EXPERIMENTAL STUDY ON THE FROST OF THE COLD-TRAP IN VACUUM FREEZE-DRYING MACHINES

摘要：

In vacuum freeze-drying machines, cold-trap is a key part to catch water vapor sublimated from freezing materials. Under low temperature and low-pressure conditions, water vapor directly becomes frost on cold-trap surfaces. But there are few studies on characteristics of frost on cold-trap surfaces, thus it is currently difficult to understand the heat and mass transfer mechanism of a cold-trap and to modify freeze-drying equipments. In this paper, frosting on cold-trap surfaces and freeze material in drying chamber has been investigated by using a dynamic pressure measurement method, studying sublimation rate along with monitoring frost formation process by a camera. Simultaneously, temperature gradient in the frost layers has been analyzed, and then the coefficient of thermal conductivity is obtained according to Fourier law.

作者: Tonghua ZOU Yutao MIAO Ying SUN Jun LIU

作者单位: College of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, China

会议类型: 国际会议

会议名称: The 22nd International Congress of Refrigeration(第22届国际制冷大会)

会议地点: 北京

会议语种:英文

在线出版日期: 2007-08-21（万方平台首次上网日期，不代表论文的发表时间）