Distillation process employing direct contact heating and condensation

Claim 1

A METHOD OF SEPARATING A SUBSTANTIALLY PURE LIQUID SOLVENT (A) FROM A SOLUTION (B) OF AN IMPURITY (C) IN SAID SOLVENT (A), USING A HEAT EXCHANGE FLUID (D) WHICH HAS AN EFFECTIVELY DIFFERENT SPECIFIC GRAVITY FROM THAT OF SAID SOLVENT (A), USING A HEAT EXCHANGE FLUID (D) WHICH HAS AN EFFECTIVELY DIFFERENT SPECIFIC GRAVITY FROM THAT OF SAID SOLVENT (A) AND OF SAID SOLUTION (B) AND WITH WHICH SAID SOLVENT (A), SOLUTION (B) AND IMPURITY (C) ARE RESPECTIVELY MUTUALLY SUBSTANTIALLY INSOLUBLE, SAID METHOD BEING CARRIED OUT WITH THE DIRECT CONTACT EXCHANGE OF HEAT BETWEEN SAID HEAT EXCHANGE LIQUID (D) AND SAID SOLUTION (B) AND SOLVENT (A) AND SAID METHOD COMPRISING THE FOLLOWING STEPS: (1) FLOWING SAID HEAT EXCHANGE LIQUID (D) UPWARDLY IN A HEATED STATE THROUGH A VERTICALLY DISPOSED FIRST HYDRAULIC COLUMN CONSTITUTING AN EVAPORATION REGION OF CONTINUOUSLY INCREASING TEMPERATURE AND PRESSURE DOWNWARDLY AND THEN THROUGH A VERTICALLY DISPOSED SECOND HYDRAULIC COLUMN CONSTITUTING A CONDENSATION REGION ALSO OF DOWNWARDLY INCREASING TEMPERATURE AND LPRESSURE, THE DIRECTION OF FLOW THROUGH SAID CONDENSATION REGION BEING PREDETERMINED INDEPENDENTLY OF WHETHER THE SPECIFIC GRAVITY OF THE HEAT EXCHANGE LIQUID (D) IS GREATER OR LESS THAN THAT OF THE SOLUTION (B) AND OF THE SOLVENT (A); (2) FLOWING SAID SOLUTION (B) THROUGH SAID EVAPORATION REGION IN DIRECT CONTACT WITH SAID HEAT EXCHANGE LIQUID AT A TEMPERATURE SUFFICIENT TO EFFECT VOLATILIZATION OF SAID SOLVENT AT A SEQUENCE OF LEVELS OF VARYING TEMPERATURE AND PRESSURE TO PRODUCE A SEQUENCE OF SEPARATE AND DISTINCT INCREMENTS OF SOLVENT VAPOR OF SEQUENTIALLY CHANGING TEMPERATURE AND PRESSURE; (3) EFFECTING THE TRANSFER OF SAID INCREMENTS OF SOLVENT VAPOR INTO SAID CONDENSATION REFION AT SEQUENTIAL LEVELS THEREIN OF COMPARABLE PRESSURE TO EFFECT CONDENSATION OF SAID VAPOR AND TRANSFER OF HEAT OF CONDENSATION DIRECTLY TO SAID HEAT EXCHANGE LIQUID WHILE AT A LOWER TEMPERATURE IN CONTACT WITH SAID RESPECTIVE INCREMENTS; (4) SEPARATING THE RESULTING CONDENSATE FROM SAID HEAT EXCHANGE LIQUID; AND (5) ADDING THE NECESSARY AMOUNT OF HEAT TO SAID HEAT EXCHANGE LIQUID (D) TO EFFECT THE VOLATILIZATIN OF SAID SOLVENT AS AFORESAID.

Claim 2

A METHOD OF SEPARATING A SUBSTANTIALLY PURE LIQUID SOLVENT (A) FROM A SOLUTION (B) OF AN IMPURITY (C) IN SAID SOLVENT (A), USING A HEAT EXCHANGE FLUID (D) WHICH HAS AN EFFECTIVELY DIFFERENT SPECIFIC GRAVITY FROM THAT OF SAID SOLVENT (A), USING A HEAT EXCHANGE FLUID (D) WHICH HAS AN EFFECTIVELY DIFFERENT SPECIFIC GRAVITY FROM THAT OF SAID SOLVENT (A) AND OF SAID SOLUTION (B) AND WITH WHICH SAID SOLVENT (A), SOLUTION (B) AND IMPURITY (C) ARE RESPECTIVELY MUTUALLY SUBSTANTIALLY INSOLUBLE, SAID METHOD BEING CARRIED OUT WITH THE DIRECT CONTACT EXCHANGE OF HEAT BETWEEN SAID HEAT EXCHANGE LIQUID (D) AND SAID SOLUTION (B) AND SOLVENT (A) AND SAID METHOD COMPRISING THE FOLLOWING STEPS: (1) FLOWING SAID HEAT EXCHANGE LIQUID (D) UPWARDLY IN A HEATED STATE THROUGH A VERTICALLY DISPOSED FIRST HYDRAULIC COLUMN CONSTITUTING AN EVAPORATION REGION OF CONTINUOUSLY INCREASING TEMPERATURE AND PRESSURE DOWNWARDLY AND THEN THROUGH A VERTICALLY DISPOSED SECOND HYDRAULIC COLUMN CONSTITUTING A CONDENSATION REGION ALSO OF DOWNWARDLY INCREASING TEMPERATURE AND LPRESSURE, THE DIRECTION OF FLOW THROUGH SAID CONDENSATION REGION BEING PREDETERMINED INDEPENDENTLY OF WHETHER THE SPECIFIC GRAVITY OF THE HEAT EXCHANGE LIQUID (D) IS GREATER OR LESS THAN THAT OF THE SOLUTION (B) AND OF THE SOLVENT (A); (2) FLOWING SAID SOLUTION (B) THROUGH SAID EVAPORATION REGION IN DIRECT CONTACT WITH SAID HEAT EXCHANGE LIQUID AT A TEMPERATURE SUFFICIENT TO EFFECT VOLATILIZATION OF SAID SOLVENT AT A SEQUENCE OF LEVELS OF VARYING TEMPERATURE AND PRESSURE TO PRODUCE A SEQUENCE OF SEPARATE AND DISTINCT INCREMENTS OF SOLVENT VAPOR OF SEQUENTIALLY CHANGING TEMPERATURE AND PRESSURE; (3) EFFECTING THE TRANSFER OF SAID INCREMENTS OF SOLVENT VAPOR INTO SAID CONDENSATION REFION AT SEQUENTIAL LEVELS THEREIN OF COMPARABLE PRESSURE TO EFFECT CONDENSATION OF SAID VAPOR AND TRANSFER OF HEAT OF CONDENSATION DIRECTLY TO SAID HEAT EXCHANGE LIQUID WHILE AT A LOWER TEMPERATURE IN CONTACT WITH SAID RESPECTIVE INCREMENTS; (4) SEPARATING THE RESULTING CONDENSATE FROM SAID HEAT EXCHANGE LIQUID; AND (5) ADDING THE NECESSARY AMOUNT OF HEAT TO SAID HEAT EXCHANGE LIQUID (D) TO EFFECT THE VOLATILIZATIN OF SAID SOLVENT AS AFORESAID.