COMPOSITION CONTROL OF A BLEACH SATURATOR

A common item of equipment in the textile industry, the saturator has been overlooked in the implementation of quality-control programs thro ughout textile manufacturing. Although these unit operations appear to be simple in nature, interactions between process variables, changes in cloth density and now rate, process deadtimes, and non-linearities (such as pH) frequently cause transients which adversely affect cloth consistency. A properly designed control system will reduce process va riation by addressing these phenomena and thus dramatically improve th e consistency of the final product. A simple saturator model is develo ped, and a control system is designed by using classical feedforward a nd Smith Predictor elements, The control system has minimal complexity but maintains saturator compositions within reasonable control limits .