Constructing Fume Hood

[Matt “Ducky”]

When I can I always try to build instead of from the store. Most the time I get frustrated because of the poor materials used improper electrical and even saw me where they use the wrong motor type. I will be trying to start building it right away since I kind of wanna start this but I will not begin until I get all the safety checks completed.

Somebody asked Aqua Regia was dangerous. it is very dangerous very corrosive will dissolve most metals. But not only is it corrosive it releases chlorine gas hydrochloric acid and nitric acid combined and normally will starIt is very dangerous very corrosive will dissolve most metals. But not only is it corrosive it releases chlorine gas hydrochloric acid and nitric acid combined and once you apply heat to it. which will accelerate the process.

If y’all are interested I will add to this post as I start building it. I’m glad to be here

 

[wabbit]

New here. Sounds like a fume hood is an overhead exhaust fan for the enclosure. Is it more elaborate than that?

 

[Yggdrasil]

New here. Sounds like a fume hood is an overhead exhaust fan for the enclosure. Is it more elaborate than that?

That is the basic idea, but depending on the kind of operations you do it can be a bit more complicated.
Many here use a venturi system in stead of a direct fan due to the corrosive gases.
Check the threads for building your own equipment.

Edit to fix autocorrect.

 

[slickster37]

I use a 4 inch pvc tube with 3/4 in. holes in one side , filled with activated charcoal and out the window. I have a plexiglass enclosure with a hole in the top. i have a waterproof 12 v. marine fan in the top and that seems to work really well. The activated carbon I make myself from mesquite charcoal and that makes it a lot cheaper. My setup moves enough air that a had to put extra holes at the bottom of the enclosure for better air movement.

 

[goldshark]

Just curious how activated charcoal works, over say Limestone gravel, for acids.

 

[Matt “Ducky”]

It’s coming along. Sorry it’s taking so long, but I had to Create a little bit of infrastructure, so to speak, for safety reasons before I even started. But it’s coming along well. I still need to put in the electrical outlets and the lights, but I’ll put the exhaust fan on top in the back. I haven’t had to run into any severe issues yet, but I’m sure one is coming. I think I designed it pretty well to cover my bases, but theory and application, you know, lol. I’ll post some later, and I got it, but I need to do some editing, lol. I have been storing up all the items I get after I depopulate, so I have plenty of gold to extract and silver. But I was not even going to do any of it without that fume hood I know how bad can be and the chlorine gas in the other ones that it releases.

Answer the question about THE is it more like a bathroom fart it’s actually made to a stand it a little bit better because of the acid really it’s more so because of the chlorine gas everybody remembers chemistry 1 oh one chlorine negative ion it is very very corrosive there’s a few things I could try to keep mine lasting a while but it should I mean I’m only planning on Doing gold and silver more than once a month unless I get a lot a lot of it and then I have no choice but we’ll see I want to maximize and minimize overhead lol. I still got it right up my pprocedures as I like to be thorough maybe too thorough sometimes but don’t wanna lose any more fingers lol.

 

[4metals]

Using the basic rule of 100 cfm per square foot of opening for general fugitive emission, you will either need a big blower or some doors or a sill to close off the opening when reactions are working.

And fume scrubbing is an entirely separate matter.

 

[Matt “Ducky”]

Using the basic rule of 100 cfm per square foot of opening for general fugitive emission, you will either need a big blower or some doors or a sill to close off the opening when reactions are working.

And fume scrubbing is an entirely separate matter.

Yes I know the equation but you realize I’m still building it right and yeah I know about the front face I it’s gonna be polycarbonate I already have it I said put it on there yet and only half of it will be able to be actually open at any time The half will be I did the calculations and it comes up to like 330 CFM is what I needed but I have a 720 CFM fan and I think I’ll be all right I also have it going from 8 to 4 so the speed will be increased pushing out the same amount of 720

The Gaussian dispersion equation. Along with the other equations this one is one of the most important that I had to deal with
If you’ve never seen this equation before Louis then you need to learn it and understand it because it will either make your life better or it’ll make your life worse for not knowing it when you don’t have scrubbers clean the air before it’s released then you can do it if you shoot it up in the air And beyond a certain point depending on a few other conditions then you don’t have to worry about the air being toxic whenever it comes back down what I did was I just did it for the worst possible conditions absolute what’s the worst possible weather conditions and then of course I wouldn’t be out doing it during those days but I made it up enough not worry

 

[goldshark]

It sounds like you are sucking the fumes through an impeller. Is this correct?

 

[4metals]

The Gaussian dispersion equation. Along with the other equations this one is one of the most important that I had to deal with

Gaussian dispersion is no substitute for proper fume scrubbing. It is simply a fancy mathematical way to describe spreading fumes out evenly so nobody notices you are not doing it properly. In populated areas it is not effective because most people have noses.

 

[anachronism]

I'm a big believer in having a proper baffle plate to provide the correct airflow rather than simply attempting to suck air up through a hole. There's a lot of resource on "t'interweb" (as we say in Yorkshire) to help you with this Ducky if you search. Simple and effective to sort out, and much much more effective.

 

[Matt “Ducky”]

Gaussian dispersion is no substitute for proper fume scrubbing. It is simply a fancy mathematical way to describe spreading fumes out evenly so nobody notices you are not doing it properly. In populated areas it is not effective because most people have noses.

Lol it's the poornans gorn of

I'm a big believer in having a proper baffle plate to provide the correct airflow rather than simply attempting to suck air up through a hole. There's a lot of resource on "t'interweb" (as we say in Yorkshire) to help you with this Ducky if you search. Simple and effective to sort out, and much much more effective.

wow thank you.

 

[Matt “Ducky”]

It sounds like you are sucking the fumes through an impeller. Is this correct?

that’s pretty accurate exhaust blowers are just a gas form of a pump so yeah it sounds very accurate. But on mine I’m not just using the pump to help move the gases away using physics to help the hopeful mass egress but I’m also not taking any chances I may not be able to afford a scrubber but it will be safe I don’t see myself well I’m gonna try my best not to extract the gold but once a month unless I build up real quickly I think once a month is fine it’ll save so much all that chlorine gas. One of the reasons I’m doing my best to make this a very portable female hood so I can move it around the property if need be .

 

[Yggdrasil]

that’s pretty accurate exhaust blowers are just a gas form of a pump so yeah it sounds very accurate. But on mine I’m not just using the pump to help move the gases away using physics to help the hopeful mass egress but I’m also not taking any chances I may not be able to afford a scrubber but it will be safe I don’t see myself well I’m gonna try my best not to extract the gold but once a month unless I build up real quickly I think once a month is fine it’ll save so much all that chlorine gas. One of the reasons I’m doing my best to make this a very portable female hood so I can move it around the property if need be .

Many here use a venturi style setup, this means the fan never sees any gases.

 

[Matt “Ducky”]

Gaussian dispersion is no substitute for proper fume scrubbing. It is simply a fancy mathematical way to describe spreading fumes out evenly so nobody notices you are not doing it correctly. In populated areas, it is not practical because most people have noses.

I am a big fan of safety, trust me I am but I’m also a proponent of cost-effective safety if we can achieve the same goal one way versus another that is cheaper and less dangerous than less harmful to the environment then we should do so scrubbers can be themselves they do clean stuff out real well but they also clean stuff out real well and hold onto it unless it’s a scrubber that can take in chemical and produce another one and safer that means it’s still holding onto it and on the inside of that chlorine gas inside makes it more environmental issue and deadly the same time as yy oh

 

[Matt “Ducky”]

Many here use a venturi style setup, this means the fan never sees any gases.

that makes sense I was also using Venturi effect but for a different reason I am also you seen a push pool method which I thought would be much more beneficial and necessary for safety if you can push it in and pull it out same time would make sense but I think I understand what you’re trying to say even even Sure method where pools air from system but it never actually goes through the pump yeah I can see how that is very that’s awesome actually do you have any of your designs by chance so I can take a look at it I can pull up basic Ventura system that’s pretty cool I didn’t even think about it that way.

 

[Yggdrasil]

that makes sense I was also using Venturi effect but for a different reason I am also you seen a push pool method which I thought would be much more beneficial and necessary for safety if you can push it in and pull it out same time would make sense but I think I understand what you’re trying to say even even Sure method where pools air from system but it never actually goes through the pump yeah I can see how that is very that’s awesome actually do you have any of your designs by chance so I can take a look at it I can pull up basic Ventura system that’s pretty cool I didn’t even think about it that way.

Search the forum, plenty of threads regarding this in here.

 

[Yggdrasil]

I am a big fan of safety, trust me I am but I’m also a proponent of cost-effective safety if we can achieve the same goal one way versus another that is cheaper and less dangerous than less harmful to the environment then we should do so scrubbers can be themselves they do clean stuff out real well but they also clean stuff out real well and hold onto it unless it’s a scrubber that can take in chemical and produce another one and safer that means it’s still holding onto it and on the inside of that chlorine gas inside makes it more environmental issue and deadly the same time as yy oh

Of course they hold onto it, that is the whole idea with it so you don't spread it around in your local area.
Every now and then you have to empty the scrubber and dispose of its content in a proper way.

 

[Dreamer]

Using a scrubber is a necessity. You're going through the process of thinking things through and trying to do everything right, you seem like an intelligent person. Why not take that last vital step? Every nail in your house will thank you and the parents of little kids in the neighborhood won't accuse you when thier child get's sick.

 

[anachronism]

Using a scrubber is a necessity. You're going through the process of thinking things through and trying to do everything right, you seem like an intelligent person. Why not take that last vital step? Every nail in your house will thank you and the parents of little kids in the neighborhood won't accuse you when thier child get's sick.

Hi Dreamer. I do see your point however it's not quite as cut and dried as it may seem at first glance. The necessity of a scrubber depends upon exactly where your lab is located and how much you are processing., and what you are processing.