Abstract: A modular microwave tunnel oven with multiple microwave sources and controlled atmosphere for the continuous processing of food products has a cruciform shaped conductive cavity of extended length through which a conveyor belt runs for carrying food products through the oven; the conveyor belt and other structure within the cavity are fabricated of non-toxic, heat resistant materials that are transparent to the microwave radiation and have inner surfaces that contact the food products that can be easily cleaned; one side of the cavity formed by one or more hinged doors opens completely along the extended length making access for changing the conveyor belt and/or cleaning the oven unobstructed; and microwave energy is launched into the cavity above and below the conveyor belt; whereby the microwave energy fields tend to be greater along the middle of the conveyor belt than along the edges thereof.

Abstract: This invention relates to an apparatus, namely a continuous microwave and vacuum dryer, useful for evaporating a liquid from a liquid containing material by means of microwave and vacuum.This apparatus, especially suitable for continuous dehydration of foodstuffs, comprises a housing forming a closed elongated space, means for evacuating said closed space, means for partitioning the closed space into two chambers which communicate through a slit provided in the partition, a conveyor belt disposed longitudinally in the two chambers, means for feeding on the conveyor belt a material to be evaporated, at least one source of microwave energy fed into the first one of the two chambers by at least one adjustable microwave cavity at atmospheric pressure through an air tight membrane provided on the first chamber.