Research On Characteristic Of Chemical Reaction Kinetics Of Cavitation Impinging Streams

The pollution of water environment of our country are serious. Printing and dyeingwastewater is a kind of typical industry waste water, which difficult to degradation. It is animportant factor of the pollution. Cavitation impinging streams is a novel flow fieldstructure, which has efficient macro-mixing and strong micro-mixing and pressurefluctuation characteristics. It’s better to promote chemical reaction. The paper based ontreatment of printing and dyeing wastewater using cavitation impinging streams, and themain purpose is that research the law of chemical reaction kinetics impacted flow fieldcharacteristics of cavitation impinging streams from the micro perspective, thus do sometheory basis for relevant follow-up study. According to the research purpose and researchcharacteristics of chemical engineering, the main research method is combining theoreticalanalysis and experimental verification.Firstly, this paper research motive law of cavitation collision zone flow field by usingthe liquid micell hypothesis, and mathematical model of cavitation collision zone flowfield is established. Then analyzes the oscillation mechanism of organ and Helmholtzresonator according to the theory of transient and fluid network, and puts forward effectivefeedback condition and calculating the inherent frequency of nozzle, and cavitationself-excited pulsed nozzle is designed. On the basis of deepening the cognition aboutArrhenius formula, activation energy and theory of molecular collision, researches the lawof chemical reaction kinetics impacted flow field characteristics of cavitation impingingstreams in theory. Finally, acetic ether saponification reaction system is selected, and fourtypes of reactor are used for contrast experiment, to verify the analysis.Through analyzing mathematical model of cavitation collision zone, decay oscillatingmovement of micell in the area is found, and the impact velocity is largest in impactsurface. Besides the pressure field distribution is not uniformity, and the lowest pressurethat enough to form a cavitation appears near the impact surface. Self-excited oscillation ofnozzle is the result of interaction between separate vortex and collision wall, and theeffective feedback is formated and inducing new disturbance. The best cavitation oscillation jet can be formed by regulating the draw ratio of cavity and flow. Throughanalyzing the experimental results, when other condition being equal, reaction rateconstant in cavitation impinging streams reactor is higher than other three reactorrespectively13.42%,27.46%,33.82%. The experimental results show that the highlyturbulent cavitation collision zone can rapidly mixed the reactant molecules, and improvethe molecular free vibration energy, and the shear stress and micro jet can improve themolecular effective collision probability, thus improving the reaction rate.