advice on fume scrubber

[delboy9891]

Hi Folks, looking for advice on a fume scrubber, I plan on having an upside down pvc funnel just over my reaction vessel which will be a 2000ml beaker with a small hose going out the side of my fume hood leading to three 500ml gas wash bottles packed with marbles and sodium hydroxide solution with an oil free 2.5 cfm vaccum pump at the end, my question is will this be enough to keep me safe from nox fumes? many thanks in advance for any answers, also how much sodium hydroxide should I add to each wash bottle?

 

[Alondro]

What sort of fumes will you have? The chemistry will be different depending upon the gas released. I'm assuming the 'nox' means nitric oxide?

You can attach an aquarium bubbler to the out-flow end of the tubes, which makes very tiny bubbles, drastically increasing the surface area for diffusion, and use hydrogen peroxide to grab NO2 or SO2 and return them to acid form as well.

Also, without a seal, the gasses will leak out around the funnel. You should find a way to close up the reaction vessel and force the gas to travel into the scrubber. Might want to think about using an addition funnel to add the acid to the material after everything in your setup is ready, with the tube going through some sort of cork in the top of a flask, rather than a wide-mouthed beaker that's hard to seal up well.

If you set it up right, you shouldn't need a pump.

 

[delboy9891]

I will be using a watch glass on top of the beaker and adding small amounts of nitric at a time to keep the fumes to a minimum

 

[4metals]

No matter how well the setup scrubs the fume the small percentage that gets past will eat your vacuum pump eventually. That is why it is best to pull your vacuum with an eductor and water pump.

 

[justinhcase]

I find the KNF Neuberger Edwards chemically hardened Laboratory Vacuum Pumps quite indispensable.
They come up quite cheap now and again on eBay.

 

[delboy9891]

No matter how well the setup scrubs the fume the small percentage that gets past will eat your vacuum pump eventually. That is why it is best to pull your vacuum with an eductor and water pump.

I bow to your knowledge sir, is there a thread on how to set this up?

 

[delboy9891]

I find the KNF Neuberger Edwards chemically hardened Laboratory Vacuum Pumps quite indispensable.
They come up quite cheap now and again on eBay.

I will keep an eye out for one of those, thank you

 

[4metals]

I believe there were some instructions to build a system in the library. Click the link on my signature line to get there.

 

[delboy9891]

Many thanks for all the advice, I have decided to go with 4 metals suggestion of using a water pump and eductor for my suction rather than a vacuum pump which will eventually get damaged with the corrosive gases, could anybody please recommend a good pump and Eductor for the suction for my gas scrubber? I would be grateful for any suggestions

 

[PeterM]

Many thanks for all the advice, I have decided to go with 4 metals suggestion of using a water pump and eductor for my suction rather than a vacuum pump which will eventually get damaged with the corrosive gases, could anybody please recommend a good pump and Eductor for the suction for my gas scrubber? I would be grateful for any suggestions

Buy a Mazzei injector, go to their website....https://www.ebay.com/itm/255163680248?hash=item3b68f0c5f8:g:Y5IAAOSwT1hhW1sb

 

[delboy9891]

Buy a Mazzei injector, go to their website....https://www.ebay.com/itm/255163680248?hash=item3b68f0c5f8:g:Y5IAAOSwT1hhW1sb

Will do, thank you for that

 

[Swissgoldrefiner]

There is paper about the mixture than you may use to quench the NOx. Few of them is a mixture of NaOH and H2O2.

 

[delboy9891]

There is paper about the mixture than you may use to quench the NOx. Few of them is a mixture of NaOH and H2O2.

Ok thank you, I will search the site for that

 

[orvi]

I use aspirator vacuum pump (made of glass) and big 50 L old plastic vat/drum, where I recycle the water using 80W 12V membrane pump (from Aliexpress). I use this setup when filtering corrosive stuff. I also add little bit of sodium bicarbonate to the water to neutralize acids. Not ideal in terms of runtime, but eventually I end up buying better pump which could run for hours without overheating.
For longer filtration I use 12V small membrane vacuum pumps (size of a fist). They are expendable, easy to buy and easy to regulate. Unfortunately, it is good to buy a regulator (like I did), since they overheat after like 15 minutes of continous pumping. But they hold vacuum when switched off, so it is not a big issue. Pump turn on at 700mbar and shut down at 200 mbar. If you have tight apparatus, it will only switch on for few minutes in a hour.

 

[PeterM]

Will do, thank you for that

Ebay has a ton of Eductors, Mazzei, makes a ton of other aspirators, most all of them work. Personally, I like using a water pump system that I put together to scrub the fumes off my electric furnace while roasting scrubbing noxious gasses(tellurides, Arsenic etc). I purchased the pump off of eBay, I recycle the water and it scrubbs the fume using two or three scrubbing bottles or containers. plugs into wall SEAFLO Industrial Water Pressure Pump - 115VAC, 3.3GPM, 45PSI | eBay $99.99. A venturi type vacuum will do the job. I used a Nalgene aspirator $22.08, works fine. Get it from Action Mining. If you need a drawing to set it up, let me know... no problem.

 

[delboy9891]

Ebay has a ton of Eductors, Mazzei, makes a ton of other aspirators, most all of them work. Personally, I like using a water pump system that I put together to scrub the fumes off my electric furnace while roasting scrubbing noxious gasses(tellurides, Arsenic etc). I purchased the pump off of eBay, I recycle the water and it scrubbs the fume using two or three scrubbing bottles or containers. plugs into wall SEAFLO Industrial Water Pressure Pump - 115VAC, 3.3GPM, 45PSI | eBay $99.99. A venturi type vacuum will do the job. I used a Nalgene aspirator $22.08, works fine. Get it from Action Mining. If you need a drawing to set it up, let me know... no problem.

Thank you for that, that looks like a really good setup, I will look at that pump, it is reasonably priced as well

 

[PeterM]

Thank you for that, that looks like a really good setup, I will look at that pump, it is reasonably priced as well

I have used two different types of scrubbing Bottles and scrubbing 2 gal buckets it's your choice. The one pic shows the aspirator next to the orange pump. It works and will keep you alive from poisonous gasses. Good Luck Delboy9891....

 

[delboy9891]

I have used two different types of scrubbing Bottles and scrubbing 2 gal buckets it's your choice. The one pic shows the aspirator next to the orange pump. It works and will keep you alive from poisonous gasses. Good Luck Delboy9891....

Thats a great setup, I plan on having a 5 litre sealed reaction vessel in my fume hood with a hose leading to three 1000ml gas wash bottles filled with sodium hydroxide solution and packed with marbles and a fourth gas wash bottle filled with distilled water to check the ph on a regular basis, this will lead to a centrifugal water pump with mazzei injector and eductor attached to the pump in a 100ltr bucket what psi from the pump would I need to have enough vacuum?

 

[PeterM]

Thats a great setup, I plan on having a 5 litre sealed reaction vessel in my fume hood with a hose leading to three 1000ml gas wash bottles filled with sodium hydroxide solution and packed with marbles and a fourth gas wash bottle filled with distilled water to check the ph on a regular basis, this will lead to a centrifugal water pump with mazzei injector and eductor attached to the pump in a 100ltr bucket what psi from the pump would I need to have enough vacuum?

Delboy9891, you just hit the Nail on the Head. Everything has to be matched in or for it to work. What ever delivery is stated on the pump, reduce it some. What ever the psi of water pressure is needed, believe it and maybe just a taste more(every mfg. lies) or used optimum conditions to which you will never have, got it? This one pictures is from amazon, it is identical to mine. It say it requires pressures as low as 7.5 psig. However, trust me it requires a little more. Th Orange pump I use delivers it. Just as long as you don't choke the hose sizes.

 

[delboy9891]

Delboy9891, you just hit the Nail on the Head. Everything has to be matched in or for it to work. What ever delivery is stated on the pump, reduce it some. What ever the psi of water pressure is needed, believe it and maybe just a taste more(every mfg. lies) or used optimum conditions to which you will never have, got it? This one pictures is from amazon, it is identical to mine. It say it requires pressures as low as 7.5 psig. However, trust me it requires a little more. Th Orange pump I use delivers it. Just as long as you don't choke the hose sizes.

Thats good to know, been studying refining for two years now havent even started yet but knew I had to get the fume scrubber right, it will be the most important piece of equipment I have as I kind of like being alive, the centrifugal water pump I am going to get has a pressure regulator on it so I can adjust the vacuum until I get it just right, cant thank you enough for your advice