可编程控制器在冷冻干燥机中的应用.doc

可编程控制器在冷冻干燥机中的应用
摘要
本文介绍了可编程控制器在冷冻干燥机的应用。传统的冷冻干燥机由程序步进器进行机械控制,其触点繁多,故障频繁,维修不便, 严重影响冷冻干燥机的正常工作,对产品的质量也产生了很大影响。
采用三菱的小型PLC对整个冷冻干燥机运行系统进行控制,可实现较高的自动化程度,并完成智能控制、状态显和故障报警等任务,同时还提供良好的人机界面与操作员进行交互,使得修改各种参数简单、易行,对于机械设备的运行能及时、快速、准确的反映。其控制系统结构清楚、线路简单、工作可靠、同时设置了受动/自动控制开关,使得系统维护更加方便,减轻了工人的劳动强度,提高了系统的稳定性和可靠性。
本控制系统具有干燥机冻干曲线设定、除霜、灭菌、在线清洗、真空控制、干燥状态检测、故障报警和维修检查的功能。控制系统能进行全自动的冻干控制,包括预冻、加热、抽真空、压塞、放气、除霜、灭菌等。在编程器上可以显示温度、压力、时间、周期、状态等,也可以显示报警信息。采用冻干曲线和设备运行全自动方法时,可由微机编程,冻干流程显示可用荧光屏或模拟板两种方式,可在微机上对PLC编程,并能提供所有软件设备。软件可记录各运行设备运行的时间和历史记录,随机和定时打印数据、报表、曲线等,同时记录多项故障和事件发生。多点记录仪可显示制品、导热液、真空冷凝器的温度和干燥腔室、真空泵的真空度,同时还对冷凝器的温度进行报警。必要时能够进行人工干预。
关键词:PLC;冷冻干燥机;上位机管理通信
I
Abstract
The thesis introduced application of programmable logic controller (PLC) on the system of frozen dryers . The traditional frozen dryer is carried on machinery to control by the procedure walking into device, its contact is various, the trouble is frequent, maintain inconvenient. The traditional frozen drye not only influence the normal work of the frozen dryer seriously, but also have severe effect on the quality of the products .
Small-scale PLC which adopt Mitsubishi runs the system to control to the whole frozen dryers , can realize higher automatic degree , such tasks as it is apparent to finish the intellectual control , stating and fault alarm ,etc. at the same time and the operator proceeds hand over with each other, make modify every kind of parameter simple, easy line, reflect the movement of the machine equipments can on time, fleetness. Its control system construction is clear, the circuit is simple and work dependable, establishes to suffer to move at the same time/ automatic control switch, which make system maintenance more convenient, alleviated the worker's labor strength, increases the stability of the system with dependable.
The control system has the frozen dryers jelly fucks the curve sets up, divided by frost, put out the germ, on-line wash, the vacuum control, dry appearance examination,