Key Technology And Application Development Of Biological Drying Tower Control System

The biological enzyme preparation industry was a high-tech industry serving food,chemical industry,environmental protection and other related industries.The biological fermentation process of the enterprise includes multiple processes.The spray drying separation technology was a key link in the production of solid enzyme preparation.In the spray drying process of solid enzyme preparation,the parameters such as water content and inlet and outlet air temperature were very important to the product quality.In this paper,according to the technical requirements of the existing biological drying tower control system,and the research on the rapid detection technology of solid enzyme preparation moisture,a set of integrated control system of biological drying tower was designed based on the moisture content,air outlet temperature to control the feed volume and air inlet temperature.Based on the actual production process of the enterprise,the biological drying tower control system uses S7-200 PLC as the controller,and uses PID control to realize the automatic adjustment of inlet air temperature and outlet air temperature.The human-computer interaction platform adopts the Siemens SMART 1000 IE v3 touch screen to monitor the parameters in the drying tower in real time and control the equipment.In order to quickly and accurately detect the water content of solid enzyme preparation,this paper designed a set of near infrared water detection system based on1750 nm,1940nm and 2100 nm three wavelength LED for solid enzyme preparation.The hardware circuits of LED light source driver circuit and In Ga As photoelectric detection circuit were designed and tested,and weak signals were collected for processing and display.The experimental results show that when the detection range of water content of solid enzyme preparation is about 7%,the detection accuracy is less than 0.35%,and the online detection of water content can be realized by communicating with S7-200 PLC through RS-485.After the development and design of the automatic control system of the biological drying tower,through the debugging and operation of the on-site equipment,the system has a fast stability time,good control effect and meets the requirements of the enterprise for various index test standards.