Jeffrey Makiel
01-08-2006, 9:36 PM
I'm on a roll with dust collection regarding this forum. My previous thread "Tablesaw with a mustache" got me going!
A while back, I made some modifications to a standard 2hp single stage dust collector that has worked very well. These modifications are really nothing new, but I believe are understated. They apply to basically all 2hp dust collector clones.
I made 3 significant performance enhancing boosts:
1. In addition to using felt bags versus the original woven bags, I also purchased a 46" tall upper bag from Penn State Industries which increased the square footage of filter;
2. I increased the inlet opening from 5" dia to 6" dia. Some single stage collectors already have 6" dia. With radial blade wheels, the more air moving, the more amps the motor draws (opposite of vacuum cleaners). Therefore, with no duct restriction, the motor is working the hardest. I believe the smaller diameter was to prevent motor overload if the unit is running with little or no duct attached. But this design reduced efficiency when connected to a ducted system that sported 6" diameter duct;
3. The fan was re-mounted vertically. This eliminated two 90 degree elbows; one right before the fan, and one right after the fan. Elbows in these locations have a profound effect on the fan's performance more so than just the pressure loss of the elbows themselves. When I use to be an HVAC engineer, we called this "system effect" because the air flow is not given a chance to properly developed, or become uniform, upon entering the fan. This condition results in a unevenly loaded fan wheel and an overall redution in system performance. Rule one was to always avoid this condition if possible by adding straight duct before and after the fan equivalent to 5 diameters or more.
With the above modifications, my inexpensive dust collector runs like a champ, and is more quiet. Here is a CAD rendered pic of the mods I'm talking about.
cheers, Jeff :)
http://i3.photobucket.com/albums/y84/Beff2/DustCollector.jpg
A while back, I made some modifications to a standard 2hp single stage dust collector that has worked very well. These modifications are really nothing new, but I believe are understated. They apply to basically all 2hp dust collector clones.
I made 3 significant performance enhancing boosts:
1. In addition to using felt bags versus the original woven bags, I also purchased a 46" tall upper bag from Penn State Industries which increased the square footage of filter;
2. I increased the inlet opening from 5" dia to 6" dia. Some single stage collectors already have 6" dia. With radial blade wheels, the more air moving, the more amps the motor draws (opposite of vacuum cleaners). Therefore, with no duct restriction, the motor is working the hardest. I believe the smaller diameter was to prevent motor overload if the unit is running with little or no duct attached. But this design reduced efficiency when connected to a ducted system that sported 6" diameter duct;
3. The fan was re-mounted vertically. This eliminated two 90 degree elbows; one right before the fan, and one right after the fan. Elbows in these locations have a profound effect on the fan's performance more so than just the pressure loss of the elbows themselves. When I use to be an HVAC engineer, we called this "system effect" because the air flow is not given a chance to properly developed, or become uniform, upon entering the fan. This condition results in a unevenly loaded fan wheel and an overall redution in system performance. Rule one was to always avoid this condition if possible by adding straight duct before and after the fan equivalent to 5 diameters or more.
With the above modifications, my inexpensive dust collector runs like a champ, and is more quiet. Here is a CAD rendered pic of the mods I'm talking about.
cheers, Jeff :)
http://i3.photobucket.com/albums/y84/Beff2/DustCollector.jpg