I am not sure what thread you are referring to here. In any scrubber the time the fume spends in contact with the scrubber fluid is what is used to figure out the flow the scrubber can handle. I am not sure what you mean by cylinder train.
A gallery of home built hoods and fume scrubbers _hood_
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The old posted about built-in eductor packing tower is here : https://goldrefiningforum.com/threads/new-fume-scrubber-design-_fumescrubber_.22553/post-236355
And i thought the 3 scrubbing cylinders below called cylinder-train (flask train)
Back to my question, i wonder if i could replace the reservoir on the right of the picture by the packing tower in your old post?
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My purpose of this replacement is just try to absorb all the toxic fume as possible.
The designs differ in that the design from a 2011 thread uses a packed tower over the vacuum reservoir. The tower is larger and can support more CFM airflow and as such scrub multiple reactions. Plus the packed tower is not full of solution, the gas flows up through the tower and scrubber water flows down over the packing. Because the wetted surfaces of the tower packing offer more surface area when the gas travels over wetted but not submerged packing, I would say the design from 2011 will be more efficient. The design also pressurizes the reservoir forcing the fume up through the packing after it passes through the reservoir. The 3 cylinder design sucks air through the cylinder by vacuum.
The smaller 3 cylinder scrubber in this thread is for smaller operations, most of which are hobby refiners not needing the scrubbing capacity and more important not having the space the 2011 design takes up in their refining space.
One design uses a venturi to pressurize the tower and force the scrubbed air out through the top and the 3 cylinder design uses a venturi to suck gas through flooded cylinders before it enters the reservoir.
Your choice of scrubbing style will depend on what you are doing and quantity of work you process, you are a new member here so we do not know much about your intentions or existing setup. Welcome to the forum.
Thank you so much for sharring these, 4metals.
Since I'm learning from scratch, its better to start with small setup first.
For short introduction, im from Vietnam, a saleguy of a diamond wholesale, in my local and most part of my country, nearly no one use fume hood for refinery. I recently have visited two big jewery companies and witness refining of 15kg of polishing dust, i directly saw they proceed the work without fume hood, gas mask, and just letting the toxic fume floating around the rooftop. After coming back, I decided to find a way to start building the thing right, first to study, then will start up a business, who know!
[Belows are some pictures where the works took place]
So its my pleasure to know this forum and great teacher are ready to help.
Thank you for your time.
Lam
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Old fume hood there, but its useless. A fumehood chinese company sold this to the jewelry company. And they never used it. What a waste!
Without vacuum filtration and a crude setup, you should inquire if they want to sell their residues after refining. You can make a lot of money properly refining refining residues that have been poorly processed.
The purple coloration on the equipment is what residue from red rouge polishing dust looks like. Do they burn it before they put it in acid?
The purple coloration on the equipment is what residue from red rouge polishing dust looks like. Do they burn it before they put it in acid?
Are you doing this in a residential building in a city?
The fumes may weaken and maybe even destroy the structures over time.
There should not even be a smell of acids if you do it like this.
Concrete and any exposed metal are attacked by the fumes from HCl and in time it may start eating at the rebars as well.
If you are working like this you will need an oversized scrubbing system to ensure nothing leaves the "building"
Another thing is that you need a separate room/space for mixing and pouring the acids and that needs to be included in the scrubbed air.
The hood with the scrubber alongside in the first photo is the way old school fume scrubbing worked. 100% of the fume went through the scrubber for scrubbing. The issue was to get sufficient flow for good exhaust, the scrubber needed to be huge to give them the retention time needed for good scrubbing. So the trade off was less flow overall (which causes the corrosion in the facility that Ygg was describing not to mention the effect on the workers) or inefficient scrubbing because the fume can't stay in the scrubber long enough.
What we propose is a general exhaust to get the hood to move enough air for worker safety and a fume scrubber to selectively pick up the majority of the nasty fumes over the reaction itself. So this requires a hood exhausted directly out of the workspace. Typically upward above the roof height. And a scrubbed exhaust, also exiting above the work space.
What we propose is a general exhaust to get the hood to move enough air for worker safety and a fume scrubber to selectively pick up the majority of the nasty fumes over the reaction itself. So this requires a hood exhausted directly out of the workspace. Typically upward above the roof height. And a scrubbed exhaust, also exiting above the work space.
Thanks for this, I just checked it and to be honest it is a little confusing but I'll keep going through it till I may begin to understand.
So basically if I don't have the meter on hand, I may have to rely on manual checking for this too I suppose. Or one of the tells is the sound of my pump which almost silences down if the vacuum is not being pulled through properly. I also decided to let go of the spiral had you not pointed out otherwise I would have been stuck in a confusion as to why there is no pull. Your educational logic combined with the sound of my pump had me moving in the right direction. Also I've now decided to use 1/2 inch pvc pipe cut into an inch and use these as my scrubber packing. The marbles were actually giving the bubbles a tough time to head up and without them the airflow is just so much more smoother.
Here, I believe it may be a matter of experience more than textbook knowledge because we probably won't know for sure how much material we may be processing hence the formation of NOx is unanticipated?
Ah yes, well aware of the fact that you used the tower scrubbers and initially about a year ago I'd only known that and was in love with the design. Had it not been for Yggdrasil to point out the flask train scrubbers I would have gone on to build myself one of those. Talking and discussing always helps! And that is what this forum has been all about.
Many thanks for your time again
Sorry for replying you late, Yggdrasil
Obviously, we can see that the working space there is no safety at all. You wouldnt imagine that when they pour to mix AR, the acid spilled a lot on the floor; and the workers there told me they got acquainted with breath in the fume whenever they do refining once a month . And they were just few of the bad things i mention here.
By the way, i noticed that you regarded to an oversized scrubbing system, so could you please give me any hints about this setup?
How about applying the setup with double - packing tower srubber (each tower : 12" pipe x 8' height, filled with bio balls and a spiral nozzle on top of) ? If it is possible, do I need any further calculations for the exhaust fan?
See 4metals comment/reply please.
Helllo again,
I wanted to confirm if using this light inside the hood would be OK? Although the bar marked in green is made from PVC but the one marked in red is more of an exposure where the leads connect to the light. I was thinking of sealing it off using a glue gun but again what should be used for the wires? Would teflon tape be sufficient? or would I need something else to use as a protection.
Thanks for your time in advance
I wanted to confirm if using this light inside the hood would be OK? Although the bar marked in green is made from PVC but the one marked in red is more of an exposure where the leads connect to the light. I was thinking of sealing it off using a glue gun but again what should be used for the wires? Would teflon tape be sufficient? or would I need something else to use as a protection.
Thanks for your time in advance
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Keeping as short a length of wire in the hood as possible is best and a bit of silicone on the metal parts is a necessity. You could also cut out a rectangle in the top of the hood, glue on a piece of plexiglass, and put the light on top of the hood and you don’t need to worry about it.
This would have been perfect but im short of the equipment required to do so.
On the other hand if I was to stick it onto one of the walls using a double side stick ons, would they work fine given we secure the exposed areas of the stick ons or both the complete sides with the silicone as well?
Cut a small opening.
Put in some glass and let the light be on the outside.
Fairly large fume hood 140x120x60 cm. Stole the layout design from a fume hood I bought and rebuild with my own wood working skills.
The first motor was way to small because the smoke turned right back down and out. The second motor sucks about 300 l/h but it's still not 100% right
The first motor was way to small because the smoke turned right back down and out. The second motor sucks about 300 l/h but it's still not 100% right
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Finally completed my DIY fume hood.
Interior measurement: 39.75 W x 34.25 H x 30 Deep
Inline fan: 12 inch fan with 1060 cfm output
PVC pipe - 4 inch pipe with 2 inch constriction
Hood and table top are made of Melamine (no wood or metal is inside the hood with the exception of some staples which are coated with 'Flex Seal'- trim pieces and baffle are made of PVC trim and paneling)
Long black mark in the center of the wye is where the 2 inch pipe ends. I originally had it at the arrow but found it better at the long mark point after re-testing with a meter. I think though anywhere between those two points would be fine.
I can try and get the cost of the hood but it took awhile because I spent months waiting for good deals and sales. I also went a little overboard on the building the table. It has a pull out table surface and a pull out trash can for 'sweeps'.
Hope this helps other DIYer's.
Interior measurement: 39.75 W x 34.25 H x 30 Deep
Inline fan: 12 inch fan with 1060 cfm output
PVC pipe - 4 inch pipe with 2 inch constriction
Hood and table top are made of Melamine (no wood or metal is inside the hood with the exception of some staples which are coated with 'Flex Seal'- trim pieces and baffle are made of PVC trim and paneling)
Long black mark in the center of the wye is where the 2 inch pipe ends. I originally had it at the arrow but found it better at the long mark point after re-testing with a meter. I think though anywhere between those two points would be fine.
I can try and get the cost of the hood but it took awhile because I spent months waiting for good deals and sales. I also went a little overboard on the building the table. It has a pull out table surface and a pull out trash can for 'sweeps'.
Hope this helps other DIYer's.
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when you says scrubbed exhaust exiting the work place. are we talking about a carbon filter or something like that? I'm having a hard time finding something to hook up to a fan and ducting system that has an intake and exhaust.
