iDRY Vacuum Kilns

Sponsors:

Nyle L53 Kiln Start Up

Started by maderahardwoods, November 13, 2017, 03:27:39 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

maderahardwoods

Hello my name is Marco Valenzuela, and I run a small milling operation out of Los Angeles, California. I just recently finished my dehumidification kiln with a Nyle L53 dehumidification unit.

The unit is on a 4" thick slab, 2x4 construction with Hardieshingle siding, all seams sprayed with expanding foam, 2" insulation between studs, 2" insulation above studs, 10 mil vapor barrier, ½ plywood interior coated with aluminized roof paint.

The interior dimensions 161" long, 84" deep, and 86" tall, the doors are 12' wide (6' each). The unit is placed dead center at the recommended height and I added auxiliary Mechatronics fans on each side of the shelf that baffles the Nyle unit. I used Velcro along the shelf to attach to 4x8 foam sheet to baffle the load.

The DB and WB sensors are mounted on the back wall, 4ft from the ground and midway between the corner and kiln unit (recommended by Stan at Nyle).

I have about 600 bd ft of 11.5' long Claro Walnut slabs and about 250 bd f t of 7' Claro Walnut slabs, they are stickered every 18" and 1" thick (stickers).  The stacks of slabs are strapped with 3" straps to I-Beam cants.

The long Claro was dropped in July and milled about 3 weeks ago, the shorter Claro was dropped about a month ago and milled 4 weeks ago, the logs sat outside in the shade for about 1-3 weeks. Before being placed in kiln.

I tried to read the moisture content (Lignomat pinless) on the logs and could not get a consistent reading. I made sure the surface was smooth and consistent. It bounced around from 25-55%, from what I under stand any moisture content above 30% gives an inaccurate reading.

I placed the logs into the kiln last Saturday morning (Nov 4th, 2017) and set it to the recommended tier for Group 3 woods, 90 DB and 86 WB. I let the load sit all night and in the morning the WB would not get past 82, I tried to make the DB over shoot a few degrees and it still wouldn't rise the WB.

At this point I wasn't sure how the logic worked in the controller, desperate to get the compressor on I lowed the WB to 82 and the compressor kicked on, after about 24 hrs I collected about 4 gallons.  The next 24 hr cycle I collected about 3 gallons. The next 24hr cycle I collected 2 gallons. I tried to get a moisture reading everyday at the same time and I could not get a consistent reading, it pinged all over the place, from 25-45%.  I looked at the end of the slabs and did not see any new checking or surface damage.

I tried to call Nyle to get some advice.  Unfortunately the expert was out all week at a trade show, so I spoke to the other representative and he said I should likely go to the next tier, which is 100DB and 96WB.

So I set the unit to 100DB and 96WB Wednesday (11/07/2017), the next day 24hrs later the unit collected 0 water as the compressor would not come on. The WB would not go above 92, the DB had no problem getting to 100-102.

I did a little work to create a better-insulated door, I added a piece of greenhouse plastic with Velcro around the doorjamb and it really helped.  I also I used some insulation and baffled the intake vent of the power vent system.

After doing some think about the DB and WB temperatures I realized that only real factor I can control is the DB temperature with the Nyle unit (heating element) and the WB will depend on the moisture content of the wood in a controlled environment.

So Thursday evening (11/09/2017) I decided to try the next tier, so I set the DB to 110F and the WB to 96F I used an auxiliary heater to help get the DB   The unit got to 110-112 DB and the WB crept up to 96-97 which made the compressor come on (I have the compressor hysteresis set at 0 degrees, otherwise it will not start till the WB is two degrees above the DB, as soon as the DB hits the 2+ degree mark over the setting the power vents kick on dropping the WB).

I checked on the kiln Friday morning and the unit pulled about a gallon or less (from Thursday night to Friday morning), I looked at the unit and the DB was around 111 and WB was at 96, so it seems the wood and kiln like this setting.

Friday morning to Saturday morning the unit collected about 4 gallons of water, the temperature stayed right around 110-112 DB, and the WB was around 96-97.  Occasionally the over temperature vent would kick on and dropping the DB and WB temps. Killinh the compressor, but after a few minutes the kiln would warm up and restart the compressor.  I would imagine the compressor cycling on and off will allow the wood to relax a bit, which is probably a good thing.

From Saturday to Sunday morning the kiln collected about 2-3 gallons, it stayed at the 110DB and 96WB all day with the power vents cycling occasionally.

I looked inside of the kiln Sunday afternoon (Nov. 12th) and did not see anything unusual, no unusual checking, or surface damage.  The environment felt like a sauna as expected, the plastic over the doorjamb really works great for trapping the heat in.

Monday morning the unit collected about 1.5-2 gallons.

So my question is, does this seem right? I would of though the wood being so fresh would have liked the lower DB and WB temperatures recommended by the drying tables, but I understand the both trees could have been in decline and possibly had a lower MC than a healthy thriving tree.

Any constructive input is appreciated, glad I found this forum.

maderahardwoods


maderahardwoods


WLC

Nothing to add other than welcome to the forum.  That's some pretty walnut.
Woodmizer LT28
Branson 4wd tractor
Stihl chainsaws
Elbow grease.

WDH

That is a nice set up.

I do not dry from green, so take anything I say with caution.  I dry wlanut slabs that have been air dried to below 20% with the DB bulb at 120 and the WB at 75.  This keeps the compressor running constantly.  Yours is cycling on and off because the WB depression is small.  This is to keep the humidity high in the kiln to keep the drying slow. 

Because you do not know the moisture content in the slabs, you have to be conservative.  If you get below 25% moisture content, you can drop the WB setting to allow the compressor to run more of the time.  If you get below about 20%, you can run the compressor full out. 

If you want to speed up the drying a bit, keep the DB at 110 and drop the WB setting to 90.  This will keep the compressor running more but not full out. 

You might consider buying the Delmhorst J2000X with the slide hammer and the 1" pins.  That way you can check the moisture content by driving the pins into the side of the slabs and taking a reading.  This way, you will know when your slabs get below fiber saturation point, which is about 25 - 30% moisture content, then you can get more aggressive with the drying. 

Do not exceed 133 degrees on the DB with the compressor on because there a high temp shut off that will shut down the compressor.  To reset it, you have to take off the side panel and push the little green button to re-set the compressor. 
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

maderahardwoods

WDH thank you, it was a lot more work than I originally expected. All the details are what really consume the time.

Thank you for the information, I checked the MC of each log on Sunday and got a reading of 29% on the short log and 25% on the longer log, rechecked yesterday and got 28% and 24%.  So it looks like I am going in the right direction.

Do you prefer the in kiln Delmhorst meter to the Lignomat pinned/probe meter system?

Thanks,

Marco

WDH

Yes.  I like the hammer probe. 
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

maderahardwoods

Update.

I was running the kiln at 110DB and 98WB, and the WB kept slipping down, dropped to about 93WB. So I decided to try the case hardening and bug kill step, I dumped about 7 gallons of water on the floor and raised the DB to 140F, took about 24 hrs to get to 138-140, and let it stay for another 12 hours. 

I then set the kiln to final stage of 120DB and 98WB, but it would only get to 96WB.  I talked to Nyle and they said it would be alright to lower the WB setting as the wood continues to dry.  So right now the DB is at 120 and the WB is at 93, looking like it is pulling about 2 gallons of water. 

I checked the moisture, on the two slabs and they varied from 14-20% MC.

WDH

With that moisture content, I would run my L53 at a WB of 75 so that the compressor runs full out. 
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

maderahardwoods

WDH, I just checked it yesterday and the shorter log was 14% and 20% (opposite ends) and the longer log was 16% and 18% (opposite ends).

I will drop the WB tonight from 92( compressor kicks on at 93), if I lower the WB to 75 the compressor runs just as hard as if it were at 80, 85, or 90 right? It just want cycle off if the WB drops below the set point?

WDH

If you set the WB at 75, it is unlikely that it will ever reach 75, so the compressor runs 100% of the time.  As I am finishing up a load, mine usually never falls below 82.
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

maderahardwoods

Thank you. I switched it to 85WB yesterday, I'll check the MC this afternoon and report back. 

Thanks,

Marco

maderahardwoods

So moisture on the two logs varies from 13-20% on where I measure. The compressor is pulling about 1-1.5 gallons/24hr cycle. 

Is this typical for walnut? I have read that claro walnut tends to dry very slowly. 

-Marco

WDH

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

GeneWengert-WoodDoc

Claro dries slowly and erratically for three reasons. First, the species has varying restrictions to moisture movement.  I recall some walnut that after a year of air drying was still way over 50% MC.  Second is baterial infections that create bacterial slime that restrictions movement.  In some species, these restrictions create what are called wet pockets, or similar names.  Third is that thicker lumber does this probably due to grain angle.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

maderahardwoods

Thanks guys, good to know the 1 gallon pull in normal.

WDH

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

Natel

Crazy, I'm new to this forum and just put my first load in my woodmizer KD150 (Nyle L53) and had the same questions, and this answered almost all the questions I had. I'm in the same boat moisture ranging between 10-20% on my slabs (mixed bag of air dried stuff) my question is should I be running in a configuration that doesn't yield any water? Or are you supposed to be continually pullingwater out of the wood? Currently at 120 wet bulb and 85dry

GeneWengert-WoodDoc

At 120-85 you should be drying 1% MC loss per day typically and maybe more.  If it is not drying that fast, then the first concern is that perhaps the moisture content measurement is off...the wood is drier than you think.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Natel

You are correct, I really opened it up today and took more readings, all 5-10%. During a cycle with green Wood should I continually be getting water out of it if I'm doing everything on schedule?

WDH

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

GeneWengert-WoodDoc

Yes, the wood should dry and moisture leaving the wood will have to get out as liquid in a DH kiln.  If the vent runs, some moisture leaves as vapor.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

maderahardwoods

Update:

Moisture content 13.5-18%, pulling less than 1 gallon  a day. 

DB 118-120 (its been cold)
WB: 86-88

-Marco

maderahardwoods

So I went 24hrs without pulling a drop of water so I decided to try another case hardening treatment as recommended by Nyle. But this time I dumped about 3 gallons of water on the floor and sprayed the slabs with water directly and set the kiln to 140F.  By Saturday 3PM I was in the high 130s and by 5PM I was at 140F. 

I let the kiln sit at 140F DB (106WB) for about 24hrs, at the 24 hr mark I opened up the doors and brought the temperature down to 120F and the WB dropped back down to 85, I then restarted the compressor. 

I checked the unit this morning and not a drop has been collected in the bucket.  I am assuming a lot of the moist air escaped with the when the high temp van kicked on as well as opening the doors. 

Does anyone have some experience the can share regarding kiln drying claro walnut?

I will take some moisture readings this afternoon.

Thanks,

Marco

WDH

Sounds like that you are there.
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

Thank You Sponsors!