Lumber kiln conveyor system

Abstract

Embodiments provide a conveyor for conveying loads of lumber through a lumber kiln or other structure without the use of lumber carts or pushers. The conveyor may include a plurality of rollers arranged to form a flow path through the lumber kiln. Groups of the rollers may be driven by separate drives that are configured to rotate the rollers in opposite rotary directions and/or at variable speeds. Some or all of the drives may be operable independently of the other drives to transport loads of lumber at different speeds/directions in adjacent areas of the lumber kiln. In the event of a fire or a shut-down, the rollers in the proximal half of the kiln and those in the distal half of the kiln can be rotated in opposite directions to evacuate loads quickly from both ends.

1 . A method of transporting a load of lumber through a lumber kiln, the method comprising:
 placing the load of lumber onto a plurality of first rollers disposed at intervals along a first flow path that extends through generally opposite first and second ends of the lumber kiln; and   rotating at least some of the first rollers in a first rotary direction to thereby move the load of lumber from the first end of the lumber kiln toward the second end of the lumber kiln.   
     
     
         2 . The method of  claim 1 , wherein a first group of the first rollers is disposed outside of the lumber kiln upstream of said first end, and a second group of the first rollers is disposed within the lumber kiln, and placing the load of lumber onto the rollers includes placing the load of lumber onto the first group of the first rollers. 
     
     
         3 . (canceled) 
     
     
         4 . The method of  claim 2 , wherein some of the first rollers are disposed in a proximal portion of the lumber kiln and others of the first rollers are disposed in a distal portion of the lumber kiln, the method further including rotating the first rollers in the proximal portion toward the first end and rotating the first rollers in the distal portion toward the second end to move loads of lumber out of the lumber kiln through both of said opposite ends. 
     
     
         5 . The method of  claim 2 , wherein a third group of the first rollers is disposed outside of the lumber kiln downstream of said second end, the method further including rotating the third group of the first rollers to move the load of lumber away from the lumber kiln. 
     
     
         6 . The method of  claim 1 , further including providing a plurality of second rollers disposed at intervals along a second flow path that extends through the first and second ends of the lumber kiln and generally parallel to the first flow path. 
     
     
         7 . The method of  claim 6 , further including rotating at least some of the second rollers in a generally opposite second rotary direction to move a second load of lumber from the second end of the lumber kiln toward the first end of the lumber kiln along the second flow path. 
     
     
         8 . The method of  claim 6 , further including rotating at least some of the second rollers in the first rotary direction to move a second load of lumber from the first end of the lumber kiln toward the second end of the lumber kiln along the second flow path. 
     
     
         9 . The method of  claim 8 , wherein the second end of the lumber kiln includes a portal, the method further including using an insulating member to reduce airflow through the portal. 
     
     
         10 . The method of  claim 6 , wherein at least some of the first and second rollers are disposed in a proximal portion of the lumber kiln and others of the first and second rollers are disposed in a distal portion of the lumber kiln, the method further including rotating the first and second rollers in the proximal portion toward the first end and rotating the first and second rollers in the distal portion toward the second end to thereby remove the loads of lumber from the lumber kiln through both of said opposite ends. 
     
     
         11 . The method of  claim 6 , further including moving the load of lumber from a distal end of the first flow path to a distal end of the second flow path and rotating the second rollers in the second rotary direction to thereby convey the load of lumber through the lumber kiln toward the first end of the lumber kiln. 
     
     
         12 . The method of  claim 11 , wherein moving the load of lumber from the distal end of the first flow path to the distal end of the second flow path includes providing a connector portion disposed at least partially between the first flow path and the second flow path, the connector portion configured to move the load of lumber from a first side of the lumber kiln to a generally opposite second side of the lumber kiln. 
     
     
         13 . The method of  claim 12 , further including providing an additional group of rollers spaced apart along an additional flow path that extends from the connector portion to an area outside of the lumber kiln, the additional group of rollers operable to convey the load of lumber from the connector portion to said area. 
     
     
         14 . The method of  claim 1 , further including detecting a moisture content of the load of lumber and adjusting a rotational speed of one or more of the first rollers based on the detected moisture content. 
     
     
         15 . The method of  claim 14 , further including:
 calculating a desired gap between the load of lumber and a second load of lumber based at least on the detected moisture content; and   adjusting a rotational speed of at least one of the first rollers to produce the desired gap between the loads of lumber.   
     
     
         16 . The method of  claim 14 , further including:
 calculating a desired gap between the load of lumber and a second load of lumber based at least on the detected moisture content;   calculating a corresponding infeed time for the second load of lumber, based at least on the desired gap and a speed of the first rollers; and   placing the second load of lumber onto the first rollers at the corresponding infeed time to produce the desired gap between the loads of lumber.   
     
     
         17 - 30 . (canceled) 
     
     
         31 . A method of installing a conveyor system for conveying a load of lumber through a lumber kiln, the method comprising:
 providing a plurality of first rollers disposed at intervals along a first portion of a first flow path that extends through generally opposite first and second ends of the lumber kiln, such that the first rollers are oriented substantially parallel to one another and transverse to the first flow path;   providing a plurality of second rollers disposed at intervals along a second portion of the first flow path downstream of the first rollers; and   coupling a drive system with the rollers, the drive system selectively operable to drive the first rollers at a different rotational speed or in a different rotational direction than the second rollers.   
     
     
         32 . The method of  claim 31 , wherein the lumber kiln includes a floor that defines a channel with generally vertical sides, and providing the plurality of first rollers includes mounting the first rollers within the channel. 
     
     
         33 . The method of  claim 32 , further including forming the channel by removing material from the floor and/or by forming two or more baffles along the floor to define the generally vertical sides of the channel. 
     
     
         34 . The method of  claim 31 , wherein the drive system includes a first drive and a second drive, and coupling the drive system with the rollers includes coupling the first drive with the first rollers and coupling the second drive with the second rollers. 
     
     
         35 . The method of  claim 34 , further comprising coupling the drive system with a controller configured to control the first drive independently of the second drive. 
     
     
         36 . The method of  claim 35 , further comprising operatively coupling the controller with a sensor, the controller configured to control the drive system based at least in part on data from the sensor. 
     
     
         37 . The method of  claim 36 , wherein the controller is operable in a first mode to convey the load of lumber from the first end of the lumber kiln toward the second end of the lumber kiln and operable in a second mode to evacuate the load of lumber through the first end of the lumber kiln. 
     
     
         38 . The method of  claim 37 , wherein the sensor is configured to detect a fire within the lumber kiln, and the controller is configured to select one of said modes based on data from the sensor. 
     
     
         39 . The method of  claim 37 , wherein the sensor is configured to detect a moisture content of the load of lumber, and the controller is configured to control each of the drives based at least on data from the sensor. 
     
     
         40 . The method of claim  65 , wherein the controller is further configured to calculate a desired gap between the load of lumber and a subsequent load of lumber based at least on a predicted travel speed of the subsequent load of lumber. 
     
     
         41 . The method of  claim 34 , further including:
 providing a plurality of third rollers disposed at intervals along a first portion of a second flow path that extends generally parallel to the first flow path, such that the third rollers are oriented substantially parallel to one another and transverse to the second flow path;   providing a plurality of fourth rollers disposed at intervals along a second portion of the second flow path downstream of the third rollers; and   
       coupling the drive system with at least some of the third rollers and at least some of the fourth rollers. 
     
     
         42 . The method of  claim 41 , wherein the drive system further includes a third drive and a fourth drive, and coupling the drive system with at least some of the third rollers and at least some of the fourth rollers includes coupling the third drive with said at least some of the third rollers and coupling the fourth drive with said at least some of the fourth rollers. 
     
     
         43 . The method of  claim 42 , further comprising coupling the drives with a control system configured to operate one or more of the drives independently of the other drives. 
     
     
         44 . The method of  claim 43 , further comprising operatively coupling the controller with a sensor, the controller configured to control the drive system based at least in part on data from the sensor. 
     
     
         45 . The method of  claim 44 , wherein the controller is operable in a first mode to convey the load of lumber from the first end of the lumber kiln toward the second end of the lumber kiln and operable in a second mode to evacuate the load of lumber through the first end of the lumber kiln. 
     
     
         46 - 60 . (canceled)