| 摘要 |
The present invention relates to a method and an apparatus for controlling crystallization and thus preventing harmful fouling of heat surfaces in the treatment of black liquor, wherein black liquor is concentrated at a high dry solids content in a falling film crystallizing apparatus. A part of the liquor flowing from the heat exchange surfaces and collected in a retention vessel is recirculated to the heat exchange surfaces and a part of the liquor is discharged for further treatment. A part of the black liquor in the recirculation system is returned to the retention vessel in order to facilitate the mixing and thus to bring about in the retention vessel as complete crystallization of inorganic salts of the black liquor as possible. |
