化工学报
化工學報
화공학보
CIESC Jorunal
2015年
11期
4438-4445
,共8页
郭天琪%黄正梁%王靖岱%蒋斌波%阳永荣
郭天琪%黃正樑%王靖岱%蔣斌波%暘永榮
곽천기%황정량%왕정대%장빈파%양영영
多相反应器%混合%气泡%射流%输入功率
多相反應器%混閤%氣泡%射流%輸入功率
다상반응기%혼합%기포%사류%수입공솔
multi-phase reactor%mixing%bubble%jet%power input
射流鼓泡反应器以液体射流代替搅拌实现液相混合,具有结构简单、制造及维护费用低等诸多优点,研究其混合特性对于反应器的设计、优化及放大具有重要意义。以空气-水作为模拟介质,采用KCl电解质溶液为示踪剂考察了表观气速和射流Reynolds数的大小对液相宏观混合时间的影响,并从能量输入的角度对射流鼓泡反应器的混合机制进行分析。研究发现,在实验条件下(表观气速变化范围为0.0006~0.0343 m·s?1,射流Reynolds数的变化范围为1.75×104~7.00×104),鼓泡的加入使得均相射流反应器内的液相混合得到改善;随着表观气速增大,液相宏观混合时间先缩短后延长;当气体输入功率或液体输入功率不变时,混合时间随总输入功率的增大而缩短。通过对多组实验数据的回归分析,提出了液相宏观混合时间与液体输入功率和气体输入功率的经验关联式,计算值与实际值吻合较好。最后基于提出的关联式,发现当总输入功率一定时,混合时间随气体输入功率的增加先缩短后延长,临界转变点在气体输入功率为总功率的61%处,此时气液两相协同作用最强。
射流鼓泡反應器以液體射流代替攪拌實現液相混閤,具有結構簡單、製造及維護費用低等諸多優點,研究其混閤特性對于反應器的設計、優化及放大具有重要意義。以空氣-水作為模擬介質,採用KCl電解質溶液為示蹤劑攷察瞭錶觀氣速和射流Reynolds數的大小對液相宏觀混閤時間的影響,併從能量輸入的角度對射流鼓泡反應器的混閤機製進行分析。研究髮現,在實驗條件下(錶觀氣速變化範圍為0.0006~0.0343 m·s?1,射流Reynolds數的變化範圍為1.75×104~7.00×104),鼓泡的加入使得均相射流反應器內的液相混閤得到改善;隨著錶觀氣速增大,液相宏觀混閤時間先縮短後延長;噹氣體輸入功率或液體輸入功率不變時,混閤時間隨總輸入功率的增大而縮短。通過對多組實驗數據的迴歸分析,提齣瞭液相宏觀混閤時間與液體輸入功率和氣體輸入功率的經驗關聯式,計算值與實際值吻閤較好。最後基于提齣的關聯式,髮現噹總輸入功率一定時,混閤時間隨氣體輸入功率的增加先縮短後延長,臨界轉變點在氣體輸入功率為總功率的61%處,此時氣液兩相協同作用最彊。
사류고포반응기이액체사류대체교반실현액상혼합,구유결구간단、제조급유호비용저등제다우점,연구기혼합특성대우반응기적설계、우화급방대구유중요의의。이공기-수작위모의개질,채용KCl전해질용액위시종제고찰료표관기속화사류Reynolds수적대소대액상굉관혼합시간적영향,병종능량수입적각도대사류고포반응기적혼합궤제진행분석。연구발현,재실험조건하(표관기속변화범위위0.0006~0.0343 m·s?1,사류Reynolds수적변화범위위1.75×104~7.00×104),고포적가입사득균상사류반응기내적액상혼합득도개선;수착표관기속증대,액상굉관혼합시간선축단후연장;당기체수입공솔혹액체수입공솔불변시,혼합시간수총수입공솔적증대이축단。통과대다조실험수거적회귀분석,제출료액상굉관혼합시간여액체수입공솔화기체수입공솔적경험관련식,계산치여실제치문합교호。최후기우제출적관련식,발현당총수입공솔일정시,혼합시간수기체수입공솔적증가선축단후연장,림계전변점재기체수입공솔위총공솔적61%처,차시기액량상협동작용최강。
The jet bubbling reactor uses liquid jet to achieve the liquid mixing instead of mechanical stirring, which brings several advantages such as simple structure and low cost of maintenance and manufacturing. The research of its mixing characteristics plays a significant role in the design, optimization and scaling up of the reactor. Based on the air-water system, the electrolyte tracer (KCl solution) method was applied to investigate the influences of gas velocity and jet Reynolds number on the liquid mixing time with the cold model experimental apparatus. The mixing mechanism in jet bubbling reactor had also been analyzed from the perspective of power input. The results showed that within the experimental range (ugfrom 0.0006 to 0.0343 m·s?1,Rej from 1.75×104 to 7.00×104), the introduction of gas bubbling strengthened the liquid mixing conditions. With the increase of superficial gas velocity, the liquid mixing time decreased at first and then increased. When the gas or liquid power input kept constant, the mixing time decreased with the increase of the total power input. Through the regression analysis of all the experimental data, relationship between liquid mixing time, and liquid and gas power inputs had been built up. An empirical correlation was proposed, and the calculated value was fitted well with the experimental data. Based on the obtained equation, the liquid mixing time was found to decrease at first and then increase with the increase of the gas power input if the total power input was remained constant. The transition point was around where gas input power occupied 61% of the total input power. At this point, the synergistic effect was the strongest.