Multiphase Numerical Simulation And Structure Optimization Of The Fold Stream UV-Fenton Reactor

The fold streaming UV-Fenton reactor is a kind of general inner loop Fenton reactor with integrated polyphase UV-Fenton technology which is for refractory organic wastewater treatment. The effect of treating high concentrated organic wastewater like landfill leachate is good. Due to its complication of the interior component, the reactor’s designing structure is mainly depending on the part of experimental results, and there is little study on the structure and the fluid mechanics characteristics for this kind of reactor at present.At first, gas-liquid two phase numerical simulation was used to analyze the two sleeve fold streaming UV-Fenton reactor, found out the relationship between the structural parameters of the reactor and the fluid performance parameters, and optimized the structure of the reactor. Then, gas-liquid-solid three phase numerical simulation was used to compare the two fold sleeve streaming UV-Fenton reactor (abbreviating as the two sleeve reactor) and three sleeve fold streaming UV-Fenton reactor (abbreviating as the three socket reactor), analyzed and concluded the relationship between the height of middle degassing sleeve and the fluid performance of mechanics parameters.The gas-liquid two phase numerical simulation results showed that a great H/D of riser area would help the liquid velocity excessive steady; a proper d/D for riser would balance the flux between the riser and the downcomer; a great (D-d)/2hiwould increase the fluid velocity on the bottom of the reactor; the h2/d have bigger influence on the turbulent kinetic energy and its dissipation rate. The optimal structure of folding streaming UV-Fenton reactor parameters are the H/D= 3.5, d/D= 0.4, (D-d)/2h1=3 and h2/d=0.5.The gas-liquid-solid three phase numerical simulation results showed that the properties of fluid mechanics of three sleeve reactor with middle sleeve was better than two sleeve reactor without middle sleeve in the increasing using ratio of solid phase cycling, the velocity of cycling liquid and reducing the loss of energy and so on. Besides, with the reducing of the degassing height, the shunt effect of the middle sleeve was increased, as well as the solid-phase reflow rate and the velocity of cycling liquid, which was benefit for improving the efficiency of cycle catalytic reaction and improving the effect of the waste water.Basing on the CFD technology, the study go on a deeply research on the fold streaming UV-Fenton reactor, and find out the found out the relationship between the structural parameters of the reactor and the fluid performance parameters, which provides the basic theory for the structural optimization and model enlargement. Comparing with the method that makes different reactors produce different reactor models in lab, CFD technology used in this paper saves design time and economic costs.