Just landed a different type of solar dry kiln. First, this is an old, used unit that I got for a great deal; it will need some repairs, and I plan on significant modifications to some of the design.
I am very impressed with their design and build quality, considering how long it has been used. The incredible support and documentation, including history of the unit that I got from Roger at solardry.com.au provided real value to me. Amazing support for their product!
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN8997.JPG?easyrotate_cache=1670986875)
This is a 40' container set up with a drain-down solar thermal array and propane backup requiring 240V to power the circulation fans.
Heat exchangers roof mounted with the fans.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9005.JPG?easyrotate_cache=1670992878)
Auxilary LP heater missing.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9007.JPG?easyrotate_cache=1670991355)
Lots of SS inside and a nice track.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9012.JPG?easyrotate_cache=1670987047)
I will need to build a roof for the unit, as well as to mount the solar thermal on. It will also require 20kw of pv to run the fans continuously at this site. Roofs are in my immediate future.
I will try to keep this thread updated with some of the lessons I learn getting this thing going my way.
Twenty thousand watts should run more fans than you can stack in a container. Are you sure that is correct? Nothing to me mind you. It just seems very high.
I would think you would need 6 fans for a 40 ft container but I'm not familiar with that kiln.
The unit uses just over 2kw to run, however, based on my experience with the site, I need about 10x generating capacity to compensate for overnight and cloudy weather. It has some pretty big fans with 3-phase motors; ill see if I can find the cfm to compare. I would like to set it up stock and run a load to get a feel for how it is supposed to work, but hopefully Ill get a roof over it before I am able.
An update: never had the energy to set the unit up stock. Tested the fans, etc. off my 5kw generator. Started working on roof.
PV roof / drying space done. PV landed, waiting to finish getting the kiln under cover to start on power. Getting close.
Building the kiln shed out of small Brushbox (Eucalyptus relative) which is very hard and heavy with lots of movement. Oiling the timbers. Trying to get the frame locked together while it is still green and I can get a nail in it. The last 2 sets of beams are too high to fly with my cx130 excavator. This was yesterday.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9118.JPG?easyrotate_cache=1692493915)
The rest of this post probably should go in the "did something dumb today" thread and a full disclaimer is warranted . Attempt similar at your own risk.
Thought about setting up a Gin Pole or an A-frame on the upper story; looked at attachments for excavators, some are quite slick. I wanted to fly beams though, not build a jib attachment. So I slept on it. Here is what I came up with. Didn't see anything similarly silly on the interweb so I thought I should post for posterity.
I used an extra 8' brushbox 6x6 and with the help of several strategic chain and binders securely attached it to the bottom of the bucket. Simplified explanation: one looped over the cutters and then 2 from that, over the bucket shoulders with chain binders to a double loop of chain on the jib. I then gained about 6' extension for lifting the last 300lb beams. Wish I took more close-ups.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9121.JPG?easyrotate_cache=1692493983)
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9122.JPG?easyrotate_cache=1692494030)
This worked quite well. Before I actually flew the beams I tested it by bringing the jib beyond vertical and shaking it, resulting in no sketchiness or slip. I then added a block screwed on to the bottom of the 6x6 jib, inboard of one of the chain loops securing the jib to the bucket as insurance to prevent the jib from slipping.
Whole operation took less than an hour after my dad showed up to guide the beams in and unhook. No final pictures; cleaned up in the rain.
I've seen these on the company's website and will be watching with interest. These kilns as far as I've are only made in Australia.
Good luck!
Another update: Got the kiln roof racked about a month ago.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9143.JPG?easyrotate_cache=1699747151)
Spent 2 weeks and got a power shed built; functional but still unfinished. Testing out some cheep inverters and batteries. So far I have been impressed. We will see how long the honeymoon lasts. 12KW output at 240v with 30kwh of lithium batteries (only one of the two inverters visible).
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9148.JPG?easyrotate_cache=1699747091)
Been taking care of deferred tasks ever since. Just cut the studs for the upstairs shear walls. Next push will be the pv array.
One more thing I learned along the way. Those front 6x8" beams are 20'6" and my lt30 only cuts 16'. I have previously cut 20' beams on it and it sucked. I opted to freehand mill these two.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9074.JPG?easyrotate_cache=1699750576)
The first beam bowed significantly as I cut the first side releasing stress. This sucked and added a lot of work later removing >1" of crown.
The next log I cut both sides alternating about 1' at a time. This worked really well and the beam stayed very straight.
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9077.JPG?easyrotate_cache=1699751015)
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9080.JPG?easyrotate_cache=1699751019)
(https://forestryforum.com/gallery/albums/userpics/40479/DSCN9081.JPG?easyrotate_cache=1699751020)
I notched and knocked the crown on the first beam, then hand power planed, and notched the bow; figured I would leave it for artistic effect. It is kind of visible in one of the previous pictures of the excavator jib.
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Just wondering about math, here.
You stated that the kiln uses about 2000 watts to run. I assume that is at the designed line voltage I trust that would include the heaters, fans, and any other circuits necessary to function. Does that allow for warmer temperatures to sterilize the wood at the end of cycle?
You also stated that you are inverting from solar to 240 volts. What voltage is the solar array operating at? What voltage is each solar panel providing? (yes, sometimes they can be different voltages).
Is that roof large enough to fit all of your solar panels up on top?
Why did you decide to use solar electric for this setup instead of having the electric company utility run main grid electric to the site?
Looks like you are having a good time with this build. What kinds of woods will you be processing?
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Friend of mine had one of Solar Dryers Australias 20' container based systems. It was a good thing, he was a little closer to the equator than you but 3000' elevation so it chewed a bit of gas in winter but great in summer.
I talked to Rodger once, nice guy, knows his product well.
Why are you building a roof over it? They were designed to have the solar panels mounted on the container roof, seems like a shed over it is self defeating.
Quote from: Sod saw on November 12, 2023, 05:22:13 AM
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Just wondering about math, here.
You stated that the kiln uses about 2000 watts to run. I assume that is at the designed line voltage I trust that would include the heaters, fans, and any other circuits necessary to function. Does that allow for warmer temperatures to sterilize the wood at the end of cycle?
You also stated that you are inverting from solar to 240 volts. What voltage is the solar array operating at? What voltage is each solar panel providing? (yes, sometimes they can be different voltages).
Is that roof large enough to fit all of your solar panels up on top?
Why did you decide to use solar electric for this setup instead of having the electric company utility run main grid electric to the site?
Looks like you are having a good time with this build. What kinds of woods will you be processing?
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The solar array doesn't generate electricity, it's a solar hot water system. The water runs through a heat exchanger in the kiln and recycles back to be reheated again in a closed loop system.
The fans run on electricity hence the need for mains hookup or a generator.
They also have a gas fired auxiliary heating unit that engages if climactic variables mean the solar heating system is that unable to hold operating temperature.
Aloha,
Thanks for the replies, to be clear, I am setting up two solar systems for this. The PV electrical, which will also be useful for other tools around the sawmill, as well as a solar thermal hot water system to generate heat. I may have to add a wood boiler to sterilize as I would like to avoid buying LP with all the extra wood I have as a resource.
LL, the roof over the container is due to a couple of considerations:
- Kiln is over 20 years old and the container has a bit of corrosion; I figured I might have 5 years before a major repair if I didnt.
- My site is big in only one direction, so the container is sitting 90 degrees from how it was designed to mount the solar hot water panels.
- I have been coveting covered space, so I pushed the roof up just a little to make the 2nd story eventually useful.
- Space for more PV if needed.
SS, The choice to go solar is a no brainier for me. A grid hookup and poles to the site would be over 6 figures and then I get to pay ~$.50/kWh.
Tested the unit, it draws 13 amps with the fans on full blast and without the water pump running, so a little over the 2200w on spec.
So let me leave my napkin maths here. Being generous and allowing for 15A draw.
Load:
- Instantaneous draw: 15A X 240V = 3.6kW.
- Daily draw: 3.6kW x 24h = 86.4kWh
PV array requirement.
- Assuming 8 hours of direct sunlight. (overestimate)
- Actual needs: 86.4kWh / 8h = 10.8kW
- I try to at least double my generating capacity to account for cloudy weather, used 5x for my house and it is rare for me to need the backup generator.
I will be setting three arrays of nine panels in series on the lower roof first, 450V. 435 watt units if I recall. I think I will need an additional array but I will design that when I know how much more I need and want.