A question on the input to the baffle . . .

Started by jtm065, February 02, 2008, 06:49:32 PM

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jtm065

Phil:

I have an older Cincinnatti Mfg. dust collector that is an aluminum top that fits on a garbage can.  The fan says it's rated at 450 CFM.  The issue is that a very high percentage of the dust ends up in the cloth bag as opposed to the garbage can.

The 4" intake is on the perimeter with a sheet metal flap that attempts to start the dust into a swirl.
The 5" fan intake is also on the perimeter with a 6" sheet metal collar around it that drops 6" down from the lid.

I've been reading this site and your posts on other WW forums and I'm interested in building a separator lid.  As I look closer at the fan housing I see why it's on the perimeter - if you center that fan intake on the lid the fan housing blocks most of the lid - enough that you couldn't have the 4" intake enter through the top. 

I have a 30 gallon steel garbage can.  I'm planning on building a lid and mounting the fan housing on the center of the lid. 

Now the question : Is there any reason why I couldn't have the 4" pipe enter the can THROUGH THE SIDE of the can in a tangential manner so that  I don't use an elbow?  I'm thinking of making a "double" lid.  The first layer holds the baffle below the inlet pipe coming through the side of the can.  The second later sits on top of the and holds the fan housing.  I'm assuming that I can set it up to remove the lower baffle "around" the bit of pipe coming into the can when you need to dump the sawdust out.

From what I see of cyclone designs on the web, the inlet ramp to the cyclone looks like what I'm describing. They are even square. If the inlet is square that would be less trouble getting the sheetmetal cut to fit tightly - less trigonometry involved . . .  An HHAC duct guy could figure out how to cut a neat round to round transition - I'd be using a lot of pop rivets and foil tape.

I'll be back eventually to post some results/pictures.

Cheers

Jim M
   


phil (admin)

The only reason(s) I have not tried this are:  (1) Limited material left in the sidewall of the can once you cut into it.  (2) I'm not that great at metalworking.  (3) I thought it may be tricky to lift the top/baffle out and around an inlet that is attached to the can itself.

From your description is sounds like you plan on mounting the baffle to the can instead of the top (to accomodate #3 above).  So #3 may not be much of an issue.

In any event, I don't think any of these items is that big a deal.  I was just doing it the easiest way I could manage.

jtm065

#2
Phil:

I didn't really explain what I was thinking about doing.  What I'm starting with is a Cincinnati Fan 2 stage dust collector.

Something like the 2 pictured at the bottom of this link: http://www.cincinnatifan.com/products/dust-collectors/dust-collectors-new.gif

A LARGE percentage of the sawdust ended up in the bag, which is a pain to empty.

What I have done is :

1 - Buy a 30 gallon steel can from HD, along with some 4" snap lock pipe and 2 4" steel elbows.
2 - I cut into the can 1" below the rim so that the 4" pipe enters the can tangentially.  This pipe does not protrude into the can.  The joint is pop riveted and sealed with foil tape and vinyl adhesive caulk. The pipe has about 10" of pipe outside the can and has one of the steel elbows.  I figure a steel elbow will be less restrictive than the flex hose hanging off the pipe.
3 - I built a "standard" top plate and baffle with a 6" hole in the center of the top plate.
4 - I removed the aluminum plate from the fan and built another round plate with a 5 1/4" hole in the center of the fan plate. I went with 2 separate "plates" because the fan weighs a bit and lifting the fan out of the can would be a hassle.  Setting it down on the baffle wouldn't be too good either.

I buttoned it up this evening and gave it a quick test run.  I ran a 2 gallon bucket of sawdust into the inlet slowly, and very little if any of the sawdust ended up in the bag.  I will be doing some work this weekend and will post a follow up review with some pictures shortly.
I'm happy so far.

Cheers

Jim

(Modified to better explain the linked pictures)

phil (admin)

Oh!!!  I had mistakingly thought the inlet extended into the can.  Okay, let me know how it works for you, I think it will work gangbusters.  Post some pictures of the finished project, too!