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, break down to report to the police with maintain the function of the check. The control system can proceed the full-automatic jelly fucks the control, including prepare the jelly, heating, take out the vacuum and press to fill, put the spirit, divided by frost and put out germ etc. The weave of the control system can show temperature, pressure, time, period, appearance...etc. it lso can show to report to the information of the alarm. Adoption the jelly fucks the curve to circulate the full-automatic method with the equipments, can be woven by tiny machine distance, the jelly fucks the process manifestation can hold or imitate plank two kinds of methods with the fluorescence, can at tiny and on board weave the distance to PLC, which also can provide all software equipments. The software can record the each circulating time that equipments circulate to record with the history, with machine and with settle print data, statement, curve...etc., record at the same time many the item breaks down with affairs occurrence. At the same time returning to congealed machine of the dry the room of the machine, vacuum pump. The necessary time can proceed the artificial interferes.
