The Forestry Forum

General Forestry => Drying and Processing => Topic started by: Bnewman712 on May 21, 2018, 09:05:44 PM

Title: Help having trouble bring the kiln up to temperature
Post by: Bnewman712 on May 21, 2018, 09:05:44 PM
Can not seem to get the kiln over 88 dry bulb.any advice would help kd150 and has been on for 24 hours
Title: Re: Help having trouble bring the kiln up to temperature
Post by: GeneWengert-WoodDoc on May 21, 2018, 10:46:02 PM
Are you using electrical strip heaters?  Is the kiln fully closed so there is no venting?  What is the outside temperature?  What type of control do you have for the temperature?  What is the approximate moisture content of the lumber?
Title: Re: Help having trouble bring the kiln up to temperature
Post by: Bnewman712 on May 22, 2018, 05:06:31 AM
Quote from: GeneWengert-WoodDoc on May 21, 2018, 10:46:02 PM
Are you using electrical strip heaters?  Is the kiln fully closed so there is no venting?  What is the outside temperature?  What type of control do you have for the temperature?  What is the approximate moisture content of the lumber?
Lumber is 17-25%. Outside is 65 low at night to 80-85 in day. I am using the kd150 unit as heat with 2 work lights...how would I use heat strips? 
Title: Re: Help having trouble bring the kiln up to temperature
Post by: WDH on May 22, 2018, 07:09:06 AM
The heat strips are built into the unit.  I believe that it is a one kilowatt heater so it is not very powerful.  If you look down thru the fans, you can see the heat strips.  The heater and the compressor cannot both run at the same time as it is a 110V unit and there is only enough power to run one at a time.  If the heater is on, it runs until the dry bulb and wet bulb parameters are met, then the compressor comes on.  When the compressor comes on, the heater turns off.  When sterilizing, you turn the compressor off and set the dry bulb temp at your sterilization temp.  If you install supplemental fans in the chamber, the fan motors generate heat so that once the kiln comes up to operating temp, you really don't need the heater. In fact, you will end up having to vent heat.
Title: Re: Help having trouble bring the kiln up to temperature
Post by: Bnewman712 on May 22, 2018, 08:27:56 AM
Yes I just seem to not be able to get it past 88ish and it's set at 120 dry 90 wet
Title: Re: Help having trouble bring the kiln up to temperature
Post by: K-Guy on May 22, 2018, 08:44:34 AM
Hi 
How big is your chamber, the KD150 is limited to a maximum chamber size of 8' x 8' x 13'. If that isn't the issue then check for air leaks. Also did you put the p-trap in the drain line? If not you will draw outside air into the chamber and not be heating the air inside.
Stan from Nyle
Title: Re: Help having trouble bring the kiln up to temperature
Post by: Bnewman712 on May 22, 2018, 09:10:56 AM
Mine is 7.5 by 7.5 by 14 so it's a feet longer but I also have 2 more lamps but I will check the drain line when I get home thank you
Title: Re: Help having trouble bring the kiln up to temperature
Post by: YellowHammer on May 22, 2018, 10:44:55 AM
With a couple heat lamps as well as the 1KW heat strips, i.e. 2 KW of heat input, with a well insulated kiln, then I would say you have a pretty decent leak, most likely the door seals, but check everything.  With a kiln having a low pressure and high pressure side, even a very, very small leak will power vent a lot of air.  Go inside, turn off the lights, and close the doors, have someone latch them.  Does the seal material compress and make a tight joint everywhere?  What about where the doors come together and meet each other, at the roof and the floor, this is a very difficult place to get a good seal.  Look for any light coming through.  Are the corner joints and seams on the inside walls of the kiln sealed with caulk?  Every joint and corner must be air tight, and the inside should be as impermeable as a walk in freezer.  One easy way to tell if you have a leaky chamber is to open a vent and close the doors.  It should be easy.  Then close the vent and shut the doors again.  That should be much harder and you should hear and feel the air being forced out the door seals as the door come together.  Then when you open the doors, they should feel like they have suction and are difficult to break open.  If the doors open and close easy with the vents shut, you have a leak.