Refrigerated Box for a Dry Kiln?

luke · February 29, 2004, 09:18:13 AM

Stainless steel dry kiln chambers are kind of expensive compared to a refrigerated box from a truck, you can buy one for about $3500.00 a stainless steel one will cost about $25,000.00. A big difference in price. But do the refrigerated boxes work as good as the stainless steel dry kilns?

We have a lot of red oak, white oak, and yellow poplar on our property that we would like to cut, dry and process into mouldings, quarter sawn plank flooring, cabinets, siding, framing, roll top desks etc. to use in our carpentry and remodeling business.

Thanks,

Luke

Fla._Deadheader · February 29, 2004, 10:54:02 AM

Frank Pender, for one, has a reefer box kiln. He thinks it works fine.

oakiemac · February 29, 2004, 12:39:48 PM

Luke,
Hawby has one and likes it just fine. I am planning on getting a reefer as well for my kiln. Around here you can get an old reefer box 24' for $1500 or less. I know a guy selling a stainless steel reefer for $2900.

The only draw backs are that you have to load by hand or make a kiln cart of some sort.

Don_Lewis · March 03, 2004, 04:24:13 AM

There are scores of dry kilns around the country made of shipping containers and sometimes reefer truck bodies. Be sure to buy one that was used for shipping frozen food and ice cream. There are insulated containers that were used for beer etc. that are not well enough insulated. Try to get a high cube container because they are 18" higher and you need that space for fans. DO NOT attempt to buy an uninsulated container and insulate it yourself. Make sure that there are fans the full length and make sure you have enough. We normally recommend one 16" fan every 8' of lenght for DH kilns and one every 5-6 feet for conventional kilns. The stack of lumber will be 4' wide (no more) and in a high cube container, you can load about 4000-5000 BF.

luke · March 04, 2004, 07:14:43 PM

Hi Don,

I found a insulated trailer on the internet looks like it might be one that may work, the price is $3,950.00. You were talking about installing the kiln fans, about how high off the floor do the fans have to be?

www.trailers-online.net/reefers.htm

Thank you,

Luke

Don_Lewis · March 05, 2004, 04:33:35 AM

We normally use a large number of small fans in a container kiln. At least one every 8 feet and more if drying faster drying species. The fan housings are 20". The cart takes up at least 10" so if you can get a High Cube oru railroad container (which are larger than ship containers) do that. I don't know where you are, but you should be able to find a high cube reefer delivered to your yard for $3000-4000.. We are in Maine and I recently had a very nice railroad container delivered to us from Montreal for $3500.

ElectricAl · March 05, 2004, 05:20:23 PM

Luke,

We used a 48' refer trailer for a kiln. It is 8' high and 8' wide in the inside. Cost $1800 delivered. Our wheel loader was used to hold the body while the dollies and suspension were removed. Now it sits on gravel.

We bought some spare kiln carts from another local sawmill and then made our own rail system. There is 20' of track outside the chamber. Then a 5' splice is set between the chamber rails and the staging rails. The carts roll with two people.

Inside the chamber are 8 - 3550cfm fans, and 2 custom built hot water heat exchangers. A 500cfm blower is used to power vent. To control the kiln we had Nyle build a custom Wet bulb / Dry bulb controller. The system works great from green to dry or 20% to dry. We follow the conventional kiln schedules.

Heat is from a Heatmor outdoor wood burner.

It also works good for quick storage when available.

luke · March 05, 2004, 07:16:17 PM

Thanks everyone,

sounds like the refrigerated reefer for a dry kiln chamber will work good and be a valueble asset to a small sawmilling operation.

Thank you,

Luke

Frank_Pender · March 07, 2004, 07:15:46 AM

Luke, a friend of mine out here on West Coast purchased a 42' stainless steel refer trailer for around $4,000. It is doing great. He uses a wood fired water furnace for heat. In fact he is heating two 42' units.

My unit began as an experiment in drying. I had a very good chance at a 24' refer trailer for less than a $1,000 and took a chance.

Larry · March 07, 2004, 04:26:27 PM

Al,
How did you size your heat exchanger and how are they made? Would a radiator out of an old truck or heavy equipment work?

Looks like you weigh down the stack with a concrete slab to insure flat lumber.

Would you do anything differently if you built a new one?

ElectricAl · March 08, 2004, 05:32:38 PM

Larry,

Boy you got a good eye. That is a 4" slab of concrete. We had two but someone got a little rammy jammy and broke one. I'll make a couple more this spring. We have a 50 yard pour as soon as the ground is fit.

The heat exchangers were custom built by a radiator shop that specializes in race car and street rod hand built radiators.

I do not know the exact btu output, but it throws out way more heat than a truck radiator. Costs a little more but it's worth it.

The core size is 24" wide and 30" high plus the 4" x 4" tanks top and bottom. Core tubes run up and down. Cost $200 each times 2. Then I added a 16" fan and shroud from Grainger and connected the radiator with an aluminum sheet stock. The whole unit is around $350 each.

You asked what I would do different next time.
If the whole thing burnt or blew away, I would build two 2000' chambers. Or even a 1000' and a 3000'. Several times pre year the kiln is tied up with 1000' of something odd, like 8/4 red oak or 5/4 quarter sawn white oak.

We'll see what our business does over the next 5 years. We may part out the old kiln and build two or three small chambers in the current saw shop.
Then build a new saw shop. ;D

As you can see I'm trying to figure out a way to justify a new saw shop. ;)

Den Socling · March 08, 2004, 05:43:11 PM

One of the companies that I work for built a new warehouse over an existing warehouse. The concrete in the old warehouse was too thin (4") so they cut it into manageable pieces and carried them outside where they still sit. Too bad they can't get to people who could use them.

ElectricAl · March 08, 2004, 06:27:17 PM

Our neighbor worked for a company that had done a building addition. The contractor had removed two concrete panels from a wall. The pieces sat in the back lot for 3 years. Finally the company decided to land fill the pieces and called a crane service for a price. The bid was $1000 minimum in advance not to exceed $5000.

Well, the neighbor being the quick thinker told the boss he could remove the pieces for $1000 even and no hidden charges.

In less than a 1/2 hour a check for the 1000 bucks was on the neighbors desk. The boss asked how the concrete would be moved. "Tomorrow, wait till tomorrow"

The next day the neighbor drives his JD 4020D into town pulling a converted school bus chassis. Then with two 8000 lbs forklifts the slabs of concrete and set on the bus frame and chained down.
Each slab was 12" thick 48" wide and 16' long and weighed 9500 lbs.

At the end of the day the neighbor fires up the 4020 and drives out to our place. Neighbor offers us one if I will set the other one in his creek with the wheel loader.

Nice neighbor.

Enjoy the story?

Now go back up to the photos posted above. The outdoor track for the kiln is sitting on my free slab of concrete. ;D

Kevin_H. · March 08, 2004, 06:50:19 PM

QuoteWe'll see what our business does over the next 5 years. We may part out the old kiln and build two or three small chambers in the current saw shop.
Then build a new saw shop. ;D

As you can see I'm trying to figure out a way to justify a new saw shop. ;)

keep working on it Al, Where theres a will theres a way. ;D

My question is where ya gonna put it?

ElectricAl · March 10, 2004, 04:57:40 PM

Kevin,

The concrete were I stack the logs cost $20,000. Bet I don't move too far away ;)

How's that new to you TimberKing?

Kevin_H. · March 11, 2004, 03:29:34 PM

Well the TK isnt running yet, we cant get the motor to run, but we are still working on it. got some new run caps comming in.

I wish we had had the time to stop back by to take a look at your kiln set up...maybe next time.

MobileSawmillNJ · January 10, 2015, 09:57:24 PM

Hey there Don,
Where are the slabs located? I am in NJ, and I get around the state pretty regularly with my NH LS190 Skid steer, and an old F600 dumper. Would love to get hold of a few of those slabs...
Anthony

Quote from: Den Socling on March 08, 2004, 05:43:11 PM
One of the companies that I work for built a new warehouse over an existing warehouse. The concrete in the old warehouse was too thin (4") so they cut it into manageable pieces and carried them outside where they still sit. Too bad they can't get to people who could use them.

YellowHammer · January 10, 2015, 10:55:22 PM

ElectricAl, really nice setup, what is the track made of, it looks like regular railroad track? Does the floor of the trailer have any issues supporting the fully loaded carts or was bracing required?
Thanks
YH

ElectricAl · January 12, 2015, 06:30:05 PM

YellowHammer,

The Track is a build up of 2 common metal parts.
First is some 3" C channel with the legs down.
Second is 2" square tube with 1/8" wall welded on top.

Works good, how every 1/8" wall thickness is too thin for long term use. It is crushing.
We just laied the channel in the grooves of the floor.
The floor does flex just a little, but the weight is close to the main frame of the trailer.
No major issuse .