| 摘要 |
FIELD: cellulose derivatives technology. SUBSTANCE: invention relates to pyroxyline powders and concerns dehydration of cellulose nitrates with ethanol, mainly on periodical-mode centrifuges, wherein water is replaced by ethanol. Cellulose nitrates are loaded into centrifuge being simultaneously moistened with aqueous ethanol, 65-75 % v/v, applied in amounts 0.16-0.2 l/kg, after which centrifuge is started and 95-96% rectified alcohol is dosed at velocity 10-11 l/min with dosing factor 0.9-1,1 l/kg, strength of leaving ethanol being continuously recorded. When leaving ethanol strength achieves 80% v/v, feeding of alcohol is stopped and cellulose nitrates are pressed and discharged. EFFECT: improved accuracy in water content control and homogeneity of water distribution in precipitate bulk. 2 cl, 2 dwg, 1 tbl
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