Continuous manufacturing with an Oslo-type salt crystallizer was tested. For the manufacturing condition, the opening of the steam valve was changed to 8, 10, and 15 percent.
The following points regarding manufacturing characteristics were clarified by this study.
1) It was possible to produce output of 81 t/day (3.38 t/h×24 h) by continuous manufacturing with 15 percent opening of the steam valve. This could thus be a useful technique for increasing production in the near future.
2) It was supposed that the large particles had a faster growth speed than the small ones in our Krystale-Oslo-type salt crystallizer, and therefore it was clarified that the cumulative residue curve on the Rosin-Rammler diagram was not a straight line, having a point at which the line deflected.
3) In comparing the Bottom Suction & Upper Feed system (BSUF) with the Upper Suction & Bottom Feed system (USBF), particle size of USBF is larger than BSUF.
4) It was clarified that production output increased more when product had smaller-size particlesthan large ones in this study. And, naturally, the larger the opening of the steam valve, the more the output increased.
5) The following was clarified by calculation. It was supposed that suspended particle size in the salt crystailizer was about 1,600μm at the under part of the crystallizer, and about 500μm at the top, and the smaller size circulated with the mother liquid, and the larger size sank and accumulated at the bottom.
6) In the above study, the frequency of the circulation pump was set to 50 Hz. If the frequency were changed to 45 and 55 Hz, perhaps there would be a change in the characteristics in cyrstallization.
This subject should be studied further.
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