Fractionation control system

Claim 1

APPARATUS FOR FRACTIONATING A FEED STOCK CONTAINING VARIABLE AMOUNTS OF AT LEAST TWO COMPONENTS TO PRODUCE CORRESPONDING SEPARATED PRODUCTS THE PURITY OF AT LEAST ONE OF WHICH IS TO BE MAINTAINED SUBSTANTIALLY CONSTANT; SAID APPARATUS COMPRISING, IN COMBINATION, A DISTILLATION COLUMN, A SUPPLY CONDUIT CONNECTED TO THE INPUT OF SAID COLUMN TO CONVEY THERETO THE FEED STOCK TO BE SEPARATED, COMPOSITION ANALYZING MEANS OPERABLE WITH THE FEED STOCK IN SAID CONDUIT TO MEASURE THE AMOUNT OF AT LEAST ONE OF SAID COMPONENTS IN SAID FEED STOCK, SAID COMPOSITION ANALYZING MEANS INCLUDING MEANS TO PRODUCE AN OUTPUT SIGNAL CORRESPONDING TO THE MEASURED AMOUNT OF SAID ONE COMPONENT, A COMPUTER CONNECTED TO SAID COMPOSITION ANALYZING MEANS TO RECEIVE SAID OUTPUT SIGNAL, SAID COMPUTER INCLUDING MEANS TO STORE A PROGRAM BASED ON THE CHARACTERISTICS OF SAID DISTILLATION COLUMN UNDER DIFFERENT CONDITIONS OF OPERATION AND RELATING THE OUTPUT PURITY OF SAID ONE PRODUCT TOTHE ENTHALPY PER UNIT OF MASS OF SAID FEED STOCK FOR VARIOUS FEED STOCK COMPOSITIONS, SAID COMPUTER ALSO INCLUDING MEANS RESPONSIVE TO SAID OUTPUT SIGNAL AND OPERATIVE WITH SAID MEANS TO STORE A PROGRAM TO PRODUCE FOR THE MEASURED AMOUNT OF SAID ONE COMPONENT A SIGNAL REPRESENTATIVE OF THE CORRESPONDING PROPER VALUE OF FEED STOCK ENTHALPY PER UNIT OF MASS WHICH WILL TEND TO MAINTAIN THE DESIRED PURITY OF SAID ONE PRODUCT, ENTHALPY CONTROL MEANS CONNECTED TO SAID CONDUIT TO PROVIDE AN OPERATIVE ASSOCIATION WITH SAID FEED STOCK, SAID EN-