Abstract: Apparatus and method for pasteurizing food products and ready meals in hermetically sealed packages (22) by means of microwaves, comprising a microwave chamber (14); a lower conveyor belt (20) for the packages (22); an upper conveyor belt (18), extending substantially horizontally and vertically movable, and a microwave source (16) located below the lower conveyor belt (20), the microwave chamber (14) being under atmospheric ambient pressure. The apparatus comprises a cooling plate (10) in close contact with the upper conveyor belt (18) so that during microwave heating the top of the package (22) is cooled to below the condensation point of water vapor and overpressure in the package is avoided.

Abstract: A microwave chamber for drying dialysis filter cartridges, cartridge filters and other closed filter systems. The microwave chamber has separate regions of high and low microwave absorption. The high energy absorption regions are in the central region of the filter where the bundle of hollow fibers or filter material is located. The low absorption areas are the microwave sensitive end regions of the filter module. To dry the wet filter module, the microwave frequency with the highest converted power is applied, and as the filter dries, the reflected microwave power is continuously determined and kept as low as possible by tracking the microwave frequency. The water is simultaneously discharged from the module. The process allows fast and gentle drying of filter cartridges and other closed filter units such as candle filters, and eliminates accidental overheating of the temperature-sensitive end sections of filter housings and modules with the seals and adhesives.

Abstract: Apparatus and method for pasteurizing food products and ready meals in hermetically sealed packages (22) by means of microwaves, comprising a microwave chamber (14); a lower conveyor belt (20) for the packages (22); an upper conveyor belt (18), extending substantially horizontally and vertically movable, and a microwave source (16) located below the lower conveyor belt (20), the microwave chamber (14) being under atmospheric ambient pressure. The apparatus comprises a cooling plate (10) in close contact with the upper conveyor belt (18) so that during microwave heating the top of the package (22) is cooled to below the condensation point of water vapor and overpressure in the package is avoided.

Abstract: The invention relates to a microwave heater comprising a plurality of microwave generators each emitting microwaves at a frequency in a range of frequencies ranging from 300 MHz to 5.8 GHz which couple into objects to be heated. At least one of the microwave generators emits the microwaves at a first frequency of an upper part of the range of frequencies, the microwaves of the first frequency displaying a first of depth of penetration into the objects to be heated; and at least one other of the microwave generators emits the microwaves at a second frequency of a lower part of the range of frequencies, the microwaves of the second frequency displaying a second depth of penetration into the objects to be heated, the first penetration depth being substantially smaller than the second penetration depth.