| 摘要 |
PURPOSE:To harden steel pipes inline and save energy by correcting the heating en route of the process of a steel pipe rolling line or right after the final process through detection of the temps. of the pipes and maintaining the pipes at prescribed hardening temps. CONSTITUTION:A computer CP controls heating temps. or conveyor speeds so that the temp. differences in the longitudinal direction of steel pipes to be introduced into a hardening vessel 5 are eliminated or minimized and that the pipe just prior to hardening minitained at prescribed temp. For example, a temp. detecting means 61 detects the temp. of the pipe just prior to entering the heating means 3 of a pipe line 1, and the computer CP recognizes the temp. distribution pattern per piece of the pipes or in their longitudinal direction first. From these, it forecasts the same pattern just prior to the hardening of the case when there is no means 3 and determines a target hardening temp. pattern. Following to this, the computer CP controls the temp. at each point of the means 3 and corrects the applied electric power at each point of the means 3 while monitoring the temps. at each point of the pipe during passing the means 3 detected momentarily with detecting means 62-6n and just prior to the hardening. |
