Automatic control system for wood drying kiln
AssigneeThe University of Tennessee Research Corporation
InventorRobert L. Little
Life of this patent
Estimating the term…
Abstract
System for kiln-drying hardwood wherein the weight of a representative sample positioned remote from the batch of wood to be dried is monitored. The moisture content of the representative sample is calculated from the measured weight continuously and operational parameters with the kiln are automatically adjusted in response to the moisture content of the sample to provide desired drying conditions.
Claims14
A method for controlling environmental conditions of a kiln within which a stack of lumber is dried comprising the steps of:
- providing a sensor within the kiln and from which a sample from the stack can be suspended and which generates a signal corresponding to the weight of the sample, at a spaced location from the stack but in the kiln;
- positioning the sensor adjacent an interior wall of the kiln and clamping the sample to the sensor so that the weight of the sample is suspended from the sensor;
- determining the actual moisture content of the sample continuously as a function of the weight of the sample and the signal generated by the sensor;
- comparing the actual moisture content of the sample with the moisture content which the sample is desired to possess;
- and
- altering environmental conditions in the kiln in accordance with variations detected between the actual moisture content and the desired moisture content.
A monitoring system for a wood drying kiln having a housing with an interior wall surface, an area within the housing for placement of a charge of wood for drying of the charge of wood, and means for heating and humidifying the interior of the kiln, the monitoring system comprising:
- support means positioned adjacent the interior wall surface for supporting a representative sample of the charge of wood adjacent the interior wall surface and remote from the charge of wood;
- sensor means operatively connected to the support means for sensing a physical characteristic of the sample which is a function of moisture content in the sample;
- signal generation means operatively connected to the sensor means for generating a signal corresponding to moisture content of the sample as a function of the physical characteristic;
- control means operatively connected to the means for heating and humidifying the interior of the kiln and to the signal generation means for controlling the heat and humidity within the kiln in response to the signal received from the signal generation means;
- the kiln including means defining a pair of plenums on opposite sides of the area within the housing for placement of a charge of wood, air circulation means above the area for circulating air from one plenum through the charge of wood to the opposite plenum, the support means being positioned in one of the plenums and structured to hold a sample in a vertically suspended orientation with broad sides of the sample extending parallel to a flow of air in the plenum.
A monitoring system for a wood drying kiln having a housing with an interior wall surface, an area within the housing for placement of a charge of wood for drying of the charge of wood, and means for heating and humidifying the interior of the kiln during a drying process, the monitoring system comprising:
- support means positioned in the housing and adjacent the interior wall surface for supporting a representative sample of the charge of wood in the housing and adjacent the interior wall surface and remote from the charge of wood during the drying process;
- sensor means operatively connected to the support means for continuously sensing a physical characteristic of the sample which is a function of moisture content in the sample, during the drying process;
- signal generation means operatively connected to the sensor means for generating a signal corresponding to moisture content of the sample as a function of the physical characteristic;
- and
- control means operatively connected to the means for heating and humidifying the interior of the kiln and to the signal generation means for controlling the heat and humidity within the kiln in response to the signal received from the signal generation means.
Dependencies are inferred from the claim text.