Author Topic: DIY Vacuum Kiln . . . HELP! (Read 5361 times)

UrbanLogger · « **on:** January 23, 2005, 10:09:25 am »

Alright Den,

Here's yer chance to show off yer know how!

I was just offered a propane tank, roughly 10' long and 3' in diameter. It appears to be sound.

Before I manhandle this thing back to the shop, will it work as a vacuum kiln chamber?

If so, what do I need to make it into one?

Will the heat coils out of a large 220v ceramics kiln work for the heat (I have one that I'm not using)?

How big would my pump need to be to evacuate this tank?

I assume that I'll have to cut the end off the tank and turn it into a door for construction access and later for loading. Would added flange, rubber seals and adjustable hood hold-downs work for this?

Many more questions to come should this tank turn out to be practical.

WH_Conley · « **Reply #1 on:** January 23, 2005, 10:21:24 am »

Don't know nothin about vac kilns, just be careful puttin the torch to that thing.

UrbanLogger · « **Reply #2 on:** January 23, 2005, 11:51:42 am »

Thanks WH!

i hadn't even considered that yet

Den Socling · « **Reply #3 on:** January 23, 2005, 12:09:06 pm »

Yes, the tank will work. Yes, you should have professionals cut one end and weld on flanges for a door seal.

I would use Sergey's design. Circulate hot water (maybe from a little outdoor furnace) through piping that runs back and forth in the bottom half of the chamber. Put a trough top center and circulate 'cool' water through some finpipe. Stack and sticker your wood with a gap in the center. I can calculate a vac pump to give you various drying rates but, in the end, you can vary the heat to match whatever vac pump you have.

UrbanLogger · « **Reply #4 on:** January 23, 2005, 01:25:44 pm »

Yea!!!! Yippieyitiyay!!!!

The fellas with the shop nextdoor to me do custom concrete castings and as part of their process have become master fabricators building the teel self releasing molds for complicated junction boxes, etc.

They're extremely nice having already offered to mix and pump all the concrete I want at cost. I'm sure they'll be more than glad to help with all the cutting and welding necessary--especially since they've been wanting me to rebuild their barn doors

What is the best way to attach the door?

Where can I find Sergey's design?

How does the water condensed by the cool water running through the finpipe exit the chamber under pressure?

Would the temperatures reached by an on demand water heater be high enough for the heating? Where I want to set it up would be convenient to wire (3 phase even) but complicated to plumb for gas or water. :-/

If I used water for heat, I'd probably run the drainlines from my sump pumps to a passive heater/storage tank. If the controller thought the water needed to be higher, I could have an on demand heater in line and waired to the controller(?)

Last question (not), can a cast iron aircompressor be turned into a vacuum pump?

UrbanLogger · « **Reply #5 on:** January 23, 2005, 01:52:52 pm »

Hey Den, don't spend too much time responding to all the questions in my last post.

I just found the "Vacuum Kiln" thread on all this and I'm studyin'

I'm sure I'll come up with a slew of more challenging questions later

Ga_Boy · « **Reply #6 on:** January 24, 2005, 06:11:12 am »

Hey Urban,

If you don't mind can you keep us upto date on your cost to put this beast intooperation.

After I get my convential kilns up, my next project will be a vac system.

Mark

UrbanLogger · « **Reply #7 on:** January 24, 2005, 07:08:56 am »

Will do GA_Boy!

I'm goin' about this opposite of you. I hope to get the vac up so I can sell a few KD crotch slabs to pay for a Nyle

Den,

I want you to know that your assistance will not be totally unpaid--I'll likely want a small controller from you!

serg · « **Reply #8 on:** January 24, 2005, 09:09:39 am »

Hello, friends! I have transferred(translated) in meters. Diameter of 2.9 meters, length of 9 meters?

? I want to lead(carry out) calculations. What thickness of a wall metal?

?
I think aircompressor the vacuum furnace poorly.
All my design on a site www.vacuums.ru

Sergey

UrbanLogger · « **Reply #9 on:** January 24, 2005, 10:43:49 am »

Sergey,

Have not me time do conversions now myself

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

serg · « **Reply #10 on:** January 24, 2005, 12:05:07 pm »

Scott, hello! You very well understand and correctly ask. I, on a forum can speak, write much. I shall tell the truth. The translator will tell all on the contrary

;DTherefore I do not want that you have gone in the bad way.

Sergey.

UrbanLogger · « **Reply #11 on:** January 24, 2005, 01:06:36 pm »

Ya best watch out Sergey, I'm fixin to get southun on y'all.

How does the translator do on that?

Den Socling · « **Reply #12 on:** January 24, 2005, 04:26:03 pm »

GA-Boy,

If you get a vac kiln, a Nyle would bore you to death.

Urbanlogger,

A vacuum cylinder is normally around 5/16" thick. Pressure vessels are thicker.

The compressor won't work. Water won't compress. get a liquid ring pump that can swallow some water.

The heating water needs to be regulated between 95'F and 140'F. The cooling water should be under 75'F.

Use 'regular' stickers and spacing.

Sweated copper for the heating coils will be fine.

Den

serg · « **Reply #13 on:** January 24, 2005, 07:10:22 pm »

Hello! I completely also in part agree with Den. soon vacuum drying chamber should be in America. We shall meet. Sergey.

UrbanLogger · « **Reply #14 on:** January 25, 2005, 08:06:43 am »

Thanks Den!

That's good news on the water temps--I was hoping that I could go with a passive tank and on-demand heater for the hot and a closed loop for the "cold". It sounds like I could at the temps you spec.

Sergey,

How soon will you be in America? If I build this thing using your ideas and share my results with other DIYs, will I be steeping on your toes?

I look forward to having you come through Memphis and see my little operation. Maybe I could take you to see a couple of the biggest conventional kilns in the country that are just down the street from me.

Be good!

Ga_Boy · « **Reply #15 on:** January 25, 2005, 08:55:50 am »

Den,

I believe you about the Nyle. Just kidding Don.

As in my e-mail last night, I need to decide between two 1500 bf convential units or a vacuum unit. Decissions, decissions, decissions......

I look forward to seeing you and Garrtett in a week or so.

Mark

serg · « **Reply #16 on:** January 25, 2005, 09:12:37 am »

I & partner, we have a lot of work Europe. One Germany, an exhibition Hannover. Two, delivery of the vacuum drying chamber to America. I shall inform in addition time. Sergey.

old3dogg · « **Reply #17 on:** January 25, 2005, 02:49:03 pm »

I sure am going to miss all of this vac kiln stuff but hey!
If you need someone to treat all of that process water that you are going to need send me an email.

UrbanLogger · « **Reply #18 on:** January 25, 2005, 04:02:56 pm »

Whaddya mean treat? Couldn't you just evaporate it outside?

old3dogg · « **Reply #19 on:** January 26, 2005, 02:36:41 am »

Unless you have an endless supply of clean,cold water for your vac pumps and condensors you are going to have to recycle your process water.Either with a chiller or cooling tower.This water will become bio fouled in no time.All of the slime that builds up in the cold loop will clog and rot your system.
I got out of drying[with vac kilns] and into water treatment.So now I can help with your process water treatment.

News:

Author Topic: DIY Vacuum Kiln . . . HELP! (Read 5361 times)