Abstract: A microwave heating system configured for heating a plurality of articles is provided. One or more of the microwave launchers can be offset slightly, such that the microwave energy introduced into the heating chamber is discharged at a launch tilt angle of at least 2°. Additionally, each launcher can include a microwave-transparent window disposed between the microwave chamber and the one or more launch openings and at least 50 percent of the chamber-side surface of the window can be oriented at an angle of at least 2° from the horizontal.

Abstract: A method for controlling a microwave heating system is provided. The method may be used with a system having a liquid-filled microwave heating chamber and includes measuring the value of one or more microwave system parameters. Suitable parameters can include, for example, net microwave power discharged, the temperature of the liquid in the microwave chamber, the flow rate of liquid through the microwave chamber, and the speed of the conveyance system disposed within the microwave chamber. The measured value of the selected parameter is then compared to a target value for that parameter in order to determine a difference. Based on the difference, one or more actions can be taken in order to start, stop, or alter the operation of the microwave heating system.

Abstract: A microwave heating system configured to heat a plurality of articles is provided. The microwave heating system includes a microwave splitter, a pair of microwave launchers, and at least one inductive iris disposed between the splitter and the launch opening of one of the launchers. A microwave launcher suitable for use in such a heating system is also provided. The launcher includes an inductive iris disposed within the interior of the launcher, spaced between its inlet and outlet and obstructing at least a portion of the microwave pathway.

Abstract: A microwave heating system configured for heating a plurality of articles is provided. One or more of the microwave launchers can be offset slightly, such that the microwave energy introduced into the heating chamber is discharged at a launch tilt angle of at least 2°. Additionally, each launcher can include a microwave-transparent window disposed between the microwave chamber and the one or more launch openings and at least 50 percent of the chamber-side surface of the window can be oriented at an angle of at least 2° from the horizontal.

Abstract: A microwave heating system configured to heat a plurality of articles is provided. The microwave heating system can include one or more microwave launchers that define at least one launch opening having a depth of not more than about 0.625?, wherein ? is the predominant wavelength of the microwave energy passing through the launcher. Additionally, in some embodiments, the launch opening may have a width or depth that is less than the corresponding inlet dimension, such that the microwave launcher has a generally tapered profile. When the microwave launcher includes a single inlet and two or more launch openings, the center points of adjacent outlets may be laterally spaced from one another relative to the direction in which the articles are passed through the heating chamber.

Abstract: A microwave system for heating a plurality of articles and a method of using the same is provided. The microwave heating system comprises at least three microwave launchers and at least three microwave allocation devices for dividing the microwave energy into at least three separate portions. Each allocation device is configured to divide the microwave energy passing therethrough according to a predetermined ratio, and at least one of the allocation devices is configured to divide the microwave energy according to a predetermined ratio that is not 1:1. The resulting energy portions can then be discharged into the microwave heating chamber via the launchers and used to heat a plurality of articles, including foodstuffs, medical fluids, or medical instruments, disposed within the heating chamber.

Abstract: A microwave heating system for continuously heating a plurality of articles and process for using the same are provided. The microwave system includes a thermalization zone for thermalizing the articles to a substantially uniform temperature, a microwave heating zone for increasing the temperature of the articles by at least about 50° C., and a quench zone for cooling the articles after heating. The heating can be carried out at a rate of at least 25° C. per minute. The system also includes at least one conveyance system for transporting the articles through each of the thermalization, microwave heating, and quench zones. The system can be commercial-sized and may have an overall production rate of at least 20 packages per minute per convey line.

Abstract: A microwave heating system configured to heat a plurality of articles is provided. The microwave heating system includes a thermalization zone for adjusting the temperature of the articles disposed therein to be substantially uniform and a microwave heating zone for heating the thermalized articles. At least one of the thermalization zone and microwave heating zone are liquid-filled and may include a plurality of fluid agitators for discharging jets of liquid medium toward the articles at multiple locations within the chamber.

Abstract: A method for heating a plurality of articles according to a prescribed heating profile is provided. The method includes heating a first test article in a small-scale microwave heating system and, based on the value of one or more parameters determined during this small-scale heating, determining a prescribed heating profile for the test article. Suitable parameters can include for example, net power discharged, sequential microwave distribution, average temperature and flow rate of the fluid in the heating chamber, and residence time. The heating profile can then be used to control a commercial-scale microwave heating system used to heat a plurality of similar articles.

Abstract: A microwave heating system configured to heat a plurality of articles and a process for using the same are provided. The microwave heating system includes a liquid-filled thermalization zone, a liquid-filled microwave heating zone, and a pressure lock system disposed therebetween. The pressure lock system includes a pair of locking gate valves and a pressure adjustment chamber configured to transition the articles being heated from the thermalization zone to the microwave heating zone, which may be operated at different pressures.

Abstract: A method and system for heating a plurality of articles is provided. The method includes discharging microwave energy into a microwave chamber and passing a plurality of articles through the heating zone. At least a portion of the microwave energy discharged into the heating zone may first be phase shifted using one or more phase shifting devices. One embodiment of a rotatable phase shifting device is also provided and includes an elongated fixed member disposed proximate a rotatable housing. The phase shifting device employed by the microwave heating system is configured such that the ratio of the article residence time in the heating zone to the phase shifting rate is at least about 4:1. Rotatable phase shifting devices, or variable phase short circuits, as described herein can also be used in other applications, such as, for example, as impedance or frequency tuning devices.

Abstract: A locking gate device suitable for selectively blocking the flow of fluid and/or articles through a pair of openings defined by two spaced-apart members is provided. The spaced-apart members may be opposing walls or flanges of two adjacent processing chambers or vessels in a pressurized heating system. The locking gate device includes a gate assembly that is movable within a gate-receiving space defined between opposed sealing surfaces of the spaced-apart members. The gate assembly comprises a pair of sealing plates and a drive member shiftable relative to the sealing plates. As the drive member is shifted between a retracted position and an extended position, a pair of bearings disposed between the sealing plates and the drive member forces the sealing plates outwardly to contact the sealing surfaces of the spaced-apart members. This substantially blocks the flow-through openings defined by one or both sealing surfaces and restricts flow therethrough.

Abstract: A microwave heating system configured for heating a plurality of articles is provided. One or more of the microwave launchers can be offset slightly, such that the microwave energy introduced into the heating chamber is discharged at a launch tilt angle of at least 2°. Additionally, each launcher can include a microwave-transparent window disposed between the microwave chamber and the one or more launch openings and at least 50 percent of the chamber-side surface of the window can be oriented at an angle of at least 2° from the horizontal.

Abstract: A microwave heating system configured to heat a plurality of articles is provided. The microwave heating system includes a microwave splitter, a pair of microwave launchers, and at least one inductive iris disposed between the splitter and the launch opening of one of the launchers. A microwave launcher suitable for use in such a heating system is also provided. The launcher includes an inductive iris disposed within the interior of the launcher, spaced between its inlet and outlet and obstructing at least a portion of the microwave pathway.

Abstract: A locking gate device suitable for selectively blocking the flow of fluid and/or articles through a pair of openings defined by two spaced-apart members is provided. The spaced-apart members may be opposing walls or flanges of two adjacent processing chambers or vessels in a pressurized heating system. The locking gate device includes a gate assembly that is movable within a gate-receiving space defined between opposed sealing surfaces of the spaced-apart members. The gate assembly comprises a pair of sealing plates and a drive member shiftable relative to the sealing plates. As the drive member is shifted between a retracted position and an extended position, a pair of bearings disposed between the sealing plates and the drive member forces the sealing plates outwardly to contact the sealing surfaces of the spaced-apart members. This substantially blocks the flow-through openings defined by one or both sealing surfaces and restricts flow therethrough.

Abstract: A microwave system for heating a plurality of articles and a method of using the same is provided. The microwave heating system comprises at least three microwave launchers and at least three microwave allocation devices for dividing the microwave energy into at least three separate portions. Each allocation device is configured to divide the microwave energy passing therethrough according to a predetermined ratio, and at least one of the allocation devices is configured to divide the microwave energy according to a predetermined ratio that is not 1:1. The resulting energy portions can then be discharged into the microwave heating chamber via the launchers and used to heat a plurality of articles, including foodstuffs, medical fluids, or medical instruments, disposed within the heating chamber.

Abstract: A method for heating a plurality of articles according to a prescribed heating profile is provided. The method includes heating a first test article in a small-scale microwave heating system and, based on the value of one or more parameters determined during this small-scale heating, determining a prescribed heating profile for the test article. Suitable parameters can include for example, net power discharged, sequential microwave distribution, average temperature and flow rate of the fluid in the heating chamber, and residence time. The heating profile can then be used to control a commercial-scale microwave heating system used to heat a plurality of similar articles.

Abstract: A microwave heating system configured to heat a plurality of articles is provided. The microwave heating system includes a thermalization zone for adjusting the temperature of the articles disposed therein to be substantially uniform and a microwave heating zone for heating the thermalized articles. At least one of the thermalization zone and microwave heating zone are liquid-filled and may include a plurality of fluid agitators for discharging jets of liquid medium toward the articles at multiple locations within the chamber.

Abstract: A microwave heating system configured to heat a plurality of articles and a process for using the same are provided. The microwave heating system includes a liquid-filled thermalization zone, a liquid-filled microwave heating zone, and a pressure lock system disposed therebetween. The pressure lock system includes a pair of locking gate valves and a pressure adjustment chamber configured to transition the articles being heated from the thermalization zone to the microwave heating zone, which may be operated at different pressures.

Abstract: A microwave heating system configured to heat a plurality of articles and a process for using the same is provided. The heating system includes at least two laterally-spaced parallel convey lines and two or more groups of microwave launchers configured to heat articles transported along each convey line. The groups of microwave launchers can include pairs of oppositely disposed launchers that are spaced apart from one another along the axis of convey. When the system includes multiple convey lines, adjacent launcher groups are staggered relative to one another in the convey direction. Heating articles, such as foodstuffs or medical fluids or equipment in such a system, minimize undesirable interference between launchers of adjacent groups and provide a more uniform heating field.