ABSTRACT
Paper production process wastewater in accordance with the main three parts: cooking liquor, the middle of wastewater, under the White Paper Network. The middle of wastewater treatment is a key and difficult. Pulp and refers to the middle of wastewater extracted by the cooking liquor in the pulp washing, screening, bleaching and beating in the process of sending the waste water.
In this paper, pulp and the middle of the characteristics of wastewater outstanding application of a simple structure of the middle effective aerobic treatment of wastewater process control program. Wastewater treatment using aerobic biological and chemical processing technology, the use of aerobic micro-organisms in the anoxic conditions of organic matter decomposition is a powerful feature, the use of artificial control technology in order to remove the paper in the middle of wastewater BOD, COD and SS components. Requirements for mid-water treatment process and characteristics of aerobic treatment process control, based on S7-300PLC's DCS control system. Combined with the principle of process control can be achieved alarm, monitoring, and advanced automatic control system algorithm.
The computer program used to monitor upper and lower PLC integrated control methods. Host is responsible for monitoring the computer to communicate with the PLC of the entire wastewater treatment process monitoring and operation and has a data recording, fault alarm, parameter setting functions. PLC-bit on-site under the PH, flow, temperature, liquid level signal and pump operation, fault, such as signal acquisition, and in accordance with pre-control procedures for the preparation of the various pump output control signal instructions, at the same time to complete the next-bit machine signal reached the monitoring computer monitoring computer to accept commands.
KEYWORDS: PLC, the middle of water, aerobic treatment, the control system
