高炉炉墙测厚的信号处理

Signal Processing in Blast Furnace Wall Thickness Measurement

摘要:

超声波反射法应用于高炉炉墙测厚时,高炉内部环境高温高噪声的特点,造成超声回波信号被噪声湮没的问题；针对这一问题,研究了超声波在金属介质中传播的机理,分析了超声回波信号信噪比下降的原因以及实验数据时域和频域的特征,设计改进了高炉炉墙测厚的超声波发射电路和信号调理电路；采用加热炉模拟高炉200~1 000 ℃温度环境,对直径40 mm、长度1.2 m的铁棒进行测厚实验；经实测,改进的发射电路发射的超声信号强度增大,回波处理电路处理后超声回波信号信噪比明显提高、峰值清晰可辩,解决了噪声湮没回波信号的问题,提高了高炉炉墙测厚的测量精度,对高炉的高产、顺产和延长炉龄具有实际意义。

Abstract:

The problem that ultrasonic echo signals submerged by noise caused by high temperature and high noise in the blast furnace internal environment when the ultrasonic reflection method is applied to measure blast furnace wall thickness. In allusion to the problem, the mechanism of ultrasonic wave propagation in metal medium is studied, the causes of decrease of ultrasonic echo signal SNR decreased and the experimental data of time domain and frequency domain features is analyzed, the improved ultrasonic emission driver circuit and signal conditioning circuit of blast furnace wall thickness is designed. The furnace simulates 200 ℃ to 1 000 ℃ temperature environment and thickness measurement experiment to iron rod of 40mm diameter and 1.2 m length is done. Proved by actual measurement, the strength of ultrasonic signal of improved launch circuit has increased, the signal-to-noise ratio of ultrasonic echo signal after echo processing circuit is obviously improving, the peak of ultrasonic echo signal is clear, the problem of the annihilation of the echo signal by noise is solved, the precision of the blast furnace wall thickness measurement is improved, it has practical significance to high yield, smoothly production and prolong the furnace life of blast furnace.