Neutralizer-Scrubber of acidic fumes & gases

[kurtak]

For testing the performance all we would be doing is the color test, looking for the red cloud, and a litmus test of the air blowing out of the discharge for a neutral to alkaline discharge.

That's what I would do

I would use a 5 gallon bucket with PH paper hanging in it - vent the discharge air into the bottom of the 5 gallon bucket with a 1 inch to maybe inch & a half vent hole in the top lid of the bucket --- the purpose of the 5 gallon bucket is to slow the air speed down for retention time ( a larger barrel would be better - the more you can slow the air speed down the better)

You would have to fabricate some kind of air tight fitting at the vac discharge port so you can connect the vac discharge with a hose to the bottom of the bucket/barrel

Kurt

 

[upcyclist]

FWIW, I did send Viy a note when he asked who was near his zipcode. He's in a NW DC suburb, and I'm partway between DC & Baltimore. If he brings one to me, I'm happy to post more in-depth pictures, share results of tests, etc. The main checks will be looking for the nox cloud & putting pH paper at the exhaust, as well as just seeing if/when the vacuum motor dies due to exposure.

I don't work outdoors, so I'm not relying zero emissions, just evaluating a product.

 

[Justincase]

FWIW, I did send Viy a note when he asked who was near his zipcode. He's in a NW DC suburb, and I'm partway between DC & Baltimore. If he brings one to me, I'm happy to post more in-depth pictures, share results of tests, etc. The main checks will be looking for the nox cloud & putting pH paper at the exhaust, as well as just seeing if/when the vacuum motor dies due to exposure.

I don't work outdoors, so I'm not relying zero emissions, just evaluating a product.

What would you run?
Just a small test digestion,or a 20L reaction vessel overnight with a slow pacifying leach.
My system has a 400w pump so I only use it when I am going to produce an excessive amount of NO2.
For small test's I just wait for a windy day,It comes down to time and cost for me.
No point in spending half an hour setting up a system for just 100ml.

 

[upcyclist]

I'll run the quantities I normally run, where 600-1000mL is my normal beaker size. I don't have reaction vessels per se yet, so while I settle overnight, I don't run reactions overnight.

 

[Viy]

Viy
Please before offering to teach someone anything first outline your own qualifications.
I for one would like to know your work history and background.
This site has a reputation for harboring some extremely accomplished individuals who are good enough to share some insights.
unfortunately, most who try and make money for nothing do not fall into that category and the precious metal trade attracts some of the lowest vermin imaginable,
If you had a paper or where the proprietor of a company of any description your provenance would be easily quantified.
If it is not easily quantified you have no foundation to be selling equipment or teaching very complicated and dangerous chemistry.
The backbone of this site is a scientific investigation and observation of what we have before us.
Please be the one in one hundred who can back up his claims and offers with some substance.
Let us start at the beginning.
Who Are You?
where do you work?[/quote]

Sorry for delay,
I was born, studied and worked in Moscow until 1993. In 1960 I graduated from the Institute of Chemical Technology named Mendeleev. My specialty is in "Technology of organic dyes and intermediates" (see Pic). I have been working in the design institute for 3 years, and then went to graduate school in the laboratory of diffusion processes (distillation, absorption, extraction). Dissertation is named "Study of mass transfer during rectification in columns with a flooded packing" (see. Pic. Abstract). Main article on the topic of my dissertation is magazine Chemical Industry (Russian #3, 1967 see Pic.- 2 pages only). If it is interesting, I will give it completely. The article explains a nature of the phenomenon, namely, a significant increase in efficiency of Raschig rings packing, if it is in continuous liquid, as compared to a conventional column. I did not become to translate consciously: I'm the author, and from the point of view of opponents, I could be interested in a distorted translation.
In the future, the study was stopped. It was found that with increasing gas speed and diameter of the column up to industrial sizes, there are non-stationary processes (gas pulsation), which cannot be controlled. However, in the apparatus of a small diameter and height, unsteadiness was not observed.
Compared to large scale production, equipment used in your workshops is small. From this perspective, the proposed apparatus has a theoretical substantiation and realization of this idea maybe fruitful.
On further briefly, as it is irrelevant. I have 2 more articles on the topic under discussion, and 9 patents. Four of these are methods of isolating amines:

1. A method for isolating Amines №322991 (1971)
2. UK Patent №1411068 (1974)
3. US Patent №4061633 (1977)
4. German Patent №2405911 (1978)

The next stage of my life is not interesting to GRF: for 12 years I have been working at total secrecy in the laboratory of decontamination of military techniques. All publications were strictly forbidden. I have 5 patents of the USSR, which cannot be read: №№72567 (1973), 152452 (1980) 152457 (1980) 148222 (1980) 154805 (1981).
I studied processes of diffusion of toxic substances in polymeric materials and wrote another dissertation titled "The mass transfer at decontamination of surface military equipment". It is completely confidential and stored in archives of the Institute in Moscow I can only show a link to it in the List of scientific papers that I have. From the viewpoint of science, the situation in a secret institute was absolutely unbearable, and I left.
Since then I am an individual in small business: art electroforming (so-called copper cold casting), restoration, manufacturing patina, garden concrete statuary casting, gas-flame spraying metal for decorative purposes, and so on.
I have been here since 1993. I had consultant agreements with Rubbermaid and then Lerio Сorp in field of decorative coatings of polyethylene items.
6 years ago I was making the copper electroformed sinks and on back of my workshop outdoor someone began to dissolve computer scrap in 5-gal plastic bucket. You know the rest.

 

[Viy]

FWIW, I did send Viy a note when he asked who was near his zipcode. He's in a NW DC suburb, and I'm partway between DC & Baltimore. If he brings one to me, I'm happy to post more in-depth pictures, share results of tests, etc. The main checks will be looking for the nox cloud & putting pH paper at the exhaust, as well as just seeing if/when the vacuum motor dies due to exposure.

I don't work outdoors, so I'm not relying zero emissions, just evaluating a product.

Please give me a little time. I remember about your inviting. I am foreigner and write hardly.

 

[Palladium]

I find your areas of research interesting. I to have done some research into those areas for scrubbing gases. Your theory is one that i have adopted for a couple of my own designs. Your problem to me is in the design aspect. Your trying to use a packed tower design and physics. The science your trying to apply is that of the kinetics of a flooded column or bubble column. Scrubbers are not a one size fits all type of thing. For a scrubber to truly be efficient each one really need to be tailored for that application. That dust buster is sucking to much air for the reactor size and i don't think you are getting anywhere near the surface area contact or residence time you need.

Take you 8 2in pvc pipes 2ft long and put clean out caps on them. Band them all together in a bundle or square. Get you some clear pvc tubing size of your choice. Drill holes in the caps 10 thousands of an inch smaller than the size of your hose. Squeeze the hose through the holes and the tubing will expand to make a good leak prof seal. You can mix your scrubber solution in a container, bucket, drum, or whatever. You can then flood the column by applying vacuum at one end and sticking the other end in the solution. When the solution is exhausted and ready to be changed it can be emptied by applying vacuum at the opposite end of the column and back flushing with clean water every once in awhile to remove salt build up.

The real key is what your going to do inside the column. I've tried glass marbles, bio balls, you name it. Though they all worked to some satisfaction, and some good, none really impressed me. You want to find some ground plastics( Google ) about 500 microns in size. Larger sizes may work, but that's where i stopped at. The type of plastic will be determined by the scrubber solution and type of gas you chose to scrub. In each column fill it up about 6in with the plastics. You will need to attach a line filter to the end of each tube inside the column. This will prevent you from sucking the media out. The type of filter you chose will again be determined by the solution type and gas. The plastic will suspend itself within the column and will serve to not only slow the progress of the bubble but provides surface area for the bubbles. Think of a snow globe.

If you use something under 500 microns it tends to ride the bubble from surface tension and not break it up. It acts like a froth column basically. Throw a 5 cfm vacuum pump on the end. You can add 2 more pvc pipes if you want to do a 2 stage scrubber like h2o2 pre-scrub and then a hydroxide scrub. add a single pipe before the scrubber tubes to catch any juice or condensation that may come from the reactor before it gets to the scrubber. That will handle a 2000 ml reaction and more! All cheap, efficient, compact, and easy to maintain! If you want to get fancy add you a ph probe.

With the proper exhaust of course !

 

[upcyclist]

FWIW, I did send Viy a note when he asked who was near his zipcode. He's in a NW DC suburb, and I'm partway between DC & Baltimore. If he brings one to me, I'm happy to post more in-depth pictures, share results of tests, etc. The main checks will be looking for the nox cloud & putting pH paper at the exhaust, as well as just seeing if/when the vacuum motor dies due to exposure.

I don't work outdoors, so I'm not relying zero emissions, just evaluating a product.

A quick correction: I do work outdoors, so I'm not relying on zero emissions. I would of course like to minimize them to the fullest extent practicable (for a hobbyist).

Sorry about that!

 

[Viy]

Thank you to all participants of the forum for views expressed and ideas. Most of messages were convincing, because presented for discussion portable Device can be dangerous for unskilled operators-refiners.
It was felt that the proposed Device replaces a fume hood in professional workshops. It is not right. Nothing can be better and safer to work in a fume hood. In my opinion, the device is an additional tool for refiners-professionals. For example, what if fume hoods are busy, but it is necessary to process a small batch of scrap, or perform procedures not associated with neutralization NOx but requiring exhaust vent (see. below)?
At other extreme is a group of non-professional Refiners without anything chemical knowledge. This is so-called "garage economy", where a fume hood is not, and most likely will not be. In addition, there are some jewelers who want to process own waste in their jewelry workshops not equipped with a fume hood.
I made a modification (see pic.) and have already experienced hydrodynamics of neutralizer in air-water system at extreme loads. In my opinion, depending on options, represented design is suitable for both amateurs and professionals. By degree of process safety there may be various options of the design (e.g.2-3).
The modified device consists of two identical interchangeable sections (conditionally basic and supplementary), connected by a transparent plastic reinforced flexible hose. At peak load, when the reaction can get out of control at a unskilled service or violation of technology, brown gas will be visible in the connecting hose. Then the second additional section begins to absorb gases and to support the first one.
Moreover, alkalinity falls in both apparatuses at different speeds. Let's say you did not do a simple test with indicator paper and did not check alkalinity in both sections of the neutralizer.
Later on at process it was found that concentration of alkali in the first section is low, it does not work well and is visible brown gas in the connective flexible hose. In this case, neutralization of vapors and gases will occur in the second, additional section of the neutralizer.
For economical use of lye, the primary and secondary unit can be interchanged. In addition, the alkaline solution can be exchanged for new in one apparatus only.
Neutralizer has two motor sections (on Pic is shown only one section). One of them is provided with a 5 or 10-m the flexible hose. During operation, it can be removed outdoor. To overcome resistance of 10 meters of corrugated flexible hose, it was necessary to install a more powerful motor (7a instead 2a). Due to the vacuum in the system, when operating the motor at full power and / or temperature conditions, it can cause collapse of 5-Gal bucket of durability 90 mil. It is not dangerous and easy to remove, if you put the motor section in an additional bucket (bucket-in-bucket). Note collapse does not occur at lower workloads.
So, if you:
- Load the reactor above the permissible loading
- Are not able to manage the process of metal dissolution at Refining
- Did not pay attention to that concentration of lye solution in both sections of the neutralizer is already below the minimum
Then fumes will go into the motor compartment of the device, which is on the outdoor. Of course, the motor will not be able to operate a long time in an acidic environment and gradually (not directly) has to stop. Therefore, an additional reserve motor section is provided. It's advisable to install this section next to the Device. Why?
Unfortunately, members of the GRF did not notice that the neutralizer is a universal unit. For example, when using the Device (not in a fume hood), refiners would be able:

- Process filings in Muriatic acid to remove iron
- Precipitate metal with zinc in platinum and palladium refining
- Capture sulfur dioxide gas at sodium metabisulphite treating
- Boil (!) sweeps in concentrated lye to remove abrasive material
- If you replace lye solution for acidic one, in some cases refiners would be able to work with ammonia at washing of diamonds from silver oxide without the hood.
Experienced Refiners can continue this list.
In addition, at refining some type of Gold waste (e.g., Gold filled nylon filters) there is a characteristic smell of nitro compounds. Then you should use the motor compartment, remote from the working space.
Thus, the two motors can be operated alternately depending on the task. Motor blocks can be switched using 3/4 in. PVC Slip Ball Valve, mounted on one sections of the neutralizer (see. pic).
What if there was a power failure. This problem is solved by using UPS. In our case, you need to purchase, for example, "APC BR1500G Back-UPS Pro with BR24BPG External Battery Pack" or simply "APC BR1500G Back-UPS Pro 1500VA 10-outlet Uninterruptible Power Supply". Then during a power failure, 7a motor will continue to run for at least 10-15 minutes. That's enough to dilute the reaction mixture in twice with cold water and prevent the gas emission after stopping the motor. (Since the reactor is under a weak vacuum, it is not dangerous to open it).
By the way, what do operators make when emergency, and electricity is turned off? Close the fume hoods and go out of the workroom? Beforehand grateful if someone replies to this question.

Thank you again. I look forward to continuing the debate, if the proposed design will be useful in your work.

 

[upcyclist]

The modified device consists of two identical interchangeable sections (conditionally basic and supplementary), connected by a transparent plastic reinforced flexible hose. At peak load, when the reaction can get out of control at a unskilled service or violation of technology, brown gas will be visible in the connecting hose. Then the second additional section begins to absorb gases and to support the first one.

A quick suggestion/question: What do you think about using transparent hoses in all sections, to visually monitor scrubbing (as a fallback, where applicable).

Obviously it won't make much difference with clear vapors and gases, but it would be a quick qualitative, visual cue to confirm that NOx is being handled appropriately.

 

[4metals]

what do operators make when emergency, and electricity is turned off? Close the fume hoods and go out of the workroom? Beforehand grateful if someone replies to this question.

Some commercial refiners have backup generators that, at a minimum, will provide power to the scrubber suction blower, the scrubber circulation pumps, and the dosing pumps and controllers.

Smaller refiners will quell a reaction with cold water and cover the reaction with a loose fitting cover and close the fume hood doors to contain any fume that seeps out if need be in a power outage.

When you described the potential causes for problems with the system, you said;

- Load the reactor above the permissible loading

Yet you have yet to quantify permissible loading. So let's make this simple, you are dissolving 14 karat gold shot in aqua regia and using your system to scrub the fumes. How many ounces of scrap can be digested using the system you showed in the picture you posted with the standard startup addition of caustic that you describe in your instructions? A simple answer in grams or ounces will suffice.

 

[Viy]

Yet you have yet to quantify permissible loading. So let's make this simple, you are dissolving 14 karat gold shot in aqua regia and using your system to scrub the fumes. How many ounces of scrap can be digested using the system you showed in the picture you posted with the standard startup addition of caustic that you describe in your instructions? A simple answer in grams or ounces will suffice.

It's my dream. Recently I've moved and now I don't have workshop. I can't work with metal dissolving.
That is why I ask GRF to determine the effectiveness of the Device in extreme conditions.
Today I received one more motor and tomorrow I make at last, the fourth section of the Device which absent on picture. I am ready to ship the neutralizer for testing free without any additional conditions. I hope the result will be known on GRF. Advise shipping address.

 

[glorycloud]

Dear Glory,
Why do not you asked me for helping?
My goal is not only to sell the Device, but also to teach of buyer a safe work on it. In addition to the device, you received 5 step-by-step instructions. If difficulties arise when assembling the device, I explain through Skype. Despite my poor English, buyers understand me.
I immediately respond to emails and never leave the customer one-on-one with the device after the purchasing.
Note, all beginners are afraid at first...

I plan to try and run 3 pounds of this type material (most like in lower left hand corner)
in the scrubber system that I bought off ebay from you. I will be using poor mans AR. I'm not
sure if I can fit more than a pound at a time in your reaction vessel. Hopefully, it will work
as described on ebay and here in this thread. 8)

 

[Barren Realms 007]

Dear Glory,
Why do not you asked me for helping?
My goal is not only to sell the Device, but also to teach of buyer a safe work on it. In addition to the device, you received 5 step-by-step instructions. If difficulties arise when assembling the device, I explain through Skype. Despite my poor English, buyers understand me.
I immediately respond to emails and never leave the customer one-on-one with the device after the purchasing.
Note, all beginners are afraid at first...

I plan to try and run 3 pounds of this type material (most like in lower left hand corner)
in the scrubber system that I bought off ebay from you. I will be using poor mans AR. I'm not
sure if I can fit more than a pound at a time in your reaction vessel. Hopefully, it will work
as described on ebay and here in this thread. 8)
Fuzzy Interconnects small.jpg

You should start of with 1/4 of a Lb first and then grow to larger amount to make sure the system is going to work.

 

[4metals]

The true test will come from a dissolve using classic aqua regia on karat gold or on a nitric dissolve for gold filled or sterling silver. That is where you will experience the NOx required to test this piece of equipment effectively. Poor man's aqua regia does will not be adequate for a true test.

The dissolving vessel pictured in the latest photo appears to be a 2 liter measuring cup. Using the rule I always apply for aqua regia dissolves it should only be filled half way with acid to prevent boil over. So 1 liter of aqua regia will dissolve about 7.5 ounces of karat jewelry, I would think that would be a good start.

Have arrangements been made to provide a unit for testing? I see from this thread that there are members willing to do this for you.

 

[glorycloud]

Thanks Barren. I will start small.

4metals - I think that Noxx volunteered to test the new and improved version of this scrubber.
I am not into gold-filled or sterling refining, so I am no help there.

 

[Viy]

Have arrangements been made to provide a unit for testing? I see from this thread that there are members willing to do this for you.

The Device is ready for testing (see pic). It has two 2-L reactors from Pyrex glass. Last year I processed in them a batch 1 lb (225g + 225g) of watch batteries with Nitric Acid (to obtain Silver) at the same time. But I was adding Nitric Acid by portions to manage the process. Dissolving lasted for approx 1 hour and I didn't feel any smell.

 

[Viy]

I plan to try and run 3 pounds of this type material (most like in lower left hand corner)
in the scrubber system that I bought off ebay from you. I will be using poor mans AR. I'm not
sure if I can fit more than a pound at a time in your reaction vessel. Hopefully, it will work
as described on ebay and here in this thread. 8)
Fuzzy Interconnects small.jpg

Sorry for delay
According to your pic, your scrap seems is Gold plate or Gold filled. If you dissolve it in AR, you receive very dilute solution of gold which will be small admixture.
Later during the deposition of gold from a dilute solution, you get dirty gold with large losses. Therefore first you need to dissolve the basic metals in nitric acid (recovery). Please read my instructions, which are tied to the equipment that you purchased from me.
If you have any questions, please continue contacting me via my email that you have. The thread of this post is a study of operating and extreme characteristics of proposed neutralizer.

 

[Viy]

Have arrangements been made to provide a unit for testing? I see from this thread that there are members willing to do this for you.

Absolutely free I could make 2-3 Devices more and ship them to GRF members in accordance with your recommendation. After testing of operating and extreme loads, I need feedback in detail and in writing. The device remains at workshop and no return is required.
Unfortunately, I cannot produce and ship the Devices at once because currently I make packing by hand and for each Device I need under 3,500 rings.

 

[Viy]

A quick suggestion/question: What do you think about using transparent hoses in all sections, to visually monitor scrubbing (as a fallback, where applicable).

Obviously it won't make much difference with clear vapors and gases, but it would be a quick qualitative, visual cue to confirm that NOx is being handled appropriately.

Thank you that you are taking an active part at development of the neutralizer. Unfortunately, this is a thin transparent polyethylene reinforced hose and its strength is insufficient. In addition, polyethylene film is leaking due to diffusion. This process is similar to one, why sometimes car tires need to pump or balloons eventually lose gas.
I feel that you need working, but you have no air purification. Since the circumstances do not allow me to come to you, you may come over. I'll give you equipment that was already in the works absolutely free, and it will protect you from fumes, gases, and neighbors.