Cyclones, a design ???

[GEDunton]

Prodded on by the many cyclone posts, I am again considering redoing by dust sucker system. (Have this thought a couple times a year, just haven't moved on it. ) From what I'm reading, I did it wrong the first time, too much 4" ducting instead of 5" or 6". That's not too hard to redo, except the one 20 foot run under the floor, now covered with 6" of poured concrete. I figure that run just has to stay. Its for the TS pickup in the middle of the shop.

I'm running a two horse bag system, so am guessing that I can use the same motor unit and impeller. Its a Grizz 2hp. Correct me if wrong there. I know there are better, but its bought and paid for.

Now the real question: I see lots of info on Terry's setup. From all thats posted, top drawer. But I have this affliction-I just don't accept things without questioning whether there is another way. So here's my quandry: most units are a push thru system, the impeller is ahead of the cyclone and all the junk runs thru the impeller into the cyclone. Now if the impeller set up was down stream from the cyclone, a pull thru system, then only the air to the filters with hopefully minor dust would be passing thru it. Seems like that might be better, but I can't confirm.

Experts please advise.

[Bill Pentz]

GEDunton,

In theory a pull through and push through would give the same performance with an ideal system. In today's severely underpowered systems as is yours with that 2 hp Grizzly trying to suck through a 4" buried pipe, you have a much bigger challenge.

I spent a few months helping resolve a similar issue for Steve Cater, another fellow engineer and woodworker. (http://cnets.net/%7Eeclectic/woodworking/Cyclone/Steve%20Cater%20Cyclone%20Project.htm) and we were successful. It did cost tossing the blower and much of the ducting to get enough static pressure to make up for the too small ducting.

Take a look at that and let me know if it helps.

bill pentz