Abstract: A microwave mode stirrer apparatus having a stirring member with microwave-transmissive regions is disclosed, along with methods of performing microwave stirring using the microwave mode-stirring apparatus. The microwave-transmissive regions can be in the form of holes or can include microwave-transmissive material. The stirring member can have a variety of configurations, and the microwave-transmissive regions can have a variety of sizes and shapes. A microwave oven that uses the mode stirrer apparatus for drying green ceramic-forming bodies is also disclosed.

Abstract: Systems and methods for rapid drying of ceramic greenwares having a high graphite content are disclosed. The methods include employing microwave drying to bring the dryness of the ceramic greenware to a first select dryness and then employing close-coupled hot-air drying to bring the dryness to the final target dryness. The judicious use of close-coupled hot-air drying reduces end defects due to unevenness in the microwave drying process while also substantially speeding up the drying process. Various configurations for and combinations of microwave drying and close-coupled hot-air drying are disclosed.

Abstract: A microwave mode stirrer apparatus having a stirring member with microwave-transmissive regions is disclosed, along with methods of performing microwave stirring using the microwave mode-stirring apparatus. The microwave-transmissive regions can be in the form of holes or can include microwave-transmissive material. The stirring member can have a variety of configurations, and the microwave-transmissive regions can have a variety of sizes and shapes. A microwave oven that uses the mode stirrer apparatus for drying green ceramic-forming bodies is also disclosed.

Abstract: A ceramic precursor batch composition, green ware formed thereof, porous ceramic honeycomb article formed thereof, and methods of making same.

Abstract: Systems and methods for drying skinned ceramic wares (10) using recycled microwave radiation are disclosed. The method includes irradiating wet skinned ceramic wares (10W) in a first applicator section (124W) with microwave radiation (212), wherein said irradiating (212) gives rise to reflected microwave radiation (212R). The method also includes capturing a portion of the reflected microwave radiation (212R) and irradiating a plurality of semi-dry skinned ceramic wares (105) in a second applicator section (124S) with the reflected microwave radiation (212R). Systems for carrying out the method are also disclosed.

Abstract: Methods for drying ceramic greenware in a manner that substantially compensates for otherwise non-uniform drying are disclosed. The methods generally include partially drying a piece (22) of greenware such that its end portions (22E) are drier than its middle portion (22C). The method also includes further drying the piece with radio-frequency (RF) radiation (88) generated by an electrode system (130) by conveying the piece through the electrode system. The electrode system has a main planar electrode (131E) with a longitudinal axis (AE), and an electrode concentrator (131C) formed thereon or attached thereto. The electrode concentrator has a central section (140) that runs in the direction of the longitudinal axis of the electrode and is configured so that when the piece is conveyed through the electrode system, the electrode system concentrates more RF radiation at the center portion of the piece than at the end portions of the piece.

Abstract: A ceramic precursor batch composition, green ware formed thereof, porous ceramic honeycomb article formed thereof, and methods of making same.

Abstract: Tray assemblies and methods for manufacturing ceramic articles are provided. In one embodiment, a tray assembly includes a tray body having a supporting surface operable to support a ceramic article for passage through a microwave drying apparatus during a microwave drying process and a microwave coupling cover associated with the tray body. The microwave coupling cover envelopes at least a portion of the ceramic article during the microwave drying process. The microwave coupling cover has a dielectric property such that a greater percentage of microwave energy is coupled into the ceramic article with the microwave coupling cover present during the microwave drying process than with the microwave coupling cover not present. Methods may include rotating the ceramic article when the ceramic article is about 40%-60 dry.

Abstract: Systems and methods for efficient microwave drying of extruded honeycomb structures are disclosed. The methods include conveying first and second sets of honeycomb structures in opposite directions through multiple applicator cavities. Each honeycomb structure has a moisture content MC, and the honeycomb structures within each cavity define an average moisture content MCA between 40% and 60% therein. The methods include irradiating the first and second sets of honeycomb structures within the cavities with microwave radiation having an amount of input microwave power PI that results in an amount of reflected microwave power PR from the honeycomb structures, where PR<(0.2)PI. This allows for a relatively high microwave power to be maintained in each cavity. Batch microwave drying methods are also disclosed.

Abstract: Systems and methods for controlling drying of ceramic greenwares accounting for the load presented to a radio-frequency (RF) source of an RF applicator to reduce the risk of overheating greenware during drying. The method includes partially drying the greenware and then substantially drying the greenware with RF radiation. The RF radiation provided to an electrode region is controlled based on the number of greenware pieces within the electrode region at a given time. The system includes a control unit electrically connected to the electrode and configured to provide a select RF voltage to the electrode based on the number of greenwares within the electrode region. The system adjusts at least one input voltage from a power supply. The adjusted voltage is stepped-up, DC-rectified to form a plate voltage, and then converted by a high-frequency DC/AC convertor to the select high-frequency AC RF voltage needed to dry the greenwares without overheating.

Abstract: Systems and methods for efficient microwave drying of extruded honeycomb structures are disclosed. The methods include conveying first and second sets of honeycomb structures in opposite directions through multiple applicator cavities. Each honeycomb structure has a moisture content MC, and the honeycomb structures within each cavity define an average moisture content MCA between 40% and 60% therein. The methods include irradiating the first and second sets of honeycomb structures within the cavities with microwave radiation having an amount of input microwave power PI that results in an amount of reflected microwave power PR from the honeycomb structures, where PR<(0.2)PI. This allows for a relatively high microwave power to be maintained in each cavity. Batch microwave drying methods are also disclosed.

Abstract: Systems and methods for efficient microwave drying of extruded honeycomb structures are disclosed. The methods include conveying first and second sets of honeycomb structures in opposite directions through multiple applicator cavities. Each honeycomb structure has a moisture content MC, and the honeycomb structures within each cavity define an average moisture content MCA between 40% and 60% therein. The methods include irradiating the first and second sets of honeycomb structures within the cavities with microwave radiation having an amount of input microwave power PI that results in an amount of reflected microwave power PR from the honeycomb structures, where PR<(0.2)PI. This allows for a relatively high microwave power to be maintained in each cavity. Batch microwave drying methods are also disclosed.

Abstract: Systems and methods for rapid drying of ceramic greenwares having a high graphite content are disclosed. The methods include employing microwave drying to bring the dryness of the ceramic greenware to a first select dryness and then employing close-coupled hot-air drying to bring the dryness to the final target dryness. The judicious use of close-coupled hot-air drying reduces end defects due to unevenness in the microwave drying process while also substantially speeding up the drying process. Various configurations for and combinations of microwave drying and close-coupled hot-air drying are disclosed.

Abstract: A method and system for drying a honeycomb structure having an original liquid vehicle content includes exposing the honeycomb structure to a first electromagnetic radiation source until the liquid vehicle content is between about 20% and about 60% of the original liquid vehicle content, exposing the honeycomb structure to a second electromagnetic radiation source different from the first electromagnetic radiation source until the liquid vehicle content is between about 0% and about 30% of the original liquid vehicle content, and exposing the honeycomb structure to convection heating until the liquid vehicle content is between about 0% and about 30% of the original liquid vehicle content.

Abstract: A method of making a honeycomb structure comprises the step of providing a honeycomb body including a first end face and a second end face, wherein the honeycomb body includes a ceramic and/or a ceramic-forming material. The method further includes the step of providing a first non-metallic extension and a second non-metallic extension along a longitudinal axis of the honeycomb body. The first non-metallic extension is positioned with respect to the first end face and the second non-metallic extension is positioned with respect to the second end face. The method further includes the step of exposing the honeycomb body and the non-metallic extensions to microwaves to dry the honeycomb body.

Abstract: A method and system for drying a honeycomb structure having an original liquid vehicle content includes exposing the honeycomb structure to a first electromagnetic radiation source until the liquid vehicle content is between about 20% and about 60% of the original liquid vehicle content, exposing the honeycomb structure to a second electromagnetic radiation source different from the first electromagnetic radiation source until the liquid vehicle content is between about 0% and about 30% of the original liquid vehicle content, and exposing the honeycomb structure to convection heating until the liquid vehicle content is between about 0% and about 30% of the original liquid vehicle content.

Abstract: A method of making a honeycomb structure comprises the step of providing a honeycomb body including a first end face and a second end face, wherein the honeycomb body includes a ceramic and/or a ceramic-forming material. The method further includes the step of providing a first non-metallic extension and a second non-metallic extension along a longitudinal axis of the honeycomb body. The first non-metallic extension is positioned with respect to the first end face and the second non-metallic extension is positioned with respect to the second end face. The method further includes the step of exposing the honeycomb body and the non-metallic extensions to microwaves to dry the honeycomb body.

Abstract: Tray assemblies and methods for manufacturing ceramic articles are provided. In one embodiment, a tray assembly includes a tray body having a supporting surface operable to support a ceramic article for passage through a microwave drying apparatus during a microwave drying process and a microwave coupling cover associated with the tray body. The microwave coupling cover envelopes at least a portion of the ceramic article during the microwave drying process. The microwave coupling cover has a dielectric property such that a greater percentage of microwave energy is coupled into the ceramic article with the microwave coupling cover present during the microwave drying process than with the microwave coupling cover not present. Methods may include rotating the ceramic article when the ceramic article is about 40%-60 dry.

Abstract: Systems and methods for efficient microwave drying of extruded honeycomb structures are disclosed. The methods include conveying first and second sets of honeycomb structures in opposite directions through multiple applicator cavities. Each honeycomb structure has a moisture content MC, and the honeycomb structures within each cavity define an average moisture content MCA between 40% and 60% therein. The methods include irradiating the first and second sets of honeycomb structures within the cavities with microwave radiation having an amount of input microwave power PI that results in an amount of reflected microwave power PR from the honeycomb structures, where PR<(0.2)PI. This allows for a relatively high microwave power to be maintained in each cavity. Batch microwave drying methods are also disclosed.

Abstract: Tray assemblies and methods for manufacturing ceramic articles are provided. In one embodiment, a tray assembly includes a tray body having a supporting surface operable to support a ceramic article for passage through a microwave drying apparatus during a microwave drying process and a microwave coupling cover associated with the tray body. The microwave coupling cover envelopes at least a portion of the ceramic article during the microwave drying process. The microwave coupling cover has a dielectric property such that a greater percentage of microwave energy is coupled into the ceramic article with the microwave coupling cover present during the microwave drying process than with the microwave coupling cover not present. Methods may include rotating the ceramic article when the ceramic article is about 40%-60 dry.