Automatic control of the viscosity of a fractionator product

Claim 1

IN A METHOD FOR FRACTIONATING THE CONSTITUENTS OF A CONTINUOUS FIRST STREAM OF A PETROLEUM PRODUCT BY PASSING SAID STREAM IN A HOT CONDITION INTO A STILL, DISCHARGING A VAPOR FRACTION AT THE TOP OF SAID STILL, DISCHARGING A LIQUID FRACTION AT THE BOTTOM OF SAID STILL, AND REGULATING THE TEMPERATUER IN SAID STILL BY CONCURRENTLY PASSING INTO SAID STILL A SECOND RELATIVELY COOL STREAM OF SUBSTANTIALLY THE SAME PETROLEUM PRODUCT, THE IMPROVEMENT WHICH COMPRISES: WITHDRAWING A PORTION OF SAID LIQUID FRACTION AS A CONTINUOS SIDE STREAM AFTER IDSCHARGE FROM SAID STILL, ADJUSTING SAID SIDE STREAM TO A SELECTED CONSTANT TEMPERATURE, CONTINUOUSLY MEASURING THE VISCOSITY OF SAID SIDE STREAM AFTR SO ADJUSTING THE TEMPERATURE THEREOF, CONVERTING THE RESULTING MEASUREMENT TO A SIGNAL PROPORTIONAL TO VISCOSITY, TRANSMITTING SAID SIGNAL TO A FLOW CONTROLLER FOR SAID SECOND STREAM OF RELATIVELY COOL PETROLEUM PRODUCT, AND AUTOMATICALY ACTUATING SAID FLOW CONTROLLER TO REGULATE THE RATE OF FLOW OF SAID SECOND STREAM IN ACCORDANCE WITH CHANGES IN THE MAGNITUDE OF SAID SIGNAL WHEREBY THE VISCOSITY OF SAID LIQUID FRACTION IS HELD CONSTANT.