Systems and methods for adaptive microwave drying of ceramic articles

A method of reducing transient temperature variations in a microwave drying process for drying partially dried ceramic logs having an initial temperature TI, comprising:

• sending the logs through at least one output microwave dryer having an input end, an output end and multiple applicators, each applicator being capable of generating an adjustable amount of microwave power;
• employing a transient drying model based on microwave-drying process parameters to determine a predicted log exit temperature TPE at the dryer output end;
• measuring an exit temperature TM of each log as the logs exit the output end of the at least one output microwave dryer;
• comparing a target log exit temperature TTE to the predicted log exit temperature TPE to define a first temperature difference ΔT=TPE−TTE;
• comparing the measured log exit temperature TM to the predicted log exit temperature TPE to define a second temperature difference dT=TPE−TM;
• and
• adjusting the amount of microwave power provided by at least one of the applicators based on the first and second temperature differences ΔT and dT so that a log temperature TR at a pack-off position remains within a select temperature band around the target temperature TT.

A method of reducing transient temperature variations in a microwave drying process for drying partially dried ceramic logs having an initial temperature TI, comprising:

• sending the logs through at least one output microwave dryer having an input end, an output end, a last applicator and a second-to-last applicator, with each of the applicators being capable of generating an adjustable amount of microwave power;
• applying the adjustable amount of microwave power to the logs using at least one of the last applicator and the second-to-last applicator, the adjustable amount being controlled by a controller operably connected to the last applicator and the second-to-last applicator;
• employing a transient drying model embodied in a computer-readable medium of the controller and based on microwave-drying process parameters to determine a predicted log exit temperature TPE at the output end of the at least one output microwave dryer;
• measuring an exit temperature TM of each log as the logs exit the output end of the at least one output microwave dryer and providing to the controller the measured temperature exit temperature as a measured temperature signal representative of the measured exit temperature TM;
• adjusting the transient drying model being run on the controller to determine a change in the amount of adjustable microwave power applied to the logs to reduce a difference between the predicted log exit temperature TPE and the measured exit temperature TM;
• and
• changing the amount of adjustable microwave power by the determined amount using the controller.