| Blast furnace is a key link in iron and steel production, and it plays a decisive role in ironand steel smelting in the global. there are thousands of blast furnace all over the world, due tolack of repair or damage assessment and other reasons, most of them that there are differentlevels of security risks cause a lot of blast furnace safety accidents, casualties and propertylosses. Blast furnace lining thickness change is closely related to blast furnace safetyproduction, accurately grasping the change of blast furnace lining and adjusting productionstrategies in time are very important for promoting safe production of blast furnace andprolonging the life of blast furnace and enhancing production efficiency. In order to eliminatepotential safety problems and reduce enterprises property loss in production of blastfurnace,real-time monitoring blast furnace lining thickness change is very significant.In this paper, the existing blast furnace lining thickness detection techniques werestudied, such as multiple-thermocouple method, resistance method, capacitance method,ultrasonic method, heat detection method, model extrapolation method, impact elastic wavemethod, etc. The principles of various methods were described, and their advantages anddisadvantages as well as their applicable scope were summarized. Blast furnace liningthickness detection technology based on impact elastic wave method was importantlyresearched. Elastic wave was excited on the surface of furnace, the elastic wave could bereflected when it met the furnace inner surface, the furnace lining thickness was inferred byreturn time of test signal. When impact elastic wave was spread among coarse grainedmaterials, such as blast furnace refractories, and met discontinuous interface, such as voidsand cracks, sensitive phenomenon which included reflection, refraction and scatteringhappened. Blast furnace lining defection could be detected by impact elastic wave sensitivityto structural defection.The main factors influencing on test accuracy of impact elastic wave method werereflection time, propagation velocity and ambient noise. To improve test accuracy of impactelastic wave method, the corresponding improvement methods were proposed, recognitionaccuracy of reflection time was improved by ameliorating repetitive reflection method, theinfluence of environmental noise was eliminated by multi-point excitation/multi-channelvibration, recognition accuracy of impact elastic wave velocity was improved by the CDPcoincidence method and NMO correction.Combining with Sichuan Shengtuo detection technology company with limited liability,field test was proceeded in Panzhihua Iron and Steel Co. blast furnace,sponge titaniumsmelting furnace and Xichang blast furnace in order to verify the superiority and rationality ofimpact elastic wave method. The test results showed that impact elastic wave test method hadbetter precision and strong anti-jamming performance. At the same time, after analysising the existing detection techniques, the writer predictedfuture developing trend, and believed that future blast furnace lining detection technologywould have been developed towards precision, automation, visualization, low-cost, andmulti-condition, and different detection techniques could be combined with each other inorder to form a effective and secure compound detection system. And research priorities werefocused on optimal arrangement of sensors, combination ’invasive’ detection with’non-invasive’ detection, detection process optimization and the application of some newtechnologies. |
