Applied Process Control

5Problem Solutions – Control Strategy Design for Processing Plants

S_5.1 5.1

1. 

2. The reflux will increase in ratio so that the distillate will decrease in order to maintain accumulator level. If the feed is mainly vapour, conditions at the top of the column will not change much as V and L streams will maintain their ratio, with the extra heat being taken out in the condenser (to maintain pressure). After a while, revapourising reflux will find its way back to the accumulator and distillate will increase again. Soon, more of the increased feed will pass to the bottoms, requiring an increase in LC valve to maintain bottom level, and the TC will ...