Absolutely baffling!

[JimmyC]

Thank you Scott.

Jimmy

 

[Bas]

I looked at the picture too - not sure what you're referring to! Of course, having OCD I'm totally flummoxed.

But, in case this is what you meant - the elbow sits about halfway the outer ridge. I did this on purpose, since the elbow is angled outwards. The thought behind this was that by blasting the dust against the side of the can, it would slow down and fall to the bottom. With the addition of the baffle, this is no longer needed. I can't move the elbow, so I shortened the distance the dust has to travel before hitting the drop slot.

I also experimented with the pipe length. I added a piece to the outlet (center pipe), which worsened things. I also added a piece in inlet (elbow), which also worsened things. The picture shows the elbow with the extra piece.

If that's not it, I just bored everyone to bits for nothing

 

[erasmussen]

Either the picture is reversed, or the air flow is backward, it should spin the other way. every thing in the northern hemisphere spins the same direction, hurricanes, toilets, bath drains, tornadoes, cyclones. vacuum cleaners, etc.

 

[Bas]

Never thought about that. Inside my DC, the dust spins counterclockwise, but that's because the inlet points that way. But you're right, it would be more 'natural' if the elbow pointed the other way. But the picture is not backward. Only the builder

I think I'll ship mine to a woodworker in Australia.......

 

[junquecol]

Either the picture is reversed, or the air flow is backward, it should spin the other way. every thing in the northern hemisphere spins the same direction, hurricanes, toilets, bath drains, tornadoes, cyclones. vacuum cleaners, etc.

DC cyclones are built with either right or left inlets. The vortex effect you are describing has to do with the rotation of the earth. This rotation is mechanically induced. Thought question: If a ship has a northern hemisphere toilet, will it work in southern hemisphere? What happens to a cyclone if it crosses the equator? Once on New Years Day of all days, one of the morning TV shows did a thing on toilets. They did a live from a toilet in Aussie land. Yep it flowed down backwards from here.

 

[KC7CN]

I recently upgraded my trashcan separator to include the baffle described in this post. As Bas said, the baffle design was done by J. Phil Thien. Phil has a dedicated forum for this topic.

In addition to adding the baffle, I also cut off the outside corner of the input elbow. A test was conducted to find the optimum position (angle) for the elbow, and to see how good the separator works.

This is the initial post for my shop-made pre-separator: http://www.ncwoodworker.net/forums/showthread.php?t=10866

Here is the link to my post on Phil's forum that discusses test results: http://www.cgallery.com/smf/index.php?topic=24.0

Photo Abum of shop-made Pre-Separator:


Photo Album of Pre-Separator Baffle Upgrade


Enjoy!

-Don

 

[scsmith42]

Don, that's some good info - thanks for sharing. What were the results of your tests with the oak?

Scott

 

[KC7CN]

Don, that's some good info - thanks for sharing. What were the results of your tests with the oak?

Scott

Hi Scott. The objective of the test was to determine the optimum orientation of the input elbow. The original position, #1 , #3 (close to the side wall of the can, or #2 (midway between #1 and #3). Of the three locations, #3 was too close to the side wall; collected 4 cups of sawdust. Position #1 and #2 was optimum for this setup - 5 cups for #1, and 5+ for #2.

Click on the picture below. Move through the album and read the comments under the pictures.

Or click on this link to the album of all the pictures - Page 1 and 2:
http://www.ncwoodworker.net/pp/showgallery.php?cat=1080

-Don

 

[McRabbet]

Don,

That is a very interesting and well-run experiment that you used to get to an optimal setup for your separator. I plan to run some experiments when I install my ClearVue CV1800 later this spring -- I want to make a chip separator that will handle the high flow rate I'll have (about 1,400 cfm through 6" ductwork) and I've got some ideas that will draw on this design, but also Bill Pentz's cyclone inlet and ramp design as well. My mind is reeling at this point over the possibilities for a workable separator for use at the high flow rates.

One might ask why I want a chip separator when I'll have one of the most efficient DC's on the market -- the reason is that my cyclone will be installed below my shop in a high crawl space and I want to avoid having to empty the bin any more frequently than absolutely necessary (access is through a door on the other side of the house from my back yard). I have a 4" chip separator that I use with my current 1 HP Penn State collector and I empty it about 5-6 times before I need to empty the bag on my DC unit in the crawl space and I'd like to achieve about the same efficiency for materials from my planer and jointer.