so i recently got a welch duoseal 1400 pump in. I had one at my last little lab but left before we ever actually used it… my simple question is about venting. the pump has a 1/2 inch machine threaded hole for the oil resevoir/vent. I plan on getting a piece to screw in, that will go into a barb fitting, with a hose out the window. My question is, what are the parameters for proper ventilation of a vacuum pump. Will the pressure of the exhaust simply push the exhaust through the hose and out the window? or will i have oil building up and flowing back down on itselt.Ive seen some people plumb out pipes from the pump to a window with metal pipe,etc. The pump is up on an industrial table, right near a window… whats the proper way to set up the exhaust venting?
You may want a oil mist eliminator on the exhaust, depending on your cold trap situation the exhaust may stink. https://www.digivac.com/product/oil-mist-eliminator-replacement/
the window may work, look into getting exhaust ventilation for your lab.
Since were on this subject, does one still get exhaust mist using this 1400 pump on a spd setup?
I’ve seen discussions on the mist filter options, but if I had the option to pipe out to a window with hard pipe or plastic hose, what would
Be the best option… like I said I’m running a Welch duoseal, that’s going to be under a window. If I were to plumb say some sort of metal piping out of the exhaust and out a window, would that work. Or am I not accounting for heavier molecules/oil/mist falling right back down.
I personally used a mist filter in my home hobby lab which then got plumbed out the sliding glass door via a setup like you describe. A large barb fitting and a press on hose. The hose teminates outside inside some charcoal briquette bags.
The mist filter is not needed at all. If you have a permanent install as likely is the case just clamp the hose to the fitting and any actual mist that can be captured will be. However the mist filter or just hose does not catch nearly all of it. The mist that my EM28 generates looks like smoke it is so fine and it blows right through the mist filter as a hyper fine aerosol. My filter did catch oil and did theoretically allow me to return that oil to the pump but it will not stop the ultra fine aerosol. I finally bent my mist filter on accident and was tired of it in the way and plus it leaked a bit etc., etc. so I trashed it and no worries since.
On the exit end I put the hose into those bags and taped the bags together to provide a quasi labrynth style of noise and mist filter but that is because I have very close neighbors in my apartment. My rig cannot be heard outside more than about two feet from the porch which is a function of those bags and noise abatement. Your pump will have more than enough power to vent through even a very long hose. If you run with ballast open that mist that emits as smoke will be non stop and will deplete the oil with the benefit of cleaner oil in the pump and a hose will catch this too. I do not run a ballist open but the choice is purely one of noise. Those ballasts have a small check valve that cannot be buried in the oil internally and the valve gets noisy so I adopted a swing pressure distillation model that lets me clear the oil intermitently in other ways.
Good luck on getting that stuff fired up! 