冷冻干燥物料水分在线测量系统设计与试验

根据JDG-0.2型真空冻干试验机的工况特点,设计了基于可重组虚拟仪器的冻干物料含水率在线测量系统,可实时采集、分析计算、存储和显示物料的质量、含水率和失水率等相关参数.并绘制含水率和失水率的变化曲线,为冻干工艺过程的判别与调控提供了准确的数据.系统运行结果表明.物料质量的相对测量误差小于0.5%,含水率的绝对测量误差小于0.5%.满足冷冻干燥生产工艺过程监控的要求.

Design and Test of On-line Measurement System for the Moisture Content of the Freeze-drying Materials

Based on virtual instrument, the on-line moisture content measurement system was designed, and the measurement condition of the JDG-0.2 vacuum freeze-drying machine was considered during the system development. The system can realize real-time data acquisition, calculation and storage. It can also display the weight, moisture content and the rate of the moved water in the samples. Moreover, the change curve of the moisture content and the rate of the moved water can be shown in this system. The result showed that the relative error to the weight of the samples is less than 0.5%, and the absolutely error to the moisture content is less than 0.5%, which achieved the requirement of the on-line monitoring.