Feasibility of using ultrasonic technique to measure the blast furnace lining thickness

Blast furnace process has been the most effective way to produce iron for over 200 years.Throughout the years, large efforts have been put on finding ways to increase the productivity and extend the campaign length. The condition of the refractory lining of a blast furnace plays a very important role to determine its campaign length. Many methods have been employed to measure blast furnace lining thickness including radioisotopes, thermal measurement and core-drilling. Temperature measurement is among the most widely used method for on-line monitoring the profile of the blast furnace inner surface, which is based on
numerically solving inverse problem using heat transfer models and readings from thermocouple. Optimization methods are applied to obtain the boundary of the domain iteratively, and hence the computation is very expensive and calculation cannot be very accurate. This paper presents the feasibility of using non-invasive ultrasonic technique in bistatic mode to measure the profile of the refractory liner of the hearth region of blast furnace.