| Control of plate tower’s gas-liquid phase dispersion uniformity has always been a key issue in the field of chemical engineering.In the process of phase dispersion,the coalescence of liquid drops and bubbles and the control of pressure on the plate make gas and liquid distribute unevenly.Despite that the conventional tower tray operation model with up-going gas can achieve the purpose of avoiding leak,producing a larger mass transfer phase interface and improving the productivity by additionally increasing the kinetic energy of gas,due to the great degree of freedom in the process of gas-liquid phase dispersion in the tower,gas-liquid distribution is still severely uneven.To thoroughly improve the distribution performance in such an operation process,this paper presents an idea that the influence of gas-liquid phase interaction must be separated,so as to,by realizing even distribution of gas,effectuate forced control of the uniformity of liquid distribution.Based on this technical thought,our lab conceived an innovative plate tower gas-liquid mass transfer model--a new model where down-going gas jet flow and liquid on the plate engage in high-efficiency mass transfer.With the goal of modifying the conventional plate tower configuration,this paper conducts tests on down-going gas-liquid jet flow phase dispersion mass transfer model,and carries out the related development and exploration work according to CFD simulation study.First,starting from the study on static single-orifice gas phase vertical jet flow,tests are conducted to examine single-orifice jet flow’s major characteristics and related influencing factors;meanwhile,aided with CFD numerical simulation,gas-liquid phase’s physical property scope is expanded to study its effect on jet penetration depth.Tests and simulation are combined to build an analytical model of single-orifice gas jet penetration depth,to measure the efficiency and effect of gas-liquid mass transfer.Based on our lab’s previous studies on rectifying tower scale-up effect and jet flow configuration tower tray,gas jet flow’s configuration is introduced into the rectifying tower gas-liquid phase mass transfer model to build a rectifying tray with new gas jet flow configuration.Meanwhile,porous gas jet flow CFD numerical simulation is used as a guidance to optimize the relevant parameters of the new tower tray and the fluidic elements on the plate,so as to obtain many effects beneficial to tower operation.Test gas jet flow configuration’s new tower tray on a φ-280 mm small tower,observe the gas-liquid contact status in the small-scale test,measure the hydraulic performance of the relevant tower operation,analyze the pressure drop characteristics of jet flow configuration tower tray,and build a pressure drop model of jet flow above the liquid surface;then,the clear liquid height on the plate is analyzed,the effect of gas velocity on the clear liquid height of the tower tray constructed in this paper is investigated,and meanwhile tower tray’s entrainment and leakage are illustrated.This paper makes clear that,given a fixed structure(total jetting distance and weir height)and fixed amount of fluid,only one gas velocity point can achieve the optimal gas-liquid contact mass transfer effect,and it also illustrates how to determine the optimum operating conditions and methods for the corresponding structure and working condition.The rectifying tray with new gas jet flow configuration constructed in this paper is proven to be a reliable and effective tower plate structure,and is hopefully to be extended to industrial scale. |
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