Thread: 2hp DE Build

Originally Posted by jack620

I'm not fussed about the shape. Rect-round was my option #2. Rect-rect was my option #1 (see post #46). I think it will be easier for me to make a Clearvue style bend than to form 150mm round into a rectangle. Your solution is elegant tho.

It's easier than I first thought to make an "rect/square to round" adapter.
I've made several from first principles, but for those that can't work this out I recommend the "duct evolution" spread sheet available on line.

Here is one of my better efforts.
Transition1.jpg

Here was the starting sheet of SS (clothes dryer drum) showing the initial marking out.
Transitions2r.jpg

BTW This thing sucks like there'a no tomorrow.

Here is my take on the transition from round to rectangle.
Cut a circle and a rectangle then join them up center with whatever length you want.

Lay the jig on the sheet with a straight edge then draw the lines
20180113_080219.jpg
20180113_080227.jpg

The "jig" then can be used to form the transition.
20180113_112405.jpg
20180113_112206.jpg
20180113_115423.jpg
20180113_150511.jpg

Hope this helps.

Hoey

The round opening Jack is going to is the inside opening of the cartridge which is about 9"/230mm across. He still has to have a flange on it to draw the cartridge against to seal it if he is flowing the air in the same way the CV's are so he might as well make his the same. I could see making a rectangular to round transition if he was venting outside and hooking up to ducting to get there.

Pete

Originally Posted by QC Inspector

The round opening Jack is going to is the inside opening of the cartridge...

Correct. If I make the connector beefy enough, hopefully I'll be able to suspend the filter(s) from it.

I got the specs for the washable polyester cartridge filter. Their initial quote said it was a Torit. It isn't- it's a generic one they make themselves. Appreciate any comments on these numbers. Good, bad, ugly?

Edit: the filter has 9.9m2 or 106 sqft of filter media. Seems a bit low.

Here is another company that has filters you might want to look over. They may have something better.
Supplier of dust collector filter, bags, cartridges and cyclones

Pete

Thanks Pete. I've spoken to Pneuvay. They have a filter for $115 I will probably purchase two of. See post #15 for the details.

I would need four of the Filterfit washable filters which would cost me nearly $800.

I finished the outlet elbow today. I'm going to attach it to the blower with two over-centre catches to allow the filters to be easily removed when the weather permits the DE to be wheeled outside (as per BobL's suggestion).

Originally Posted by jack620

I finished the outlet elbow today. I'm going to attach it to the blower with two over-centre catches to allow the filters to be easily removed when the weather permits the DE to be wheeled outside (as per BobL's suggestion).

Looks good.
Like the idea o the over-centre catches.
What is the acron nut in the middle of the top/bot panel?

Originally Posted by BobL

What is the acron nut in the middle of the top/bot panel?

There's a piece of M6 allthread pulling the sides together. I used it to hold everything together while I attached the flanges to the ends. I've decided to leave it there as it provides strength in the middle and should produce negligible reduction in airflow.

Hummmm . . . . I wouldn’t leave it there. You need every bit of flow you can get with that small blower. If needed I’d put one on each of the outsides.

The DE is all but finished. I just have to fit-off manometer to the blower outlet and measure the pressure with clean filters. I'll probably add a clear window to the dust bin. I'm impressed with the performance. I put most of the improvement down to the 5" inlet over the original 4" and the pleated filters. According to my power measurements, the two clean filters add almost no resistance to the airflow (1%). It will be interesting to see how much that changes when they are seasoned. The old felt bag was as tight as a drum when the old DE was running.

I don't have the facility to measure airflow, but I took some power measurements for those who are interested.

Sorry about the rotated photo. I hate the way this forum deals with pictures.

I hate to see rotated photos and being such an important endpoint in the project I just had to fix it!

A more representative performance change from the power figures can be made by subtracting the power when the DC is not moving any air from all the other powers.

This means
695W is then going into moving the max amount of air
695 - 548 W is lost by the cyclone
695 - 543 W is lost by cyclone + filter
695 -470 W is lost by cyclone, filter a flex
and 430 W is used to maintain the rotation of the motor/impeller and just the air inside the impeller.

Now work out the % losses based on the above.
That flex sure is a killer isn't it.
I would expect the filter to increase as the fine dust eventually comes though the cyclone.

You really will need to keep an eye on the level in the bin. If it over flows it will spew dust seriously clog the filters.

I would also seriously put something protective around the filters. Being exposed like they are and with the DC on wheels it's going to bang into stuff as you move it around and stuff is going to bang into it. It might not look like any collision has made a puncture but you won't see minuscule leaks until weeks later when you start to notice fine dust everywhere. Eventually the leaks will show up as beige/brown stains on the outside of the filters.

These are all good reasons DC should be either outside or located in a enclosure that vents outside. But enough of that.

Anyway I think a more significant problem will still be insufficient fine dust collection at source.

Bravo!