Newbie--first post...

[Mainebarn]

I've managed to go without a dust collector for 25+ years.  However, I just picked up a used, 1 hp, single-stage, Delta dust collector (AP400) and I quickly realized it would be highly advantageous to add a Thien cyclone.  I'm sure these questions have been asked a million times before, so I apologize in advance.  I've been reading posts, but trying to decipher the current consensus...

1.  Does it matter which way the cyclone is designed to operate—clockwise or counter-clockwise?  Is there a preferred direction and why?

2.  Is there a recommended size for the cyclone container for this particular 1 hp DC?  I was leaning towards a 32 gal Brute with a "top hat" Thien cyclone, unless your experience recommends otherwise...

3.  Is there an optimum size for the container (other than the amount of sawdust it can collect)?  If the container is sized too big or too small, will that affect the suction efficiency?

Thanks for your help.  Looking forward to build one!

[jdon]

Okay, I'll give my .02, as a relative newbie myself, until wiser and more experienced posters jump in to elaborate a/o correct.

1. With a "standard" separator, the air exiting spirals in the same direction as it enters. Common wisdom has been that if the spiral is the same direction as the rotation of the DC impeller, air flow will be improved to some degree, esp. if the distance between separator and impeller is short.

However, there are data which suggest that a straight (non-spiral) air flow produces the best impeller efficiency. To that end, now many builders are putting "air straighteners" in the exit port of their separators, to eliminate spiral air flow. For a lot of info, check out retired2's extensive thread.

2. I'm not aware of any hard and fast rules re: cyclone size and DC power, other than the larger the separator, the more it robs DC performance, so more power is needed. That said, 32 gal Brute seems okay for a 1 hp DC; I wouldn't go any larger, assuming you're making your separator diameter about the size of the Brute.

3. Other than size-DC performance penalty, no optimum size. With a top hat design, you can put a smaller diameter collector on a larger waste container. Container size then depends on convenience (weight, difficulty emptying, etc), available space, cost, etc. A taller waste container is better than a stubby one: as the dust pile rises and gets closer the the bottom of the baffle, more of it will be scrubbed and sucked back up into the separator.

[Mainebarn]

Thanks for the response.  I understand the desire to have laminar flow, when possible.

To be more clear, I've attached a photo of my DC showing clockwise impeller rotation (when viewed from the top).  I've also attached two examples of Thien top-hat cyclones--one that enters from the left (also "clockwise" direction) and one that enters from the right ("counter-clockwise" direction).  I would think the air exiting the top of the cyclone and going into the DC might still have some rotation.  Therefore, in my case, I would think I would also want the cyclone to be built with the "clockwise" orientation (air entering from the left side of the cyclone)?  Is this incorrect, or does this make any difference?

[jdon]

Okay, I assume that the intake to your DC is on the bottom (opposite the motor). Looking into the impeller from the intake, the impeller spins counterclockwise, so the common wisdom is that you want the incoming air to "match" the impeller spin. My personal image of it- as a non-engineer- is somewhat like trying to jump onto a fast moving merry-go-round" it's a lot easier and less traumatic to hop on if you run in the same direction as the merry-go-round is spinning. The left side separator would match your DC in this case.

It just occurred to me that rather than describing rotation as clockwise or counterCW, which depends on your viewpoint, it might be easier to describe and visualize by labeling flow as either right- or left- handed thread. Your DC matches left thread. Just a random thought.

[retired2]

Search:  "rotation"

[Mainebarn]

Thanks, R2.  I think I'm good with my previous questions.  However, got some more...

I'm thinking about making a smaller seperator first for my shop vac just to try it out.  Looking at Phil Thiens's lid separator on the metal trash can, I just wanted to verify two things:  (1) the PVC elbow shown does not actually fit directly into the angled 2-1/2 inch dust port on top of the lid.  It says it is just hot-glued to the lid.  Therefore, I assume it's just lined up with that opening in the lid--there's no real connection piece between them, correct?  (2) for the other angled dust port in the center of the lid (exit port)--is there any extension piece that drops below the lid, or is it just bolted to the lid with only the hole in the lid?

Thanks again,

Brian

[retired2]

Thanks, R2.  I think I'm good with my previous questions.  However, got some more...

I'm thinking about making a smaller seperator first for my shop vac just to try it out.  Looking at Phil Thiens's lid separator on the metal trash can, I just wanted to verify two things:  (1) the PVC elbow shown does not actually fit directly into the angled 2-1/2 inch dust port on top of the lid.  It says it is just hot-glued to the lid.  Therefore, I assume it's just lined up with that opening in the lid--there's no real connection piece between them, correct?  (2) for the other angled dust port in the center of the lid (exit port)--is there any extension piece that drops below the lid, or is it just bolted to the lid with only the hole in the lid?

Thanks again,

Brian

Sorry, I can't help with lid separators.  i never had a need and never built one.  In fact I haven't even followed the threads for lid separators.  Maybe one of the guys who has built one or more of them can help you.