The Lyophilizer Research And Design Of The Control System

Vacuum freeze drying technology is widely used in different fields such as food, pharmaceutical industry, biologicals industry and so on. Vacuum freeze-drying technology application areas also in enlarging. The development and research of freeze-dried technology, freeze-dried theory and freeze-drying equipment caused attention by the researchers at home and abroad.In this paper, the object is medicinal freeze drying machine. It realizes the vacuum system, refrigeration system and control system optimization. We use the programmable logic controller (PLC) and fuzzy forecasting PID control algorithm in the freeze drying machine control system. Fuzzy forecasting PID control theory applied to the temperature of freeze dryer control system, help to increase the temperature response curve follow sex and speed up the reaction time, which can increase the temperature control precision. PLC to realize the automatic control of the freeze-dried, including the frozen, heating, vacuum, pressure plug, deflated, defrost, sterilization, etc.I adopt PLC control of frequency conversion technology, vacuum system, compressor in the vacuum system and refrigeration system of freeze dryer. Through the inverter, compressor not only to realize soft start, but also reduce the impact of the mechanical parts of the vacuum pump in the system starting and stopping process. It extends the motor, compressor, vacuum pump and related components of life span and reduces the vacuum pumps and compressors no-load operation load power consumption.Using force control configuration software development the monitoring system of freeze dryer. The monitoring system collects and acquires parameters such as temperature, vacuum degree and other data in the process of collecting the freeze dryer. The monitoring system controls the operation condition of freeze dryer and set up an emergency alarm display.The freeze-dryer control system enables the operator who can effectively understand and grasp freeze drying process in the production of running condition and technological parameters. The operator can optimize the process of operation, control of the freeze drying vacuum, pressure and temperature control volume changes. This control method can improve control accuracy, save energy consumption and the operation management level.