Control system for chemical reactions

Claim 2

The method of claim 1 wherein a first signal is established which is representative of said calculated concentration and a second signal is established which is representative of said measured concentration, a third signal obtained in the manner to be described hereinafter is delayed to establish a fourth signal, said fourth signal is compared with said second signal to establish a fifth signal representative of the difference therebetween, said fifth signal is added to said first signal to establish said third signal, said fourth signal is compared with said third signal to establish a sixth signal representative of the difference therebetween, and said sixth signal is compared with said second signal to establish a seventh signal representative of the difference therebetween, the amount of reactant passed to said reaction zone being controlled in response to said seventh signal.

Claim 3

The method of claim 1 wherein a first signal is established which is representative of said calculated concentration and a second signal is established which is representative of said measured concentration, a third signal obtained in the manner to be described is delayed to establish a fourth signal, said fourth signal is compared with said second signal to establish a fifth signal representative of the difference therebetween, said fifth signal is added to said first signal to establish said third signal, and said third signal is compared with a set point signal, the amount of reactant passed to said reaction zone being controlled in response to the comparison of said third signal with said set point signal.

Claim 4

The method of claim 1 wherein said reaction is exothermic and wherein the concentration of reactant is computed from measurements of the heat generated in said reaction zone.

Claim 5

The method of claim 5 wherein the reaction is a polymerization reaction and the reactant is monomer.

Claim 6

In a system which includes a reactor, inlet means communicating with said reactor to introduce a reactant, and outlet means communicating with said reactor to withdraw product; control apparatus comprising computing means connected to said system to calculate the concentration of reactant in said reactor and to establish a first signal representative thereof, said computing means measuring variables in the system other than the actual reactant concentration; analyzing means connected to said system to measure the concentration of reactant in the system and to establish a second signal representative thereof; lag means; means to pass said first signal through said lag means to establish a third signal; means to compare said second and third signals; and means responsive to said means to compare to control the introduction of reactant into said reactor.

Claim 7

The apparatus of claim 7 wherein said means to pass, said means to compare and said means to control comprise a first signal summing means, means applying said first signal to the first input of said first summing means, first signal subtracting means, means applying said second signal to the first input of said first subtracting means, means applying the output of said first adding means through said lag means to the second input of said first subtracting means, means applying the output of said first subtracting means to the second input of said first adding means, second signal subtracting means, means applying the output of said lag means to the first input of said second subtracting means, means applying the output of said first adding means to the second input of said second subtracting means, second signal adding means, means applying the output of said second subtracting means to the first input of said second adding means, means applying a reference set point signal to the second input of said second adding means, a controller, means applying said second signal to the input of said controller, means applying the output of said second adding means to the set point of said controller, and means responsive to the output of said controller to regulate the flow of reactant into said reactor.

Claim 8

The apparatus of claim 7 wherein said means to pass, said means to compare and said means to control comprise a signal summing means, means applying said first signal to the first input of said summing means, signal subtracting means, means applying said second signal to the first input of said subtracting means means applying the output of said adding means through said lag means to the second input of said subtracting means, means applying the output of said subtracting means to the second input of said adding means, a controller, means applying a reference set point signal to said controller, and means responsive to the output of said controller to regulate the flow of reactant into said reactor.

Claim 9

The apparatus of claim 7 wherein said computing means comprises a heat balance computer connected to said system to provide a fourth signal representative of the concentration of reactant in said reactor and a fifth signal representative of the rate of production of product within said reactor, signal summing means, means applying said fifth signal to the input of said signal summing means, means applying a signal representative of the rate of flow of reactant into said reactor to said signal summing means, a first signal multiplier, means to apply a signal representative of the rate of product withdrawal from said reactor to the first input of said first multiplier, a signal subtractor, means to apply said fourth signal to the first input of said signal subtractor, mEans to apply the output of said signal subtractor to the second input of said first multiplier, a second signal multiplier, means to apply the output of said first multiplier to the first input of said second multiplier, a third signal multiplier, means to apply the output of said second signal multiplier to the input of said signal summing means, means to apply the output of said signal summing means to the first input of said third multiplier, means to apply a reference signal to the second input of said third multiplier, a signal integrator, means to apply the output of said third multiplier to the input of said integrator, and means to apply the output of said integrator to the second input of said second multiplier, the output of said integrator being said first signal.