Integral controller applied to aeration tank for sewage treatment

Abstract

The invention discloses an integral controller applied to an aeration tank for sewage treatment. The integral controller comprises a central processor and an analog input circuit, an on-off input circuit, a dissolved oxygen control output circuit, a backwash control output circuit, a communication module, a parameter setting key, a keyboard, a display module, a remote fault alarm circuit, a temperature and humidity data acquisition circuit, a calendar clock module, a network interface circuit, an SD card storage module and a power supply module. The integral controller disclosed by the invention realizes control on dissolved oxygen of a blower by a combination mode of relative input parameters such as dissolvent oxygen content, oxidized reduction potential, mixed liquid suspended solid, suspended solid, water temperature, pipeline pressure, air flow rate and the like, simultaneously realizes intelligent control on backwash, and organically combines the two control processes to optimize the treatment, thereby really fulfilling the aims of ensuring water quality and fully saving energy, and the integral controller not only has the characteristics of quite low cost, strong function, high energy conservation and easiness in popularization, but also is convenient to install and debug.

Description

technical field [0001] The invention relates to a control device, in particular to an integrated controller applied to an aeration tank for sewage treatment. Background technique [0002] Oxygen consumption reaction is an important reaction stage in the aeration tank of sewage biochemical treatment. At present, the oxygenation work of the domestic sewage biochemical treatment aeration tank is realized by high-power blower, which needs to consume a lot of electric energy. In the case of ensuring water quality, how to realize energy-saving control and reduce costs is a problem that needs serious consideration both at home and abroad. Microbes in sewage have a certain demand for oxygen. If it is too little, it will reduce the water quality. If it is too much, it will not only fail to guarantee the water quality, but also waste energy. Usually, the oxygen supply is determined by the content of dissolved oxygen. However, the dissolved oxygen required by the aeration tank is not...

AI Technical Summary

Problems solved by technology

When my country's sewage treatment plants started, a complete set of automatic sewage treatment systems was introduced from foreign products and technologies. Although hardware systems can be produced in China in the future, the control technology has not been absorbed by the system.

The domestic sewage treatment industry has relatively low automation expertise. The automation systems of many sewage treatment projects are designed, programmed and debugged by engineers in the fields of metallurgy, chemical industry, and light industry. They have little understanding of sewage treatment processes and cannot combine specific processes. The control strategy design generally adopts the practice of applying the existing technology of other industries, so the operation effect is not ideal

[0007] 2. The automatic control system training is not in place

Many sewage treatment plant operators have not received systematic training from the control system supplier manufacturers. In addition to basic operations, they have not explained in detail theoretically such as the adjustment technology of the aeration system, so that the management personnel can only re-explore in their work.

[0008] 3. Operational experience has not been utilized

A very important point of a sewage treatment plant is that after long-term operation, it can summarize the daily laws and obtain control plans; for managers, these laws are often more valuable than expensive automatic control equipment, but in the construction of sewage treatment plants, many designs do not There is not enough room for adjustments for managers, and these useful experiences are also lacking in the construction of other sewage facilities

[0009] 4. Difficulties in dissolved oxygen control

1. Hardware reasons: Most of the gas control systems used in the factory area are butterfly valves or gate valves to control the flow of the system, and the control range of butterfly valves or gate valves is generally below 70%; more than 70% is nonlinear control, making the control The difficulty is increased; there is no uniform standard for the installation position and installation depth of the DO detector used, resulting in inaccurate data collection points; in terms of measurement methods, the probes of the membrane method are prone to aging, resulting in deviations in data measurement

2. Software reason: From the perspective of popular control modules, most manufacturers rely on the DO value as the basis for control data. During operation, the system (control parameters) of each season needs to be adjusted to the appropriate system environment, but The control points of this kind of data cannot be accumulated in a short period of time; during operation, due to changes in water volume and water quality, it is quite difficult to find the control points under a large amount of changing data

In some small sewage aeration tanks, due to the high cost of use, it is not easy to accept

Backwash control in foreign countries is based on the structure of the aeration tank, and its control form is included in the large-scale sewage treatment control system, so there is a certain limit to its domestic promotion

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