cannibalizing a 1 1/2 hp delta dc system
woodhoarder | Posted in General Discussion on
I am trying to eek as many cfm out of my delta DC as possible. I know that sharp bends are terribly inefficient, and there are 3 in my system right now; one where the main trunk drops from the ceiling, and another where the drop enters the vertically mounted impeller on the DC. Then delta “engineered” a third from the outlet of the impeller to the mounting ring for the filter bags! I am thinking of re-arranging the parts of the collector as shown in the attachment to improve efficiency.
Any and all thoughts about this set-up are appreciated!
Thanks,
Tony
Replies
Very interesting! Thought provoking!
I like the 8" drop tube to the separator and the 8" outlet to the bags - seems like that would reduce backpressure.
I need to think about this.
P.S.
One Problem. I expect that an 8" column of air blasting at approx 3100 fpm into the bottom of the separator barrel will NOT allow debris to settle out.
Any ideas?
I can tell you that the blower on a Dewalt planer (375???) will blow the chips thru 5' of 2" flex, 10' of 4" flex, 20' of 3" PVC with 3 90 degree bends, a 55 gallon cyclone, and into the bottom of chip collection bag.
You really want to keep the air flow down.
Nothing wrong with the placement of the motor and fan. They don't much care which way they point.
It's going to be pretty hard to keep a good seal on the "separator", since you will be emptying it a lot. I would think about putting the separator on the intake side of the blower so that the slight negative pressure would help it seal, and you would avoid sending some of the solids through the blower. Most industrial systems I have been around had the blower in the cleanest air possible.
Don't be surprised if a trash-can sized separator doesn't do much, especially if you dont control the airflow. I would at least put the inlet near the side of the barrel and take the air out from the center and put in a little rudimentary baffling on the lid to give the material a chance to drop out.. You can always build a homemade cyclone later on......
Michael R
Good points. The separator I want to use is a 50 gallon fiber board drum with a metal lid with a lock ring on it, so that should keep the pressure from "lifting the lid". As far as the in flow problem is concerned. What if I put a smooth bend in the drop pipe, and brought it into the side of the drum near the top, at a tangential angle to the curve of the wall, and attach the 8" flex to the center of the lid, as you say? Wouldn't that essentially be a "poor man's cyclone"? I realize that as the barrel fills, the airflow inside it will become steadily less efficient.
Your lid might not pop off, even though its surface area is around 300 square inches, but it will leak a lot more dust if it is pressurised than it will if it is under a slight vacuum. On the other hand, I'm not sure how much vacuuum a fiber drum will stand. We're only talking about a few inches of water column, but the forces do add up. Ever tried carrying sheets of plywood on a breezy day? They do make steel drums with the same sort of locking ring.
Directing the pipe as you describe might help some. It may have a better chance if, in addition, you let the outlet tube stick down into the drum about 10 or 12 inches. That might let you get the benefit of a little centrifugal action. Take a look at some of the plans for homebuilt cyclones on the Web and you'll see what I mean. No matter what, you won't be able to let the separator get very full before it becomes ineffective, but it will most likely help a bit. Making separators work is a little more complicated than it looks. What you are planning will be better than nothing, but it won't be very efficient. That is not to say don't bother to do it. If I were in your position, I'd try something similar, but given half a chance, I'd build or buy a proper cyclone. Anything to keep from having to mess with those dust bags!
Michael R
First of all, thanks for all the info. I agree, a cyclone would be ideal. I just don't think there's a way to incorporate my current motor/blower into a cyclone system. I came up with that configuration primarily because I don't think the motor I have is built to run mounted vertically, (i.e. on top of a cyclone tower) and I have no idea how to find out if it is. Also, I'm working with parts from a delta 50-850, which is only 1 1/2 hp and 1100 cfm. From what I've read so far, both on Bill Pentz's site and others, that is just not enough power to run a Cyclone.
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