Thread: Summary for North Americans

Long cone cyclones are a better thing when filters are used but venting to atmosphere with a short cone is not a problem. Using a short cone and filters means the filters require cleaning more often. I am the first to admit my ideas have changed in the last few years as I became more involved in Men's Sheds. My local MS has a short cone 7.5hp cyclone and nothing visible comes out of the exhaust that is vented to atmosphere.

Using a large impeller means it can be driven slower, at a guess a 17" impeller in a cyclone for a hobbyist would be able to drive a 150mm ducted system at its maximum capacity at 40hz and the same impeller driven at 70hz would be able to be used in a Men's Shed. Making a 17" impeller costs about $10 more than a 14" but the impeller housing would have to increase in size which won't cost a fortune either. The cyclone intake would be made for the larger duct used for the 17" and sized down to suit a 150mm duct, again with very little extra cost. Using a VFD means that using that the different speeds are only a turn of the knob to change speed as required. I would not buy a single phase DE even if someone gave me the money as 3 phase with a large impeller covers 99% of wood workers needs.

Originally Posted by Chris Parks

Long cone cyclones are a better thing when filters are used but venting to atmosphere with a short cone is not a problem. Using a short cone and filters means the filters require cleaning more often. I am the first to admit my ideas have changed in the last few years as I became more involved in Men's Sheds. My local MS has a short cone 7.5hp cyclone and nothing visible comes out of the exhaust that is vented to atmosphere.

Using a large impeller means it can be driven slower, at a guess a 17" impeller in a cyclone for a hobbyist would be able to drive a 150mm ducted system at its maximum capacity at 40hz and the same impeller driven at 70hz would be able to be used in a Men's Shed. Making a 17" impeller costs about $10 more than a 14" but the impeller housing would have to increase in size which won't cost a fortune either. The cyclone intake would be made for the larger duct used for the 17" and sized down to suit a 150mm duct, again with very little extra cost. Using a VFD means that using that the different speeds are only a turn of the knob to change speed as required. I would not buy a single phase DE even if someone gave me the money as 3 phase with a large impeller covers 99% of wood workers needs.

Thank you, Chris. Venting a short cyclone outside is not something I had considered.

I know you advocate for a VFD, so I researched that when I was buying my ClearVue. At the time I concluded that using a VFD was more complication than I wanted to deal with. It seemed that the inexpensive VFDs were not that inexpensive and were not well documented. I also read that if they aren't run for a year, they have to go through an elaborate reset process. I talked to both ClearVue and my electrician about it and decided it wasn't for me.

Interesting, Oneida builds a VFD into some of their cyclones. It automatically increases the fan speed to improve static pressure.

Mark