Numerical Simulation And Experimental Study On Multiphase Internal Circulating Fluidized Bed Reactor

With the increasingly stringent requirements of water environment regulation,the economic,efficient and advanced treatment of landfill leachate has become the focus of research at home and abroad.As a general type of high concentration organic wastewater treatment reactor,multi-phase circulating fluidized bed reactor because of its relatively simple structure,using multi-Fenton technology,which can efficiently for the advanced treatment of landfill leachate and to be taken seriously.In view of the current structure and flow reactor has been studied,in order to further understand the reactor gas inlet velocity,solid catalyst effect and treatment effect of flow quantity and adding method of multi-phase reaction,the multi-phase circulating fluidized bed reactor was studied the numerical simulation and the corresponding.Based on the platform of Workbench FLUENT software on multi-phase circulating fluidized bed reactor was simulated and the influences of main parameters of the reactor inlet velocity and solid dosage on fluid flow.The simulation results show that the inlet velocity has a significant influence on the gas holdup,liquid phase velocity,turbulent kinetic energy and dissipation rate of the reactor,but has little influence on the solid holdup and the liquid circulating velocity.The gas holdup of reactor increases with the increase of gas phase velocity.When the gas inlet velocity reaches 0.4m/s,the gas holdup tends to be stable and no longer increase.The central liquid velocity also increases with the increase of gas inlet velocity.When the inlet velocity reaches 0.3m/s,the liquid velocity at the center of the reactor is no longer higher,but lower.The turbulent kinetic energy and dissipation rate of reactor decrease first with the increase of gas phase velocity,and then begin to flip and increase when gas phase velocity is 0.3m/s.Therefore,considering the influence of the related parameters,the intake air velocity control is appropriate for 0.3~0.4m/s in the internal circulating fluidized bed reactor.The simulation results of the solid phase dosage of the reactor on the fluid mechanics parameters also show that the gas holdup of the reactor can be improved by the increase of the amount of solid phase catalyst.However,the increase of solid phase catalyst dosage will not only lead to the increase of the kinetic energy of the reactor,but also lead to the deposition of some solid phase catalysts at the bottom of the reactor,leading to the waste of solid phase catalyst.The optimum amount of solid phase is 0.3%~0.5% of the volume ratio of the reactor.In this paper,the effects of different gas inlet velocity on gas holdup and treatment efficiency of landfill leachate were studied.The experimental results show that the increase of gas velocity can improve the reactor gas holdup,liquid solid circulation significantly faster,but imported gas velocity was 0.4m/s,the gas holdup increases no longer and tends to be stable,this result is consistent with the numerical;when the gas inlet velocity is 0.3m/s,reactor good COD removal.This paper studies the effect of solid dosage,amount and adding way of reactor effluent showed that solid catalyst dosage has little effect on the reactor effluent water quality results,but the solid catalyst has certain influence on the reactor effluent water quality.In addition of the same amount under the condition of solid catalyst can improve the treatment effect of multiple dosing reactor.