Abstract: A Directional Freeze Crystallization system employs an indirect contact heat exchanger to freeze a fraction of liquid to be purified. The unfrozen fraction is drained away and the purified frozen fraction is melted. The heat exchanger must be designed in accordance with a Growth Habit Index to achieve efficient separation of contaminants. If gases are dissolved in the liquid, the system must be pressurized.

Abstract: Ice formed in a batch crystallization apparatus is melted by causing an ice sheet 20 to be cut into approximately equal size pieces by the knife-edge 32 of melter 26. The pieces of ice are induced to slide against the sides of melter by inclined rails 28. Temperature sensor 40 and controller 44 are used to operate a heater to maintain the melter at a temperature setpoint 54 for a fixed time period while the ice sheet is cut into pieces. While the ice pieces melt the heating means is maintained fully on and the product drain valve is kept open. When the ice has melted the temperature exceeds the setpoint signaling the controller that the melting phase is complete. Failure of the apparatus to freeze ice is diagnosed by the temperature exceeding the setpoint at the end of said time period. Failure of the apparatus to melt ice is diagnosed by the temperature not reaching the setpoint after a sufficient amount of time.

Abstract: Ice formed in a batch crystallization apparatus is melted by causing an ice sheet 20 to be cut into approximately equal size pieces by the knife-edge 32 of melter 26. The pieces of ice are induced to slide against the sides of melter by inclined rails 28. Temperature sensor 40 and controller 44 are used to operate a heater to maintain the melter at a temperature setpoint 54 for a fixed time period while the ice sheet is cut into pieces. While the ice pieces melt the heating means is maintained fully on and the product drain valve is kept open. When the ice has melted the temperature exceeds the setpoint signaling the controller that the melting phase is complete. Failure of the apparatus to freeze ice is diagnosed by the temperature exceeding the setpoint at the end of said time period. Failure of the apparatus to melt ice is diagnosed by the temperature not reaching the setpoint after a sufficient amount of time.

Abstract: An improved water purification apparatus and method includes the freeze plate of a refrigeration system disposed in contact with the surface of water to be purified for transferring heat from the water substantially only through the surface and for forming a layer of ice only near the surface that is nearly as thick as the volume of water is deep. Electrostatic field is produced to improve the rejection of impurities at the ice-water interface. System and operating parameters are described for the optimum production of purified water through recurring cycles of freezing, draining, melting, and recovering melt water in batch processing of impure water using a refrigeration system of selected heat-removing capacity.

Abstract: A water purification method and system, employing at least a first chamber and a second chamber to freeze a portion of a volume of impure water in the first chamber while melting ice in the second chamber. The unfrozen liquid, which has a high impurity concentration, is drained from the first chamber. The melted ice, from which up to 95% of the original impurities have been rejected during the freezing operation, is drained from the second chamber. Then, a new volume of impure water is supplied to the second chamber, and the process continues with the roles of the chambers reversed. The system includes at least one heat transfer fluid coil portion wrapped around (or disposed within) each chamber. The system requires no scraping or transporting of frozen ice, requires no chemical or cartridge replacement, and can be embodied in a small housing suitable for use as a home or restaurant appliance.