30 GAL Trash can lid for dust separation drawing

[Carl Weber]

All, I thought I would share this since I have it drawn and built and seems to be working good. If anyone has any questions I will try to answer them. Also is anyone does build this I would like their feedback. The only thing I would change is the length of the input baffle, it seems to be a bit long. I have had large planer ships build up there. One option would be to point the baffle down more.

307755

[Anthony Whitesell]

My concern/comment would be the small space between the baffle and the side of the can. Providing the drawing is to scale, the inlet is 4" diameter (12 sq in) but necks down to about 4 sq in at the end of the baffle (4" tall and 1" gap between the baffle and the side). The other 8 sq in of airflow has to go somewhere. I don't know where it is going or what effect it is having inside the can. Though I think the baffle is a novel idea, I think the separator would work better without. I think the baffle is disturbing and pinching the airflow.

The general idea for the trash can separator is to mimic a cyclone DC. The inlet on the perimeter and the outlet in the center. Which is why most of the store bought ones don't work well. The store bought ones generally have both the inlet and the outlet along the perimeter.

I cannot see the cone baffle around the outlet doing much. It would help if the chips were above the cone, but gravity will be pulling them down and therefore there are minimal chips above the cone. SOmeone developed what is/was know as the top-hat outlet design. The design premise there is to pull the air from the very top center of the lid where the chips are least likely to be. The further you reach into the can the more likely chips will be airborne and more likely to be exhausted through the outlet. I placed Thein-style baffle under the inlet pipe. The opening runs all the way around the can but fits tight to bottom of the inlet elbow forming a make-shift downward ramp. The trick so far has been to find the right size gap between the baffle and the can. I plane a lot of pine with produces stringy shavings and tends to get stuck on the baffle rather than falling down into the can. I just recently increased the opening by another inch. While I was working on opening the gap, I began to consider if it would help to place a 6-8" diameter cylinder in the center of the baffle, below the outlet leaving a 1-2" gap between the top of the cylinder and the bottom of the lid. The drawback would be the airflow would have to make a tight 90 degree corner to exit and thereby adding to the SP loss.

[Carl Weber]

The reason for the baffle was to limit the chance of chips heading right to into the outlet as they are fairly close. I was looking at the baffle in the drawing and it is a bit misleading. The baffle is open on the end not closed as it looks in the drawing. The baffle is nothing more than flat sheetmetal formed half way around the inlet pipe.

[Anthony Whitesell]

It took me a while to put the drawings into 3D in my head, but the sheet metal semicircle is what I had envisioned.

307761

In the direction the air should flow, it is pinched to a +/-1" window approximately 4" tall (diameter of the inlet).

If you remove the outlet pipe from inside the can, the outlet suction would further away from the inlet.

[Carl Weber]

You are correct. I will have to remove the baffle and see if that makes a difference. This on a per-separator before a temp Cyclone. I have a new Clear Vue on order to replace my existing set up.