On-line Control Studies of Continuous Emulsion Polymerization Systems

A redesigned latex reactor train configuration for the continuous production of emulsion poly (vinyl acetate) is being employed in order to test and implement on-line computer control stategies. Multivariable computer control of the final latex polymer particle size and monomer conversion is achieved using several algorithms which manipulate the feedrate of initiator to the first reactor of the train, and the flow split of the monomer and water feedrates between the first two reactors. The control algorithms include simple single loop feedback, multivarable, and optimal controllers. Both set-point changes and disturbance rejection (mainly water soluble impurities or oxygen contamination) are being covered. Control is implemented using a VAX 11/750 with a PDP-11 front end system interfaced to our pilot plant stainless steel 1-gallon reactors.