A gallery of home built hoods and fume scrubbers _hood_

[Yggdrasil]

Like I said earlier, I gave the setup too many tries but I just couldn't get the blower to bubble even the water bottle... let alone the other setup for it, so I decided to give up on that

The yellow opening is the fumehood exhaust other than blower. Since the blower wasn't that powerful for entire fumehood suction and just from the opening of the pipe as marked in red. I decided to install another fan for any fumes that don't go through the overhead opening. Both these pipes will connect where the Y-T can be seen and then an extension of the pipe will further go upward 9 feet for clearance. Hope this clears

You really do not understand this.
The bottles are NOT used with blowers but a vacuum source.
The vacuum source are supplied by either a mechanical pump or an eductor (Venturi system).
https://marineengineeringonline.com/operation-maintenance-eductor-ships/
https://en.wikipedia.org/wiki/Vacuum_ejector

For creating a proper venturi system you need a powerful high volume fan that blows past the suction pipe.
And there are no upsides on letting it go through the hood as it will occupy a lot of space.
Let it go behind the hood or what ever fits the area.
But since you are on the "street" you NEED a scrubber and a stable power source, you and the surroundings need to be safe if the power disappears.

 

[Yggdrasil]

Like I said earlier, I gave the setup too many tries but I just couldn't get the blower to bubble even the water bottle... let alone the other setup for it, so I decided to give up on that

The yellow opening is the fumehood exhaust other than blower. Since the blower wasn't that powerful for entire fumehood suction and just from the opening of the pipe as marked in red. I decided to install another fan for any fumes that don't go through the overhead opening. Both these pipes will connect where the Y-T can be seen and then an extension of the pipe will further go upward 9 feet for clearance. Hope this clears

Different possible configurations:
Different routes different color



Edit one illustration was wrong

 

[J.Najam]

You really do not understand this.
The bottles are NOT used with blowers but a vacuum source.
The vacuum source are supplied by either a mechanical pump or an eductor (Venturi system).

I'll admit it, you're quite right I did not. Since we use an air bubbler for aeration I thought this was just supposed to be an extension of the same concept. This means that I wasted a lot of my time after something that wasn't going to work in the first place. A HUGE conceptual error. lesson learnt. But on the other hand I also do not understand ; do we connect the blower pipe directly to the bottle and then the vacuum extracts it from the other end? Is that how it goes?

The piping goes as long as 14ft, post blowing. SO I read the fumes would dissipate by the time it reaches the clearance point by 15-20 ft. Hence the plan. Below is the diagram of my plan, although I directly shared the real life picture but I thought Ill share this one too. It is somewhat close to your 3rd image.

The suction works fine through the single inlet inside the hood. This is how the end result would be

 

[Yggdrasil]

I'll admit it, you're quite right I did not. Since we use an air bubbler for aeration I thought this was just supposed to be an extension of the same concept. This means that I wasted a lot of my time after something that wasn't going to work in the first place. A HUGE conceptual error. lesson learnt. But on the other hand I also do not understand ; do we connect the blower pipe directly to the bottle and then the vacuum extracts it from the other end? Is that how it goes?

The piping goes as long as 14ft, post blowing. SO I read the fumes would dissipate by the time it reaches the clearance point by 15-20 ft. Hence the plan. Below is the diagram of my plan, although I directly shared the real life picture but I thought Ill share this one too. It is somewhat close to your 3rd image.

The suction works fine through the single inlet inside the hood. This is how the end result would be

That depends entirely on what you do.
A Cupric Chloride leach or simple HCl it will do.

For NOx it is not sufficient, that is why I suggested the flask train.
Or you need a scrubber of sorts.
The flask train is driven by by a proper vacuum system, either with an e-ductor system or a real vacuum pump.
The e-ductor system is cheapest and will last the longest.
It can be driven by a sufficient water flow either directly or if that is not available, a tank with a water pump circulating the water.

I still do not understand why you plan a dual system.
You either use a Venturi system or a direct system, both are not necessary.

The rest fumes from the flask train will go into the water tank, if there is any fumes at all.

 

[J.Najam]

It may require some time for further flask train experimentations, bearing in mind the technique you have mentioned.

I still do not understand why you plan a dual system.

I hadn't thought a small venturi setup could take care of an entire hood given the size so a dual system was always in play. Be it with a scrubber or without, Now Ive already carved a couple of holes as can be seen... Is a scrubber with only the blower (overhead pipe) still an attachable/ operational option? If yes, I'll hold onto my current venture as that is my first priority. Will carry out experiments for an understanding and proceed from there.

I cant refill the holes again. Please let me know if it still seems feasible. And there are too many scrubber posts, which of those would help me in this situation?

Thanks

 

[Yggdrasil]

It may require some time for further flask train experimentations, bearing in mind the technique you have mentioned.

I hadn't thought a small venturi setup could take care of an entire hood given the size so a dual system was always in play. Be it with a scrubber or without, Now Ive already carved a couple of holes as can be seen... Is a scrubber with only the blower (overhead pipe) still an attachable/ operational option? If yes, I'll hold onto my current venture as that is my first priority. Will carry out experiments for an understanding and proceed from there.

I cant refill the holes again. Please let me know if it still seems feasible. And there are too many scrubber posts, which of those would help me in this situation?

Thanks

I'd start looking in the build your own equipment section.

 

[J.Najam]

View attachment 63727

I put them all together and resized them so they are close (not to scale) to what the setup will look like. The main red pipe is inch and a half PVC and the drops 1". The piping thru the scrubber is still 1/2" but the flow is less restricted in the larger pipe.

The blue line is vacuum and is selected at the valve by the vacuum generator. Each 1/2" vacuum port needs a shut off valve and a PVC barbed fitting.

The fatter pipe provides a vacuum reservoir but when you shut the system, that reservoir can suck water from the reservoir and flood the pipes and become a general pain to deal with. The vent valve by the vac generator solves that. Open it to drop the vacuum and then shut the pump and it will not draw water.

I also have the tubes about 18" off the floor so a bucket can go underneath them to drain into when changing fluids.

Hello sir,

My mind this past week had been so clogged that I completely missed this one and now I think this is probably the closest of how I can imagine my setup to be like given what I have already built.

I do have questions here :

1, The overhead blower does not seem to be connected to the red pipes, so what is its main purposes here? the regular fumes of the hood only?
2, The red pipe does not have any suction or blowing therein as can be seen, so is the science of the entire unit being taken care of by that lone pump at the bottom right end only?
3, 'The blue line is vacuum and is selected at the valve by the vacuum generator. Each 1/2" vacuum port needs a shut off valve and a PVC barbed fitting.' I really don't understand if this would be needed... I would be highly grateful for your response as I'm brain cooked at this point of trying to make this thing work properly.

Many thanks in advance.

 

[4metals]

1, The overhead blower does not seem to be connected to the red pipes, so what is its main purposes here? the regular fumes of the hood only?

The overhead pipe (black in the drawing) is for what the EPA refers to as fugitive emission, it is separate from the scrubbed emission which is indicated with the red pipes.

 

[4metals]

2, The red pipe does not have any suction or blowing therein as can be seen, so is the science of the entire unit being taken care of by that lone pump at the bottom right end only?

The red pipe is powered by a venturi (actually a water powered venturi also called an eductor). The eductor is powered by the pump which recirculates water through the eductor to generate suction which transferred into the red pipe.

 

[4metals]

3, 'The blue line is vacuum and is selected at the valve by the vacuum generator. Each 1/2" vacuum port needs a shut off valve and a PVC barbed fitting.' I really don't understand if this would be needed... I would be highly grateful for your response as I'm brain cooked at this point of trying to make this thing work properly.

The blue line is to use the same vacuum source to pull suction for filtration and solution transfer. The valves are needed to separate the vacuum going to the scrubber from the vacuum going to the filtration suction line (blue). They cannot be used at the same time because the vacuum is not strong enough to supply adequate CFM for both. Similarly but not shown, shut off valves should be on the blue pipe that runs through the hood where little blue circles indicate ports to install suction shut off valves. If you are using the system for filtration having one suction port in use and the other open will result in no vacuum as the vacuum air takes the path of least resistance . That is why we need valves.

 

[Yggdrasil]

Hello sir,

My mind this past week had been so clogged that I completely missed this one and now I think this is probably the closest of how I can imagine my setup to be like given what I have already built.

I do have questions here :

1, The overhead blower does not seem to be connected to the red pipes, so what is its main purposes here? the regular fumes of the hood only?
2, The red pipe does not have any suction or blowing therein as can be seen, so is the science of the entire unit being taken care of by that lone pump at the bottom right end only?
3, 'The blue line is vacuum and is selected at the valve by the vacuum generator. Each 1/2" vacuum port needs a shut off valve and a PVC barbed fitting.' I really don't understand if this would be needed... I would be highly grateful for your response as I'm brain cooked at this point of trying to make this thing work properly.

Many thanks in advance.

To simplify 4metals answer.
Both the red and the blue line is vacuum lines and the colomns are the flask train.

 

[4metals]

I have edited the image to include the vacuum system working to filter a solution. Please keep in mind it can be one or the other, scrub fumes or filter solutions. Open and close valves accordingly.

 

[J.Najam]

The overhead pipe (black in the drawing) is for what the EPA refers to as fugitive emission, it is separate from the scrubbed emission which is indicated with the red pipes.

Oh okay

The red pipe is powered by a venturi (actually a water powered venturi also called an eductor). The eductor is powered by the pump which recirculates water through the eductor to generate suction which transferred into the red pipe.

I think I now understand the concept of an eductor for vacuum generation. I really had no idea how it works, although its late here, but I'll just be on my way to carry a baby experiment with a water pump I have to fully grasp the concept.

Both the red and the blue line is vacuum lines and the colomns are the flask train.

Ah yes but if I understood it correctly both these pipes are obviously for different purposes. While the red goes to the scrubbers, the blue is an extension of the scrubbing unit in terms of only using its vacuum for filtration. But this one I think will be challenging for a novice in my situation so Ill just use a regular gas suction pump that I have. They're not non-corrosive but they're cheap so Ill just keep buying once they're about to die down. Their sound of the coil and machine is a tell. I've used these a lot for past filtrations.

I have edited the image to include the vacuum system working to filter a solution. Please keep in mind it can be one or the other, scrub fumes or filter solutions. Open and close valves accordingly.

Really appreciate it sir! I cant thank all of you enough.

On the other hand, looking at my own setup. I'm thinking 2 possibilities :

1, replace the 3inch pipe of the blower and use a 1 or 2 inch pipe with openings for suction in a closed system with a pvc tube flask train as as shown in these diagrams above.

2, build a scrubber with buckets using the same setup as blower from the left with a venturi into the fumehood as it already is and then lower the pipe into bucket trains as well as eductor suction from the other end?

 

[J.Najam]

Which of these would be better suited for scrubbing? 10 mason jars 7inch by 3.4inch or 5 buckets 7.6inch by 7.6inch?

 

[Yggdrasil]

Which of these would be better suited for scrubbing? 10 mason jars 7inch by 3.4inch or 5 buckets 7.6inch by 7.6inch?

What kind of scrubbing do you think of?
Bottle train or general scrubber?
If you think for the main flow from the hood you need something that leys that volume spend 9 seconds to pass through.

 

[J.Najam]

What kind of scrubbing do you think of?
Bottle train or general scrubber?
If you think for the main flow from the hood you need something that leys that volume spend 9 seconds to pass through.

Oh no not for the hood. Train for reactions

 

[Yggdrasil]

Oh no not for the hood. Train for reactions

Check this thread it has been given to you long time ago.

Even 4metals drawing show it.

Any strong tall bottle that can be made airtight or pvc pipes capped in one end and screwcap in thevother end with two holes for tubes.

 

[J.Najam]

Check this thread it has been given to you long time ago.

Even 4metals drawing show it.

Any strong tall botle that can be made airtight or pvc pipes capped in one end and screwcap in thevother end with two holes for tubes.

Oh yes, Im aware of it. Just checking if these available items are feasible enough for effective scrubbing or no. Otherwise Ill just go with the PVC pipes.

4metals got 4ft pipes of 4 inches in thickness. That'll be too much for me to handle. Given he changed the chemistry 'everyday' due to the nitrate crystals thay would form. Also my material may not be that much in play at the moment.

Just double checking this one if it would be enough

Which of these would be better suited for scrubbing? 10 mason jars 7inch by 3.4inch or 5 buckets 7.6inch by 7.6inch?

 

[Yggdrasil]

Oh yes, Im aware of it. Just checking if these available items are feasible enough for effective scrubbing or no. Otherwise Ill just go with the PVC pipes.

4metals got 4ft pipes of 4 inches in thickness. That'll be too much for me to handle. Given he changed the chemistry 'everyday' due to the nitrate crystals thay would form. Also my material may not be that much in play at the moment.

Just double checking this one if it would be enough

Nothing you have here are suited.
You want tallish containers, they can be thin but should be tall.
Next, they do not have to be inside the hood, only the reaction vessel/beaker need to be in the hood.

 

[J.Najam]

Nothing you have here are suited.

Well thats sad, I thought I could put it to use.

You want tallish containers, they can be thin but should be tall.

but yeah sure, Ill go with this

Many thanks!