Study on the Mixing Effect of Gas-Liquid Flow in the Stirred Tank with Double Paddle
Aiming at the double-paddle stirred tank,having the RNG k-ε turbulent multiphase flow model adopted to investigate gas-liquid flow's mixing characteristics of such three combined double paddles as the radial-flow RT straight paddle and axial-flow PB oblique blade paddle was implemented.The result show that,the RT-RT double paddle brings about several symmetric and uniform vortexes in the stirred tank,which results in the gathering of the gas which entered the tank bottom in the lower pressure area near the center of the paddle.The axial flow brought in by the PB-RT significantly improves the liquid flow velocity between the two paddlers and makes the overall eddy flow in the stirred tank move to the inlet direction of the gas;in addition,improving the local gas holdup in the middle region of the two paddlers slightly and making it higher than the overall gas holdup of the RT-RT double paddlers will cause the stirring power re-duced by 57%.The PB-PB double paddle has the highest gas holdup,and its stirring power is 49%higher than that of PB-RT.