Microwave heating apparatus having two cavities and method of using the same

摘要

A system is provided for heating non-metallic material or a discrete layer of the non-metallic material. Microwave energy is introduced into an enclosure defining a first cavity and capable of substantially containing the microwave energy. A semiconductive sheet is positioned at the bottom of the first cavity. Thermal insulation overlies the semiconductive sheet. A second cavity is defined by the undersurface of the semiconductive sheet and flexible microwave shielding in the form of a skirt which is attached to, and depends from, the enclosure. The flexible shielding is composed of a material which also substantially contains the microwave energy. The semiconductive sheet is effective to convert some of the microwave energy into thermal energy and to transmit the thermal energy into the second cavity while transmitting the remainder of the microwave energy directly to the discrete layer, thereby rapidly heating the discrete layer. The system includes a carriage with a handle for moving the apparatus across a surface of the non-metallic material and for adjusting the height of the semiconductive sheet above the surface of the non-metallic material.