Application of display control instruments in wastewater treatment

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　　The intelligent display control instrument is designed and manufactured based on years of development and production experience; it is a new generation of intelligent display control instrument that incorporates numerous innovative functions. It performs tasks such as acquisition, display, control, remote transmission, communication, and printing for various signals including temperature, pressure, liquid level, velocity, and flow rate on-site, thereby forming a digital acquisition and control system that is widely used in fields such as electricity, petrochemicals, metallurgy, light industry, pharmaceuticals, and aviation. Working principle and solutions: The wastewater treatment plant uses an anaerobic followed by aerobic treatment process, with the aerobic stage being treated using the SBR method. SBR is one of the ideal approaches for treating high-concentration organic wastewater. The initial design handles 100 cubic meters per hour of wastewater; it includes 2 aeration tanks, 2 anaerobic towers, an oxidation ditch, and 12 other treatment tanks. The control devices are scattered, requiring bus-based remote monitoring and control. 　　To achieve automatic control of the entire system, it is known that the following parameters need to be monitored automatically: pH, oxygen level, temperature, flow rate, real-time measurements, high/low liquid levels in the regulation tank, high/low levels in the CASS tank, coarse/fine screen machines, blowers, feed water pumps, and the start/stop of aeration devices. On-site, local instrument cabinets are installed to house the analysis instruments; at the same time, Hongrun series guide-rail-mounted intelligent modules are also installed (including M32 single/dual-channel temperature transmitters, M35 multi-channel digital and analog input/output modules, 7400 single/dual/quadruple-channel PID temperature controllers, 5300 artificial intelligence PID regulators, and flow integrators). The monitoring and management system is located in the central control room, where it is responsible for monitoring the wastewater treatment processes both inside and outside the plant, as well as the operating status of the equipment. It monitors in real time the changes in process parameters, equipment operation, and faults throughout the plant using industrial control software, enables operation in various modes, and is also responsible for printing daily reports, accident reports, and maintaining data records. The computer monitor at the control station displays various types of screens, including: the overall process flow screen, sub-screens for processes such as slurry, water, and gas, screens showing the process equipment in each structure, screens displaying various process parameters, screens showing trends in these parameters, fault screens, and screens with data on equipment operation. Through these visuals, staff can gain a thorough understanding of all aspects of the processing process; the data and images related to each stage of the process are displayed in a comprehensive and detailed manner in real time, allowing them to keep track of whatever happens at each stage. It also features voice prompts, alarms, and online help. The printer can print various documents as needed at any time, and it can also be set to print daily, weekly, and monthly reports on a scheduled basis. 　　Given the widespread use of information technology, installing computer network connectivity devices in the control room and establishing interfaces to the local area network and the Internet enables transparent remote management. Equipment in the control room and sub-control stations can be accessed via web pages and email to view information or send alarm messages. Conclusion: The automatic control system for wastewater treatment projects has completed all tasks, from design to construction, installation, commissioning, and ultimately to its official operation. This system not only achieves automatic control as required by the sewage treatment process, but also ensures that the sewage is discharged up to standard. In summary, it has the following characteristics: 1. The system design is reasonable; the selection of the upper-level computer, electrical cabinets, and instruments takes into account factors such as advancement, stability, and reliability, while also considering cost efficiency, so that the entire control system can achieve the lowest possible price while ensuring long-term safe operation. 　　2. The monitoring and management computer monitors the entire system in real time; the process flow diagrams are clear and easy to understand, allowing operators to promptly grasp the status of the on-site processes and electrical equipment, and to adjust parameters online as needed based on the process conditions. 　　3. The system has strong resistance to interference; this aspect is taken into full consideration throughout everything from the computer power supply system and hardware selection to cable installation and grounding. As a result, it offers good stability and high reliability, **reducing the workload on workers – the number of operators per shift has been reduced from 5 to 2.