Dryer apparatus having an improved air circulation

A dryer apparatus comprising an enclosure which contains a drying chamber for receiving articles to be dried, an air return heating passage and an air return cooling passage, wherein the heating passage is situated underneath the drying chamber and has inlet means and outlet means communicating therewith on opposite sides of the said chamber, respectively, air heating means being provided in the heating passage between the inlet and the outlet means thereof to heat air flowing through said heating passage, wherein the cooling passage is vertically disposed adjacent the drying chamber and has inlet means through which the top of the drying chamber directly communicates with the top of the cooling passage and outlet means at the bottom of the cooling passage, the inlet means of said cooling passage being situated in closely spaced relation to the top of the drying chamber and at the top of the cooling passage and the outlet means of said cooling passage communicating with the heating passage upstream of the heating means therein, air cooling means being provided in the cooling passage between the inlet and outlet means thereof to condense moisture from air flowing downwardly in the cooling passage, and water collecting or draining means being provided underneath the outlet means of the cooling passage to collect the water dripping from the cooling means, and wherein a refrigerating circuit, acting as a heat pump, is incorporated in said enclosure, said refrigerating circuit including an electric sealed compressor, a condenser, a throttling element and an evaporator in flow series with each other, the condenser and the evaporator being in the form of respective heat exchangers to constitute, at least in part, said air heating means and said air cooling means respectively, the arrangement being such that a major air flow is circulated between the drying chamber and the heating passage and a minor air flow of the air having the highest moisture content and lowest density adjacent the top of the drying chamber is circulated from the drying chamber to the heating passage through the cooling passage.

A dryer apparatus comprising an enclosure which contains a drying chamber for receiving articles to be dried, an air return heating passage and an air return cooling passage, wherein the heating passage is situated underneath the drying chamber and has inlet means and outlet means communicating therewith on opposite sides of the said chamber, respectively, air heating means being provided in the heating passage between the inlet and the outlet means thereof to heat air flowing through said heating passage, and wherein the cooling passage is vertically disposed adjacent the drying chamber and has inlet means through which the top of the drying chamber directly communicates with the top of the cooling passage and outlet means at the bottom of the cooling passage, which outlet means communicate with the heating passage upstream of the heating means thereof, air cooling means being provided in the cooling cooling passage between the inlet and outlet means thereof to condense moisture from air flowing downwardly in the cooling passage, and water collecting or draining means being provided underneath the outlet means of the cooling passage to collect the water dripping from the cooling means, the arrangement being such that a major air flow is circulated between the drying chamber and the heating passage and a minor air flow of the air having the highest moisture content and lowest density adjacent the top of the drying chamber is circulated from the drying chamber to the heating passage through the cooling passage, and regulating means being provided to decrease the flowrate through the cooling passage as the heat exchange efficiency of the cooling means decreases and vice-versa.