Research And Application Of Safe Control System In Sewage Water Treatment

Water pollution and impeded economic development to improve people's livelihood issues, and now urban sewage water is one of the main in pollution of rivers and lakes. Effective treatment of urban sewage is to transform the economic growth, sustainable development, adhere to a strong guarantee. The Dissertation distributed control system for wastewater is studied.Based on the actual characteristics of the sewage treatment process, analysis and comparison of a variety of field bus, the choice Profibus fieldbus DCS built sewage treatment system. In order to ensure sewage treatment system does not control or reduce the failure probability of failure, you can create a safe control system structure and equipment. With industrial production and increasing demand for engineering applications, the specification of security will be more stringent, and security control will be more in-depth research. Safety PLC thesis analyzed the structure of research, analysis of the PLC system applications in safety-related lack of safety PLC designed redundant microprocessor module. Studies on the security structure of the PLC digital input and output modules. In ordor to obtain a safe PLC, then each module must also be a failure - security type. Therefore, increased by adding redundant channel and the method of test module PLC, AC and DC digital input and output module has two relay output, transistor output, and study the structure thyristor output. The practical application of the paper used the three-tier network of Siemens Profibus build a sewage treatment fieldbus control system, and achieved satisfactory results.