J. Phil Thien's Projects

Quote from: giovanotti on January 25, 2014, 11:40:43 AM
Team work. Comments welcome.

Let me revive this topic.
As said long time ago, I am using Thien baffle between 5 gallon bucket and shopvac's bucket. Small Thien on left not used.
My problem is ultrafine dust as it cloggs vac's textile filters. Have to clean them on weekly basis - annoying.

Idea in works: install another baffle within shopvac's bucket. This time Thien buffles would have approx 70mm (2,7 in) in diameter, there would be 5 of them. For the beginning made of CNC cut styrofoam.

Idea:

Per my experience, not.
Point of separation is particle centripetal speed, crashing against the wall, reducing the speed and falling down to the container. Lighter is the particle, smaller must be diameter, generally more tough (unefficient) is separation.
This is written out of my experience, dealing with fine wood pellet ash.
I cannot back it up with any calculation.
Just idea: Dyson uses bunch of small cyclones in one device. They have very small diameter.

Yesterday, I was checking separation results of "hot shot duo". Not good. Air velocity (which is main factor for good centrifugal separation) was not there. There was also another mistake: I used two separators - first with 200mm diameter and next with 300mm diameter. I think, order should be reverse, since pressure drop.

I am aspirating very fine ash from pellet boiler.

Commercial product would still require some industrial design. This could be done on inlet, which would incorporate element to connect tube, round to rectangular transition and nicer shape. This could be done with plastics (maybe 3D print on the beginning). I strictly remained on full metal design because of primary usage with (hot) ash. To shape metal nicely is a bit of challenge...

I am lucky to live few miles from producer of buckets. I also have sheet metal fabricators with CNC punch and laser facilities in walking range available.

Can you see this video? Maybe "Save link as..." and open it from local computer? I do not want to publish over Youtube yet (too amateurish)

http://freeweb.t-2.net/e-stack/MVI_6661.mp4

I did some experiments.
According to the producer, my vac has 500W motor, which gives at measured voltage 228V current of 2,19A.
Vac out of can only with its own filter, produced 1,84A.

1 Cyclone (under vac) draws 1,79A. Fully closed inlet tube (maximum load to the vac): 1,74A. Using simple U-tube manometer, I measured 510mm water column

2 Cyclones draw 1,8A without load. Fully closed tube: 1,78A. 340mm water column
For info: "regular" shop vac with motor power of 1500W should provide between 2000 - 2500mm H20

Level of separation is very high, still last part of very fine dust has to be filtered with (disposable) bag filter.

I filmed 3 videos, but I still need to reduce file size.

You can see my (full metal, 5 gal) design in other post. Since, I am dealing with very fine ash dust, I went with 10mm (~0.4 inch) gap. I plan to test it with dry wall grinder in the near future as well.

After few trials (I promise to post some quazi scientific research results) I can say following:
- bigger/heavier particles can be separated easier than lightweight ones.
- I still suspect, that very fine particles will still have to be filtered by paper/non wowen filter. Definitely need to change bag or shake the filter is already reduced.
- Question for me is, how to efficiently measure particle size and weight and consequently adjust separator dimensions.

Team work. Comments welcome.

Hello,
question for experts: basic design positions outlet in the center of the separator circle (looking from the top).

What about positioning it off center in a way, which is used for radial ventilators?

Hello to everyone. Here are photos of my build. It is made of zinc plated metal canister and some sheet metal for inlet.
Baffle plate is laser cut from stainless steel. Baffle is inserted to the slits on the side walls of canister (made with Dremel).

Exhaust tube is lathed out of steel and tries to mimic trumpet air intake.

Final build is used in combination with cheap vacuum and is used to vacuum ash out of pellet oven. Cheap vacuum was clogged instantly, now I need to clean the filter of vac maximum 2 times in winter. Beside metal build, you can see prototype, made of two plastic canisters (10liters each), some plastic tubes and hot glue gun magic. It works!

Cheers!