| 摘要 |
PURPOSE:To enable to prevent the thickness decrease of a tube securely without dismantling the tube by a method wherein the temperature of the tube, which is risen by the collision and friction of an abrasive material, is detected to detect that the tube is in a condition in which the thickness of the tube is decreasing. CONSTITUTION:Upon separating and removing a substance adhered to the inside of a tube, the energies of collision and friction of an abrasive material are converted into a heat energy, however, since the adhered substance such as carbon or the like has an insulating effect, a temperature difference DELTAt between the tube temperature at the outer peripheral surface of the tube 1 and a normal temperature is indicated by indicating members 5a, 5b respectively as a low value. On the other hand, when the substance adhered to the surface of the inner wall is separated and removed, the energy of the collision and friction with respect to the surface of the inner wall is transmitted to the tube 1 directly and the tube temperature is risen, therefore, the temperature difference DELTAt becomes a high value whereby an operator decides that the tube 1 is in a condition in which the thickness thereof is decreasing and controls the flowing speed of the nitrogen gas into a low speed to prevent the decrease of the thickness thereof. |
