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Filtration for Jewelry Repair Shop

We are small jewelry repair shop. We have a rectifier for plating and do torch soldering repairs with flux and melt gold. We wish to filter the air in the shop. What products do you produce that will work. We do not want to go into the roof or incur a lot of expense.

Thanks,

Susan Sandberg
owner - Skokie, Illinois, USA
2003

Well, Susan, that all depends on how much you have to spend and what you are trying to filter from the air. Not many places recycle air, they exhaust it and bring in makeup air. It also will depend on what size you need and where else you can exhaust the air.

James Watts
- Navarre, Florida
2003

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2003

Susan,

There is something that will do a fairly good job and that is called a mist eliminator.

However ! I'm not talking about mesh but about a horizontal unit with 2 banks of sine curved blades. This would need to be constantly washed down ... easy, get a small Poly tank, a float valve (to maintain water height) and an inexpensive m.s. pump delivering min. l0 psi along with a centrifugal aluminum or mild steel fan.

Size? Well that depends on your shop size. For 'office' ventilation they talk about 8-10 air changes per hour. So if your room were 30'x 20' x l0' high, you'd need max.max. 1,000 cfm. .... and the float valve (which works like a toilet valve) is an absolute necessity because due to evaporation the water level will drop especially on a warm, dry day.

A good, well designed and well made eliminator with, as said, two banks of blades @ 20mm centres, will capture l2 microns using 2 gpm/l,000 cfm. ... If you want further data, let me know. P,S, Construction is from PVC.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

A mist eliminator with a constant washdown and the exhaust recycled back into the shop is going to have a very, very high relative humidity. I doubt that you can live with that. If you are not recycling the air, why would you filter it?

James Watts
- Navarre, Florida
2003

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2003

James,

You sure are negative!

Certainly the humidity can rise ... but in some States, where it is already very high, it will drop especially if cold water were sprayed ! And in arid wintertime conditions, believe-it-or-not, a humidity increase is often WELCOME !

I have them in use, albeit the 3 micron design, for l00% air recycle for chromic! Others inspected last week were l5-20 years old and the smell/odour was hardly noticeable, so said an engineer who had never seen them in operation.......and they are constantly sprayed !

At G.M. Oshawa (battery plant manufacture) ... and copied by Delco Remy at least twice ... the air is recycled but l0% - l5% goes to atmosphere to get rid of excess hydrogen ... and these are LARGE manufacturing operations. These were the ordinary CT-120/2 design, as originally suggested, and good for l2 microns capture at full efficiency. This air recycle at G.M. is not new ... what was new was the use of these highly efficient inertial (mist eliminator) scrubbers.

So James, R.I.P. please.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

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Well, Skokie, IL is not arid and a chrome plating shop or a battery manufacturing plant surely is not a jewelry shop. The water temp will go to about 6 degrees below ambient unless you are using 100% new water. Unless there is some steady make up air, I think that the humidity will rise. Your device operation is rather similar to some humidifiers. I fail to see how the humidity could drop. If nothing else, it will decrease the efficiency of the air conditioner in the summer. I will be further pessimistic and say that I doubt if they really want to spend the money for a special designed fume scrubber. Rather than spend that kind of money on a maybe, I would start with a small HEPA with carbon filter-the kind that you get at WallMart. Finally, I do not need to be berated for having an opinion that is different than yours. It is at the very least, inappropriate for this site.

James Watts
- Navarre, Florida
2003

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Maybe in addition to the various icons we attach to letters on our Hotline-letters page, we need oil and water icons to warn oil people to steer clear of letters that have been answered by water people and vice versa :-)

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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James,

You started this off by stating that they would have a very, very high relative humidity. Yes, they would if the ENTIRE room/workshop were 'scrubbed'. But as you know, one only vents those items that need exhausting, not an entire room!

Your suggestion of HEPA would work, could work IF the air is dead clean and not having occasional flux compounds being captured, in which case, the HEPAs being extremely efficient, they would, you must agree, plug up pdq. Also aren't they quite large? One hears of HEPAs being used in computer mfg. rooms where the entire ceiling is HEPA.

Anyhow, what I had proposed was very compact and pretty low cost! Capture? l2 microns versus a 'good' HEPA of 2 microns but dead easy to maintain. (Maybe I'm wrong and HEPA's go down to 0.2 microns but they'd plug up in a second)

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
2003

OK. Till we know how much air they are willing to evacuate to the outside, we are at a dead stop. They said that they did not want to go thru the roof,so do they have a wall to go thru. On the HEPA filter, it should have the charcoal wrap around the filter which will take the larger material out and is cheap to replace. Some of the filters sold are really pseudo HEPA as they only go to about 1 micron and a few even larger. Had another thought, type "smog hog" into google and there is a great number of possibilities available in the links that include units other than the smog hog, which is electrostatic. I looked up Skokie, which is basically Chicago, so they will have access to virtually anything and to installers. I had misplaced their fair city by over 100 miles and had it in the rural IL, where options would be far less.

James Watts
- Navarre, Florida
2003