【作者】 李春亮；

【导师】 谭蔚；

【作者基本信息】 天津大学 ， 化工过程机械， 2010， 硕士

【摘要】 本研究课题是“十一五”国家科技支撑计划课题资助项目,目的在研究海冰离心脱盐以及连续化生产。海冰盐度主要来自海水结冰时被包裹在内部的卤水盐胞,海冰离心脱盐正是依据此,将海冰破碎,使卤水暴露出来,进而通过离心机施加超重力,脱除卤水,淡化海冰。本文总结了海冰的特性,通过理论分析得出海冰离心脱盐后盐度与时间的理论关系式为S（t）= PK1/t^1/2,采用该式的计算结果与文献中的实验数据对比表明两者吻合较好。对海冰离心脱水的过滤过程和相变过程模拟得出,过滤主要在前0.12s完成;低温下海冰表面卤水易结冰。通过实验确定了粒度、加入海水比例、温度等对海冰离心脱盐的影响。实验结果表明,淡化盐度随着粒径呈现先减小后增大的趋势,并且当颗粒在6-9mm左右达到最小;随着温度的升高,海冰离心脱盐效果变好;加入海水比例对海冰脱盐有相当大的影响,但受温度影响,当温度大于-2℃时,加海水十分有利于离心脱盐,且当水冰比例为60%达到最好;温度小于-6℃时,加海水后效果反而变差。为了便于离心机进料,本文结合传统的搅拌器和推料器,设计了新型离心机进料搅拌设备,使其同时具备搅拌和推料功能,解决了物料进料堵料问题,降低了能耗。通过现场布置和设备连接,实现了海冰离心脱盐系统的连续化。经现场的工业化实验与计算,当前连续化海冰离心脱盐,盐度可降至1.0～1.5‰。更多还原

【Abstract】 This research is a project funded by Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period to study sea-ice desalination and its continuous production. The salinity of sea ice is mainly from brine salinity cell wrapped inside when sea ice is freezing and According to it, the methods of centrifugal separation of sea ice follows: break the ice so that salt brine is exposed, and then apply very large gravity by centrifuge, remove sea brine and dilution sea ice.In this paper, the characteristics of sea ice are summarized. Through the theoretical analysis, a theoretical formula between salinity and time after centrifugal desalting of sea ice, S（t）= PK1/t^1/2, is obtained. It shows good agreement to contrast the results of theoretical formula to the data in the literature. From the numerical simulation of the process of filtration and phase transition of centrifugal desalting of sea ice, the following conclusions were got: it is about 0.12s to cost in the process of filter, it is easy to freeze for the brine in the ice surface at low temperature.Through the experimental, the effect of particle size, the ratio of seawater added, temperature and so on is determined. The experimental result shows that the diluted salinity shows the trend of increase to decrease with the particle size, and reach the minimum when the particles is about 6-9mm;the diluted results get better with increasing of temperature; the ratio of seawater added have a considerable influence on the diluted salinity, but affected by temperature: adding seawater is very beneficial for centrifugal desalting when the temperature is higher than -2℃; and the best ratio is 60% ,but it is worse when the temperature is less than -6℃.In order to facilitate feeding for centrifuge, a new kind of equipment of feeding and mixing for it is designed which can stir and push at the same time and solve the material jam and save energy by combining traditional blender and push feeder. The continuous system of centrifugal desalting of sea ice is realized through the site layout and the equipment connections. From the experiment and calculation, the current salinity of continuous centrifugal desalting of sea ice can be reduced to 1.0¹.5‰.更多还原