The Design For Detecting Molten Steel Level By Differential Electromagnetic Mathed

In the process of continuous steel casting,the molten steel level in the crystallizer directly affects the quality of the steel billet.With the development and improvement of the society,the requirements of the quality of the steel are getting higher and higher,and the measurement accuracy of the molten steel level in the crystallizer is increasing.Therefore,the research of the detection technology of the molten steel level in the crystallizer has become an important research direction in the control field of the continuous casting machine.Based on the research and analysis of the detection system of the molten steel level in the crystallizer of continuous casting machine,the design of the differential electromagnetic molten steel level detection system is completed.Using the modular concept,the different functions of the circuit is designed in different modules.The system is mainly composed of a differential electromagnetic sensor,a power amplifier,a preamplifier,a signal processing unit,a current output unit,a main controller unit,a digital quantity input and output and a display part.The amplitude and frequency of the sensor excitation signal can be adjusted,the amplitude is controlled by the controller of D/A converter AD7524 input control,the frequency is regulated directly by the frequency of the output excitation signal of the controller.In order to transmit the long distance,the signal is amplified and received by the preamplifier,which is designed for the amplification of the signal from the sensor.In order to facilitate the filtering process,the programmable filter MAX261 and the phase lock amplifier AD630 are used for filtering.The design of the main controller of the whole system adopts FPGA+Nios II software and hardware to design,which improves the system's real-time performance and stability.Differential electromagnetic molten steel level detection system is to convert the molten steel level in the crystallizer to the standard industrial current signal 4-20 mA output.The whole system has reached the design requirements.