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darryl
03-29-2005, 11:22 PM
Some of you may recall that I'm involved in cabinet making currently. At this point, we're moving into a shop where we can produce a higher output from. Questions are- since we have only three phase power panels, we have only 110, 208, and three phase outputs. Is it standard procedure to run 220 v motors on 208 v where there's no single phase service?

Second question relates to spraying lacquer. We need to vent the spray room, but need to keep the smell from leaving our shop, and inhabiting our shop. What's required to accomplish this? We're thinking of absorbing the airborne lacquer itself in a filter of sorts that we can throw out and replace. There must be such a thing- ? How effective?

Then the solvent component has to be either fully recovered or neutralized. We don't have thousands to spend on this - what might our options be?

CCWKen
03-30-2005, 12:09 AM
Since you're not in the US, the usual Fed & State EPA rules don't apply. There are paint booth exhaust filters that will trap the paint solids. Your problem is the VOC's.

Since lacquer thinner (solvent) evaporates so fast, I don't see how you could capture it for recovery. It turns to vapor too fast. If you MUST recirculate the air, you'll need carbon filters to trap the vapor or everyone in your shop will be asleep in 5 minutes and dead in about 15.

I don't know of anyone that recirculates paint-room/booth air. It's just too hazardous. Even EPA controled sites in the US exhaust the VOC's into the air. This is to dilute the concentrations of VOC's. To make it clean enough to breath will cost much more than your budget. If this is a must, you better consult a professional.

precisionworks
03-30-2005, 12:18 AM
Darryl,

Paint spray booths are rarely a do-it-yourself project. Even though filters are available from lots of places ( http://www.airguard.com/paint-spray.html ) you'll also need an explosion-proof exhaust fan, explosion-proof lighting, etc. A Google search of "paint spray booths" will yield a number of sources.

Have you looked at water-based finishes (laquers & polyurethanes)? There is no explosion or fire hazard. The clarity, durability, ease of application & quick cleanup make them a good option. I've been spraying the Enduro brand of products from Compliant Spray Systems ( http://www.compliantspraysystems.com/ ). Everything they make is top notch, stain, filler, sealer, topcoats.

All disclaimers apply.

------------------
Barry Milton

jimfun
03-30-2005, 01:37 AM
I've had some dealings with voc's. The only way I have ever known or used is a afterburner or a thermal oxidizer. An oxidizer is more than likely out of the question so that will leave the afterburner. You may be able to find a small one. Ours was a 25 H.P. 1,500,000 B.T.U. unit used to burn off MEK fumes from an adhesive coating room. There are probably smaller units out there but they use a lot of natural gas. With fuel costs I shudder at the thought of running an afterburner. You may want to consider farming that part of your process out.

darryl
03-30-2005, 01:38 AM
Thanks, Ken and Barry. I didn't think there would be an easy answer to this, so I guess we'll be trying to spray on windy days only- an existing tenant is allergic to solvents and we share the building. Hmm. I will propose the water based coatings and maybe we will be wanting to go that way anyway, for our own satisfaction.

We have an option to exhaust through a roof-top vent, but on this flat roof it could mean that the solvent vapor would be trying to invade the entire building from above. As well, that exhaust path is very short, leaving not much room for filters, etc. My first idea was to vent through a wall, and use a long duct going towards the ground from the second story level room which must be the 'paint booth'. This duct would (hopefully) condense much of the lacquer mist before it has a chance to excape as a cloud. The duct would be open at the bottom near ground level, so voc's would come out there. I expect to find a layer of lacquer laying under that duct in short order, but my hope is, or was, that we could maybe prevent a cloud of it from drifting around the complex.
We definitely don't have any plans to re-circulate this 'air' inside the building, so - safety points noted, as with the explosion proof electrics.

Just occured to me, what of introducing a water mist into the exhaust- (into the duct outside the building) might that facilitate a reduction of the lacquer mist cloud?

Thanks again for the advice.

Jim, your post must have come in as I was preparing this reply. I like the afterburner idea (always liked jets http://bbs.homeshopmachinist.net//smile.gif ) and maybe something could be done here with that idea. I doubt the insurance co would like it though. I'll propose that anyway, maybe it will help to raise some more ideas. Thanks.

I have a feeling that most of the spray work will be farmed out, but we'll still need to do some of our own. Hopefully we can get away with that much.

Almost forgot to ask - is lacquer thinner heavier than air or lighter?

[This message has been edited by darryl (edited 03-30-2005).]

CCWKen
03-30-2005, 03:14 AM
If you have good exhaust filters, you shouldn't have a "puddle" of lacquer at the exhaust port. You WILL have solvent gas (VOC) comming out. You need to filter lacquer spray before it goes into any piping (ducting); Otherwise, it will dry and harden on the sides of the pipe.

The best exhaust outlet will be one that directs the fumes straight up. It's more likely to be dispursed by winds or diluted. The normal exhaust stack is usually 10-12 feet above the highest part of the building and the nearest building within 150 feet.

Your exhaust fan size/HP will depend on the the size of your booth. A booth that is 10'w x 9'h x 25'l will generaly have a 10,000 cfm fan. A quick calc shows that the air in the booth is being changed about 4.4 times per MINUTE! The exhaust stack would be about 36" in diameter and will "shoot" the gasses up pretty high.

I would shy away from exhausting voc's at ground level. They are appt to linger at ground level and accumulate. These gasses are HIGHLY explosive! More so than gasoline.



[This message has been edited by CCWKen (edited 03-30-2005).]

jimfun
03-30-2005, 04:10 AM
Kenccw,
You can't just shoot voc's into the atmosphere.
IT'S ILLEGAL!!! There are 2 ways that the U.S. government will you allow to release voc's into the air. (1) thermal oxidize. Raise the tempature of the voc to over 1600 deg F. for a period of greater than 10 seconds. This will oxidize the the the voc effectively changing it to an inert disolved solid that will fall out of the atmosphere. (2) Afterburner. This will burn off any unspent hydrocarbons and oxidize the voc. One may not release a voc to the atmosphere.

Rich
03-30-2005, 08:43 AM
Darryl,You might want to check out the following forum.They have lots of information on all aspects of finishing and even a couple of threads on the pros & cons of a homebuilt spray booth.There is also a lot of discussion on waterbased finishes.I've been using H20 finishes for the last 15 yrs and won't go back to solvents.Fast dry and recoat time,low VOC and odor,and easy cleanup was why I switched.There are a lot of good products out there to meet any specification and application you might have.I have used the Enduro Barry mentions with excellent results.I'm currently using Bona Kemi Mega,which is a floor finish that also lays out nicely when sprayed for trim or cabinets.
Rich
http://www.woodweb.com/cgi-bin/forums/finishing.pl

jamscal
03-30-2005, 09:28 AM
Industrial Painting and Powder Coating is a good book by Norman Roobol, and can help with a bunch of your questions, I'm sure.

There are also some trade publications which may help.

Electrical:

My 3 phase panel had three 'legs'. Using one leg with the smallest breaker was 120v, single phase, using the double was 220v (or 208?, I'm not an expert) single phase, from which you can run 230v single phase equipment, and finally, using the 'triple', 3 phase breaker, you're pulling power from all three legs, 3 phase, and from this you run your 3 phase equipment.

You cannot run 230v 3ph equipment with 208 3ph power. You'll have to have buck-boost transformers.

But the main point is, according to my experience, you do have 220v single phase.

Again, I'm no expert, maybe one on the board can explain this more clearly and definitively than I have.

Good Luck,

James

kmccubbin
03-30-2005, 11:57 AM
Check the tags on the motors, many 220V 1Ph motors are rated for 208V-240V. You can use two legs of the 3 Phase to get 1 Phase, but spread it out, don't hook all your 1 Phase stuff to the same 2 legs.

Kerry

darryl
03-31-2005, 02:59 AM
Thanks for the replies. I think we'll be fine using 208 for the motors, that's what I'm gathering. If we get a slow-to-start motor or unacceptable rpm drop out of it, then boost transformer it is.

One thing that confuses me is the lack of a ground wire from the breaker panel to the wall mounted junction boxes. Same goes for one of the machines, there's no place for the ground wire to attach. Surely that can't be right- no chassis ground wire? I wired a ground lead to the junction box from the machine, and made my own chassis connection to the machine, but the junction box has no ground return lead to the power panel, except through the conduit itself. Normal or not?

Anyway, the lacquer problem may not be a big one now, as for now it looks like we'll be continuing to farm that out for the most part. What little we still do shouldn't pose a problem. We'll still vent appropriately of course, and it looks like our fan motor won't have to be in the spray room, nor will the switch for the motor. The room will have a dust filter on the opening for air to come into the room, and the air exchange rate looks like it will be pretty fast.

Thanks again for the advice everyone.