Apparatus for the automatic control of a continuous distillation process

Claim 1

APPARATUS FOR THE AUTOMATIC CONTROL OF A CONTINUOUS DISTILLATION PROCESS FOR THE SEPARTION OF A FEED STREAM INTO TOP AND BOTTOM PRODUCT STREAMS IN A DISTILLATION COLUMN IN WHICH BOTH REFLUX AND REEVAPORATION ARE APPLIED AND WHEREIN AN ACCUMULATOR FOR THE TOP PRODUCT IS PROVIDED COMPRISING: MEANS FOR DETECTING THE LEVEL OF THE LIQUID IN THE BOTTOM OF THE COLUMN AND ADJUSTING THE BOTTOM PRODUCT FLOW TO MAINTAIN THE LIQUID LEVEL IN THE BOTTOM OF THE COLUMN BETWEEN DESIRED LIMITS: MEANS FOR ADJUSTING THE FEED STREAM FLOW TO A DESIRED INDEPENDENTLY CONTROLLED VALUE; A FIRST ANALYZER FOR MEAUSING THE QUALITY OF THE BOTTOM PRODUCT; A FIRST CONTROLLER RESPONSIVE TO THE OUTPUT SIGNAL FROM SAID FIRST ANALYZER FOR DETERMINING THE VARIATION BETWEEN THE MEASURED AND DESIRED VALUES OF THE QUALITY OF THE BOTTOM PRODUCT; MEANS FOR MEASURING THE QUANTITY OF HEAT SUPPLIED TO THE REBOILER FOR REEVAPORATION; FIRST CONTROL MEANS RESPONSIVE TO THE OUTPUT SIGNALS FROM SAID FIRST CONTROLLER AND SAID HEAT MEASURING MEANS FOR ADJUSTING THE QUANTIY OF HEAT SUPPLIED TO SAID REBOILER TO MAINTAIN THE QUALITY OF THE BOTTOM PRODUCT AT A DESIRED VALUE; A GUAGE FOR MEASURING THE LIQUID LEVEL IN THE ACCUMULATOR; AND SECOND CONTROL MEANS RESPONSIVE TO THE OUTPUT SIGNALS FROM SAID GAUGE AND TO ONE OF THE OUTPUT SIGNALS FROM SAID FIRST CONTROLLER AND SAID HEAT MEASURING MEANS FOR ADJUSTING THE TOP PRODUCT FLOW AND THE REFLUX FLOW TO MAINTAIN A PREDETERMINED RATIO BETWEEN THE REFLUX FLOW AND THE HEAT FLOW TO THE REBOILER, WHEREBY UPON A CHANGE IN THE HEAT FLOW TO THE REBOILER TO MAINTAIN A CONSTANT QUALITY OF THE BOTTOM PRODUCT, THE RATIO BETWEEN THE REFLUX FLOW AND THE VAPOR FLOW IN THE TOP OF THE COLUMN IS MAINTAINED AT A DESIRED SUBSTANTIALLY CONSTANT VALUE AND THEREBY PREVENTS VARIATION OF THE QUALITY OF THE TOP PRODUCT.