Quote from: dbhost on September 11, 2009, 01:06:50 PM
You are close to right. Yes the center of the baffle is indeed the center of the lid, and yes it is over the center of the trash can, drum, or whatever your vessel is.
The elbow in question empties out at the start of the solid part, not the drop slot, or aperature as you called it, so that they loaded air is slightly deflected away from the shavings / dust below.
The slot / aperature is 1-1/8" wide. I do not know why Phil designed it this way, and if it needs to be adjusted for larger sizes. For my HF 2HP DC I made the drop slot 1-3/8" wide by sheer measurement mistake and it still worked fine. On the one I am building for the 55 gallon drum, 4" pre separator the drop slot will be 1.25" wide. Right or wrong that is how it will be made.
Hope this helps, and sorry about the slow reply. I didn't notice your post for the longest time...
Is there a "rule of thumb" for the size of the slot in the baffle? I'm thinking that the area of the slot should be similar (larger? smaller?) to the inlet or outlet area. This information would help in scaling the design to other duct and drum sizes. I expect that the angular dimension of the slot at 240 degrees is fixed so the only available variables are the slot width and the diameter of the drum. Any comments and suggestions welcomed.