3 Stage Fume extractor using Water as first Stage - Page 1
Forum section: electronics / general

author: Zenrei
author_rank: Contributor
timestamp: October 28, 2017, 02:24:00 am
content: Back in the day my father had a nifty Vacuum cleaner from brand called Rainbow. I still think these are around today.Basically there is a chamber with 40% water and the other 60% is cabin head room. The rest is just a normal vacuum extractor mounted on top.The inlet hose feeds straight into the water reservoir. the water acts as a fluid release valve between the vacuum generated in the headspace and the inlet tube.this is also used broadly in hospitals and most pneumatic shop guns to mitigate moisture trapped by compressors.Nevertheless, its a good design for most debris and dirt. however, how effective would such a technique be against smaller particles like those being generated by flux and soldering fumes.im curious if this could be useful as a initial stage filter for a fume extractor.Granted, if it works the water is contaminated and cannot be drained by normal means, however it could be filtered.normal cellulose or carbon filters lose airflow pressure as they get clogged.but back to my original question, would water be a decent media to filter soldering fumes?Im thinking HCL is water soluble and heavy metals would precipitate or bind with the water as well.

author: Ian.M
author_rank: Super Contributor
timestamp: October 28, 2017, 02:52:01 am
content: There shouldn't be any HCL in soldering fumes as acid chloride fluxes are unsuitable for electronics work. Lead has the lowest boiling point of metals commonly used in solder alloys in more than trace quantities, at 1749 °C, and its vapour pressure at normal soldering temperatures is negligible. Any metals present will be bound up in rosin microparticles from the rapid condensation of the flux vapours as the airflow moves them away from the heat source.A water trap is likely to become heavily bacterially contaminated unless flushed, disinfected and refilled daily, and aerosols from bubbling air through a contaminated water trap would be a serious health risk.

author: Zenrei
author_rank: Contributor
timestamp: October 28, 2017, 04:39:02 am
content: Quote from: Ian.M on October 28, 2017, 02:52:01 amso your saying the fume particles would stay in aerosol form even after being submerged in water?I was also under the impression that rosin had anti bacterial properties

author: Zenrei
author_rank: Contributor
timestamp: October 29, 2017, 09:26:32 pm
content: Quote from: Ian.M on October 28, 2017, 02:52:01 amthank you Ian for taking the time for me.im trying to avoid sinking a lot of money into an off the shelf version, if it can be DIYed

author: Ian.M
author_rank: Super Contributor
timestamp: October 29, 2017, 09:54:00 pm
content: If you use a water trap, bubbing air through it will invariable pick up microdroplets of the water in the trap. Unless its kept scrupulously clean, that puts you at risk ofLegionnaires diseaseand other illnesses caused by bacteria that can breed in water at room temperature, and be transmitted by inhalation of microdroplets or dust particles containing spores from dried up microdroplets. You cant use most anti-bacterial chemicals in the water, as inhalation of microdroplets containing them is also harmful.

author: Gregg
author_rank: Super Contributor
timestamp: October 29, 2017, 11:38:12 pm
content: A miniature water curtain would work. I remember paint booths that had a water curtain at the back wall. It consisted of an inclined surface that the water ran down in a continuous sheet. The incline was about 15 degrees from vertical so that the water wouldn’t spray much into the air. A pump circulated the water from the sump below and spread it evenly at the top of the water wall. Baffles directed the air to the water wall and the exhaust fans pulled air from behind the upper baffle. A quick search will find lots of pictures that might give you inspiration. A miniature water wall may be more efficient than trying to bubble air through the water. Some surfactant like non foaming dish detergent would reduce surface tension to trap maximum particles and provide some protection from growth of bacteria and other nasty things. There are lots of biocides available from companies that cater to water treatment of cooling towers as well as swimming pool chemical suppliers. Bromides and iodides are effective and don’t smell as much as chlorine bleach. Or you could just change the water every couple of days as most municipal water systems use sufficient chemicals for that amount of time.Another vacuum cleaner that used water to trap dust was the Rexair which, if I remember correctly, merely had a pan of water at the bottom that the intake port was directed toward.

author: Zenrei
author_rank: Contributor
timestamp: November 04, 2017, 10:47:43 pm
content: Quote from: Ian.M on October 29, 2017, 09:54:00 pminteresting. i only thought of the water trap as a first stage for most solids, the other 2 stages would be your typical air filters, but was hoping the water trap would extend the life of the other filters and curve the loss in suction.

author: cdev
author_rank: Super Contributor
timestamp: November 05, 2017, 12:38:59 am
content: Ian is totally right. Fountains and air conditioners and anything like that with water inside serve as a habitat for bacteria like Legionella.I am a advocate of one specific way of getting rid of solder fumes, and its something called a heat recovery ventilator.One could be built one's self. They sell cores for them on Aliexpress.But I own a commercial HRV and its been very useful. Basically its a powered ventilator that exchanges air in your indoor space with outdoor air, year round, while moderating the temperature difference. There is no need to buy filters, the filters it comes with last forever and are washable.Activated charcoal filters in home air cleaners don't effectively remove toxic fumes for anything even distantly approaching the length of time they are used, they are mostly just for show.It seems to me that most solder fume extractors do perform a valuable function of moving the smoke some distance away and diluting it, but only something like an exhaust vent or an HRV will remove the smoke A one way exhaust vent also pulls make up air into your house and if its pulled through holes in the walls its likely dirty air. An HRV is balanced and it replaces the air it exhausts with clean outdoor air, after warming or cooling it with the outgoing stale indoor air.I think they pay for themselves pretty quickly in reduced energy bills.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 05, 2017, 02:11:44 am
content: Here's a long discussion about building your own HRV:http://ecorenovator.org/forum/conservation/891-diy-ventilation-heat-exchanger.html

author: Marco
author_rank: Super Contributor
timestamp: November 05, 2017, 03:16:32 am
content: HRV makes sense if soldering is your job. For a hobby I'd be surprised if you ever recover the cost from the lowered heating bills compared to just venting period and having a little more incoming cold air.PS. maybe it's different on Antarctica

author: SeanB
author_rank: Super Contributor
timestamp: November 05, 2017, 06:07:44 am
content: Cheap filter media is the $2 refill pack for a regular kitchen extractor. that has a spun polyester mat that is large and which can be cut to make a good number of filters, and if you stack 3 or so to grab most of the smoke it will do for occasional use, just toss when finished. otherwise just a fan to dilute it, will work in most cases, though if you want to just using disposable charcoal AC filter media will work, use one per job, and keep them in a hermetic sealed bag so they do not adsorb ambient odour before you use them.

author: cdev
author_rank: Super Contributor
timestamp: November 05, 2017, 01:45:57 pm
content: Marco, you're very right about climate making a big difference.So, I made a very long post here giving a half dozen cost-based arguments for HRVs and powered ventilation. They were so good that they are scary. And the costs which people could avoid are so large as to be life altering.There is much much more to this issue than solder fumes. Do you want to hear them?Quote from: Marco on November 05, 2017, 03:16:32 amWith all the potential problems caused by things in our indoor air, there is now a growing need for powered ventilation that impacts people in a great many settings. Much newer construction in the US and elsewhere needs powered ventilation. Other problems exist commonly in older homes, also people retrofit and bring a lot of things into their homes that have problems. They are causing hundreds of billions of dollars annually in increased health costs for the world, and those costs are rising rapidly.Some of the causes are non-obvious. For example, flame retardants used in foams used in furniture and insulation. Plastics used in carpeting and flooring. Binders and plastics used in construction materials and wood substitutes. The ambient dust in many homes is now estrogenic.Also, there are major problems with mold which can occur due to humidity and once the toxins that cause these problems are generated some of the worst ones persist indefinitely until physically removed.When these problems occur, sometimes fixing them can entail substantial costs. Costs that can exceed the cost of completely replacing the building. The human costs of these issues can be astronomical.So HRVs to constantly dilute indoor air with fresh air all the time make a lot of sense for everybody, even people who do no soldering at all, ever.

author: Zenrei
author_rank: Contributor
timestamp: November 05, 2017, 03:05:02 pm
content: Quote from: cdev on November 05, 2017, 12:38:59 amQuote from: Marco on November 05, 2017, 03:16:32 amthanks guys. i had come across these briefly before. i would see them typically get mounted on window.unfortunately for me my only access is a big sliding door. during the summer i wouldn't mind putting something up but for the cold winter days its not an easy option. so i would definitely need to contain it inside.I'm glad i posted this, in the last 3 weeks I've read so much about legionella.the driver for the water phase was to suction drop from clogged filters and extend filter life, but it seems more trouble than its worth.unless there is some sort of other medium (oil, glycerol etc) or cheap additives to mitigate the issue at a low cost, i don't see this being worth it.im also glad given it sparked a great conversation about safety and ideas for ventilation among other things.

author: Ian.M
author_rank: Super Contributor
timestamp: November 05, 2017, 03:35:26 pm
content: Oil and Glycerol mists also carry a high risk of lung problems so again avoid bubbling air through them. Probably the best option is to use the cheapest possible filter media (e.g. cut to size cooker hood filters) as a first stage filter to reduce the rate that later, more effective filter stages get loaded up.However it may be possible to set up effective ventilation via the sliding door. One approach would be to get a board long enough to fit from top to bottom in the tracks and fit it with similar latch hardware to the door, or some other means of holding it tightly between the door and frame or between the two doors. Apply some foam draft excluder tape to the edges to get a reasonably good seal. Mount your vent duct intake and outlet through the board. You'll probably need to chink between the sliding glass door and the fixed glass with a long strip of bubblewrap or similar.

author: Marco
author_rank: Super Contributor
timestamp: November 05, 2017, 05:52:56 pm
content: Quote from: cdev on November 05, 2017, 01:45:57 pmMy point is that solder fumes venting is such a tiny part of your heating cost that there is not so much more to the discussion for HRVs, but solder fumes are almost entirely irrelevant to the discussion.You can vent regardless. If you have a small window get some plexiglass, put an airduct through and jerry rig it in the window when you solder.PS. how about a solder fume extractor which simply puts an extra hollow tube around a T12 tip? The heater is far in front, so it shouldn't inordinately heat up the air and you could guide the air path go through the handle without making it bulky.

author: cdev
author_rank: Super Contributor
timestamp: November 05, 2017, 08:51:17 pm
content: A tube around the soldering iron tip would cool it too much - as far as dust it would work well as a collector but better thermally if the collection tube was offset some distance,At least my soldering iron.. would be cooled too much by a tube around it, (it's a Hakko clone, and not such a great one.)

author: Zenrei
author_rank: Contributor
timestamp: November 07, 2017, 03:40:47 am
content: just for the sake of discussion, here is a very rough sketchStage 1 - Liquid Medium to encapsulate mayor DebrisStage 2 - Normal Filter (hepa)Stage 3 - Carbon Filter.

author: Ian.M
author_rank: Super Contributor
timestamp: November 07, 2017, 05:24:27 am
content: Well that wont give you Legionnaires if the HEPA filter is fully sealed at the edges, as it will trap the aerosol, but the combination of humidity and trapped dirt will almost certainly result in bio-film growth blocking the HEPA filter. IMHO it will be a maintenance nightmare for very little benefit.

author: cdev
author_rank: Super Contributor
timestamp: November 08, 2017, 02:18:04 am
content: This design makes me shudder because of the strong possibility of creating more health problems than it solves.

author: Zenrei
author_rank: Contributor
timestamp: November 08, 2017, 03:36:07 pm
content: Quote from: cdev on November 08, 2017, 02:18:04 amits not a design, but a 30 second sketch for clarity and to spur the creative environment for ideas

author: Zenrei
author_rank: Contributor
timestamp: November 08, 2017, 03:41:48 pm
content: maybe some plastic condensers near the surface to promote condensation down?also is there other media other than water that could help in preventing bio film and calcification etc. maybe copper silver treatment. or antifreeze.we are not talking about huge amounts of liquid.let the ideas flow!

author: cdev
author_rank: Super Contributor
timestamp: November 08, 2017, 07:18:25 pm
content: The best thing you can do is just exhaust that smoke outside.