Separation column control

Claim 1

IN THE SEPARATION OF A FEED MIXTURE IN A SEPARATION COLUMN FROM WHICH AT LEAST OVERHEAD AND BOTTOM COMPONENTS ARE WITHDRAEN, THE IMPROVEMENT COMPRISING, PASSING SAID BOTTOM COMPONENTS INTO A HEAT EXCHANGE ZONE, HEATING SAID BOTTOM COMPONENTS IN SAID HEAT EXCHANGE ZONE BY PASSING SAME IN INDIRECT HEAT EXCHANGE RELATION WITH A HEATING FLUID, PASSING VAPORS FORMED BY SAID HEATING FROM SAID HEAT EXCHANGE ZONE INTO THE LOWER PORTION OF SAID COLUMN AS THE SOLE SOURCE OF HEAT THERETO, SUPPLYING HEATING FLUID TO SAID HEAT EXCHANGE ZONE IN AN AMOUNT SUFFICIENT TO SATISFY A GIVEN DEMAND FOR VAPORS AT A SUBSTANTIALLY CONSTANT FIRST FLOW RATE, CONTINUOUSLY MEASURING THE TEMPERATURE WITHIN SAID HEAT EXCHANGE ZONE, AND ADJUSTING THE DEMAND FOR VAPORS FROM SAID FIRST FLOW RATE TO A SECOND FLOW RATE IN ACCORDANCE WITH SAID TEMPERATURE MEASUREMENT, THEREBY CHANGING THE RATE AT WHICH HEATING FLUID IS SUPPLIED TO SAID HEAT EXCHANGE ZONE.