Need help with designing a all in one reclaim~separater~dust collection blast cabinet

Heyyyya there everyone,

As a Millwright my background is mostly in metal working~metal machining~ and mechanical. But I do have enough experience with wood working to get in and out of trouble most of the time.
A couple months ago I stumbled across a brand new never used HF sandblast cabinet with 10~20lb bags of grit for 20$!(No not stolen~lol... wife was divorcing and was selling everything of his off cheap) Since the cabinet did not come with a vac/recovery system I learned really quick why you Do Need one in about 30sec of using the first time do to my whole shop was covered in grit dust! And Yesss I am still finding grit dust after about 2months later. Since I am the the kinda person that has a hard time buying something that I can take pride in making not only Bigger~Badder~Better but make last, I started researching on how to make a recovery dust separater for going on 2 months in my spare time and boy have I have learned a lot and also have been confused several times!
There is many ways to do this right and wrong. Everything from cyclonic~multiple cyclone~baffle system~ to axial cyclone systems like Dyson’s vacuum cleaners. After searching page after pages~forum after forums this is the first forum I registered with after reading all of the posts here!

This forum has taught me a lot and has answered a lot of questions thanks to You and all of your comments and posts!!!! This forum not only actually answers your questions and helps you understand the “what~why~where” but dosnt treat you like your stupid!
So here is my question/questions and I feel real confident that I’m in good hands here!.....
How I got the idea for this was one night a while ago during some research on the inter~web I needed to a break to let my thoughts settle and grabbed the vacuum cleaner to vacuum up my shop floor and work benches ( yes I said vacuum cleaner not shop vac! It’s our old house one and works great 👍 for cleaning shop floors~better than broom and dust pan!!! Faster too) it does not have a cyclone or multiple cyclones in it but it is bag less..it is a cyclonic style. I’ll post pic of it... but anyway as I was doing this the 💡 came on and then confusion/dyslexia set in at same time....lol

I would like to build a bag less all~in~one system to reclaim~separate~and filter out the fine dust blast media or sand using a shop vac... I am not sure if I want to make an R2D2 pancake system or not yet. I have 2 different shop vaca. One is a standard Crapsman wet/dry 3.25 hp 8 gal one that blows exhaust out the sides below motor. The other one is a 16 gallon Hoover 2 tank wet/dry with a wet tank and dry separator switch that has 216 airwatts of suction (which I have found out that is a true suction reading vs hp~but I can’t find what it converts to as hp) and has a blower accessory port but also exhausts like other on.

I learned from from a different sight that a cyclone system takes more to pull air through than Thien’s baffle system.
So that being said... what I want to build (and since I’m trying to reclaim sand everything needs to be metal) since space is a problem I’d like to try and build a cyclone inside either one of my 30 or 35 gal metal oil drum. Or I can build a Jp baffle top hat system or combine them both. But here’s the one of the problems I also need help with... i need to pull media/sand from blast cabinet and separate the media/sand from dust/garbage and have the dust in a separate container or compartment. Preferably on top of drum. I have drawings of what my thoughts are that I will post.
Has anyone tried putting a cyclone inside drum instead of on top like a vacuum cleaner?
Ty
Shawn
Ps...
I’m adding some pics of a horizontal system that I stumbled across and looking for thoughts on that too...

Shoot I can’t upload pics from phone!!! This makes things harder! Grrrr help!!!

I've only ever used used commercial blasters and they have never had large drum containers full of grit. They usually have an inverted pyramid catch area below the cabinet with a grating on top to do the blasting on. The vacuum sucks the dusty air from the cabinet and most of the grit falls back down into the inverted pyramid. A venturi suction pipe sucks the grit to the gun from this small reservoir of grit. Biggest mistake people make is to dump a sack full of grit into the machine and it blocks up. You should be able to run them for several hours on just one cup full of grit. Obviously the grit gets contaminated and some is lost to the vacuum cleaner but it can be dumped, cleaned or replaced easily. I think a cyclone shop vac that vented outside the shop should work well for a small blaster. You shouldn't be trying to suck the sand through the vacuum. You just need enough vacuum inside the cabinet to be able to see what you are doing and keep a negative pressure to stop dust escaping into the shop. Seal it well and keep your grit dry. To prevent contamination of the grit it is best to strip paint, grease and oil, before grit blasting but when you chose to blast the paint off something it will just need more cleaning. Parts should also be dry before blasting. If you need a big drum to recover the grit, something is wrong with the system.

Toolinsane,

I agree with Moby Duck in all points. I did try to design a dual Thein/cyclone system for a Jewelers blast cabinet. Basically placed a small Thein on top of the cyclone and came in at right angle with the low pressure side and the intake from the blast cabinet. The proto worked and made from acrylic but the design parameters were toooo constrictive as in using a 12VDC fan. With higher SP/DP (Static/Differential pressure) I could get particles down to 3-5 micron (typical for these type cabinets) separate them and manage dust with 1 micron filters on the fan to keep it out of the room. Basically one needs to have sufficient HP/SP/DP to achieve these kind of results and 12VDC fans don't have a lot of SP. The abrasives for these cabinets can be toxic, let alone the dust side of it so getting everything one can is important. Commercial systems with recovery/filter for Jewelers are incredibly expensive and now know why...however my system would work if I could find something off the shelf and overcome the 12VDC - HP/DP/SP issue. CFM is important but only as related to SP/DP and available HP.

The Thein for mine was ~4" and attached to a 3" translucent plastic jar with a conical funnel (Had to experiment with size and length) inside. The jar could be detached from the lid the Thein was attached to, to be emptied or recycled. Basically could see the additional speed of the vortex as particulates passed through the system.

You didn't specify if your HFT cabinet was a bench or free standing 40lb unit? Each will require its own design based on volume, Pressure, nozzle type and size. If your vacuum cleaner has enough HP/DP/SP for the cabinet size it should work with the right design. Two other things: First pick up a Flow meter, they are a lot cheaper now (Amazon) it's decent for this kind of work. Second is that it takes 7 Diameters to get straight air from the low pressure side (Vacuum side) which is preferred.

Had 12 years in Airflow Management & Control...Here are some links that may help.

Dust Collection Research - Dust Collection Basics
https://www.dwyer-inst.com/primer.cfm
J. Phil Thien's Cyclone Separator Lid w/ the Thien Cyclone Separator Baffle
This is about Jewelry but informative for design
http://azglassclasses.com/portal/com...rving-nozzles/

Hope this helps. Good Luck with your project.

PJ

Thank you very much for your replies! Amazing 175+ peeps looked and only 2 responses... hmmm
I figured out how to upload pics and sketches... I hope this give you a better �� idea.. and it’s a stand alone not bench setup.
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I’ll try and explain pics...
I’m going to pull from bottom of cabinet by converting trap door lid to have a 1 1/2” flanged pipe that will attach to 1 1/2” pvc pipe that connects to the holding and separation tank. I am hard piping with long sweeping elbows to keep as much resistance down as possible with rubber hose at junctions to eliminate any issues with vibration. Looking at drawings/sketches the inlet is going to be 1 1/2” and exhaust or suction side is 2” in hopes that I won’t loose suction or air flow. I will have to experiment with this I am sure.

In the pics you can see a red 25 gal drum along with a blue section of a drum that I built a jig that I put drum on with skate wheels and a holder for plasma cutter so that I could get a good even true cut. I was going to use the blue section as a top hat and if you look at pic fits nice and tight in drum and seals great. I will slice rubber hose down middle and put on red drum to create a sealing ring. I looked and stared and measured and cried for hours... lol.. to make sure that where I made cut it would slide into red drum to make a natural kinda seal.

I have multiple ways of making/designing this. I want to use the blue section as a removable lid that holds whichever way I decide to go. This will make it totally accessible and I can change or improve it. There has to be a screen, deflecting plate, or ??? in the second ring down in drum. The media should settle under that so the becomes a holding area. I will install another cone under barrel to guide media to a air pressure valve for blast cabinet.
I don’t know is how should I bring the blast media into separater? If I go with the axial cone design like vacuum cleaners do (or a reverse flow system) then (hmm idea popped in me head) then the inlet is installed on the side and exhausts out top. This allows the media to spin around the out side walls of drum and if and “I Mean IF I”ninstall and design baffle plate correctly then media falls to bottom under plate allowing the dust to be extracted through center of cone which is installed in center of blue top.
Nowww “the brain fart” :idea: idea... I will make up a sketch of this. What if I put the exhaust pipe at the edge of top which is also the edge of cyclone with a 90* elbow facing the same way or opposite way of inlet like Jp’s Baffle? But do I make another baffle plate under elbow??? Putting and baffle under elbow like Jp’s design would make it to where most of actual dust stays in drum... uggg anyway Ill have to figure this out and experiment as I go.. This would make 2 cyclones in one. One outside and one inside utilizing the inside walls of the cycle to help extract more dust and separate more media?...! Or I could reverse the inlet and exhaust. The 1 1/2” inlet could be in the top and 2” exhaust out the side Or 1 1/2” intake on top and 2” exhaust on the side. GREAT Grrrrrr my brain is hurting now!!! Uggg more confusion! :brickwall:

The thing is that I can make it so efficient that NO dust escapes! That’s not what I want... I want to separate dust into a separate container...

On I have a headache now :idea:so I’m going to draw this up and get back to you with more ?’s and thoughts! Please respond with help and ?’s!!!

Thank You Again
“MetalMan”

Wowwww over 300 people have looked at this and only 2 replies! I thought more than a couple people would have some advice to help! I’m getting let down! Dammm

Toolinsane do not despair . A lot of the guys who have done this do not check in every day. I've never had a call to need a collector or I could offer some insight.

Quote:

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Originally Posted by ToolInsane

Wowwww over 300 people have looked at this and only 2 replies! I thought more than a couple people would have some advice to help! I’m getting let down! Dammm

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Toolinsane,

Whelp, after trying to digest your pics, xplanations, and no further sketches or drawings of your idea, I am still confused about where you are going.

First here is a link to some YT videos that may give some clue about what others are doing with these cabinets and some are quite good. Here is an additional link to a Garage Journal thread of a pretty cool but expensive mod.

Second as to whether to side port or bottom port the cabinet, I would choose side port (existing), mainly because you will need much higher DP/SP/HP to do a bottom port design like the one at Garage Journal and it will mess with your feed to the gun from the hopper without some serious engineering of size, elbow, return, etc. to keep your gun fed. In a bottom port design you will be recycling crud from the blasting and getting clean media back from your collection system will be a Big Pita in plumbing and HP requirements, maybe even two systems.

With the side port you are only working to get the finer dust and particulates out and separated, plus keep your viewing clear...and don't need much in DP/SP or HP. Another addition would be to put a baffle on the inside (like Garage Journal) of the cabinet where the inlet port in the back is and build a small sliding gate on the outside to help regulate your internal pressure and flow to the dust collection system. Keep in mind with that port just open with out a filter or gate dust and particles will inundate your shop. If you block it off you could oil can the cabinet with a big vacuum system...a sliding gate is a good inexpensive way of regulating internal pressure.

Additionally sealing the unit well and maybe using LED strips will give you more lighting and likely better flow control over all.

Third, If you understand my previous post it will work on your system if you. Most people out there are using a Dust Devil ($60) for a basic cyclone and a small vac to get good results. I believe if you go this route and add a home built Thein unit (see links in previous post) on top of the Dust Devil you will get even better results. A lot of people out there just experiment around with these things without understanding anything about flow (fluid dynamics) but usually don't get as good of results but may fit their budget or needs.

As a final thought and a good clean build on a smaller HFT cabinet Mod....Note the addition of the shaker!

https://www.youtube.com/watch?v=RFUYl6Z6w9I

Think that is all I can offer without some more cohesive offerings and less "Dammm's". Perhaps there are others that may have alternate ideas on how to help you.

PJ

Thank you guys for your response! And PJ thank you for for info! I watched the video and he had some great ideas on several keys things that I will address as I move forward with this project Ö~mine..

I am in the process of setting this up to where I can experiment and make it to where I can change things to find the right combo. I’m using the blue top of the can to put the cyclone in but I’ll be able to remove it and make a jp baffle to see how it performs and then I might try using both. I will post updates and pics as I go.

I was reading/surfing through another web sight that has a lot of info on sand blasting and blast cabinets and one of the members ask the original member who had made the post why he didn’t run the exhaust from the vacuum back into the cabinet through the pre~exhaust dust hole on side of his cabinet to make a full recirculation system instead of using a filter..? :idea: And that was one of answers that I was looking for..! How to set this up so that I don’t have to run an actual filter. Since one of my shop vacs has a blower port for exhaust I’ll pipe it back to the cabinet. Yes I will have to seal everything up tight since I’m making a reclaim system and while I have cabinet tore apart I’m going to drop the floor down 3-4” also.
Ty again!