Acrylic and Lexan tall tophat (Help!!!)

Started by manoverboard, January 23, 2015, 10:06:34 PM

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manoverboard

Hello All
     I've been wrestling with the idea of a top hat that you can see into made from acrylic and Lexan. The plastics guy in town says that with Weldon 16 you can glue both types of material together. There is about half a sheet of cell cast 1/2" acrylic that has been taking up space in the garage for awhile now(the other half was used to make a windshield for my utv)
   A couple of Questions I cant find the answers to
          1.Do you loose more cfm with a taller ,say 8-10in ,top hat than a 5 or 6in? I'm pushing it as it is with the 1 1/2hp dc.
          2. Can the vortex chamber of the separator be a smaller diameter than the trash can?Without impacting separation much. I can only get 3 - 18in circles from the acrylic I have and want to use a 32 gallon brute can.
          3.My dc1100rc has  2-4in inlets when I take that off its a 6in port does anyone know of a short pipe or fitting(height is a issue)that reduces down to a 5in
          4.What would be the max thickness of the baffle if its beveled ? From what I've read 1/2in is to thick.
    The Bones of my system are a underpowered jet dc 1100 rc bought second hand it has the 2 micron canister,thought about the hf 2hp but don't trust some of their tools for every dayuse (Prolly just me there are good reviews)   
   Ducts are 4in s&d (Trying to stay cost efficient)ran with all 22.5degree and y's. The longest run is up 4 ft then across 20ft along the ceiling and finally 4 or 6ft to my ras and mitersaw.All the heavy dust producers are within 15 feet of the collector ie jointer, planer, lathe
   This is a one man shop and only one gate opened at a time .Ive remounted the motor and impeller on its side  to go directly into the canister inlet cone welded it to a frame.In the summer months I think I will vent it outside into a bucket of water bypassing the canister filter.Any ideas appreciated .
Thanks

retired2

#1
I have a 1-1/2 hp Delta DC that was rated as one of the best in a test several years back.  It is rated at 1200 CFM. Actually, none of these published numbers mean very much without a fan curve that shows actual performance at various SP.

That said, I think you are going to be very disappointed in the pick-up at your RAS and mitersaw.  I have a band saw that is just a little farther from my DC than what you are planning.  The pick-up is not that great, and the band saw is one of the easiest tools in the shop to contain.  By contrast a RAS and mitersaw are two of the worst.

My system is plumbed with 5" metal pipe, so my line losses are less than what you will see with 4" plastic pipe.  I have a 4" port on my old Powermatic bandsaw, but at that distance I am just not moving enough air to do a good job of keeping it clean.  Frankly, you will have trouble with a mitersaw if it is 4' from your DC!

manoverboard

Guess i will leave the shop vac under that bench to help out.Not that big of a deal its just my shop is to full of equipment to drag a shop vac around.

retired2

#3
Quote from: manoverboard on January 24, 2015, 02:46:28 PM
Guess i will leave the shop vac under that bench to help out.Not that big of a deal its just my shop is to full of equipment to drag a shop vac around.

Well, if you still think you are going to proceed then here's my responses to your original questions:

1). I don't think anyone has done any measurements on two separators that are identical except for height.  So, the correct answer is no one knows with certainty.  However, quite a few people have built 2x high separators and are happy with the performance - and some say it performs better.  Again, I'm not sure there is hard data to confirm or quantify that.  But if I were building another one, I would build a double high on the premise that it is not likely to hurt, and there is a good chance that it could help.  Either way a top hat separator imposes a significant penalty - my data shows 35% - 40%.

2) Yes, the separator diameter can be smaller than the drum.  There will be a small performance hit, not because of the diiference in the separator and drum diameter, but because a smaller diameter separator has more resistance than a larger one.  Phil just commented on this question to another writer very recently. 

3) You can find metal reducers at any HVAC supply house, and you can find the very common ones at Lowe's or Home Depot.  6"x 4" and 6"x5" are readily available.

4) There is no problem with a 1/2" thick baffle as long as the edge at the drop slot is thin, and the chamfer to accomplish that should be as long as you can make it.  Using a 45 degree router bit may be O.K., but a longer bevel would be better.

One last comment.  I think your desire to use your clear plastic for your separator is driving you to some compromises that are not in the best interest of performance.  As  I just recently confirmed, it is tremendously valuable to see in a glance what is going on inside your separator.  It is equally important to be able to easily remove it and open it up when disaster strikes.

Holbs

in regards to ducting, consider saving some footage by not running it up, over, and then down.  But instead, like how I did, horizontal at the same height of your baffle inlet.  My 6" HVAC ducting is 54" off the floor around 2 of my walls, while #3 wall is more dedicated to storage and misc, and #4 wall of my garage square is my roll up door.  So that is a total of...  30' length with only 1 45to45 bend that will be my main supply line branched off to 4 6"x6"x6" wye's and 2 6"x6"x4" wyes.  hay... it works :)  Does it get in the way?  nope.  And gave me a good reason to put a 30' long shelf above the ducting.