| 摘要 |
<p>A strip break detection system is disclosed for a process line in which strip material is being payed out from a payoff reel to a rewind reel. The system is digital, and is based on the concept that for normal mill operation, with continuous strip being payed out from a payoff reel to a rewind reel, equal increments of rotation of the rewind reel, results in ever increasing increments of rotation of the payoff reel. A payoff counter is coupled to the payoff reel. The break detection system is controlled from a rewind counter coupled to the rewind reel which triggers a sequence controller for comparing the successive counts in the payoff counter to ensure that they are ever increasing under normal processing conditions, if the comparison indicates the converse an alarm is sounded; however, since there may be transient and self correcting conditions in the process line during which the latter count of the payoff counter may be less, the system is desensitized by further comparison with a dead band count. If the comparison of the sequential counts in the payoff counter produces a difference which is equal to or greater than the dead band, an alarm signal then indicates that a break has occurred.</p> |
