木质文物真空冷冻干燥脱水研究
发布时间：2018-12-10 18:45
【摘要】：文物是一个国家和地区的历史见证。随着我国大规模基础建设的开展,如何保护好出土的文物是亟需解决的问题。冷冻干燥法通过将水变成冰然后使冰升华的方式去除水分,已经在食品和生物材料保存、制药、超细粉体制备等领域得到广泛应用。在文物脱水方面,采用冷冻干燥法去除饱水文物中的水分是一种较为新颖的方法。与其它物理化学方法相比,该方法能有效消除干燥过程中的开裂现象,基本保持文物的原貌；处理时间大为缩短；处理过程不受环境和季节的限制。 为给采用辐射加热的大型冷冻干燥装置进行出土文物的批量冻干提供参考,本文在自行研制的采用辐射加热的小型实验装置上进行了木质文物样本的冻干研究,以确定可行的冻干过程参数。实验结果表明,经浓度50%的PEG2000溶液处理后,尺寸大至72mm×62.5mm×124mm的木质文物块可以被成功地冻干。冻干具体操作参数如下：预冻温度-35℃；预冻时间2h；真空度7-10Pa；干燥结束点：1h内质量变化小于0.1%的时刻。 为了对木质文物冷冻干燥过程的机理有更加深入的认识,论文还在采用导热加热的冷冻干燥装置上进行了实验研究。利用动态实测数据拟合得到了一次干燥过程中干燥区内的水蒸汽扩散系数,并进行了误差分析。在真空度l0Pa、慢速预冻条件下,-30℃、-33℃、-35℃等三个一次干燥温度位的水蒸汽扩散系数分别为1.665×10-4m2/s、1.141×10-4m2/s、1.133×10-4m2/s。在真空度10Pa、一次干燥温度-33℃保持不变时,快速预冻条件下的水蒸汽扩散系数约为慢速预冻条件下的49%。这些数据能为优化冻干过程参数、预估冻干时间、提高冻干过程经济性提供帮助。
[Abstract]:Cultural relics are the historical testimony of a country and a region. With the development of large-scale infrastructure construction in China, how to protect unearthed cultural relics is an urgent problem. Freeze-drying has been widely used in the fields of food and biomaterial preservation, pharmacy, preparation of ultrafine powder and so on, by changing water into ice and sublimating the ice. In the aspect of dewatering of cultural relic, freeze-drying method is a new method to remove water from saturated cultural relic. Compared with other physical and chemical methods, this method can effectively eliminate the cracking phenomenon in drying process, basically keep the original appearance of cultural relics, shorten the treatment time greatly, and the treatment process is not limited by environment and season. In order to provide reference for large-scale freeze-drying device with radiation heating for freeze-drying of unearthed cultural relics, the freeze-drying research of wood cultural relics samples was carried out on a small experimental device with radiation heating developed by ourselves. To determine the feasible freeze-drying process parameters. The experimental results show that the wood relics with the size of 72mm 脳 62.5mm 脳 124mm can be freeze-dried successfully after the treatment of 50% PEG2000 solution. The operating parameters of freeze-drying are as follows: Pre-freezing temperature -35 鈩，
本文编号：2371038
[Abstract]:Cultural relics are the historical testimony of a country and a region. With the development of large-scale infrastructure construction in China, how to protect unearthed cultural relics is an urgent problem. Freeze-drying has been widely used in the fields of food and biomaterial preservation, pharmacy, preparation of ultrafine powder and so on, by changing water into ice and sublimating the ice. In the aspect of dewatering of cultural relic, freeze-drying method is a new method to remove water from saturated cultural relic. Compared with other physical and chemical methods, this method can effectively eliminate the cracking phenomenon in drying process, basically keep the original appearance of cultural relics, shorten the treatment time greatly, and the treatment process is not limited by environment and season. In order to provide reference for large-scale freeze-drying device with radiation heating for freeze-drying of unearthed cultural relics, the freeze-drying research of wood cultural relics samples was carried out on a small experimental device with radiation heating developed by ourselves. To determine the feasible freeze-drying process parameters. The experimental results show that the wood relics with the size of 72mm 脳 62.5mm 脳 124mm can be freeze-dried successfully after the treatment of 50% PEG2000 solution. The operating parameters of freeze-drying are as follows: Pre-freezing temperature -35 鈩，
本文编号：2371038
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