| 摘要 |
PURPOSE:To prepare and supply the seed crystal automatically in a closed system by adding a suspension of the seed crystal to a treating soln. which is in the process of crystallization and kept at an adequate temp. CONSTITUTION:A soln., wherein a substance to be crystallized is dissolved, is charged into a seed crystal forming vessel 2 from a liquid spraying pipe 4 through a filter 1. An inert gas is blown into the said soln. through an inert gas introducing part 5. A part of the solvent is evaporated by accompanying with the said gas, and a suspension of the seed crystal is obtained by cooling etc. On the other hand, a soln. to be treated is charged into a crystallization tank 8, and made into a nearly saturated or a slightly supersaturated state by reducing the pressure or by an external cooling while operating a stirrer 9. Then the suspension in the seed crystal forming vessel 2 is transferred by opening a valve 7 to start the crystallization. Thereafter, the pressure is further reduced or the cooling is intensified to obtain the prescribed amt. of the crystal. In addition, all the above-mentioned operations can be performed in a closed system and automatically.
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