【Design total explanation】 With the development of the sewage treatment technology, the request of the automatic control has been higher and higher. As the sewage treatment process has characteristic of multi-variable, non-liner, huge-lag, and difficult to establish precise model, the process automatic control level hangs, which result in toughen up the system been well controlled. Aim at the serious water pollution condition in our in this paper the biological treatment of been studied.
At present sewage treatment in the PLC control system has been widely applied at home and abroad. The industrial design of the sewage purification process for the treatment system: Press the start button and up and running open-purification tank valve, the inflow of industrial nap purification tank, and to detect water level in the normal range, and begin measuring temperature measurement pH and temperature digital signal gave PLC, and in the processing, as well as temperature-regulating valve opening of the regulation; Detection and regulate water drainage valve, the control handle from the water.
This paper introduced a method of automatic control system design which decontaminate sewage carried with Oxidized iron impurity ,control system based on PLC type of S7-200 belong to Siemens company. in this paper the system‘s hardware and software is also introduced in detail.
【Key words】 PLC;sewagetreatmentsystem; Break down diagnosis;programming-skill; running blender