Abstract
Inside wall of blast furnace is frequently defected by its high pressure and temperature process and solid bodies like iron ore and cokes. For the safety and efficient operations of blast fuanaces, state-based detection of the defect of the inside wall is of great importance. One of the authors previously proposed a detection system which used an ultra-sonic sensor and measured the thicknesses of the entire and inside walls.
The paper presents an improved system which measures the wall-thicknesses even when many reflected waves from the inside of the wall are complicatedly superposed under a time-variant unknown bias caused by the measurement process. The system also makes use of the phase infomation of the reflected waves to raise the reliability of the measurement result. Finally, the effectiveness of the proposed system is verified with experiments on a furnace-type steeve and an actual blast furnace.
