高校化学工程学报
高校化學工程學報
고교화학공정학보
JOURNAL OF CHEMICAL ENGINEERING OF CHINESE UNIVERSITIES
2013年
5期
785-790
,共6页
李绍果%薛天艳%齐涛%刘长厚
李紹果%薛天豔%齊濤%劉長厚
리소과%설천염%제도%류장후
多级环流反应器%三段进气%进气量比%气泡参数%体积传质系数
多級環流反應器%三段進氣%進氣量比%氣泡參數%體積傳質繫數
다급배류반응기%삼단진기%진기량비%기포삼수%체적전질계수
multi-stage airlift loop reactor%three air-in spargers%gas inlet ratio%bubble parameters%mass-transfer coefficient
多级环流反应器通常在段间安装多孔分布板或其它内构件,增加了流体流动的阻力,导致环流液速降低。为此,今在多级环流反应器研究的基础上,设计了一种新型三段进气、多级环流反应器,利用新通入气体的抽提力和喷射力,缓解了段间的流动压降,并加速气泡的破碎;重点考察了进气量在各段中的分配比例对分段进气多级环流反应器流体力学的影响。应用多通道电导探针气泡特征参数测量仪和溶解氧分析仪分别测量气泡参数(气含率、气泡速度、气泡直径)及体积传质系数。实验结果表明:三段同时进气时,气泡直径明显减小,气液接触比表面积增加显著;体积传质系数远高于多级环流反应器,最大值约为多级环流反应器的2.3倍。根据修正双膜理论,计算得到了三段进气时体积传质系数的经验关联式,较好地反映出体积传质系数的变化规律。
多級環流反應器通常在段間安裝多孔分佈闆或其它內構件,增加瞭流體流動的阻力,導緻環流液速降低。為此,今在多級環流反應器研究的基礎上,設計瞭一種新型三段進氣、多級環流反應器,利用新通入氣體的抽提力和噴射力,緩解瞭段間的流動壓降,併加速氣泡的破碎;重點攷察瞭進氣量在各段中的分配比例對分段進氣多級環流反應器流體力學的影響。應用多通道電導探針氣泡特徵參數測量儀和溶解氧分析儀分彆測量氣泡參數(氣含率、氣泡速度、氣泡直徑)及體積傳質繫數。實驗結果錶明:三段同時進氣時,氣泡直徑明顯減小,氣液接觸比錶麵積增加顯著;體積傳質繫數遠高于多級環流反應器,最大值約為多級環流反應器的2.3倍。根據脩正雙膜理論,計算得到瞭三段進氣時體積傳質繫數的經驗關聯式,較好地反映齣體積傳質繫數的變化規律。
다급배류반응기통상재단간안장다공분포판혹기타내구건,증가료류체류동적조력,도치배류액속강저。위차,금재다급배류반응기연구적기출상,설계료일충신형삼단진기、다급배류반응기,이용신통입기체적추제력화분사력,완해료단간적류동압강,병가속기포적파쇄;중점고찰료진기량재각단중적분배비례대분단진기다급배류반응기류체역학적영향。응용다통도전도탐침기포특정삼수측량의화용해양분석의분별측량기포삼수(기함솔、기포속도、기포직경)급체적전질계수。실험결과표명:삼단동시진기시,기포직경명현감소,기액접촉비표면적증가현저;체적전질계수원고우다급배류반응기,최대치약위다급배류반응기적2.3배。근거수정쌍막이론,계산득도료삼단진기시체적전질계수적경험관련식,교호지반영출체적전질계수적변화규률。
There are some perforated plates or other internals in multi-stage airlift loop reactor (MSALR), which can increase the flow resistance, and lead to reduce circulating liquid velocity. In order to solve these defects, a three sparger multi-stage airlift loop reactor (TS-MSALR) was proposed, in which because of the gas ejection force, the flow pressure drop is reduced, and the bubble breaking is enhanced. This study focuses on the gas inlet ratio among the three air-in spargers, which plays an important role for the hydrodynamics in the reactor. The gas-liquid two-phase flow hydrodynamic properties including gas holdup, bubble velocity, bubble diameter and mass transfer coefficient at various gas inlet ratios were measured by dual electrical resistivity probes and DO probe. The results show that the bubble diameter decreases obviously, the gas-liquid surface area increases significantly, and the volumetric mass transfer coefficients of TS-MSALR are much higher than that of MSALR. The maximum mass-transfer coefficient of the TS-MSALR is 2.3 times of that of the MSALR. Based on the modified double film theory, correlation of volumetric mass transfer coefficient of TS-MSALR was obtained.