at 65 u00b0 c after passing through the humidifying and dehumidifying chambers 18 and 22 and through the heater 40 and at a flow rate of 2 4 kg per minute for a system producing 1 m 3 of purified water per day operating 24 hours per day meanwhile the carrier gas 14 e g air initially at about 25 u00b0 c can be fed by a blower through the system in counter flow to the flow of liquid feed composition 12 i e from the bottom to the top of the humidifying chamber 18 from the top of the humidifying chamber 18 to the top of the dehumidifying chamber 22 and from the top to the bottom of the dehumidifying chamber 22 at a flow rate of 20 40 kg per minute for a 1 m 3 per day system the concentrated remainder 34 of the liquid feed composition 12 can be collected in a concentrated remainder collection receptacle 42 at the bottom of or beneath the humidifying chamber 18 meanwhile the condensed purified water 24 can be collected in the receptacle 44 at the bottom of or beneath the dehumidifying chamber 22 in particular embodiments the liquid feed is sprayed into the humidifying chamber with such a concentration of solutes that the liquid feed becomes super saturated in the humidifier at the outlet or both but not sufficiently super saturated for precipitation to occur within the humidifying chamber in other embodiments the liquid feed is sprayed into the humidifying chamber with such a concentration of solutes that the liquid feed reaches a level of super.