Study On Blast Furnace Condition Monitoring System Based On Gas Flow Distribution Information

Blast-furnace iron making is a predominant iron-making way in steel industry and as a keydevice in iron making, blast-furnace has an internal complex production process of physics,chemistry and dynamics under the environment with high temperature, high pressure andconfined condition, which is a multi-variable nonlinear smelting system involving interaction ofsolids, liquids and gas materials. Therefore, it’s of great significance to master and control theblast-furnace inner production in real time to ensure the safety, environment protection and highefficiency of blast-furnace iron making. However, in a very long time, blast-furnace productionprocess is so black a box that workers adjust the operating system according to the blast-furnaceinner parameters obtained from kinds of sensors, which severely decreases theproduction-mastering accuracy for the blast furnace workers because of non-intuition,non-independence and non-real time of sensor acquisition. In addition, there exists that thecurrent studies of blast furnace intelligent technology with computer application lack completesets of technology solution. For the above problems, this paper designed a blast furnaceconditions monitoring system based on gas flow distribution information using infrared laserillumination, thermoelectric refrigeration, image processing and microcontroller technology andalso some key technologies in the system design are analyzed.According to the top-down mainline, it researched and analyzed the key technologies ofblast furnace conditions monitoring system design from five aspects of high-temperatureresistant fiber optic lighting, CCD camera cooling and temperature control, blast furnace burdenimage acquisition and data transmission, burden image processing and blast furnace conditionrecognition and safety alarm. First, infrared laser technology is used to invent thehigh-temperature resistant fiber optic lighting system in which808nm-wavelength infrared laseris chosen and power and focus adjustment controller is designed. By TracePro modeling andsimulating and analysis of laser spectrum, illumination and light intensity and simulating tests,the results show the success of the standard lighting index. Second, the CCD camera coolingsystem based on the thermoelectric cooler uses a semiconductor thermoelectric cooler as thecooling source, digital temperature sensor and PWM technology to realize automatic temperaturecontrol, keeping the CCD camera working at a constant and lasting temperature. Third, blastfurnace burden image acquisition and data transmission system is designed. The burden imagescaptured by CCD camera are transmitted via a video transmission line to the video capture card.The CCD camera temperature captured by digital temperature sensor and nitrogen pressure andcooling water pressure captured by electric contacting pressure gauges enter the upper microcontroller to be packed and transmitted to the outside monitoring room via the RS485transmission lines. Forth, the blast furnace conditions recognition system is designed based ondigital image processing. After a frame static image is extracted from the video andpre-processed by filtering de-noise, sharpening enhancement, OSTU threshold segmentationalgorithm and local statistical feature recognition algorithm are applied to identify the blastfurnace conditions. Fifth, the temperature and pressure alarming apparatus is designed to detectthe CCD camera working temperature, Nitrogen pressure and cooling water pressure which arecontrolled by the lower microcontroller to alarm automatically to provide safety protection forthe blast furnace production. Finnaly, the mathematical model building of the whole monitoringsystem is completed. Blast furnace conditions monitoring system with characteristics ofnon-contact, low cost, easy maintenance and real time has a wide range of industrial applicationprospects.