An apparatus and method for dehydrating biological materials, such as vaccines and microorganism cultures, in which the materials are dehydrated in an evacuated container which is in a microwave waveguide that is open to the atmosphere. The apparatus comprises means for freezing the container of biological material, a microwave generator, a waveguide, means for introducing the container into the waveguide, means for applying a vacuum to the container and means for removing the dehydrated material from the waveguide. In the method of the invention, the container of biological material is put in a microwave waveguide open to the atmosphere, a vacuum is applied to the container, the material is frozen and is radiated to dehydrate it. The dehydrated material is then removed from the waveguide.

A method and apparatus for drying foodstuffs of plant or animal origin that includes introducing the foodstuffs to be dried into a drying chamber for drying and heating the foodstuffs to a temperature which causes an evaporation of water contained in the foodstuffs until the amount of water contained in the foodstuffs is reduced to a predetermined value indicating that the foodstuffs are dried. The heating of the foodstuffs is performed by generating an oscillating magnetic field such that prior to said heating, the pressure inside said drying chamber is reduced to a predetermined value below atmospheric pressure.

A method and apparatus for drying foodstuffs of plant or animal origin that includes introducing the foodstuffs to be dried into a drying chamber for drying and heating the foodstuffs to a temperature which causes an evaporation of water contained in the foodstuffs until the amount of water contained in the foodstuffs is reduced to a predetermined value indicating that the foodstuffs are dried. The heating of the foodstuffs is performed by generating an oscillating magnetic field such that prior to said heating, the pressure inside said drying chamber is reduced to a predetermined value below atmospheric pressure.

An apparatus 20 for microwave vacuum-drying organic materials such as foods and bioactives has a plurality of microwave generators 50 actuated so as to cause interference between their respective microwave streams and evenly distribute the microwave energy across the vacuum chamber 34. The microwave-transparent window 36 in the chamber is arranged so the organic material to be dried is moved across it on a conveyor belt 60 and the microwave energy passing into the chamber 34 immediately encounters the organic materials, thus attenuating the energy and reducing arcing.

An apparatus 20 for microwave vacuum-drying organic materials such as foods and bioactives has a plurality of microwave generators 50 actuated so as to cause interference between their respective microwave streams and evenly distribute the microwave energy across the vacuum chamber 34. The microwave-transparent window 36 in the chamber is arranged so the organic material to be dried is moved across it on a conveyor belt 60 and the microwave energy passing into the chamber 34 immediately encounters the organic materials, thus attenuating the energy and reducing arcing.

A radiofrequency heating system and methods for processing agricultural products are provided herein. The method may include positioning an agricultural product between two electrode assemblies of a radiofrequency (RF) circuit, closing the RF circuit, and heating the agricultural product to a threshold temperature in greater than a threshold amount of time.

A continuous asphalt mix system for using a microwave heating vessel at the point of production that includes a microwave energy suppression tunnel with one or more mesh flaps for substantially reducing or preventing the leakage of microwave energy from a microwave system, while having a continuous flow of product through the vessel and suppression tunnels. The suppression tunnels are installed on the inlet and/or the outlet side of the system and are sized to suppress leakage.

A continuous asphalt mix system for using a microwave heating vessel at the point of production that includes a microwave energy suppression tunnel with one or more mesh flaps for substantially reducing or preventing the leakage of microwave energy from a microwave system, while having a continuous flow of product through the vessel and suppression tunnels. The suppression tunnels are installed on the inlet and/or the outlet side of the system and are sized to suppress leakage.

A continuous asphalt mix system for using a microwave heating vessel at the point of production that includes a microwave energy suppression tunnel with one or more mesh flaps for substantially reducing or preventing the leakage of microwave energy from a microwave system, while having a continuous flow of product through the vessel and suppression tunnels. The suppression tunnels are installed on the inlet and/or the outlet side of the system and are sized to suppress leakage.

A continuous asphalt mix system for using a microwave heating vessel at the point of production that includes a microwave energy suppression tunnel with one or more mesh flaps for substantially reducing or preventing the leakage of microwave energy from a microwave system, while having a continuous flow of product through the vessel and suppression tunnels. The suppression tunnels are installed on the inlet and/or the outlet side of the system and are sized to suppress leakage.