Method for removal of contaminants from gas

Claim 1

THE METHOD OF COOLING A GAS WHICH CONTAINS CONTAMINANTS THAT DEPOSIT IN LIQUID AND SOLID FORM AT THE TEMPERATURE TO WHICH THE GAS IS TO BE COOLED, SAID METHOD COMPRISING OPERATIONS (A) AND (B) FOLLOWS: (A) PASSING THE GAS INTO INDIRECT HEAT EXCHANGE WITH A LIQUID REFRIGERANT EVAPORATING IN A FIRST EVAPORATIVE COOLER WHEREIN THE REFRIGERANT IS EVAPORATING AT A TEMPERATURE AT WHICH SAID CONTAMINANTS LIQUEFY WITHOUT LIQUEFYING THE GAS, THEREAFTER PASSING THE GAS IN INDIRECT HEAT EXCHANGE WITH SAID REFRIGERANT EVAPORATING IN A SECOND EVAPORATIVE COOLER, WHEREIN SAID REFRIGERANT IS EVAPORATING AT THE LOWER TEMPERATURE TO WHICH THE GAS IS TO BE COOLED WITHOUT LIQUEFYING THE GAS WHEREBY SAID CONTAMINANTS WILL SOLIDIFY, PASSING SAID REFRIGERANT FROM SAID FIRST EVAPORATIVE COOLER TO SAID SECOND EVAPORATIVE COOLER THROUGH AN EXPANSION DEVICE, AND REMOVING LIQUEFIED CONTAMINANTS FROM SAID GAS BETWEEN SAID COOLERS; (B) REVERSING THE FLOW PATHS OF THE GAS AND REFRIGERANT BY PASSING SAID GAS IN INDIRECT HEAT EXCHANGE WITH SAID REFRIGERANT EVAPORATING IN SAID SECOND EVAPORATIVE COOLER WHEREIN THE REFRIGERANT IS EVAPORATING AT A TEMPERATURE AT WHICH SAID CONTAMINANTS LIQUEFY WITHOUT LIQUEFYING THE GAS, THEREAFTER PASSING SAID GAS IN INDIRECT HEAT EXCHANGE WITH SAID REFRIGERANT EVAPORATING IN SAID FIRST EVAPORATIVE COOLER WHEREIN SAID REFRIGERANT IS EVAPORATING AT SAID LOWER TEMPERATURE TO WHICH SAID GAS IS TO BE COOLED WITHOUT LIQUEFYING THE GAS AND AT WHICH SAID CONTAMINANTS SOLIDIFY, PASSING SAID REFRIGERANT FROM SAID SECOND EVAPORATIVE COOLER TO SAID FIRST EVAPORATIVE COOLER THROUGH AN EXPANSION DEVICE, AND REMOVING LIQUEFIED CONTAMINANTS FROM SAID GAS BETWEEN SAID COOLERS; SAID METHOD INVOLVING THE STEPS OF SUPPLYING SAID GAS, FIRST CONDUCTING OPERATING (A) ON SAID GAS, THEREAFTER CONDUCTING OPERATION (B) ON SAID GAS AND CONTINUING SAID OPERATIONS IN ALTERNATING SEQUENCE WHILE THE SUPPLY OF GAS CONTINUES.

Claim 2

THE METHOD OF COOLING A GAS WHICH CONTAINS CONTAMINANTS THAT DEPOSIT IN LIQUID AND SOLID FORM AT THE TEMPERATURE TO WHICH THE GAS IS TO BE COOLED, SAID METHOD COMPRISING OPERATIONS (A) AND (B) FOLLOWS: (A) PASSING THE GAS INTO INDIRECT HEAT EXCHANGE WITH A LIQUID REFRIGERANT EVAPORATING IN A FIRST EVAPORATIVE COOLER WHEREIN THE REFRIGERANT IS EVAPORATING AT A TEMPERATURE AT WHICH SAID CONTAMINANTS LIQUEFY WITHOUT LIQUEFYING THE GAS, THEREAFTER PASSING THE GAS IN INDIRECT HEAT EXCHANGE WITH SAID REFRIGERANT EVAPORATING IN A SECOND EVAPORATIVE COOLER, WHEREIN SAID REFRIGERANT IS EVAPORATING AT THE LOWER TEMPERATURE TO WHICH THE GAS IS TO BE COOLED WITHOUT LIQUEFYING THE GAS WHEREBY SAID CONTAMINANTS WILL SOLIDIFY, PASSING SAID REFRIGERANT FROM SAID FIRST EVAPORATIVE COOLER TO SAID SECOND EVAPORATIVE COOLER THROUGH AN EXPANSION DEVICE, AND REMOVING LIQUEFIED CONTAMINANTS FROM SAID GAS BETWEEN SAID COOLERS; (B) REVERSING THE FLOW PATHS OF THE GAS AND REFRIGERANT BY PASSING SAID GAS IN INDIRECT HEAT EXCHANGE WITH SAID REFRIGERANT EVAPORATING IN SAID SECOND EVAPORATIVE COOLER WHEREIN THE REFRIGERANT IS EVAPORATING AT A TEMPERATURE AT WHICH SAID CONTAMINANTS LIQUEFY WITHOUT LIQUEFYING THE GAS, THEREAFTER PASSING SAID GAS IN INDIRECT HEAT EXCHANGE WITH SAID REFRIGERANT EVAPORATING IN SAID FIRST EVAPORATIVE COOLER WHEREIN SAID REFRIGERANT IS EVAPORATING AT SAID LOWER TEMPERATURE TO WHICH SAID GAS IS TO BE COOLED WITHOUT LIQUEFYING THE GAS AND AT WHICH SAID CONTAMINANTS SOLIDIFY, PASSING SAID REFRIGERANT FROM SAID SECOND EVAPORATIVE COOLER TO SAID FIRST EVAPORATIVE COOLER THROUGH AN EXPANSION DEVICE, AND REMOVING LIQUEFIED CONTAMINANTS FROM SAID GAS BETWEEN SAID COOLERS; SAID METHOD INVOLVING THE STEPS OF SUPPLYING SAID GAS, FIRST CONDUCTING OPERATING (A) ON SAID GAS, THEREAFTER CONDUCTING OPERATION (B) ON SAID GAS AND CONTINUING SAID OPERATIONS IN ALTERNATING SEQUENCE WHILE THE SUPPLY OF GAS CONTINUES.