Apparatus and method for controlling accelerated cooling of hot rolled strip material

TLDR: In this paper, a rolling mill runout table is provided with a plurality of selectable spray banks, each bank applying the same unit amount of liquid coolant from a low pressure source.

Abstract: Cooling of hot rolled strip material, such as low carbon steel strip, is controlled while the strip moves along a rolling mill runout table. The table is provided with a plurality of selectable spray banks, each bank applying the same unit amount of liquid coolant from a low pressure source. A time-sharing mill computer receiving operating information signals selects a number of spray banks based on a feed forward calculation of a cooling factor and a calculation of a predicted cooling error term, the latter term being based on stored signals from previous strips cooled. Control means, including a full time special purpose computer, establishes the minimal unit amount of coolant application. When spray bank selection is held constant, this computer takes over the control function and varies the minimal unit amount of coolant proportional to strip velocity error and strip discharging temperature error during strip cooling.