Studying The Effect Factors On Gas-liquid Two-phase Flow Fluid Mechanic Behaviors In Bubble Columns

Gas-liquid two phase flow reactor is an important reaction equipment of gas-liquid two phase to make chemical reaction, which can realize the transfer between the mass, momentum and energy. Bubble column reactor on the structure design is simple,, and it also has a large contact area in gas-liquid two phase reaction. It has convenient operation in the process of chemical production, especially has high heat and mass transfer in the process of gas-liquid two phase chemical reactions, so that this reactor has been widely applied to all kinds of industries, such as energy and new energy industries, biomedical engineering, environmental engineering, chemical reaction engineering. This paper was based on the computational fluid dynamics (CFD) numerical method to simulate bubbling tower internal fluid mechanics behavior under the four different installation height, and four different gas superficial velocity, and made a detailed analysis on the gas holdup and liquid velocity distribution. It also compared the distribution of turbulent kinetic energy and turbulent kinetic energy dissipation rate. The result concluded that the distributor installation height of bubbling tower was between the given height1/5H≤h≤1/2H. In this conclusion, it analyzed the phase flow of the distributor installation height of h=240mm inside the bubbling tower. The calculation results concluded that in the same height of the bubbling tower body fluids, the local gas holdup has a tendency to reduce with the increase of r/R; when r/R <0.5, gas holdup on the same radial location, has a decrease trend with the increase of liquid level height; when r/R>0.5, the local gas holdup in the bubbling tower increased with the increase of liquid level height. The calculation results are displayed that the extent of the turbulent kinetic energy dissipation is big when the liquid phase turbulent kinetic energy values is big, that is to say energy in the region has suffered a serious losses.This paper applied CFD numerical method to simulate the gas-liquid two phase flow under four different gas superficial velocities. It applied the turbulence model to analyze the overall gas holdup distribution, and the liquid velocity distribution with the change of time in the cross-section of the tower body axis (X=0). Through the calculated results, it showed that gas holdup is gradually increasing with the time of the gas continuous ventilation; bubbling tower in the same level, with the increase of superficial gas velocity the the gas holdup has largely increased; when H/D<3, liquid distribution presented a single flow state; when H/D(?)3, liquid distribution presented a dual cycle flow state, and this state is more complex; when turbulent kinetic energy has a large area, the energy loss has a serious area. Therefore it optimized the bubbling tower structure, we can gain a better energy saving effect.