keep recycling 'em. At $6 a bag, they're gonna get used till they disintegrate!

[David Romano]

Interesting modification. I also have a DC1200 and Wynn filter combo. Can I ask what type of plastic bags you use for the lower portion? I got some from Wynn, but find that they don't fit--I have to stretch them too much. I wonder if they were made for a DC1100, though I'm not even sure if that DC is a different size. --Rob

I just use contractor clean up bags inside the Jet cloth bag. Works great.

[David Romano]

Looks like another easy mod I can copy. Have you done any type of test to verify increased air flow?


Mike

No, no test, but if you run the DC with the filter off, you'll see what I mean by the airflow. Then mount your canister without the bottom bag, look up through the separator and see the gap. I'd like to get a piot tube to do some testing of a few things. Maybe someone will do it for us.

David

[David Romano]

Without the modification I'm suggesting, the air is being forced into a dead end. This is the worst kind of turbulence since the air must make a 180 turn and there is no purpose served by it. It would be like blowing air into a coffee cup. With the modification, the air is deflected up into the canister. The total amount of deflection being much less.

David

[Don Abele]

Mike, the inside diameter of the ring is 17.25 - I know that for certain because the Wynn canister is 17.5 and it took a little "persuasion" to get it to fit in. But the bags that Wynn sells fit perfectly for me. When I get home on Friday, I'll measure the OUTSIDE diameter.

Without the neutral vane and downdraft tube the smoke came out the top opening in the ring (heading towards where the canister would be) in an uneven manner. Fast here, slow there, very turbulent - but it did come up straight. With the mod, it poured straight up like water coming out of a tube, no turbulence at all.

Be well,

Doc

[Don Abele]

Without the modification I'm suggesting, the air is being forced into a dead end. This is the worst kind of turbulence since the air must make a 180 turn and there is no purpose served by it. It would be like blowing air into a coffee cup. With the modification, the air is deflected up into the canister. The total amount of deflection being much less. David

David, I really am trying to understand this, but I'm just getting more confused.

When the air enters the ring it blows down into the bottom bag (because of the overhang on the top of the ring) then back up through the hole in the ring into the top canister. When it hits the top of the canister it deflects back down and eventually exits through the filter.

So where does the gap between the canister and the ring come into play? If there is a gap there where it won't fit tightly, that will cause some turbulence as the air rushes past, but I can't imagine it to be very much as the air has already slowed and is exiting the filter.

Or am I completely off base with what you are describing? I really don't understand (of course, me being a visual kinda person doesn't help me ).

Be well,

Doc

[David Romano]

David, I really am trying to understand this, but I'm just getting more confused.

When the air enters the ring it blows down into the bottom bag (because of the overhang on the top of the ring) then back up through the hole in the ring into the top canister. When it hits the top of the canister it deflects back down and eventually exits through the filter.

So where does the gap between the canister and the ring come into play? If there is a gap there where it won't fit tightly, that will cause some turbulence as the air rushes past, but I can't imagine it to be very much as the air has already slowed and is exiting the filter.

Or am I completely off base with what you are describing? I really don't understand (of course, me being a visual kinda person doesn't help me ).

Be well,

Doc

Don,
Perhaps I was getting a bit ahead of myself. I've been very involved with the testing and discussion of the baffle designed by Phil Thien
http://www.cgallery.com/jpthien/cy.htm

When I observed the airlflow exiting at a shallow angle, I had the baffle installed in the separator ring and I lost sight of that when I started this thread. It is this shallow angle that causes the air to blow directly into the gap, not just rush past it. I'll take your word for it that in the stock configuration it comes straight up through the hole. At this point though, I can't imagine not having the baffle and so I'm trying to address whatever issues might have arisen from using it.

The cansister is 17.5" OD and 12" ID at the bottom. The ID inside the the foam gasket is bit less, leaving about a 1.75" flat spot around the bootom of the cansister. It is this area that leaves the gap I mention. After mulling it over a bit more this morning, probably an even better (and simpler) solution is just to fill the gap with low density foam, like a thick, wide weather stripping. I will try this later on.

What I'm curious about now is which design is a better compromise, the one you show or Phil's baffle. You show a neutral vane and an outlet pipe that extends down toward the collection bag. Phil's baffle works completely different. Neither are as good as a true cyclone, but both improve separation. I wonder which has the bigger impact on airflow.

David

[Mitchell Andrus]

Interesting modification. I also have a DC1200 and Wynn filter combo. Can I ask what type of plastic bags you use for the lower portion? I got some from Wynn, but find that they don't fit--I have to stretch them too much. I wonder if they were made for a DC1100, though I'm not even sure if that DC is a different size. --Rob

I use the black 3 mil 'contractor cleanup' bags from the Borg. My canisters have gotten pretty clogged and I haven't had a blow-out yet.

[Glen Blanchard]

What I'm curious about now is which design is a better compromise, the one you show or Phil's baffle.

I am wondering which design does a better job of keeping the fine dust from clogging the filter. I just ordered my Wynn this week, so I'll have to implement one of these soon.