Patent ID: 7658817

Claim:
An industrial evaporation apparatus in which a liquid containing a material having a lower boiling point than that of said liquid is made to flow down along an external surface of a guide that does not themselves have a heat source, during which time said lower boiling point material is evaporated, wherein improvement comprises: (1) said evaporation apparatus comprising a liquid receiving port; a liquid feeding zone for feeding said liquid via a perforated plate to said guide provided in an evaporation zone; said evaporation zone having a plurality of guides that extend downward within a space enclosed by said perforated plate, a side-wall casing, and a bottom-wall casing; an evaporated material outlet provided in said evaporation zone; and a liquid discharge port provided in a lowermost portion of the bottom-wall casing; (2) a flow path controlling member which has a function of making said liquid fed onto the perforated plate from said liquid receiving port flow mainly from a peripheral portion toward a middle portion of the perforated plate being provided in said liquid feeding zone; (3) an internal sectional area A (m 2 ) taken through a horizontal plane of the side-wall casing of said evaporation zone satisfying the following formula (1): 0.7≦A≦300 (1); (4) a ratio between said A (m 2 ) and an internal sectional area B (m 2 ) taken through a horizontal plane of the liquid discharge port satisfying the following formula (2): 20 ≦A/B≦ 1000 (2); (5) the bottom-wall casing constituting the bottom portion of said evaporation zone being connected at an internal angle C (°) to said side-wall casing on said bottom-wall casing, wherein said angle C (°) satisfies the following formula (3): 110≦C≦165 (3); (6) a length h (cm) of each of said guides satisfying the following formula (4): 150≦h≦5000 (4); (7) a total external surface area S (m 2 ) of said guides satisfying the following formula (5): 2≦S≦50000 (5).