| 摘要 |
A method and apparatus are disclosed for measuring the thickness of the layer of refractory brick 15 on the inside of the steel wall 5 of a cement kiln and of any layer of clinker 19 adhering to the inner face of the brick layer. The method may be applied from the outside of the kiln during normal operation. The method depends on the measurement of the response of the kiln wall to an impulsive force applied at a point 17 by a hammer 13. The vibration response at the point is monitored by a transducer 7 so as to determine the mechanical impedance at the point. The vibration response is, at the same time, monitored by a transducer 9 at a small distance from the point so as to determine the velocity of flexural waves in the kiln wall. Thickness can then be calculated from the determine impedance and velocity and from a knowledge of the thickness of the steel wall and of the density and elastic property of the steel, the brick and the clinker. |
