|Forum topic by Dave_London||posted 01-24-2015 01:48 PM||748 views||0 times favorited||3 replies|
01-24-2015 01:48 PM
Starting with a ‘minimum’ unit that used a plastic garbage can and a lid separator, I wanted to improve air quality without a massive expenditure. Coupling this upgrade with a ceiling unit using a HEPA filter (found elsewhere in this forum), I’m very pleased with improvements not only to a much higher air volume and velocity, but also to air quality. (I just retired after 45 years in the classroom to enjoy more time here …. I want it to be a long adventure honing my skills with wood.)
The Super Dust Deputy (SDD) was chosen more for its size; I’d wanted to use the Clear-Vue system but I’m not disappointed in the results so far. As you can see in this second photo, the biggest challenge was to separate the air box connecting the blower to the bag frame. Both were originally 4”W x 5”H but I turned the motor up 90 degrees resulting in a rework of the flange (remove a bit here / add a bit there….). It’s sealed and the air has a smooth path. The motor is now bolted to a torsion box made of plywood and in turn suspended from a joist. You can see the ‘bags’ on the right side. If I’d had adequate space, a replacement pleated filter would have been added; however, a furnace duct interfered with this plan so I’m using the 1 micron bag. It works well but gives up the big surface area of the other filter. (i.e. a shorter cleaning cycle). The main duct is only 10’ long and with 2 blast gates. This services all of my main machines organised in a central location, I use 1 – 10’ plastic corrugated hose only to interchange as needed. To keep turbulence to a minimum, I’m using smooth pipe (PVC / metal) and keep the flexible corrugation pipe to a bare minimum. The dust must have the ‘smoothest ride’ you can provide, which translates into higher velocity and more volume.
The SDD has some interesting sizes for intake / exhaust ports and I found sheet metal furnace pipe adaptors worked well. The intake of the blower is only 4” OD and the exhaust of the SDD is 6” OD. I used a 4” x 6” adaptor, drilled out the 2 rivets that hold the 6” sleeve on, carefully trimmed the bottom of the cone and got a nice tight fit inside the SDD inner sleeve. I then made a plywood ring to fit over the sheet steel adaptor and then inside the SDD sleeve. I inserted 3 pan-head screws through the plastic into the plywood and sealed the edges with silicone. Three brackets were fabricated to hold the SDD to the blower housing. A bit more sealant there and all was securely together.
The SDD empties into a commercial container. (Rubbermaid Brute). I tried a regular plastic can and it started to collapse from pressure. (a good sign) The SDD is fixed vertically so the container is lifted into place using a plywood base that has wedges glued to the bottom. These ride up 2 more wedges to firmly hold the container. I fashioned 3 clamps to ensure the gasket under the container top was sealed but I suspect these are redundant.
Finally, I added a simplistic manometer (thanks http://www.stumpynubs.com/ ) This should give me a ‘heads-up’ when air flow through the fabric bag indicates cleaning.
So …. after a week with my first load of dust and shaving, I have ‘near zero’ material in the plastic bag. These are qualitative observations; I have no quantitative data to demonstrate a substantial improvement to a once single stage dust collector.