How to Protect Impeller on DC

[Jon Kleiman]

Hi all,

After many more months than I care to publicly admit, I put the final touches on my dust collector set up yesterday. I'm running a 3HP blower with SDD XL and venting directly outside with no filter.

It sucks...hard. I'm pleased. But as I was testing it out yesterday, I sucked up a long strip of the paper backing from the foil tape (essentially, a long strip of wax paper), and it got caught right in the blades of the impeller. It was not a pleasant sound. My assumption is that the paper was too light to fall into the Dust Deputy.

So I've been thinking – Do I need some sort of a screen that sites between the SDD and the blower to protect the fan blades?

Thanks all.

[Frank Pratt]

No, the cyclone will protect the impeller. The only thing (other than a little fine dust) that will get through is stuff like that tape liner.

[Andy D Jones]

I suspect the reason the tape did not go into the bin, and instead went through the impeller, is that it was too long, not too light. Once part of the tape goes into the bin, the rest cannot twist freely as it continues to rotate around the vortex, and gets caught up in the suction to the impeller.

I think a screen on whatever nozzle you were using on the end of the hose would be much easier to deal with. If you had a screen in front of the impeller, it might not make as much noise, but it would stop or seriously reduce the airflow, and require disassembling the dust collector to rectify.

-- Andy - Arlington TX

[Bill Dufour]

I have seen efforts to put vanes in the inlet to straighten the flow and make it more laminar for more efficiency. I think in jet engines with more and faster air flow. In generating water turbines they can inject air just at the start of the venturi to reduce friction and increase flow enough to offset the power to run the air compressor. I think a similar design is used in high bypass jet engines but that is partly for fuel efficiency and sound reasons.
Bill D

[Bill Dufour]

People seem to get all concerned about smooth clean bends and a final straight shot into the cyclone. For some reason they ignore the outflow plumbing and often dump it into a rectangular box with sharp ninety degree drops to the filters.
Bil lD

[Jon Kleiman]

Thanks all for your advice!