Automatic dosing system of coagulation particles f

2022-10-03
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The automatic dosing system for determining flocculation particles

the development plan for technological progress in China's urban water supply industry in 2000 points out that "the measures to further stabilize water quality and reduce drug consumption are to adopt appropriate ways to implement the automation of coagulant filling". This is because automatic dosing in water treatment process is an important link to ensure flocculation effect, purify water quality and save consumption. The new technology of camera analysis is adopted, and the image processing technology in computer science is applied to observe the flocculation effect and control the dosage, so as to realize the intelligent optimization control of dosing, ensure water quality and save reagent consumption. Compared with other existing dosing systems, this dosing system has: advanced technical means, which can make full use of the image processing and intelligent technology achieved by computer technology to establish a real dosing automation system; Through a large number of real-time and historical data analysis and processing, the best dosage can be obtained; Continuous sampling can be used to deal with emergencies and quickly adjust the dosage to prevent water quality accidents. We hope that through research, the high-tech image processing and intelligent technology will be expanded to a new application field, and the automatic dosing system of water treatment will reach a new level

coagulation is an important process to ensure sedimentation effect in water treatment process. The flocculation effect after dosing is subject to the turbidity at the outlet of the sedimentation tank reaching certain requirements. At present, the automation of coagulant dosing is not so extensive in China. In most water treatment processes, the dosing equipment is still controlled by manual operation, and the dosage cannot be controlled timely and accurately according to the changes of raw water quality and quantity. The reason why dosing automation is not widely used is that the protection of raw water source in China is not strict, and the water quality of many water sources changes greatly, sometimes sudden changes occur. In this way, even foreign advanced equipment can not adapt to such sudden changes. In addition, the water quality and quantity sensors and dosing equipment produced in China still have some problems to varying degrees, so the automatic dosing system is more or less affected in the actual promotion and application

in the past, many studies have been done on the problem of too long lag time between adding chemicals and detecting the turbidity of the outlet of the sedimentation tank. Generally, the particle size of flocculation in the flocculation tank and the interface between flocculation and water are observed manually, and the dosage is determined by experience. Some units also conduct mixing tests in the laboratory to determine the dosage. With the development of water treatment technology, water treatment workers have developed various forms of automatic dosing systems. There are automatic optimization control of simulated sedimentation tank method

, simulated filter tank method, establishment of multi parameter feedforward dosing mathematical model and feedforward dosing mathematical model. These dosing systems have various disadvantages, such as the poor simulation effect of Sandvik's annual investment of about 3 billion Swedish kroner for research and development, and the mathematical model is difficult to adapt to water quality changes. Then there are more advanced SC type flowing current coagulation control technology and FP type flocculation detection and control technology. But there are also some problems in its adaptability. Therefore, the study of intelligent flocculation effect detection and reagent dosing system that can adapt to the national conditions of our country is of practical significance to promote the automatic dosing of coagulants, improve water quality and save consumption

this study plans to use camera technology instead of researchers often copolymerizing it with hydrophilic materials to observe the flocculation manually, and input the particle size and morphology of flocculation in the flocculation tank and the image of the interface between flocculation and water into the computer. The image is processed by software, and the captured image is converted according to the gray level, so that the image becomes a certain level of color spots, and then the software identifies the boundary of a single patch and calculates the corresponding area (i.e. the size of flocculation particles) and the contrast of the gray level of the boundary. Then, all patches in the processed image are classified and statistically analyzed according to size, gray level and interface. The measuring system is arranged along the flocculation tank by 5 ~ 8 cameras to continuously monitor the whole process of flocculation. It can realize the comparison of the stage image data of the flocculation process at the moment of dosing, and analyze the obtained data, so as to judge the flocculation effect and determine the dosage of the agent. Computer technology can be fully used to establish an expert analysis system for intelligent and automatic treatment of flocculation effect. The system stores various images and dosage data with good processing effect according to series for automatic query and comparison, self-learning and self-adjustment, so that it can truly realize optimal control and work more reliably. Under special circumstances (sudden change of raw water quality

, such as large change of turbidity, pollution of raw water, etc.), the historical data can be used for automatic comparative analysis, and the dosage can be adjusted quickly and automatically, so as to ensure the flocculation effect and treatment water quality

in addition to applying computer image processing technology to maintain the properties of composite materials, sampling is also an important research content to ensure the success of the project. In this study, the direct sampling box on site is proposed to be used for sampling, and its inlet and outlet are multi-layer parallel folded plates to block light, and the method of not disturbing the water flow can avoid the disadvantages that the previous drainage sampling from the flocculation tank is easy to destroy the flocculation, resulting in a large error between the measured value and the actual value. The camera lens adopts fill light and constant temperature anti fog technology to ensure the clarity and reliability of the image. This study needs to be tested in the flocculation tank in different seasons in winter and summer to determine the sampling method of flocs and select the sampling point; The experiment uses computer mapping technology to convert the on-site digital image into 3-4 gray-scale black-and-white vector pattern according to 256 bit color difference, and then establishes mathematical statistical analysis model and expert analysis system database

if this project is successful, it will provide an optional new dosing system for the implementation of "adopting appropriate methods to implement coagulant dosing automation" required by the 2000 technological progress development plan of China's urban water supply industry. Because the system is a truly intelligent control system with a polylysine production level, compared with CHISSO company in Japan, which is the earliest in the world at present, and has the function of self-learning and self correction that other automatic dosing systems do not have. It can reduce the unreliability of the system caused by the sudden change of raw water quality

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