Development of non-contact detection device for coal moisture based on microwave transmission method

In order to quickly and accurately detect the moisture content of coal and realize online non-destructive testing. An on-line measurement system of coal moisture content based on the principle of microwave transmission is designed. The measurement principle is introduced emphatically, and a method for quickly detecting the moisture content of coal by detecting the voltage signal is proposed. Different fitting models between decay voltage and water content were established, and the best calibration equation was determined by comparing different fitting models. On this basis, a coal moisture detection device applied to the conveyor belt was developed. The device consists of a 10GHz microwave signal source, a horn antenna, a detector, a single-chip microcomputer, an electric conveyor belt machine and a sample holder. Finally, coals with different moisture contents were evaluated experimentally. The results show that the measurement accuracy and deviation of the system are within the acceptable range.