# A benchtop scrubber.



## ReapHer_6 (Jan 8, 2012)

Hi All. I have been lurking more lately as I have not been able to process scrap because I don't believe it is safe enough in my lab because of the fume management system.

I would like to see if I can get some help on building a small benchtop scrubber so I can get back to processing instead of just firing experiments and money at the problem. I have used the search function and I have done my homework. I am ready to begin trying to solve the problem on my own which I find really enjoyable but by the time I reinvent the wheel I will have spent more than the cost of an actuall scrubber and it will be weeks before I can actually just process scrap.

First, my setup. I know it might not be the best setup but it works really well.

I will try to attach a pic, but this is what I have done.
I use a jacketed 500ml 3 neck flask (24/40) as my reactor. I have a 250ml pressure equalizing additional funnel in the center neck. I have a 400mm Allihn condenser then I vent the top of the condenser to atmosphere. I use a exhaust fan to pressurize a 4" smooth wall plastic pipe that is 40' long. I use the suction side of the exhaust fan to draw negative pressure through the reactor. I then use a fish tank air pump to add air into the chamber aiding the circulation of the gasses up to the condenser. I tested the setup and the pipe from the fan will suck out a bic lighter flame. So I got it right. I just add air in the reactor as it seems to stagnate in the chamber somewhat.

Now, I use hot water in a glass 2 gallon tank on the left of the reactor and a pump circulates the heated water around the reactor. I can precisely control the temps allowing me to warm up the reactor and the acids. I then keep the temps as close to but not over 135 degrees. 

I have a 2 gallon glass tank on the right of the reactor that I put a bag of ice into the water and circulate it to chill the condenser. (I add blue food coloring so I can see the movement in the condenser). I chill the condenser to less than 40 degrees and then I begin the process. I have an additional funnel on the right neck of the reactor that is filled with DH20 to act as an emergency reaction shutdown. 

I use the calculation of 150ml of reactor space per 1oz of material. I process no more than 1.5oz at a time.

The reason for the additional funnel and the condenser is to recover nitric. as I understand it, what condenses back down is pure nirtic.? I use the method of adding nitric then HCL, then nitric, then hcl until the process is over and I avoid overdosing the nitric.

Laslty I have used the NOx reduction with the ethelglychol / 35% peroxide process. It does work but only by putting it into use with a bulk AR process. The process of adding nitric then hcl back and fourth makes the math downright unbearable if not just about impossible. 

Ok so here is the issue I need help with. Some of you might have seen the posts on my building layout and the limitations I am under but I will briefly recap them. I am in a section of the building that has car and foot traffic directly outside. The only outlet I have access to without altering the building is a 4" vent that is 45' away from my lab table. This is not the entire length of exhaust path, just the straight section in the ceiling. I tried to build a venturi and it worked really well until I hooked up the 40' length of pipe. I asked the forum about this (and a friend that is an engineer) and everyone agrees, I need to put a blower at the end of the run and suck the fume hood through it. The problem is I don’t have a fan or the funds to get an acid rated fan. And the outlet just so happens to be above the lawyers conference room. I have access to the outlet but I can't put a large or noisy fan there. So I turned my thinking to a scrubber. I have tons of ideas and I have read hundreds of posts here about them. But I wanted to ask for help with specifics.

I don't see an answer to the fume hood in the near future so to get me back to the fun, I want to get a scrubber up and running as soon as I can to treat the fumes from the reactor. I have 3/8 fitting on the top of the condenser, so that is my ID of my outlet to the scrubber. I have access to some money (just not a great deal), and just about every tool known to man in my shop at our disposal. 

I don’t know what to do to get the fumes through the scrubber. Positive pressure is easiest for me to do. But it is not the right way.
So I need to solve the air movement issue. Use a blower, a vacuum fan, a compressor as a vacuum source?? (I have a new wine cooler that I removed the compressor from so I could use the actual cooler itself as a small fume hood. I have heard that these can make good acid fume suction devices....) Regardless of the device, I don't know how to size it. I don't know type to get or where to get it. I would like to try to not spend a ton on it. As far as the scrubber, sizing it depends on the volume of air to process which is determined by the air movement source. The condenser does a good job of recouping acid but the final amount of NOx vs. air is unknown. So I don't know what to do next.

I would like to do it right and on a budget. I understand wet scrubber principles and construction, and I have a supplier of water misters and bio balls and pumps etc. I can get a continuous PH digital meter and then add alkali as needed so I think I could build one that would keep the final air going through the vacuum good enough to keep it healthy.

I would love any help I can get so I can stop dreaming of processing stuff and actually get back to doing it. I am going crazy (ier)

John S.


----------



## Ardibash (Jan 8, 2012)

John, 

Here is a photo of a scrubber I'm building, its a 1:10 copy of an industrial one. You will need misting nozzles, some fine mesh and mist eliminator. As for the extraction you will need centrifugal fan, this has much more power, I'm using 2KW one and it's coping with about 30-40 meters of 110mm pipe. 

See photo attached. 

P.S. I'm working on detailed drawings and will post ASAP.


----------



## ReapHer_6 (Jan 8, 2012)

[email protected], I never thought of actually building a scrubber for the hood too!!!!.. Brilliant.

But I need a much smaller one. I was going to build one just like yours (I saw it as you were building it).
I still need to get some help on one to scrub a small amount of fumes.

John S.


----------



## ReapHer_6 (Jan 9, 2012)

88 Views and no takers  ?

John S.


----------



## qst42know (Jan 10, 2012)

Bench top scrubber using flasks, two hole stoppers, glass tubing, and run with an aspirator. Much like the sketch.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=5480&p=47002&hilit=flask+scrubber#p47002


----------



## ReapHer_6 (Jan 10, 2012)

That is perfect. Except I dont have a sink.  

But thank you for replying. 

John S


----------



## qst42know (Jan 10, 2012)

A pump a bucket and an aspirator would work.

Do you have a vacuum cleaner motor? If you don't restrict the flow to much this could work as well.


----------



## ReapHer_6 (Jan 11, 2012)

Ahhhh.. a pump to drive the aspirator!!! Now we are on to something. Let me get to the lab and see what I can come up with. You might have just pushed me in the direction I have been trying to find. 
Thank you very very much!

John S.


----------



## Dendrite (Apr 23, 2012)

Look at myeBay that i am selling: Item number: 130679604793, etc. In my opinion, it's that you need

serge


----------



## publius (Apr 23, 2012)

Dendrite said:


> Look at myeBay that i am selling: Item number: 130679604793, etc. In my opinion, it's that you need
> 
> serge


*Snork!*

Someone has some brass ones!


----------



## Palladium (Apr 23, 2012)

Let's see what the fellow has to say. Would you mind if we ask you some questions about the design or some test you have done to verify your design?


----------



## Geo (Apr 23, 2012)

Dendrite said:


> Look at myeBay that i am selling: Item number: 130679604793, etc. In my opinion, it's that you need
> 
> serge



good job, Serge.

have you ever dissolved any material using that yourself? does it work with AR? can you smell any NO2 fumes while its operating?
ive heard that no filter can remove nitrogen dioxide, how do you get around this?
are you worried that after a few years of using your product in their home on the kitchen counter that your costumer or his family may develop respiratory disease due to inadequate filtration of chemical fumes?
are you worried that after that happens, there may be a class action lawsuit that will never be paid off because theres not enough insurance on the planet to pay off all the plaintiffs.

hmm, other than that it seems like a good design.


----------



## Palladium (Apr 23, 2012)

I would like to hear about his qualifications as to even design a system like this. Then i would like to hear about the trial and error phase he had with the design issues. What are this products strong points? What are it's faults? I'm sure since this is made with products from several manufactures that those don't fit together just perfectly do they. That means you yourself have had faults develop. What are those faults? If you can show me some of those i will start to believe. I've designed to many things for me to set here and believe any of this. Actually it kind of pisses me off because i know somewhere out there somebody is fixing to get hurt because they are to stupid to know any better and your waffle baker will be the reason. Think i might do a little research on this new project. I try not to pre judge things but this time something is just telling me to.


----------



## philddreamer (Apr 23, 2012)

In another post he gave us his e-mail address:
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=42&t=13957#p140474

:roll: Private consulting!?


----------



## Palladium (Apr 23, 2012)

For the love of god! he silconed the bowl to the bucket top. :lol: 
http://www.ebay.com/itm/1-Gal-Plastic-Filter-Device-for-Gold-Platinum-Scrap-Refining-Funnel-600ml-D-85mm-/130685174134?pt=LH_DefaultDomain_0&hash=item1e6d718176

Please tell me this is a prototype?


----------



## goldenchild (Apr 23, 2012)

Geo said:


> Dendrite said:
> 
> 
> > Look at myeBay that i am selling: Item number: 130679604793, etc. In my opinion, it's that you need
> ...



Doubtful. By my calculations he has made nearly $8000 off of these units in the last 3.5 months. And there's no shortage of fools in the world so... :roll:


----------

