how to build an acid resistant hood & scrubber _hood_

[PreciousMexpert]

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=4776
In this picture the fumes are going into the water
I am not sure if this is right or the water level should not be so high
I thought the media should not touch water

 

[4metals]

The fumes are not going into the water, the height the fume enters the scrubber is higher than the tank that holds the water. If those fumes are going into water the room has 2 feet of water in it!

The fume enters under the grating that holds the packing, that is not the water level. This allows the fume to disperse and fill the column as it rises.

 

[golddie]

I filled in the scrubber with all the things I have
The bottom layer pvc pipes sliced
over that I cut up a basket and threw that in there
over that the balls
over that the sliced up antifreeze bottles also I threw in small water bottles
The only thing I regret doing is throwing in bottle that had paint on them I thought about it later because the paint can have lead
Also when you look at the space these Jagger balls occupy it is really amazing
it is so dense compared to the bottles
I am thinking of ordering the smallest size of those balls and throwing it in there so it will fill up the space in between the balls.
Thanks for all you help
I am sure I will have more questions in the future

 

[golddie]

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=4776
The model of my system is similar to this
The only difference is the scrubber and that is 8 feet high and its a bit wider than the picture

This is the blower and the motor I am using
http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=2c863&op=search&Ntt=2c863&N=0&sst=subset
http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=3k771&op=search&Ntt=3k771&N=0&sst=subset
I have not tested this thing yet but I am thinking what will happen if it does not work
For example how is the air going to be pulled out from where its marked no 1 in the fume hood in the second picture

I forgot to mention that the scrubber is not completely full
About a quarter of it is still empty

 

[Oz]

Save some room for your spray heads.

 

[golddie]

Hi Oz
Thanks
I need all the help I can get
When you are doing something for the first time you don't think of the most basic things
When I threw in the pvc pipe in the bottom layer I didnt pay attention to see if the 2 holes in the bottom of the tank hand their entrance open
I will find out later on today
I hope they are not blocked
If they are than it will be more work for me
I will have to push something in the holes to free the path
I hope today I will be able to use this fume hood and the scrubber
Thanks again

 

[Oz]

When I threw in the pvc pipe in the bottom layer I didnt pay attention to see if the 2 holes in the bottom of the tank hand their entrance open

Use a butter tub with perferations inverted to get your free space for draining if it is a problem.

 

[golddie]

Hi Oz
The thing is I cant get to the inside of the scrubber
It is impossible
Thanks

 

[golddie]

Hi Folks
The fume hood and the scrubber is working
For a moment I thought something might go wrong but thank God Everything was OK
I boiled some polishing dirt in HCL and water
I have a separate room for refining there is a slight odor of acid but I always have to check for leaks here and there
But the place where I have my other room is perfect and no acid smell
I am very happy about this
Now I can concentrate on my refining
Thanks to 4metals for his design
Also Thanks Barren Realms 007 & qst42know and all others who helped me

 

[jeneje]

I have read this thread and have a question. I have built a 5' hood and two 12" x12" stacks. in the first stack i have done what you suggested cut up 2-liter bottles for the packing. I have alot of birds and wildlife around my house, whitch brings me to my question. Can I use the same packing in the second tower to remove the rest of the contaminates. And will it be safe for my wild neiagbors, I dont want to endanger them. I will be using this system to refine e-scrap. I have several tons of pins and boards along with jewerly scrap. I will be using electrolisos with acid and glycerin. I will also be using AR and a nictric acid bath to remove the foils from the pins. will this system be safe to me and my friends.

Thanks
Ken

 

[4metals]

This design scrubber definitely works but the design has a finite capacity. Every design does. This scrubber can handle a moderate quantity of NOx, as in the quantity outgassing off a 100 oz karat digestion. You have to slowly work up to your efficient scrubbing capacity and once you learn what it is, don't exceed it without upgrading. You also have to determine when to change out the scrubbing liquid to lower the TDS and restore efficiency. It's a learning curve.

Then both you and the birds will be happy.

 

[golddie]

For now I am boiling water and HCL
The first day I did this there was a big hole in the system and I didn't notice it because it was the first day
yesterday was the second day I patched up all the holes big and small
the air seems much better than the first day
I know that there are companies that do air quality checks and give you a report on that
I was wondering if I can do something myself or do I have to rely on my nose for that.

4metals
Since my tank is a bit larger that what you have in your design I guess I would be able to process more gold.
My tank is about 8 and a half feet high and 4 feet in diameter.
how do you calculate this amount
also I guess the kind of material you have in the scrubber can make a small difference
Thanks

 

[jeneje]

Thanks 4metals, but I have another question, how tall should the scrubber be at 12" square using a 3500 cfm blower. I made my 10" square 4'6" tall I dont think it will work. I noticed that after the fact yours in the digram was 12" square. Thanks

 

[Barren Realms 007]

Thanks 4metals, but I have another question, how tall should the scrubber be at 12" square using a 3500 cfm blower. I made my 10" square 4'6" tall I dont think it will work. I noticed that after the fact yours in the digram was 12" square. Thanks

I think you have just a little bit too much air movement there.

 

[jeneje]

Ok Berran,
I will agree with that, how do I figure out the cfm for say a 12'" square scrubber 8' feet tall. Any help here would be appreciated.

Thanks
Ken

 

[Barren Realms 007]

Ok Berran,
I will agree with that, how do I figure out the cfm for say a 12'" square scrubber 8' feet tall. Any help here would be appreciated.

Thanks
Ken

Well you are using the wrong place to do you calculation. You want to do your calculation on the size of your hood not the size of your scrubber tower. You want to make sure that you have enough air flow that it is always pulling air into your fume hood from the opening so you do not get any whiffs of fumes. Looking at the size of your hood I would guess 200-300 CFM would be adequate for what you are trying to accomplish.

 

[jeneje]

Thanks Berran,

The hood is 4' x 2' x 30" tall. I will down size the cfm's. Just to make sure on something else the longer the fumes are in the scrubber before exiting the better the cleaning, is this right.

Thanks
Ken

 

[Barren Realms 007]

Thanks Berran,

The hood is 4' x 2' x 30" tall. I will down size the cfm's. Just to make sure on something else the longer the fumes are in the scrubber before exiting the better the cleaning, is this right.

Thanks
Ken

You can't go on the amount of time your air coming from the fume hood stays in your scrubber. You will need to test the air exiting the scrubber on ocation to make sure no residue is exiting the scrubber.

 

[4metals]

Jeneje

An option is to use the majority of the exhaust for the hood and throttle down the draw that sucks through the scrubber if you have 4 cubic feet of packed scrubbing area, with a full flow through the scrubber you will turn about 14.5 times the air per second more than needed. You want the air to be in the packing being scrubbed for a half second, the more the better. With a 4 cubic foot packed bed you should be looking for 120 cfm, that's pretty small, double the height and aim for a 250 - 300 cfm flow. You could also reverse the pulleys on the blower (unless it is direct drive) to lessen the cfm. I would break the exhaust into 2 streams, one to scrub with a slow flow to assure scrubbing, and the balance to a hood for the fugitive emissions. (un-scrubbed)

 

[Refiner232121]

1) 4metals diagram design is 12 inches diameter and about 9 feet high
2) there is another picture on this thread I think its hoover and strong it looks like about 24-30 inches diameter and about 10 feet high
3) the one golddie made which is about 8 feet high and 4 feet in diameter
golldie said there is some odor where he refines ,does he need a stronger blower is it normal to have a bit of smell in a room like that or a scrubber that size is too large and maybe the adjustment of the damper is something important