Apparatus and method for microwave treatment of process liquids

A microwave device for treating process liquids, comprising

• an elongated microwave cavity which is formed by a tube having a tubular wall and two opposing end-walls;
• means coupled to said two opposing end walls for moving said two opposing end walls along a longitudinal axis of said tube;
• an antenna for radiating a microwave field, said antenna extending into said elongated microwave cavity between said two opposing end walls;
• a first opening and an opposite second opening each of which perforate the tubular wall and each of which is located above midway between one end of said tubular wall and an opposite end of said tubular wall;
• two coaxial bars, each coaxial bar extending through a respective end-wall towards the center of the tube, said two coaxial bars being disposed centrally in the tube and having two mutually facing end surfaces,
• a sample container which is intended to be filled with process liquid and to be inserted in said first opening and said opposite second opening to subject said process liquid to the influence of the microwave field in said elongated microwave cavity;
• and
• means for adjusting the distance between said mutually facing end surfaces of said two coaxial bars to concentrate said microwave field within said sample container.