The sewage treatment plant has become a major polluter, which sounds new, but the failure of sludge disposal technology does affect the healthy development of the entire sewage treatment industry. Recently, the reporter learned that a new type of solid-liquid separator-planetary solid-liquid separator developed by Niu Zhongyuan, a retired senior engineer of the Tianjin Dagang Oilfield Drilling Technology Research Institute, has broken the technical bottleneck of sludge disposal and is beneficial to the sewage treatment plant. Solve the sludge problem from the source.
Speaking of the development process of the solid-liquid separator, Niu Zhongyuan told reporters that because mud plays an important role in oil drilling, people say that mud is the blood of drilling. The solid content has a significant impact on drilling speed and wellbore quality, and also affects oil production. , So the oil field uses the most solid-liquid separation machinery, but the key technical problems have not been well resolved. The solid-liquid separation method commonly used in oilfields is a five-step solids control method with high energy consumption and low efficiency: mud is filtered through a vibrating screen → deaerator → cyclone desander → cleaner → centrifuge. In the 1980s, the United States developed the MAX machine and tried to use a device to remove 95% of the particles in the suspension to achieve one-step solid control, but it was unsuccessful.
Niu Zhongyuan, who originally wanted to solve the problem of solid-liquid separation for oilfield drilling, discovered during the development process that this technology will have a larger market for sewage treatment. After collecting data, it was discovered that this technology is also a blank in the world. He introduced that \"Science Times reported on February 18, 2004 that the United Kingdom invented a new water treatment system. The DEHOAR spiral separator is a gravity settling device that can only thicken sludge. This shows that it treats The latter sludge has a high water content because it is not a filter and has no drying function.\" Niu Zhongyuan, who often reads \"Science Times\", has been very concerned about technical reports on solid-liquid separation. After analysis and research, he found that sewage treatment at home and abroad is still at the stage of sedimentation technology, which is the crux of the development of the sewage treatment industry.
\"Filtration is one of the most effective unit operations to separate the suspension. Clean liquid or solid products can be obtained through the filtration operation. In some cases, the filtration is the subsequent operation of the sedimentation, which can make the separation of the suspension faster and more thorough. .\"Wang Xiaojing, deputy director of the Department of Process Equipment and Control Engineering, School of Chemical Engineering, Tianjin University, made such a comparative evaluation of the two technologies of filtration and sedimentation. Niu Zhongyuan pointed out that if sewage treatment wants to get rid of the predicament, it must get rid of the sedimentation technology and fully implement the filtration technology.
At present, the filtering machines used in the chemical, coal, paper and other industries must be shut down to process the material on the screen. The filtering process is intermittent and cannot handle a large amount of suspended matter. \"The condition for continuous filtration is that the screen must have the function of continuously and automatically removing the substances trapped on the surface of the screen. If there is no such function, the material on the screen will thicken, which will cause the mesh and make the filter lose its filtering function.\" Niu Zhongyuan's eyes focused on the key technical core issue of solid-liquid separation-the self-cleaning function of the screen. After hard thinking and constant experimentation, he adopted the principle of compound rotation of the planetary structure to make the cylindrical screen rotate while rotating at the same time, so that there is an alternating law of yin and yang in the relative revolution center of the screen and the material on the net. ―The suspension sprayed from the catheter enters the screen from the positive position to filter, rotates at a certain angle to the negative position, and throws away the material on the net. This is the mechanism that the cylindrical screen automatically removes the material on the net every one week of rotation. \"This is the core of the entire technology and the difficulty of rotating continuous filtration machinery. If the western mathematician Leibniz was inspired by the theory of oriental yin and yang and gossip, he invented the binary system of the computer. From the principle of solid-liquid separation, it can be clear Seeing the principle of yin and yang transformation, the road to Jane. \" \"
In recent years, domestic and foreign are vigorously researching how to use ultra-fine screens on vibrating screens. If 0.075/0.05 (200 mesh) or even 0.045/0.032 (325 mesh) can be used, the equipment after the vibrating screen and before the centrifuge , Including degreasing machine, desilter, cleaning machine, etc., can be completely omitted, greatly simplifying the solids control equipment and system, resulting in huge economic benefits. The reason why this study was unsuccessful is that the use of ultra-fine screens inevitably increases the separation factor, and this kind of equipment is vibrating, which can easily cause the screen to be scrapped. \"Niu Zhongyuan told reporters that because the distribution of the filter unit on the planetary solid-liquid separator and its cylindrical screen on the platform is symmetrical, and there is dynamic balance during rotation, vibration-free filtration can be achieved. It is for the use of high mesh screens. The mesh and increase the life of the screen create conditions.
The reporter learned that the key technology of the planetary solid-liquid separator: the continuity of filtration and the non-vibration, rely on three technical supports, namely the transmission system, the injection system and the filter unit. In the pilot test, these three technologies passed the experiment smoothly. After three years of research on the solid-liquid two-phase recovery technology, technological breakthroughs were also made, and two invention patents were obtained. The prototype is about to enter the production test.
\"The current sewage treatment is still at the stage of sedimentation technology, and the degree of dryness of the treated sludge is not up to the requirement. The emergence of this technology will end the sedimentation technology and achieve the implementation of mandatory filtration at the source of the sewage, To meet the dryness requirements, the separated purified water meets the requirements of reclaimed water, and realizes circular economy. Therefore, this is a bottleneck technology that can greatly change the face of sewage treatment in China.\" Niu Zhongyuan believes that the crux of sewage treatment in China is cities The essential disadvantage of the construction of a large sewage treatment plant is that domestic sewage and industrial wastewater are mixed and then treated. The sedimentation technology can not be used to dry the sludge. The result of the treatment is to convert water pollution into mud pollution. A large amount of domestic sewage and industrial sewage are related. The mixed sludge is difficult to dispose. The best hope for getting out of the predicament is to treat domestic sewage and industrial sewage separately: build small sewage treatment plants in residential quarters, after simple treatment, mechanical filtration and de-drying of sludge Reclaimed water can be used to water flowers and grow grass nearby, and the sludge is organic fertilizer; the industrial wastewater is treated separately, after biological treatment, heavy metal passivation technology application, and filtration and drying, the water and mud become valuable resources and realize circular economy , To achieve a virtuous circle\".