The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 14, 2017
Filed:
Aug. 27, 2015
Mitsubishi Chemical Engineering Corporation, Tokyo, JP;
MITSUBISHI CHEMICAL ENGINEERING CORPORATION, Tokyo, JP;
Abstract
A distillation apparatus for NMP including a first distillation column in which the spent NMP as a liquid to be treated is subjected to distillation; and a second distillation column in which bottoms from the first distillation column are further subjected to distillation, the distillation apparatus being provided with an automatic treatment function including a start-up function, and then a continuous treatment operation of the distillation apparatus being initiated; and an operational mode switching function in which upon the continuous treatment operation, an operational mode of the distillation apparatus being switched again to the circulation operation according to a level of the liquid in the raw material tank or a level of the liquid in the product tank.