| The position of each layer interface in the self-baking electrode is essential for the safe production of the calcium carbide furnace,While the self-baking electrode’s length determines the furnace’s production efficiency.To ensure the high efficiency and safe production of the calcium carbide furnace,the position of each layer interface in the self-baking electrode and the length of the self-baking electrode should be ensured to be fixed.At present,plants often use manual measurement methods with large measurement errors to measure the length of the selfbaking electrode,but cannot measure the position of the interfaces inside the self-baking electrode.The purpose of this paper is to study the influence of electrode geometry,sound source power,acoustic receiver position,sound source position,and electrode depth in the furnace on the acoustic-thermal coupling results,and to make a theoretical reference for the practical application of the length measurement device afterward,and the specific work contents and research conclusions are as follows:Because the actual production process of calcium carbide is complicated,the model is studied by simplifying the model.the steady-state temperature field model of the calcium carbide furnace during average production was first established,followed by the research idea of one-way coupling between the electrode temperature field and the ultrasonic acoustic field,and finally,the model simulation and analysis were carried out by using the electrothermal module and the ray acoustic module in Comsol software.The simulation results are basically consistent with the internal temperature field of the electrode,and the approximate solution of the temperature field of the graphite electrode is obtained.Comparing the results of the acoustic field with and without temperature field coupling,it is found that the echo signal at the bottom of the electrode with temperature field coupling reaches the acoustic receiver about 0.002 s earlier at the echo moment;the amplitude of the sound source frequency 25000 Hz is greater at the frequency domain with temperature field coupling.from the analysis of the acoustic pressure distribution at the electrode boundary,it is found that the temperature field has a focusing effect on the acoustic wave propagation(the acoustic wave propagation tends to be more towards the bottom of the electrode).In this paper,the four factors of electrode height,electrode diameter,sound source power,and sound source frequency are analyzed separately,and it is found that the electrode height of8.9m,electrode diameter of 1.1m,source power of 150 W and sound source frequency of23000 Hz are more favorable for the electrode length measurement device.Four factors are studied through the orthogonal experimental method to influence the degree of model coupling results.The orthogonal numerical experimental results show that the four factors influence the model coupling results in the following order: electrode diameter,sound source power,sound source frequency,and electrode height.To avoid the inability to receive the echo signal of some interfaces in the electrode,the acoustic receiver position is best located in the electrode paste,for the echo signal of the interface between air and electrode paste,the acoustic receiver can be placed in the air domain alone to receive its echo signal;if it is found that the intensity of the received echo signal is small and the source position is not on the electrode paste interface,the source position can be set on the electrode paste interface to obtain better reception effect.From the analysis of the electrode boundary sound pressure distribution,it is found that the total sound pressure at the bottom of 0.6m of the electrode into the furnace decreases compared with that when the electrode is not into the furnace,and the focusing effect of the temperature field on the acoustic wave is enhanced at the depth of 0.4m of the electrode into the furnace,while the focusing effect of the temperature field on the acoustic wave is weakened at the depth of 0.8m of the electrode into the furnace. |
