DIY Vacuum Kiln . . . HELP!

Fla._Deadheader · March 04, 2005, 06:50:45 AM

Hi Reid. We bought them off Ebay, as Liquid Ring. Teech did some digging, and thinks they MAY be vane pumps. Being as how I only will pull ½ vacuum, with the discontinuous Vacuum system, I don't see why they won't work.

From my Dairy Farmin days, I know that Vane Pumps will take moisture and not hurt them, if they are taken care of properly. Besides, they were cheap enough to play with, and get the drying experience, so I could upgrade if needed.

Haven't figgered out all the "terms" involved in Vacuum, but, we would pull 15-16 on the Vacuum guage, with preset "Bleeders" to control vacuum. I am sure we could pull over 17, whatever that equates to ???

I had figgered that ANY decent Vacuum would help in keeping the temp down in a kiln, until time to set pitch. Our Timber is pretty finicky. :

;D

If yer interested, talk to Glenn and he can deal with you. We have more than we need, and he was talkin about changing his plans. HEY TEECH. ;D

FeltzE · March 05, 2005, 07:04:14 AM

fdh

They are hollow on some aircraft with a ribbed surface and others are an inflatable tube, uses about 2 psi.

One advantage you have is that with a simple medium soft solid seal when the door closes and vacum is applied, the seal will be crushed in place by the pressure from the door.

a 12x12 inch door would have 144 inches of surface space with a 7 psi vacum you would incure 1008 lbs of crushing force on the door jam assuming you had a one inch wide seal on that 12x12 opening the pressure per sq inch on the seal would be 21 lbs I don't think that would slip around much

PS I'm sure my simple math has missed some other issues...

Eric

Fla._Deadheader · March 05, 2005, 11:31:19 AM

Thanks Eric. I was referring to the seal coming loose, in case it was knocked by a board or something. The channel would just be insurance and very strong for the door to close into.

Buzz-sawyer · March 05, 2005, 12:05:01 PM

This is , I believe, some thing like the hing you plan on fld?
This is an air tight tank built for wood gas production, but as you can see, the door swings wide out of the way and comes down straight on the gasket (not on in this pic).

And one of it closed

Fla._Deadheader · March 05, 2005, 12:17:07 PM

Dat's basically it, Buzz. Dish Network won't preshiate ya using their antenna mount, though . :D :D :D :D

The way that's constructed, as you said, the door swings OUT, then away. Can't tear up the seal thata way. ;) I'm gonna leave ours loose a little, where the bracket meets the door, so the door can "settle" into place. It will pull down even, then.

With the door swinging away, you don't hafta worry about the bunks of lumber hitting the door when ya load and unload.

Gotta get me a bigger Propane Tank. Need one off a delivery truck. ;) :D :D

Have kiln---will deliver. ;D ;D :D :D

Buzz-sawyer · March 05, 2005, 12:33:06 PM

Use the a/c compressor on the truck to draw you vac and dry while you deliver...just paint it black and its cookin....
I Thought you would like that hinge :D
Suprised you didnt comment on my high tech tank 8) 8) 8)

Den Socling · March 05, 2005, 02:42:06 PM

I couldn't find a good picture but the Italians have an easy way of swinging doors. They weld a boom on two pieces of nested pipe (one inside the other). The inner pipe is welded to the top of the cylinder. The boom pivots. The door hangs from a fork with a roller bearing. The bearing rolls on the boom. yeah I need a picture.

Fla._Deadheader · March 05, 2005, 02:56:19 PM

Den, what's yer opinion on trying things with the Vane Pump, if that's what we really have ???

Den Socling · March 05, 2005, 03:48:01 PM

Rotary vane pumps can pull low pressure and can tolerate moisture but they are intended for applications that require relatively low volume (from what I know).

If you want to dry only 100 bf of Red Oak at a rate of 1% per hour, you have to vacuum-pump out 1/2 gallon of water. That 1/2 gallon of water makes about 114 cubic feet of vapor. A rotary vane might handle that but if you go up to 1000 bf, I'm not so sure.

Fla._Deadheader · March 05, 2005, 04:09:18 PM

Thanks Den. We have several of them, sooooo, how about using more than 1 ?? ;D

Minnesota_boy · March 06, 2005, 12:28:57 PM

Harold,
That soulds like a good idea. As soon as one goes bad, replace it with another. ;D

Doc · March 08, 2005, 09:43:02 AM

Quote from: UrbanLogger on January 24, 2005, 10:43:49 AM
Sergey,

Have not me time do conversions now myself ;);D :D

But I will double check yours as I give you more exact dimensions myself. The dimensions I posted to begin with are a guess from having seen the tank once and if it's like my initial judgement of logs, it'll actually be much bigger. ;)

I would appreciate all the help you can lend

I hear you on the compressor/vacuum question and I am looking into getting a good pump that I could use for laminations too.

How hot does the water in the heating coils need to be? How cold does the water in the condenser need to be?

Are you using stickers to separate the lumber in the chamber? If so, how thick?

I see on your website that your heating coils loop back and forth up the sides of the chamber. Can I use sweated copper for these or will that be a problem in the vacuum?

More questions and specs on the propane tank when I come up with them,

Scott

Hit Surplus center up on the vaccum pump. They had some larger units in the last catalog that may be big enough to do waht you are looking for.

www.surpluscenter.com

carl · March 08, 2005, 09:28:24 PM

HELLO MY NAME IS CARL WINNIPEG MB CANADA
I HAVE BEEN FOLLOWING THE VAC DRYING THREADS FOR QUITE A WHILE. VERY INTERESTING.
IAM A WOOD TURNER AND WOULD LIKE TO GET SUGGESTIONS FOR MY NEEDS EG DISCONTINIOUS VAC DRYING OF BOWL BLANKS. WALL THICKNESS 1-1 1/2 IN USING ELM ASH OAK ETC.
I HAVE A GAST 1/4 HP ROTARY VANE PUMP I USE FOR VAC CHUCKING ON MY LATHE. COULD THIS BE USED....OR HOW ABOUT AUTOMOTIVE A/C UNIT... CHAMBER WOULD BE 14-15 DIA HD PVC WATER/SEWER PIPE. HEAT.. CONVECTION AT NORMAL ATMOSPHERIC PRESSURE. DRYING TIME IS NOT AN ISSUE, WOULD BE MANUAL OPERATION. WOULD THESE SMALL PUMPS BE ABLE TO GET LOW ENOUGH VAC TO LOWER TEMP OF WOOD.. BOWLS WOULD BE HEATED TO APPROX 110 F. CHAMBER WOULD BE APPROX 5FT LOG AND HOLD APPROX 10-15 BOWL BLANKS. SOME OF THE BLANKS WOULD BE GREEN SOME AIR DRIED. THANKS CARL

Furby · March 08, 2005, 09:39:29 PM

Hmmmmmmmm..........
Interesting!
I wanna hear what ya all have to say because I'd make a longer one and do a couple boards here and there, as that is all I need sometimes.