A gallery of home built hoods and fume scrubbers _hood_

[SRM]

My first hood was based on a discarded fiberglass shower enclosure. I cut it down, fabricated a top and a door. I left the drain in, cut a hole in the table and used a plastic grid to allow drainage into a catch bucket for any spills. I laid some tile pieces on the grid for heat resistance and cut a 4-inch (100mm) vent for ducting to the scrubber.

 

[J.Najam]

Hello everyone,

I acquired a cupboard yesterday but Im confused on how to further setup the exhaust fan with a scrubber. Although this entire thread is about the same. I would really like some suggestions here before I do any take of my own.

I have a 12v 155 cfm fan, the dimensions of this compartment alone are length 31 inches, height 15inches and depth is about 19 inches.

I thought to cut an 8 inch hole on the side for a fan but I dont know if the fan size is good enough for this compartments gas suction.. then I saw 4metals post about the pvc pipes suction from just the sprout and that probably seems workable here too. So I'm just open to any suggestions.

Also the colour seems very dark so I'd like to brighten it too. Just the regular paint would do? Or do I have to get some acid resistant one specifically

Thanks for your time on this one.

 

[Yggdrasil]

You need a source of suction to suck air through the work area in the cabinet.
Make sure it do not suck the air from inside if you do this in a small room.
Scrubbing is done with the exhausted air from the work area.
If you use a closed system with sucking through vacuum and bottles, it do not need much exhaust anyway.

 

[J.Najam]

Im doing it out in the alley, but its a residential area so scrubbing and exhausting may both be required. A closed system? Sorry I didnt catch this properly.

I also wanted to clear this out, if ee use a blower from one end but not use the vacuum pump on the other end instead just redirect the last opening to a fan or leave it open will it be effective?

 

[Yggdrasil]

I consider the vacuum with bottles as a "closed" system,
as "all" the fumes will go through scrubbing in the bottles and the residual will be drawn into the water system.
A blower system will come in handy to clear out what ever fumes leak out when handling bottles, beakers and such.
What blower system are you planning?
A venturi system?

 

[J.Najam]

I consider the vacuum with bottles as a "closed" system,

Oh OK

What blower system are you planning?

attached pic for what I think

 

[SRM]

For what it is worth, I would suggest using a large plastic tote as a fume hood instead of the cabinet.

 

[J.Najam]

Oh OK

attached pic for what I think

Although Ive read so many scrubbing and fumehood posts, im kind of anxious now with the working space and how to utilize it with the correct techniques and procedures. what do I really do in my case?

Does my diagram suffice for my operations? Do I need to make any changes here?

Thanks for your time.

 

[J.Najam]

For what it is worth, I would suggest using a large plastic tote as a fume hood instead of the cabinet.

Unfortunately, I'd little to no space for a large plastic tote operation. Hence had to decide upon using this one

 

[SRM]

Just be aware that exposing wood fibers to some of the acids used in refining can create a fire hazard at the minimum.

 

[J.Najam]

Just be aware that exposing wood fibers to some of the acids used in refining can create a fire hazard at the minimum.

Oh alright, will bear that. Ive to replace a shelf on this anyways as its wood is torn exposing the underlying fibers as mentioned. Also Ive to cover it with an epoxy paint I guess Ill give it a white one.

But the main concern is the scrubbing setup and Im kind of trying to figure that out atm.

 

[J.Najam]

I have decided to let go of the scrubber as it doesn't seem to be a viable option here if someone has a better suggestion kindly redirect me there. Im planning on using and installing an exhaust fan directly and draw a PVC shaft from the cabinet to near the pipes then install a blower under the PVC pipe
View attachment VID20240922174514.mp4
and extend the opening straight atop. I still am confused about the fan and/or blower needed in this setup.

If anyone thinks a scrubber can be easily setup here, kindly enlighten me with the knowledge. This video is all the working space I really have.

 

[Martijn]

if someone has a better suggestion kindly redirect me there.

Slow reactions in large beakers filled to max. one third to leave room for the vapors (NO2, HCl) to condense back on the wall and watch glass to reuse the acid and your fume hood fan will dilute and disperse the few vapors that do will be escape below emission levels in terms of grams per kubic meter of expelled air.

 

[Martijn]

I still am confused about the fan and/or blower needed in this setup.

If you use a venturi to suck air from the hood, it does not matter which kind of fan you use. As long as the output is good enough to make it work.
Test the flow at the opening of the fume hood with the smoke of an incence stick.
A venturi basically means creating a conical restriction at the point where the fume hood air comes in.

 

[J.Najam]

Slow reactions in large beakers filled to max. one third to leave room for the vapors (NO2, HCl) to condense back on the wall and watch glass to reuse the acid and your fume hood fan will dilute and disperse the few vapors that do will be escape below emission levels in terms of grams per kubic meter of expelled air.

Thanks for the response,

All my procedures are carried out with a watch glass, barely do I remember doing any without it.. I have seen some fume emissions but if they can be controlled by so much then I think as you have mentioned it ahould be okay.

If you use a venturi to suck air from the hood, it does not matter which kind of fan you use. As long as the output is good enough to make it work.
Test the flow at the opening of the fume hood with the smoke of an incence stick.
A venturi basically means creating a conical restriction at the point where the fume hood air comes in.

On the other hand I redrew the diagram based on what I understood so please do correct me if wrong again. Also would I really need a blower here or another simple fan would do the trick too?

 

[Yggdrasil]

I'd do it the opposite way.
Let the blower blow through the venturi and then let the suction in from the side.

 

[J.Najam]

I'd do it the opposite way.
Let the blower blow through the venturi and then let the suction in from the side.

Like this?

 

[Yggdrasil]

Like this?

Like this

 

[J.Najam]

Oh OK. Well here's the issue, if you notice I don't have an opening from the top, rather from the side in the video I have shared. And at this point in time, I'm trying to figure out the best possibility of fume extraction from the hood itself...

 

[Yggdrasil]

Does not matter as the fan should be at the end and blow as straight as possible through the venturi.