Liquid-liquid extraction tower

Claim 1

AN IMPROVED APPARATUS FOR CONTACTING TWO INCOMPLTELY MISCIBLE LIQUIDS, COMPRISING AN UPRIGHT VESSEL HAVING CONDUITS FOR INTRODUCTION AND WITHDRAWAL OF THE LIQUIDS; A PLURALITY OF CONTACTING STAGES DISPOSED ONE ABOVE THE OTHER, EACH STAGE COMPRISING AN UPPER IMPERFORATE HORIZONTAL PLATE EXTENDING ACROSS THE MAJOR PORTION OF THE CROSS SECTION OF THE VESSEL AND HAVING DOWNWARDLY EXTENDING VERTICAL LIP MEMBERS ON DIAMETRICALLY OPPOSITE SIDES, ONE OF SAID LIP MEMBERS BEING ADAPTED TO FORM AN UNDERFLOW WEIR, A SMALLER IMPERFORATE PLATE DISPOSED BELOW SAID FIRST NAMED PLATE ATTACHED AT ONE END TO THE WALL OF SAID VESSEL AND EXTENDING SUBSTANTIALLY HORIZONTALLY INWARDLY TO A POINT BEYOND SAID UNDERFLOW WEIR MEMBER, AN UPWARDLY EXTENDING VERTICAL LIP ATTACHED TO THE OTHER END OF SAID SMALLER PLATE FORMING A TORTUOUS PATH WITH SAID UNDERFLOW WEIR MEMBER, A VERTICALLY DISPOSED SEPARATOR PLATE, THE LOWER EDGE OF WHICH IS ATTACHED TO THE UPPER SIDE OF SAID UPPER HORIZONTAL IMPERFORATE PLATE AND EXTENDING TO A POINT ABOVE THE LOWER SURFACE OF THE LIP MEMBER OPPOSITE SAID LAST NAMED UNDERFLOW WEIR MEMBER, A HORIZONTAL PLATE ATTACHED ON ONE SIDE TO SAID SEPARATOR PLATE ANE EXTENDING TOWARDS THE ADJACNET WALL OF SAID VESSEL TO A POINT CLOSER TO SAID WALL THAN SAID WEIR MEMBER AND TERMINATING IN A DOWNWARDLY EXTENDING BAFFLE, A CONDUIT WEIR MEMBER EXTENDING THROUGH SAID LAST NAMED PLATE, AND A DOWNCOMER FORMED BY TEHE SECOND LIP MEMBER OF SAID UPPER IMPERFORATE HORIZONTAL PLATE WITH THE WALLS OF SAID VESSEL, SAID DOWNCOMER EXTENDING TO A POINT BEYOND THE UPPER EDGE OF THE VERTICAL SEPARATOR PLATE OF THE NEXT LOWER STAGE, SAID LAST MAMED SEPARATOR PLATE BEING ON THE DIAMETRICALLY OPPOSITE SIDE OF SAID VESSEL FROM THE SEPARATOR PLATE OF SAID FIRST STAGE.