Day-to-Day Kiln Operation

[CKWoodCutter]

I was looking at getting a KD250 or L200 kiln and was just curious about what it takes each day to operate one of those kilns. I can't seem to find much about actually operating them. Also if anyone has some pros or cons to either that would be great. Thanks in advance.

[scsmith42]

I've been running an L200 version for about 14 years.  From a day to day perspective, you want to check the actual MC% of the load and also what the drying trends are (amount of MC% loss per day).  

Daily checks can be in the form of measuring a sample board via the oven-dry method, or once you are below 30% you can use a moisture meter to determine the MC%.

Other daily checks are to ensure that the baffling is still in place, and that the drain is working properly, the fans are all working properly and just visually check that everything is as it should be.

Sporadically you will need to change the temp and compressor / RH% settings as the wood dries.

Usually it is only 5 minutes or so per day to check, and once you understand the trending as long as you are not trying to dry aggressively you can probably skip a few days if you're going out of town, etc.

[CKWoodCutter]

Thanks scsmith42! That is very helpful. I'd really like to add a kiln to my operation and didn't know how feasible it would be.

[Escavader]

I run 4 large capacity nyles kilns,each hold 15000 bf or more.
 Daily checks all fans and vents operating,moisture checks ,keep eye on suction line tempertures to know if it has proper gas charge.make sure oil is in site glass on compressors.,reverse fans twice a day.when lumbers ready apply steam to condition it and high temp to set the pitch.dump ,reload repeat.

[jimbarry]

...reverse fans twice a day...

How do you do that? Is that an option only available on larger kilns?

[GeneWengert-WoodDoc]

The reason we reverse fan direction is that the side the air enters is drier than the exit side, because the humidity increases as the air moves across or through the pile.  So, reversing every two hours, or three, provides even drying without shocking the lumber when reversing.  Reversing is most critical with wet lumber AND with air path of over 12'.  Reversing is not critical for air dried lumber.

[Escavader]

...reverse fans twice a day...

How do you do that? Is that an option only available on larger kilns?

My units large air moving fans are reverable,yes i think its a feature on larger units.my kilns are heated with a large oil fired boiler ,of course they pretty much heat themselves when up to temp.
 The air cannot flow around the lumber,its forced through the packs ,so the one end of the kiln gets the heat first.by reversing the charge is dryed more even.
 We loaded 15000 bf of frozen green ice covered 1 by 10 in at 845 yesterday .when i left at 1145 the temperture  was 120 degrees lol.
  I accomplish this by starting my normal oil boiler and starting my steam boiler to get it up to temp,
 Once i get up to temp my thermostat is at 90 vents open automatic at 95. A slow even drying monotored each day ,and conditioned and brought up in temp at the end to help set pitch.
  These methods produce us nice dry flat eastern white pine to mill at our planer mill
Typically fresh cut 4 to 5 days in winter.we partially air dry all year usually in kiln overnite or two nights.i fill it with green over long weekends or if my pre planing warehouses are getting full.typically my kiln guy who lives near just reverses our fans for us.ive been thinking of automating that though.kind of a balancing act.not a real big operation 6 to 8 million  bf annually.
  I know its a little bigger kilns then alot on here,but principles are the same.i do have a small L500 Unit i teamed up with an L 1200.to speed things up and pull more water.

[YellowHammer]

I check my L200 and L53 once a day.  For the L200, I don't open it up, look at the controller, check the WB, DB, moisture values, temp, etc on the front panel and that's about it.

On the L53, I check the control panel, look at the internal temps, timer cycle period, etc, and amount of water in the catch bucket. 

Rarely do I go inside the unit actual kiln unit during a run.  Mostly just a five minute per day fly by to make sure they are operating as expected and on their drying schedules.   

  

[WDH]

I open my L53 once per day for a quick check and to refill the WB water bottle.  Takes about 30 seconds.

[K-Guy]

jimbarry
Reversing fans are used in kilns where the lumber packs are more than one deep, usually 3 or more. For the L200 they are usually only one deep so reversing isn't necessary.