and this is why i wanted to discuss it. first off what is the error with scrubbing 100 percent of the air from the fumehood? to me this sounds like a positive thing not a negative when dealing with these gasses. second what do you mean about the carbon filters? im not really going for longevity im going for safety in my space but also the only carbon filter in that diagram is in the air scrubber itself and those filters are replaceable. and i argued with a.i. for about 4 hours on different designs before settling on this one. firstly with perameters i specified only refining 10 ozs of gold a week or less i also stated that i want the least corrosion of my equipment and i want to safely expel the air 15 ft above the ground. i asked it to run some models using my design and about a hundred other questions.Don't exactly know how AI can generate a design but it seems to have settled on two things, both in error. One is that you will experience any longevity with a carbon filtration unit working on pass through air, and Two, you are scrubbing 100% of the air exhausting from the hood.
Exactly what design parameters did you give it?
I seem to remember a quote (from the internet?) by Abraham Lincoln where he said you can't believe everything you read on the internet!The flaw in AI is that it isn’t intelligent at all. It only collects the most wide spread opinions from the web and is designed to determine that information as being the most correct.
thanks for the responses brothers,I seem to remember a quote (from the internet?) by Abraham Lincoln where he said you can't believe everything you read on the internet!
i want to stress that i am not a commercial operation i will not be doing commercial amounts and my operation will not be in use 24/7 i dont know if that makes a difference to your understandiung of my goals. and i am well aware of a.i. being a text prediction more than intelligence but what it does do is search through amazin amounts of data for you and brings you the highlights and just like humans sometimes its wrong i have a respect for that and thats why im comparing these notes here. now i hear you on the cfms and all that. so lets assume i change the size from 4x3x3 to 3hx2dx3w and recalculate? the air scrubber im looking at is an alorair hepa550 3 stage with charcoal filters are relatively inexpensive my booster fan will be placed closer to exterior but before a final merv filter with activated carbon sheets.The most economical scrubbing is wet scrubbing which will neutralize the fumes, carbon will entrap some of the fume but it needs replacement and that can be costly. If carbon were the method of choice I would expect to see it used more often yet no refiners use it commercially.
The reason you do not scrub everything is size. For effective fume removal, the rule of thumb is 100 CFM for every square foot of hood opening. If your hood opening is 4 feet wide and 3 feet tall that translates into a blower removing 1200 CFM of air. For NOx scrubbing to be effective the fume needs to be retained in the scrubbing section (where the wet chemistry happens) for 8 seconds. To contain 1200 cubic feet of scrubbed air the scrubber needs to be quite large with the packed area alone being 160 cubic feet. For this reason the air exhausted from your hood needs to be the 1200 CFM suggested but that is called fugitive emission and it is un-scrubbed. The scrubbed air can get by with substantially less by using scrubbed drops to pick up the concentrated fumes from each reaction.
I recently worked with a company that set up a modestly sized operation for aqua regia refining and their 3, 8' hoods were serviced by a scrubber with a 625 CFM fume scrubber. To give you an idea of the size that is, I posted a thread about the setup here
man i looked through that thread but its overwhelming i dont know how to construct a wet scrubber like that. the beaker set up i can understand your pulling fumes through the solutions to clean it but i am overwhelmed. all the home refiners ive ever watched dont seem to have that apparatus and just duct it straight out there roof and deal with replacement costs but that method sounds very taboo here id like to find a comfy medium.. now the air scrubber i mentioned is a plastic unit not metal i dont know about the filters but i mentioned those are also fairly cheap too. now im not gonna be sucking the fumes right of the stack they will be dissipated 15 feet of the ground so im not looking for absolute purity just good enough not to harm a nest of birds on my chimney. is there a setup i can build that youd recommend that is both economical and safe for the amounts ive mentioned? and would you have a diagram or image for me to better understand how to implement it in my garage?A HEPA filter will not absorb NOx ask AI it will tell you. Activated carbon will absorb and trap NOx but it will overload.
Then there is the nasty little fact that HEPA filter units with carbon absorption packs are made of metal. Refining fumes eat metal for a living. That's why fume scrubbers are PVC or fiberglass resin.
You can make a very small fume scrubber that will handle your fumes from the reaction sizes you mention. Go to this thread and click on the searches mentioned about fabricating hoods and scrubbers. HERE
View attachment 63665
I built this small scrubber from 4 liter vacuum flasks and used it successfully to refine 50 ounce karat gold lots in my lab. This, or something similar will handle the lots you mention.
can you post the specs on it? i assume its inside the fume hood and with an exhausting fan as a redundancy for fugitive emissions? i also assume you would put a seeing glass over your beaker and the straw in the spout opening and that there is a vacuum pump on the other side out of this picture frame? when i say specs what is the liquid in the flasks and how do i mix the solutions and i see a medium in them what is that and is there a specific amount of it i need? how often does it need to be refreshed?
if i do this and then eliminate the air scrubber and filter box i can essentially vent straight out, but when considering boil overs spills broken glass bad reactions that might be a bad way to do it. but building that is another 500 bucks on top of the grand id need to build my fume hood with an air scrubber and filter box so besides that scrubber what do you use on that rig to vent the fume hood and expell?
edit: i have been on this forum every waking minute since i found it and i just want to say thank you for addressing my questions here while i also look for them everywhere else. i just want you know i appreciate that even though its an annoyance and probably makes look pretty stupid. but i am here in the pursuit of knowledge and passion my kids deserve to see what that looks like AND afforded the opportunity to do it them selves. much love and respect
i found these on amazon i think will work do i need 3 and can i add on after that? do you think this would suffice? than ill need the medium and solutions that go in themI built this small scrubber from 4 liter vacuum flasks and used it successfully to refine 50 ounce karat gold lots in my lab. This, or something similar will handle the lots you mention.
Glassware has gotten expensive and some members made similar setups using PVC pipe and fittings, they were mentioned in the threads I linked above.
That’s it. Thanks.His username here is goldenchild.
Dave
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