摘 要真空冷冻干燥是先将含水物料冻结到共晶点温度以下，使其中的水份变成冰，然后在适当的温度和真空度下，使冰升华为水蒸汽从物料中逸出，再用冷阱将水气凝华，从而获得干燥制品的技术。干燥过程是水的物态变化和迁移的过程，由于这种变化和迁移发生在低温低压条件下，所以冻干过程是低温低压下的传热传质过程。但目前食品冻干机的设计和使用大都仍停留在被动的模仿和经验型阶段，高消耗、低效率依然是阻碍食品冻干更广泛应用的关键, 迫切需要新一代冻干机。本文发展了食品真空冷冻干燥实验机NTFD05E系统。该系统由由干燥仓体、加热系统、制冷系统、真空系统、控制及数据采集系统等五个部分组成，在深入研究冻干原理及冻干工艺的基础上，完成了各系统的结构设计及参数设计，并给出了各部分系统的结构图、原理图及设计要点，解决了结构设计的难题。根据结构设计的结果，建立了实验平台并完成了食品冷冻干燥机的实验研究。通过冰实验得到了加热板温度与加热功率的关系图、十块加热板的均匀性分析图，分析了系统的最大蒸发与冷阱捕集能力及冷阱温度对应饱和压力和干燥仓压力的关系，将实验数据和计算结果进行对比分析，发现该系统的各项指标均达到了设计要求，为标准化、系列化开发此冻干系统提供了依据。最后进行了一些物料（主要以海参为主）的冻干实验，得到了不同物料的冻干工艺及冻干曲线，积累了宝贵、丰富的实验数据。 关键词：真空冷冻干燥 共晶点温度 升华 冻干工艺 冻干曲线

AbstractVacuum freeze drying is a technique which can freeze materials with water to eutectic temperature, converting water to ice, then in proper temperature and vacuum degree, making ice sublimate to water vapor and escaping from materials, finally freezing by cold trapper. The drying process is the change of states and migration of water, because these happen in low temperature and voltage, so freeze-drying is a process of heat transfer and mass transfer in low temperature and voltage. But recently the design and use of freeze-drying machine is still in stage of passive imitation and experiment, high consumption and low efficiency is the key hindrance of the wide application of freeze-drying technique, so new generation freeze-drying machine is urgently demanded.In this thesis, the third generation food freeze-drying experiment machine is presented. The system is constructed by drying bin、heating system、refrigerating system、vacuum system and control and data acquisition system. In the basis of profound research of freeze-drying principle and technology, structural design and parameter design are finished, and structural and principle drawings of every part are presented, solving the problems of structural design.Finally, to the basis of structural design, an experiment system has been built to do experimental research on freeze-drying machine. By ice experiment, graphs of relation of heating temperature and heating power and ten board of heating uniformity are drawn, then maximal evaporation and ability of cold trapper and the relation of saturation pressure of cold trapper and drying bin are analyzed. After comparing results from calculation and stimulant experiment, the conclusion that the designed freeze-drying machine performance has been reached is drawn, which will be of great help to develop this kind of freeze-drying machine in standardization and series. Finally, some materials (specially for sea cucumber) are experimented, freeze-drying technology and graphs are presented, accumulating valuable and abundant experimental data.Keywords: Vacuum freeze drying Vacuum degree Sublimate Freeze-drying technology Freeze-drying graph