The microwave energy from the microwave generator is emitted by a special radiator (antenna) through a layer of thermal insulation to the interior of the high-temperature furnace. Ceramic plates which absorb microwaves and heated with microwaves to a preset temperature are usually placed inside the furnace. The thermal insulation placed in the furnace chamber is made of insulating material with special properties, it is transparent to microwaves (does not absorb microwaves). The temperature inside the furnace is controlled by a pyrometric sensor connected via a controller with a microwave generator with adjustable output power.
Construction of the furnace is shown in the diagram below:
Microwave Generator with a continuous wave magnetron (generation lamp), Microwave Radiator emitting (antenna) directs a stream of microwave energy into the chamber, Microwave Absorbing Insert usually made of silicon carbide (SiC) or graphite, Pyrometer for measuring the temperature inside the furnace, mounted on the wall of the furnace chamber and connected to the controller, Thermal Insulation made of ceramic material with a very low microwave absorption coefficient.
Parameters of the available microwave generators:
The output power in the range 3 – 10 kW (CW) frequency 2.45 GHz, or 10 – 100 kW (CW) frequency 915 MHz.