Air refrigerant ice forming equipment

An air refrigerant ice forming equipment having formed therein a refrigeration cycle using air as a working medium, said refrigeration cycle comprising a passage for air circulation incorporating an air compressor, a compressed air cooler for cooling the air compressed by the compressor with heat transfer media outside the refrigeration cycle, an air expander for expanding the air which has passed through the cooler to provide cold air and a heat exchanger for ice formation using the cold air which has passed the air expander disposed in the indicated order along the flow of air, said passage for air circulation including a return passage for returning the air which has passed through said heat exchanger for ice formation to said air compressor characterized in

• that said equipment further comprising a heat exchanger for heat recovery wherein the air before entering the air expander is heat exchanged with the air which has passed through the heat exchanger for ice formation before the latter air is returned to the air compressor,
• that said air expander has a rotor caused to rotate by the action of air flowing through said passage for air circulation, a rotating shaft of said rotor being coupled via a one-way clutch to a rotating shaft of a power means for driving said air compressor and
• that the air circulated through the passage for air circulation is dry substantially free from moisture and said equipment is further provided with an exit port for discharging a part of the dry and cold air outside the equipment after the dry and cold air has passed through said air expander either on its way to said heat exchanger for ice formation or while it is passing through said heat exchanger for ice formation and with an inlet port having an air dehumidifier in said return passage for introducing dry air into said passage for air circulation by inhaling atmospheric air.