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:
Sep. 05, 2006
Filed:
Sep. 21, 2001
Fumio Ohkoshi, Okayama, JP;
Takahisa Furuya, Okayama, JP;
Fumio Ohkoshi, Okayama, JP;
Takahisa Furuya, Okayama, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Toyo Boseki Kabushiki Kaisha, Osaka, JP;
Mizushima Aroma Company, Ltd., Kurashiki, JP;
Abstract
The present invention proposes a crystallization process comprising the steps of feeding a slurry solution in which a terephthalic acid solution or a part of the terephthalic acid is precipitated to a crystallization vessel, precipitating the terephthalic acid in the crystallization vessel, generating a slurry containing crystals and solvent, discharging the slurry, and further comprising the steps of introducing the slurry in a tangential the direction of a hydrocyclone, returning the slurry flowing out as a downward swirling flow from a lower part of the hydrocyclone to the vessel, and discharging the slurry overflowing from the upper part of the hydrocyclone. According to the present invention, crystals of large particle size is obtained and a stable driving ranging long term can be achieved because any adhesion or accumulation of the terephthalic acid crystals does not appear at all in the crystallization vessel.