New System For Controling Wood Drying Kilnxingnan
The present invention relates, in general, to kilns for drying and, in particular, to a new and useful control system for temperature and humidity within a wood drying kiln hardwoods.
It is known that by controlling the temperature and humidity within the interior of a hardwood kiln, lumber positioned within the kiln may be dried at a controlled rate to minimize drying related defects of the lumber as it is dried. In order to control the wood drying kilns temperature and humidity, a sample piece of lumber is selected from the lumber being dried, and the moisture content of the sample is determined outside the kiln, at preselected intervals of time. With the moisture content information, the kiln temperature and humidity are altered, if necessary, to ensure that the lumber is dried at the desired rate.
Such a process is time-consuming, is susceptible to error in calculating the moisture content, is likely to effect the environment of the kiln interior as the kiln interior is exposed to ambient conditions during removal of the sample from the kiln and is uncomfortable and potentially dangerous in that the operator must enter the hot kiln. In addition, the sample used to monitor the moisture content is re-positioned within the bulk of the lumber situated within the kiln following each moisture-determining operation. Such a re-positioning of the sample renders it inaccessible for unhindered visual inspection.