Feedback Control of Composition

Condensate receiver level control cascaded to distillate flow ccmtrol 

Overhead composition control cascaded to reflux flow control 

Base level control cascaded to bottom-product flow control 

Base composition control cascaded to steam flow control 

For all four loops we assume that the secondary flow controls are fast compared with the primary level and composition loops. This permits us to ignore flow control loop dynamics. Then to go from the primary controller output to flow we need oiUy multiply by 1/R, where K is the flow-meter static gain (linear flow meters assumed).  

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