Electromagnetic Slag Detection Sensor Structure And Working Parameter Design Based On Finite Element Simulation

Because of the steel slag could affect the energy consumption of molten steel and quality of billet,and controlling the slag in molten steel to enter into tundish is important.So the slag detection is necessary for the steel casting.The method of slag detection includes weighing method,laser method,vibration method and so on.Electromagnetic slag detection method is accurate and timely.However,Electromagnetic slag detection method demands highly sensitive sensor.In this thesis,finite element analysis and experiment are combined to design the structure and excitation parameters to enhance transducer sensitivity.The research contents of the thesis are as follows:(1)Theory analysis of electromagnetic slag detection.Principles of electromagnetic slag detection were made out to design detection scheme.Magnetic field distribution that produced by alternating current in heliciform wire calculated firstly.Eddy current distribution of molten steel was deduced by electromagnetic osmotic equation in coils.Induced voltage equation in coils was received in the end.(2)Analysis of sensor structure.Fistly,analysis the single-layer distribution mode of coils.The past anslysis method to research was in-outside and up-downside.Secondly,analysize the cross-distribution of exciting coils and receiving coils.The distribution could not only enhance the strength of the induced voltage signal,but also make the sensor size smaller.The model of double-layer coils could improve the signal intensity of sensor.Metal shell could recede signal intensity.The weakening extent could be neglected.(3)Analysis of sensor working parameters.The sensitivity calculation formula of the tube electromagnetic detection sensor is deduced by the theory of electromagnetic detection.Firstly,the influence of slag signal distribution to the sensor sensitivity is studied.Secondly,the optimal values of the excitation frequency and the excitation current are found in the different distribution of slag signals.Finally,the excitation frequency and the excitation current amplitude of the maximum induced voltage variation are studied under different slag distributions.(4)The experimental validation and analysis.Make the experiment scheme,complete the design of experimental samples and the sensor coils.The data acquisition is completed under the different excitation.The experimental data is analyzed and compared with the simulation resultsIt is concluded from the above work that the double-layer intersecting arrangement can get a stronger reception signal.The metal shell will not affect the sensor's sensitivity,but it will weaken the signal strength.The higher the excitation current,the stronger the signal strength;The excitation current is 0.3A and the sensor has the highest sensitivity.The excitation frequency is 2kHz,which can get strongest signal and the sensor has the highest sensitivity at this time.