Sandblasting Cabinet filter design Question.

[Mr Fixit]

Hello Group,

I have this blasting cabinet that I got recently and it does not have a filter for the discharge of the media reclaimer. I have a thick walled drum that I'm looking at using for a filter housing for the reclaimer and blower.
My question is would it be better to pull or push the dust through the filter for final dust removal. I have attached some pic's for reference.

The link below is similar to the one I have, mine is just quite a bit older .

https://clemcoindustries.com/product...ts/bnp/bnp55s/





TX
Mr fixit for the family
Chris

[reggie_obe]

See: https://en.wikipedia.org/wiki/Baghouse

[Franz©]

Search up Thein baffle or Thein separator and save a lot of aggravation. Use one for your primary after the cabinet and you'll increase filter life considerably.

Sucking through a filter is preferred over blowing into a filter. Sucking maximizes filter surface in use, blowing minimizes and quickly causes holes.

Far as reclaiming is concerned, generally not worth the cost since the sharp edges are gone. Best case you get 2 passes, one cutting and delivering the cost of the compressed air and a second where cost of air kills profit.

[lakeside53]

If the cyclonic separator is working will the output filter is almost inconsequential. You won't need much and the way it's set up you will just be blowing though the final filter after the main separation.

[Mr Fixit]

Hey Lakeside & Franz,

Lakeside, are you saying that the reclaimer by itself should be enough and a bag filter on the discharge should be enough?
Franz, the reclaimer is a cyclone separator like the Thein cyclone you reference. the rest makes sense about the air flow direction. Product recycling will be as much as possible since this is a Hobbyist home shop.

TX
Mr fixit for the family
Chris

[lakeside53]

yes. Very little will get past the separator.

[1/2 dun shed]

I use draw through setups. I don`t like anything coming in contact with fan blades. Its not a real problem for the home diyer but I have come across worn fan blades or build up on blades that can led to out of balance systems in the commercial world.
With the effectiveness of the cyclone (or separator) it depends a lot on what blast material you are using and how much air is being drawn through the system. I use steel shot, garnet, plastic beads and sodium carbonate as blast material. If I forget to reduce vacuum to the cabinet after using garnet it does not take long to loose a heap of soda to the filters.

Tony

[Doozer]

Cyclone separators work because air flow creates a directional velocity to start the air spinning.
You need to blow the air through. Sucking the air through just pulls the air around a corner and
down to the bottom where it exits. No spinning is induced. Yes it will drop the dust from the downward
direction change, but nothing is spinning in there. Blow through a cyclone.

We had a huge sandblast system when I worked at Michelin, and they got rid of it for whatever reason.
The centrifugal blower sucked right out of the cabinet, exposed to the abrasive sand. When they
dismantled it, I looked over the blower real good, and the impeller was made of 1/8" steel plate.
While white and clean, it looked pretty good as far as wear goes. It had a 3hp motor as I recall.
I would not worry about sucking abrasive with a blower. Conventional wisdom might be to think that
isolating the blower from abrasive by installing it as a suck through system, after the filter might
be the best thing... but then the cyclone really does not work at all. It becomes minimally effective
and the filter life is really bad as a result.


-Doozer

[Tundra Twin Track]

This is Pressure Style system I have no product is stored in cabinet,it is stored above pressure pot.

[JoeLee]

This is Pressure Style system I have no product is stored in cabinet,it is stored above pressure pot.

That thing just dwarfs the bead blast cabinet. My shop ceilings aren't high enough for anything like that. I'm sure it works well but I find it hard to believe that we have to go to that length to get a good dust collector.

JL..................

[JoeLee]

Mr. Fixit..... please keep me posted on your progress as I'm in the process of adding / modifying a filter to my dust collector. I'm not interested in any particle separation, I just want to keep the dust from sifting through the fleece lined bag and blowing through the motor and into the air. I'm going to make a mount for this shop vac filter and install it under the motor. that should help me some. If not I will then add a shop vac bag fitting to the canister and use one of those fine filter bags.

JL................









https://postimg.cc/SY7HxydR

[Franz©]

Look at how ZeroBlast cabinets work. They put their drawings on line because they know nobody will copy their product, and if somebody does they'll miss the critical elements.

Also factor in how many CFM of air are coming from the blast nozzle. 101 factor when you add in the air from the nozzle has dropped to 1 Atmosphere.

I continue to recommend the Thein design.

[Mr Fixit]

Hello Group,

Great suggestions. That tower that Tundra Twin Track shows would require a building of it's own at my place as the wife would not allow such a thing on the property without a visual block, and I'd agree with her on the visual thing.. I'm in a city neighborhood. Joe Lee, I'll keep up on what I do as I'm sure it will help you as well as others.
.
I have the cyclone separator that is part of the manufacturer's original design as this picture shows.



What I'm trying to work out is the discharge of this 600 CFM blower inside the shop. I'm sure it's not just air and that is what I'm asking about is what would or would not work. I had the idea of putting the blower on the filter barrel and drawing through the cyclone and filter which is an option from the manufacturer (check original post) and from what I gather by suggestions, it's not such a good idea. So I'm going with a bag filter with a frame inside the barrel that will then exhaust into the room clean air. I hope !

Looking forward to continuing the discussion.

TX
Mr fixit for the family
Chris

[Tundra Twin Track]

Hello Group,

Great suggestions. That tower that Tundra Twin Track shows would require a building of it's own at my place as the wife would not allow such a thing on the property without a visual block, and I'd agree with her on the visual thing.. I'm in a city neighborhood. Joe Lee, I'll keep up on what I do as I'm sure it will help you as well as others.
.
I have the cyclone separator that is part of the manufacturer's original design as this picture shows.



What I'm trying to work out is the discharge of this 600 CFM blower inside the shop. I'm sure it's not just air and that is what I'm asking about is what would or would not work. I had the idea of putting the blower on the filter barrel and drawing through the cyclone and filter which is an option from the manufacturer (check original post) and from what I gather by suggestions, it's not such a good idea. So I'm going with a bag filter with a frame inside the barrel that will then exhaust into the room clean air. I hope !

Looking forward to continuing the discussion.

TX
Mr fixit for the family
Chris

A visual block,are you saying my setup is ugly LOL! All three peices normally would sit side by side on the floor,I stacked dust collector over reclaimer/preasure pot to save space.The socks must be very fine as mine vents inside shop and have been up top numerous times to check for any fine dust.

Canablast website shows good schematic on both Preasure and Siphon style setups.

This setup works fantastic as Preasure style gets job done with less air than siphon style, my compresser in not huge and I use 3/16" carbide nozzle,my Commpressor keeps up.

[Mr Fixit]

Tundra, your lucky to have a building tall enough to stack them which is a great idea for much needed floor space. I see Canablast has their manual filters with a design that I'm going to try, pushing the discharge of the blower through the filters. 1 more example of what I'm looking for.

Joe Lee, I see your dust collector picture, after googling it, it looks like it's a draw through the filter and discharge out the top. What about a second filter bag on the discharge of the blower to catch the finer dust? I had a shop vacuum filter like your suggesting on a HF blast cabinet I setup and it kept plugging very quickly, which became a real frustration when doing more than 1 part in a session. I realize your thinking of the filter after the bag and before the discharge so it might last a bit longer, time will tell. Something that you might consider is what Frank has suggested, a Thien separator which you could build between the blower and your filter in the stack of the canisters. It would draw a lot of the particles out of the air before it gets to the filter, then a second filter on the intake of the blower or on the discharge of the blower could give you a very clean setup. Let me know what direction you go too.

TX
Mr fixit for the family
Chris