Abstract: A microwave melting furnace for treating a liquid, comprising an upper furnace body, a lower furnace body, means disposed to the upper furnace body for supplying material to be treated, a crucible disposed in the lower furnace body, means for detecting the position for the upper surface of the material to be treated supplied into the crucible and a controller for stopping the means for supplying the material to be treated depending on a detection signal from the detection means. The liquid supplied to the crucible can be surely prevented from overflowing automatically.

Abstract: A microwave device for treating process liquids, preferably precursors to radiopharmaceuticals, with microwave radiation, with the intention of reducing reaction time and increasing reaction yield. The method and the device are characterized in that the geometry of the microwave cavity is varied proportionally to the geometry of the sample container in order to concentrate the microwave field within the container. The reaction time can also be shortened and the reaction yield also increased by varying the microwave field energy or microwave field frequency. The reaction time can also be decreased by adding salts to the process liquid or by adapting the frequency of the microwave field to the resonance frequency of the process liquid in the microwave spectrum.

Abstract: The present invention relates to a method of treating aqueous fluids for the purpose of increasing the heat absorption characteristics thereof. The method also relates to treating aqueous fluid in applications where it is desired to use a certain amount of heat input to achieve a higher temperature for the fluid or where it is desired to achieve a certain temperature for the fluid using a lesser amount of heat input or to accelerate fluid heating. The treatment comprises directly injecting into the fluid electromagnetic radiation, most preferably electromagnetic radiation having a frequency between 1 KHz and 1000 MHz. In the most preferred embodiment, electromagnetic radiation is injected through a conductor directly in contact with the fluid.

Abstract: A plurality of samples in a moist medium are treated simultaneously in a microwave cavity. The samples are conducted into the cavity through apertures formed in an upper wall of the cavity. Each aperture is surrounded by a chimney configured to create a barrier opposing the propagation of microwaves from the cavity. The samples are introduced into receptacles which extend through the chimneys. Each receptacle can be supported on the chimney a lower end of the receptacle disposed within the cavity. Alternatively, the receptacles can be in the form of continuous tubes extending through upper and lower walls of the cavity in order to convey continuous flows of the sample.

Abstract: A high-frequency heating device includes a power converter for converting an electric power from a commercial power source or the like into a high-frequency power, a step-up transformer having a high-voltage winding and a low-voltage winding, a magnetron receiving high-voltage and low-voltage outputs, a resonance circuit connected in series or parallel with the filament of the magnetron, and a control circuit. The control circuit controls the power converter so that the operation frequency of the power converter approximately coincides with the resonance frequency of the resonance circuit at the time of activating the power converter to thereby achieve a rapid start of the oscillation operation of the magnetron while suppressing a high voltage from taking place at the activation time to prevent the possible occurrence of the moding phenomenon.