摘要 |
<p>It is an object of the present invention, in the case of an apparatus in which a liquid containing material having a lower boiling point than that of the liquid is made to flow down along external surfaces of guides, during which time the low boiling point material is evaporated, to provide a specific apparatus that can be operated stably for a prolonged period of time on an industrial scale such that not less than 1 ton / hr of the liquid is produced through the evaporation, and furthermore to provide a specific industrial evaporation apparatus in which there are no problems due to degeneration caused by some of the liquid residing in the apparatus for a prolonged period of time. The present inventors have reached to the present invention upon discovering that the above object can be attained, and a high-quality and high-purity concentrated liquid or condensation polymer or thermoplastic polymer can easily be obtained, by using an industrial evaporation apparatus having a specified structure in which there are guides that do not themselves have a heat source, a flow path controlling member having a function of making the liquid fed onto a perforated plate from a liquid receiving port flow mainly from a peripheral portion toward a middle portion of the perforated plate is installed in a liquid feeding zone, the distance K (cm) between an internal wall of a side-wall casing of an evaporation zone and the guide closest to the internal wall is in a specified range, and formulae (1) to (5), preferably formulae (1) to (11), more preferably formulae (1) to (14), are satisfied.</p> |