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Nyle operators wondering how your kiln works in the end of cycle

Started by Kelvin, December 08, 2009, 08:45:37 AM

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Kelvin

Hey there all.  My kiln compressor might be having problems but i don't know what to expect.  When my lumber gets closer to dry the compressor quits making any water and i think that the moisture that is left is merely getting out through the gaps.  from 20% to 12% i can drive off about 4% or so a day at 100% compressor time and 120 degree, but when i get near 10% or so, it goes down to about 1% a day in oak, cherry, walnut.  Does this happen for your schedule?  Also with 8/4 stuff the compressor really quits working at all and i need to turn it off and turn the temps up to 150 to drive out the remaining core water at about 1% per 24hrs.
help?
thanks
kelvin

Kansas

Our Nyle quits pulling moisture after you get to about 10 percent or so. It depends on the temp of the kiln, and possibly how tight your kiln is. I don't really worry about it. We keep everything running until it is down near 6%. It eventually gets there.

red oaks lumber

the core water is always the hardest to remove, if your kiln is more than 3 years old you might have a freon leak, the copper capularies(sp?) tubes that come from your comp. to the condensor will get pitted and start to get pin holes in it, mine gets soldered every other year. check with your refrigeration man tofind out if you can run different freon, which runs for higher temp.
my nyle dries from12% to 6% in3 days (hardwoods)
the experts think i do things wrong
over 18 million b.f. processed and 7341 happy customers i disagree

oakiemac

Kelvin, your kiln sound pretty normal as compared with mine. On thicker stock, I very often have to raise the temp up to 145ish then let it cool down to get rid of the remaining moisture. Check your humidity level and I bet you will find it pretty dry inside the kiln. I just had a load of 8/4 that I couldn't get below 10-12% and the RH% in side the chamber was 35% which corresponds to about 6-7%mc. So the Nyle was doing all it could but the wood had to be heated up to release the final few drops of moisture.
Mobile Demension sawmill, Bobcat 873 loader, 3 dry kilns and a long "to do" list.

woodhick

I have had the same problems with my Nyle Kelvin. See my post on 8/4" walnut, kinda parallels this conversation.    I need to get the core MC down also.   I have done it on Oak and done the way others have stated.  Shut the compressor down and raise the heat, but I would like to see some type of schedule if some one has one.  After I raised the heat on mine to get the core down  and got it dry, I added moisture to raise the RH in the 35-40% range for  a couple of days to condition the lumber.   I came out ok but was a hit and miss, thats why I asked the question on the walnut I have in the kiln now.   Hope we can figure this out.
Woodmizer LT40 Super 42hp Kubota, and more heavy iron woodworking equipment than I have room for.

Kelvin

Howdy all,
I was wondering what time frame it took you on 8/4.  Say you turn the compressor off and run the heat high for awhile, how long?  Mine seems to be a week or so.  How do you ad moisture at the end?

woodhick

Kelvin when I done it on the last load of Oak I dried and it was a guessing game.  I put a  RH meter in the kiln and when it dropped below 32% I would pour a 5 gal. bucket of water on the floor of the kiln.  Compressor off , temp around 140-150 and circ fans still running. 
Woodmizer LT40 Super 42hp Kubota, and more heavy iron woodworking equipment than I have room for.

5quarter

Kelvin,

   Heres the contact info for the guy who wrote the book on drying hardwood lumber (literally):

Eugene Wengert
President, The Wood Doctor's Rx, LLC
Professor Emeritus, Univ of Wisconsin
(608) 271-4441
WoodDoc@uwAlumni.com

   Alternatively, you can check out his numerous articles on Woodweb, where he is a moderator. I would bet that he knows more about this subject than anyone now living.

Also, You may be able to call Nyle and discuss the problem with them. I have heard that their service is excellent.

Best regards,

Chet
What is this leisure time of which you speak?
Blue Harbor Refinishing

beenthere

Squarter
Welcome to the forum.

I believe (know) the kiln drying of hardwood 'book' was written BW (before Wengert).
:) :)

That doesn't mean he doesn't know a lot.  :)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Kansas

Gene Wengert writes a number of articles for Sawmill and Woodlot Magazine, and has written quite a few for them regarding kiln drying.

Den Socling

Gene sometimes appears arrogant but he has been here at the shop and I have had dinner with him. He's actually a pretty nice guy. WoodWeb, on the other hand, can be arrogant. They have even cut out post that Gene and I had between each other. It's all big business over there. It's the opposite of the family business we have here at the Forestry Forum.

OneWithWood

In my kiln, a Nyle 200 with a Honeywell controller sold by Woodmizer as a WH4000, I average about 2.5% moisture drop per day.  I change my settings as the moisture drop changes.  I usually start out at 90-95°F and RH at 65-70.  As time passes and the moisture loss drops I increase the temp and lower the RH.  I monitor sample boards daily both by weight and meter.

I routinely dry 3500bf of 8/4 most hardwoods from green to 8% in 58 days (oak may take longer).  I condition at the end of the cycle.

My kiln chamber is very tight and there is a constant stream of water exiting the drain pipe until the last few days.

At the end prior to conditioning the temp is usually 145°F and RH 19-20.  I condition by pouring water on the floor of the kiln, kicking the temps up to 160°F and RH to 80 for two days.
One With Wood
LT40HDG25, Woodmizer DH4000 Kiln

DR_Buck

What they said.   ;)

I do about the same thing with my DH4000.   At around 10-12% mc  when the RH drops below 30%  I bump the temp up and turn  the compressor off.   I usually run the temp all the way up to 160°.  This both drives out the final water and kills bugs or set pitch if I'm drying pine.    The few times I was drying 8/4 oak when I did final conditioning I dumped a bucket of water on the floor as others do.   As an after thought I'm wondering if it would serve just as well to sit a few buckets of water in the kiln chamber and let them evaporate.
Been there, done that.   Never got caught [/b]
Retired and not doing much anymore and still not getting caught

scsmith42

Quote from: DR_Buck on December 10, 2009, 02:38:05 PM
As an after thought I'm wondering if it would serve just as well to sit a few buckets of water in the kiln chamber and let them evaporate.

I've found that it doesn't work as well out of the bucket as opposed to on the floor of the kiln.  The problem is the relatively small surface area of the bucket.
Peterson 10" WPF with 65' of track
Smith - Gallagher dedicated slabber
Tom's 3638D Baker band mill
and a mix of log handling heavy equipment.

Kelvin

My kiln floor isn't the most water tight thing, idea of dumping bucket on it is a little worrisome.  Goes into my basement of barn.  I wonder if spraying stack with garden sprayer would be effective, or to quick a wetting of lumber?  I'm worried about case hardening especially in my 8/4 stuff. 

I dried green QS white oak in about 3 1/2 months with the compressor off the last month and temps up.  Used sampling by weight method, and removed about 1% mc per day.  All honey combed, but could still use.  Just about wrecked the whole load, well i did wreck it, but useable.  Had a lot of patching and fiddeling to do, and still worry they may open up on client.  Sure makes me nervous to dry other peoples wood. 

Just did a bunch of 4/4 red cedar for a friend.  Came out all curved.  I sticked and weighted well.  Did the trees have stress?  Is Cedar squirrely?  Not sure i'll know, but you always wonder if you did something wrong.  I've gotten to adding more stickers to cherry, apple, and now for cedar.  I usually used the max suggestion of 5 sticks on 8' board... lets see how far apart is that?  24"?  16" is probably a better idea.
KP

OneWithWood

Kelvin,
Your kiln really needs to be as air-tight as possible.  You cannot effectively control the drying if the chamber leaks much at all.  If your floor is not water tight I don't think you will ever achieve what you desire.
One With Wood
LT40HDG25, Woodmizer DH4000 Kiln

scsmith42

Quote from: Kelvin on December 11, 2009, 07:46:49 AM
My kiln floor isn't the most water tight thing, idea of dumping bucket on it is a little worrisome.  Goes into my basement of barn.  I wonder if spraying stack with garden sprayer would be effective, or to quick a wetting of lumber?  I'm worried about case hardening especially in my 8/4 stuff. 

I dried green QS white oak in about 3 1/2 months with the compressor off the last month and temps up.  Used sampling by weight method, and removed about 1% mc per day.  All honey combed, but could still use.  Just about wrecked the whole load, well i did wreck it, but useable.  Had a lot of patching and fiddeling to do, and still worry they may open up on client.  Sure makes me nervous to dry other peoples wood. 

Just did a bunch of 4/4 red cedar for a friend.  Came out all curved.  I sticked and weighted well.  Did the trees have stress?  Is Cedar squirrely?  Not sure i'll know, but you always wonder if you did something wrong.  I've gotten to adding more stickers to cherry, apple, and now for cedar.  I usually used the max suggestion of 5 sticks on 8' board... lets see how far apart is that?  24"?  16" is probably a better idea.
KP

Kelvin, direct wetting of KD lumber is usually not a good idea.  What you want is for the water to evaporate in the chamber, raising the RH% and have the wood absorb the moisture that way (and uniformly). 

Honey comb is usually due to too aggressive drying from green down to 35% MC. 

I sticker on 16" centers and  usually don't have a problem with the wood moving.

Ditto Robert's comments re the importanceof having a tight chamber.
Peterson 10" WPF with 65' of track
Smith - Gallagher dedicated slabber
Tom's 3638D Baker band mill
and a mix of log handling heavy equipment.

solidwoods

Quote from: Den Socling on December 10, 2009, 12:41:37 PM
WoodWeb, on the other hand, can be arrogant. They have even cut out post that Gene and I had between each other. It's all big business over there. It's the opposite of the family business we have here at the Forestry Forum.

I joined on wood web close to its beginnings.
Then yrs later they changed the rules for the drying forum.  I don't dry enough to be allowed to post. (?)

Kelvin.
Why not use the humidity adding system that your kiln has to increase the humidity?
If it doesn't have enough oommph! then a water mist head on a valved water line will mist all one could need. 
Or attach the mister to a lg. cotton towel that is opened up, the towel soaks up the water and has a lg. evaporative surface.

Also if your kiln has a wood floor without a moisture barrier, the kiln may be having to dry the floor at each kiln cycle end.  Also if the floor isn't insulated or the moisture barrier is on the wrong side (the non kiln side) the floor may be condensing moisture from the temp difference from the room below.

If you have a wood floor/walls you can seal them with paint (only on the kiln side).
jim
Ret. US Army
Kasco II B Band mill
Woodworking since 83
I mill & kiln dry lumber, build custom furniture, artworks, flooring, etc.
If you mill, you'll be interested in some of my work in one way or another.
We ship from our showroom.
N. Central TN.

GeneWengert-WoodDoc

I am indeed an author of the only two books devoted to drying hardwood lumber...DRYING EASTERN HARDWOOD LUMBER (about 1976) and DRYING HARDWOOD LUMBER (about 2002).  The second was an update of the first.

There is also DRYING OAK LUMBER that I wrote in about 1990.

I use the term "about" because there is a delay between writing and printing.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Glenn1

Quote from: GeneWengert-WoodDoc on May 28, 2015, 02:22:07 PM
I am indeed an author of the only two books devoted to drying hardwood lumber...DRYING EASTERN HARDWOOD LUMBER and DRYING HARDWOOD LUMBER.  The second was an update of the first.

We are very happy to have you share your thoughts on this forum.  And it is a privilege to receive your help. 
Vacutherm IDry, Nyle 53 Kiln, New Holland Skid Steer, Kaufman Gooseneck Trailer, Whitney 32A Planer

GeneWengert-WoodDoc

Thanks.

Just a small correction to previous info above...my phone is 608-692-4441.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Woodslabs

how often do you guys check on the waterbottle for the wetbulb to make sure it has water in it?
check out www.woodslabs.ca

xlogger

Timberking 2000, Turbo slabber Mill, 584 Case, Bobcat 773, solar kiln, Nyle L-53 DH kiln

WDH

For me, at least once per day.  Usually, though, once in the morning and again in the evening.  I like to keep the bottle full so that the wick does not get crusty. 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

DR_Buck

Quote from: Woodslabs on October 08, 2017, 12:19:32 PM
how often do you guys check on the waterbottle for the wetbulb to make sure it has water in it?

smiley_headscratch

What is this water bottle you speak of?      I've dried a lot of lumber in my Wood-Mizer DH-4000 over the past 12 years and I've never seen nor heard of any water bottle..  :o
Been there, done that.   Never got caught [/b]
Retired and not doing much anymore and still not getting caught

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