Research On The External And Water Disinfection Characteristics Of A Rotational Hydrodynamic Cavitation Reactor

With the rapid growth of the world’s population and the deteriorating ecological environment,the safe supply of drinking water has become a topic of continuous concern throughout the world.According to statistics,there are 1.2 billion people in the world who lack safe drinking water,and 1 billion people suffer from water-borne diseases every year.The key to ensuring the safety of drinking water is water disinfection.Recycling sewage in a more environmentally friendly,effective and economical way has become a problem that needs to be solved all over the world.Elimination of pathogenic microorganisms is a key step in the water treatment process.Disinfection technology based on hydraulic cavitation has become a research trend for many domestic and foreign scholars.The performance of a hydraulic cavitation device determines the degree of occurrence of hydraulic cavitation,and at the same time determines the effectiveness of hydraulic cavitation disinfection.Based on experimental research,this paper uses the rotating hydraulic cavitation device independently designed by the Hydrocavity Research Group of the School of Mechanical Engineering of Shandong University to carry out three parts of research:the first part is the design of the internal structural parameters of the rotating hydraulic cavitation;the second part is Analysis of the external characteristics of the rotary hydraulic cavitation;the third part is the application research of the rotary hydraulic cavitation in water disinfection.The specific research content is as follows:(1)Aiming at the problem of the unclear mechanism of cavitation induced by the rotating hydraulic cavitation,the rotating hydraulic cavitation device was independently designed,and the experimental operating system of the rotating hydraulic cavitation device was built.The periodic characteristics of the rotating shear cavitation were studied,and the periodical characteristics of the rotating shear cavitation were investigated.And revealed the mechanism of cavitation induced by rotating hydraulic cavitation.(2)Aiming at the problem of the unclear characteristics of the existing operating conditions,the changes of heat generation rate,shaft power and thermal efficiency under full flow and speed conditions are explored;the external characteristic model and response surface are established,and the similarity law is proposed to reveal The influence law of flow and speed on external characteristics is described.(3)Aiming at the problem that the influence of current working conditions on cavitation disinfection is not clear,the influence law of flow rate and rotation speed on disinfection performance is studied.By comparing the disinfection performance of the rotary hydraulic cavitation device in this study with that of the traditional cavitation device,the advantages of the rotary hydraulic cavitation device in water treatment and disinfection are highlighted.Finally,through the plate colony counting method and the biological scanning electron microscopy experimental study,the mechanism of the microbial destruction caused by the rotary hydraulic cavitation device was verified.