Method and apparatus for controlling the composition of fluids

Abstract

Abstract DISCLOSED ARE METHODS AND APPARATUS FOR CONTROLLING THE COMPOSITION OF A FLUID SUCH AS THE SOLVENT MIXTURE UTILIZED IN SOLVENT DEWAXING PROCESSES. A PREFERRED METHOD FOR CONTROLLING SAID SOLVENT COMPOSITION INCLUDES THE STEPS OF GENERATING A FIRST SIGNAL REPRESENTATIVE OF A TARGET VALUE OF THE CONCENTRATION OF THE WAX ANTI-SOLVENT COMPONENT OF THE SOLVENT MIXTURE, SEPARATING THE SOLVENT MIXTURE INTO TWO FRACTIONS, ONE OF WHICH IS RICHER AND THE OTHER POORER OF THE WAX ANTI-SOLVENT COMPONENT, COMBINING THE FRACTIONS TO RE-ESTABLISH THE SOLVENT MIXTURE, SENSING THE CONCENTRATION OF THE ANTI-SOLVENT COMPONENT IN THE RE-ESTABLISHED SOLVENT MIXTURE AND PROVIDING A SECOND SIGNAL REPRESENTATIVE THEREOF, AND CONTROLLING THE AFOREMENTIONED COMBINING STEP IN RESPONSE TO THE FIRST AND SECOND SIGNALS IN A MANNER TENDING TO REDUCE THE DISPARITY BETWEEN THE CONCENTRATION SECOND SIGNAL AND THE TARGET VALUE FIRST SIGNAL, THEREBY TENDING TO ACHIEVE THE TARGET VALUE COMPOSITION OF THE RE-ESTABLISHES SOLVENT MIXTURE. A PREFERRED APPARATUS FOR CONTROLLING THE COMPOSITION OF THE AFOREMENTIONED SOLVENT MIXTURE INCLUDES SIGNAL GENERATING MEANS FOR PROVIDING A FIRST SIGNAL REPRESENTATIVE OF THE AFOREMENTIONED TARGET VALUE, MEANS INCLUDING A FRACTIONATOR FOR SEPARATING THE SOLVENTMIXTURE INTO THE AFOREMENTIONED FRACTIONS, MEANS INCLUDING A MIXING TANK WITH AUTOMATIC INLET FLOW CONTROL VALVES FOR COMBINING THE FRACTIONS TO RE-ESTABLISH THE SOLVENT MIXTURE, MEANS INCLUDING A PHOTOMETRIC ANALYZER FOR SENSING THE CONCENTRATION OF THE WAX ANTI-SOLVENT COMPONENT IN THE REESTABLISHED SOLVENT MIXTURE, AND MEANS INCLUDING A DUPLEX CONTROLLER RESPONSIVE TO THE FIRST AND SECOND SIGNALS FOR CONTROLLING THE MIXING TANK INLET VALVES IN A MANNER TENDING TO ACSHIEVE THE TARGET VALUE COMPOSITION OF THE REESTABLISHED SOLVENT MIXTURE.

Inventors

• 👤 William F Brown
• 👤 William E Crockett
• 👤 Charles H Brodeur

Bibliographic Details