# Fume hood and a scrubber



## Refiner232121 (Apr 15, 2011)

I sent 4metals a private message but I dont know how he is going to respond but in the mean time I will post this and see if I can get help.
I am thinking of having the fume hood made in plastic to this size
4 feet length
4 feet height
24 inches depth
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I am planning on making 2 holes and than placing 2 lamps 
from the outside of the fume hooed
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I am thinking of buying a blower that is above 2,000cfm
Also attach a device for changing the speed of the motor
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I dont know if I will need a damper
http://img339.imageshack.us/i/41958822.jpg/

Thanks


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## Refiner232121 (Apr 15, 2011)

Already I see something wrong here
The 6 inch pipe that's going inside the scrubber will be too heavy.
I think I will keep the outside pipes at 6 inches and the pipe that goes inside I will make it 3 inches.
I need help from someone who has done this

Cant I place something in there that is lighter and flexible 
I will ask the place where I will order that fume hood


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## Barren Realms 007 (Apr 15, 2011)

Build you a support above the scrubber to hold the 6" pipe and don't reduce it. Also it wouldn't be a good idea to build your hood out of plastic.


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## Refiner232121 (Apr 15, 2011)

Hi Barren
When I say plastic I meant polyethylene


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## Barren Realms 007 (Apr 15, 2011)

Plastic, polyethelen same difference in a situation of the fume hood. You should conside building it out of something that is non flamable or corossive in nature.


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## Refiner232121 (Apr 15, 2011)

Hi Barren
The person making the fume hood said pvc is better
Do you have any suggestions


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## Refiner232121 (Apr 15, 2011)

That 6 inch pipe inside the pipe could be flexible and I guess it should not be with holes all over it just in the bottom and I may have to put a net or something like that so something from the inside does not get in


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## Refiner232121 (Apr 15, 2011)

affinazione.pdf 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=9197
What kind of material is this company using


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## Barren Realms 007 (Apr 15, 2011)

Metal with an epoxy or ceramic coating would work. Just make sure it is fully coated to protect from fumes. I wouldn't worry about a net on the end of your pipe shouldn't be anything getting up inside of it.


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## Refiner232121 (Apr 15, 2011)

Hi Barren
To make the hood in metal is good but to make the holes will be very hard
unless you find a place that will make the holes or make them with the acetylene torch


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## 4metals (Apr 15, 2011)

> I sent 4metals a private message but I dont know how he is going to respond



I just looked, you didn't send it to me.

I would run the 6" pipe down outside the scrubber and weld it to the side where it goes in. what diameter is the scrubber? And the height?


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## Barren Realms 007 (Apr 15, 2011)

Refiner232121 said:


> Hi Barren
> To make the hood in metal is good but to make the holes will be very hard
> unless you find a place that will make the holes or make them with the acetylene torch



You can use a hole saw that you should be able to get at Home Depot, plumbing supply house, electrical supply house or HVAC supply house.


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## qst42know (Apr 15, 2011)

You could run the pipe right to the bottom of the tank to take the weight. And cut a 6" hole at the proper height above the solution, or many 2" holes if that would be easier.

The area of eight 2" holes would be roughly equal to 6" pipe.

It will be a while before I have the funds for a hood but I was considering this material, expanded PVC, reduced weight and cost expanded pvc foam core. Several companies produce it and some is UV stable but this line isn't.

http://www.usplastic.com/catalog/item.aspx?itemid=44936&catid=733&clickid=searchresults


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## Refiner232121 (Apr 15, 2011)

1) I have to make sure that i buy a sealed container for the lye



2) Barren I like the idea of metal but do you think the Italian machines have metal fume hoods
I mean if I can use pvc than that would be easier to work with
I guess I can make it myself but it is a lot of work
I dont want to make this from wood 
Anyway the person making these pvc fume hoods didnt return my call today so I will
talk to him and see what he says on Monday
I still have time to decide 
If I can do it with pvc that would be better what do the experts think

3) qst42know I made a picture here
http://img34.imageshack.us/i/12167309.jpg/


4) In the picture I have the pipe on the outside 
welding is good or screw it on


5)4metals I was saying that if you can design a system than I can pay for your services
but this is a small project and it might not interest you
My friend wants the refine 2 kilos of gold
so i said 12 inches in diameter for the scrubber


6) This is a frame for the 2 spot lights
http://img863.imageshack.us/i/1copyvg.jpg/
http://www.google.com/imgres?imgurl=http://www.tlc-direct.co.uk/Images/Products/size_3/FL7001BS.JPG&imgrefurl=http://www.tlc-direct.co.uk/Manufacturers/Firstlight/Single_Spots_GU10/index.html&usg=__X8Ue8OvdzAtpZcH_YA68RlQxlPw=&h=537&w=600&sz=24&hl=en&start=15&zoom=1&tbnid=OM8B6SdGlbCK0M:&tbnh=127&tbnw=165&ei=J9OoTbvNIKG00QHsjpn5CA&prev=/search%3Fq%3Dspot%2Blights%26hl%3Den%26sa%3DG%26biw%3D1024%26bih%3D578%26gbv%3D2%26tbm%3Disch0%2C342&itbs=1&iact=hc&vpx=464&vpy=231&dur=358&hovh=212&hovw=237&tx=167&ty=91&oei=H9OoTfHmCIbn0gHx26D5CA&page=2&ndsp=16&ved=1t:429,r:2,s:15&biw=1024&bih=578


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## Barren Realms 007 (Apr 15, 2011)

If you are not going to be using a lot of heat in the hood you could probably get by with a PVC hood. But if you are going to be incinerating and melting in the hood I would not go with PVC. Murphy's law will come into effect.


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## Refiner232121 (Apr 16, 2011)

Hi Barren
He is not going to incinerate or burn ,just boil acids on the hotplate
So I think pvc or polyethylene will be OK

The supplier said he has nuts and bolts in plastic but I am thinking how I will have the Plexiglas door on the hood
I don't want plastic hinges 
I want sliding type how can I mount the rails on the hood
I will ask the supplier for ideas.

Also how am I going to mount the 2 lamps
The design I have is with metal but I don't like it that much


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## Barren Realms 007 (Apr 16, 2011)

If that is all you are going to use in the hood you should be ok.

You can try a 2 part epoxy putty and press the rails on with C clamps to hold pressure to the item. Do a test with the the epoxt and see if it will work before you commit to it.

You could have a piecr of plexiglass between the inside of the hood and your light's. I would use a flouresent light to keep the heat down.


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## Refiner232121 (Apr 17, 2011)

Hi Barren
I have used that type of glue many times before but not for something like this however I have a feeling it will not do the job
I am going to ask the people casting that thing for their advice 
If they can cast the tracks than that would be good.

I forgot to mention that I will have another blower in that system taking the air out direct without a scrubber

Also I will have a sealed container for the lye and not like the one golldie made and that should keep the smell out
However would I need a 3rd blower in that room because he will have buckets of acids and waste water with lye and it can be very strong that smell.
Does anyone have any suggestions
Thanks


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## qst42know (Apr 17, 2011)

Here are some options for a well sealed fluid tank.

http://www.absorbentsonline.com/Poly-Drums/lab-pack-drums.htm

You can see better images on the Eagle site.

http://www.eagle-mfg.com/drums.html


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## Barren Realms 007 (Apr 17, 2011)

qst42know said:


> Here are some options for a well sealed fluid tank.
> 
> http://www.absorbentsonline.com/Poly-Drums/lab-pack-drums.htm



Screw on top's. I like that idea.


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## goldnugget77 (Apr 22, 2011)

Once you have nitric acid boiling in a confined space than the chances are very good that this substance becomes a part of the air that you breath.
When the system has many pipes than that is more of a problem and whatever blower you have isn't going to suck up that nitric in the air.


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## qst42know (Apr 22, 2011)

> I forgot to mention that I will have another blower in that system taking the air out direct without a scrubber
> 
> Also I will have a sealed container for the lye and not like the one golldie made and that should keep the smell out
> However would I need a 3rd blower in that room because he will have buckets of acids and waste water with lye and it can be very strong that smell.
> ...



You have to be careful with adding to many blowers. You may over come the ability of the important one to function properly.


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## Refiner232121 (Apr 23, 2011)

Hi qst42know
When a person does refining in their back yard than they have no problem with the deadly fumes but when it is in a closed shop than it is very dangerous,
The bad thing is that a person does not know the quality of the air they breath because they get used to it 
Before you know it they start to breath in that deadly air and it can have all kinds of bad effects on a person
too many blowers are no good or draft from there and there is no good
I think some kind of a gauge to monitor the quality of the air is very important and that is something we should have.
I don't know where they sell these things maybe someone could find a link


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## 4metals (Apr 23, 2011)

If you have the recommended air flow through the hood, 100 cfm per square foot of hood opening, you shouldn't have an issue. The money you would spend on any air monitoring equipment would be better spent on a decent blower.


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## Frankk12 (Apr 23, 2011)

Hi 4metals
When you boil onions or garlic than the smell goes all over the house and no matter what you do it spreads.
I have been in many places where nitric is boiled and I think it is the same for that.
With a good blower you minimize the amount of the particles spreading but I don't think you can eliminate it completely.
I am just speaking from experience 
I could be wrong.


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## qst42know (Apr 23, 2011)

I think that's the whole point of a fume hood. A kitchen is not designed to contain smells. Who doesn't want to smell fresh bread in the oven? 8)


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## Harold_V (Apr 24, 2011)

Frankk12 said:


> When you boil onions or garlic than the smell goes all over the house and no matter what you do it spreads.
> I have been in many places where nitric is boiled and I think it is the same for that.


Do not confuse a stove hood with a fume hood. They have little in common, including the fact that the vast majority of stove hoods aren't even ducted, but just filter and return the same air. 



> With a good blower you minimize the amount of the particles spreading but I don't think you can eliminate it completely.


An effective fume hood will maintain a slight negative pressure in the room, which should prevent fumes from escaping. It also should be designed such that anything emanating from the operation at hand isn't capable of escaping so long as the blower is operating. Otherwise it's not much of a fume hood and will lull one in to a false sense of security. 

Harold


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