METHOD AND APPARATUS FOR CRYSTALLIZATION - MITSUBISHI GAS CHEMICAL CO

Title:

METHOD AND APPARATUS FOR CRYSTALLIZATION

Document Type and Number:

WIPO Patent Application WO/2002/028498

Kind Code:

A1

Abstract:

A method for crystallization which comprises sending a solution or a slurry formed by partial precipitation of a solute to a crystallization tank, precipitating the solute in the crystallization tank to yield a slurry comprising crystals and the solvent, and discharging it, wherein a crystal return device for separating crystals from the resultant slurry and returning them or for concentrating the slurry and returning the concentrate is installed and part or all of the resultant slurry discharged from the crystallization tank is introduced into the crystal return device to conduct crystallization while returning either crystals taken out of the resultant slurry or a slurry concentrate to the crystallization tank. By thus installing the crystal return device and conducting crystallization while returning crystals or a slurry concentrate to the crystallization tank, the crystal residence time in the crystallization tank can be increased or the slurry concentration can be heightened. By controlling the flow rate of crystals returned, the particle size distribution is improved and crystals having any desired average particle diameter are obtained. Further, crystal deposition in the crystallization tank and on those surfaces of peripheral instruments which are in contact with the liquid can be prevented.

Inventors:

FURUYA TAKAHISA (JP)

Application Number:

PCT/JP2001/008004

Publication Date:

April 11, 2002

Filing Date:

September 14, 2001

Export Citation:

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Assignee:

MITSUBISHI GAS CHEMICAL CO (JP)
FURUYA TAKAHISA (JP)

International Classes:

B01D9/00; B01D9/02; (IPC1-7): B01D9/02

Foreign References:

JPS59199528A	1984-11-12
JPS4735184B1
JPH0691103A	1994-04-05

Other References: