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Project background
Infrared thermal imaging technology is widely used in industrial detection fields such as electric power, rail transit, equipment manufacturing and so on by virtue of the characteristics of full image surface accurate temperature measurement. With the continuous expansion of its application field, infrared thermal imaging technology also plays an important role in the detection and control process of metallurgical industry.
As one of the ferrous metallurgy, the iron and steel industry has developed towards refinement, intelligence and high quality after rough development. On the basis of ensuring the production capacity, the quality of steel has become an important indicator in the competition, and the purity of molten steel is very important.
In the process of steel production, converter steelmaking is an important part. When the steelmaking ends and the tapping begins, the molten steel flows into the ladle from the tapping port, and the liquid level of molten steel and slag in the furnace gradually decreases.
At the end of converter tapping, steel slag will also flow out with molten steel. Excessive steel slag will not only reduce the quality of molten steel, but also easily block the tapping hole, accelerate the wear of ladle refractory layer and shorten the service life of the equipment. Therefore, it is necessary to detect the slag situation of the converter in time, so as to stop slag or steel tapping in time.
Infrared application
The detection steps of tapping and slag of infrared thermal imaging converter are as follows:
1) Read the image, and preprocess the converter tapping image through denoising, enhancement and other algorithms;
2) Image region segmentation, a geometric active contour model for BOF tapping image is established, and the target contour curves of molten steel and slag and the average gray value of the segmented target region are obtained by solving the level set method;
3) Identification and content detection of steel slag, comparing the regional gray to determine the steel slag and calculate the steel slag content;
4) When the steel slag content reaches the set warning value, alarm and output signals to the converter control unit to stop the converter tapping in time, which can maximize the output of steel water and ensure the quality of steel.
Case analysis
Because the emissivity and temperature of steel slag generated in the steel-making process are obviously different from that of molten steel, the infrared thermal imager outputs the temperature image in real time, observes the outflow of steel slag, extracts the steel slag part by using the image segmentation technology and the given temperature threshold, calculates its proportion, and realizes the automatic control of the start and stop of steel tapping.
Advantage
1) The detection of converter steel slag by infrared thermal imaging technology is low cost and easy to maintain;
2) It can effectively avoid the disadvantages of low accuracy of traditional manual judgment and poor working environment of workers;
3) It has strong noise resistance and can realize rapid image segmentation and steel slag content detection;
4) Accurate and real-time automatic detection can improve the purity of molten steel and prolong the service life of the equipment.
