提升管CSVQS系统预汽提段颗粒速度和停留时间分布
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摘要
在一套φ600 mm CSVQS的环流预汽提段冷态实验床装置上,在导流筒区气速为0.2 m·s-1和0.3 m·s-1,环隙区气速为0.03 m·s-1和0.07 m·s-1,汽提段气速为0和0.13 m·s-1时,考察了预汽提导流筒区和环隙区的颗粒速度分布,同时在上述条件下,根据提出的计算方法,考察了由提升管引入环流预汽提段颗粒的平均停留时间分布。结果表明,在上述几种操作条件下,预汽提段均为中心气升式环流,汽提段气体大部分进入导流筒区。在导流筒区气速相同时,在无汽提风时,导流筒区颗粒速度随环隙区气速的增加沿径向由陡峭分布转变为平缓分布;在有汽提风时,导流筒区颗粒速度径向分布随环隙区气速的变化很小。在环隙区气速相同时,在有汽提风时,导流筒区颗粒速度随其气速的增加由平缓分布转变为陡峭分布;在无汽提风时,两种导流筒区气速下的颗粒速度径向分布均比较陡峭。与导流筒区相比,环隙区颗粒速度径向分布几乎不随操作条件的不同而变化。随着导流筒气速的增加或环隙气速的降低,颗粒平均停留时间分布变窄,质量分数降低;随着颗粒循环强度的增加,颗粒平均停留时间分布变窄;质量分数变化不一。
Particle velocity distributions were investigated in draft tube and annulus region of a φ600 mm CSVQS cold-state setup under conditions of gas velocities at 0.2 and 0.3 m·s-1 in the draft tube, at 0.03 and 0.07 m·s-1 in the annulus region and 0 and 0.13 m·s-1 in the stripper. Mean residence time distribution of particles in the pre-tripper section was also calculated by the method proposed here. Experimental results demonstrated that gas flowed as center-airlifting circulation in the pre-stripper section and most of the gas went into the draft tube under the above-stated operating conditions. Under constant gas velocity in the draft tube and increased gas velocity in the annulus region, the radial velocity distribution of particles changed from steep to smooth without stripper wind whereas that distribution changed slightly with stripper wind. Under the same gas velocity in the annulus region and increased velocity in the draft tube, the radial velocity distribution of particles changed from smooth to steep without stripper wind whereas distribution remained quite steep with stripper wind under the two different velocities in the draft tube. Compared to that in the draft tube, the radial velocity distribution of particles in annulus region kept almost no change with varied operating conditions. When the gas velocity was increased in the draft tube or was decreased in the annulus section, the average residence time distribution of particles was narrowed and the mass fraction of particles was decreased. When the circulation strength of particles in the pre-stripper section was increased, the average residence time distribution of particles was narrowed but the mass fraction of particles was changed irregularly.
Particle velocity distributions were investigated in draft tube and annulus region of a φ600 mm CSVQS cold-state setup under conditions of gas velocities at 0.2 and 0.3 m·s-1 in the draft tube, at 0.03 and 0.07 m·s-1 in the annulus region and 0 and 0.13 m·s-1 in the stripper. Mean residence time distribution of particles in the pre-tripper section was also calculated by the method proposed here. Experimental results demonstrated that gas flowed as center-airlifting circulation in the pre-stripper section and most of the gas went into the draft tube under the above-stated operating conditions. Under constant gas velocity in the draft tube and increased gas velocity in the annulus region, the radial velocity distribution of particles changed from steep to smooth without stripper wind whereas that distribution changed slightly with stripper wind. Under the same gas velocity in the annulus region and increased velocity in the draft tube, the radial velocity distribution of particles changed from smooth to steep without stripper wind whereas distribution remained quite steep with stripper wind under the two different velocities in the draft tube. Compared to that in the draft tube, the radial velocity distribution of particles in annulus region kept almost no change with varied operating conditions. When the gas velocity was increased in the draft tube or was decreased in the annulus section, the average residence time distribution of particles was narrowed and the mass fraction of particles was decreased. When the circulation strength of particles in the pre-stripper section was increased, the average residence time distribution of particles was narrowed but the mass fraction of particles was changed irregularly.
引文
[1]卢春喜,徐文清,魏耀东,等.新型紧凑式催化裂化沉降系统的实验研究[J].石油学报(石油加工),2007,23(6):6-12.LU C X,XU W Q,WEI Y D,et al.Experimental studies of a novel compact FCC disengage[J].Acta Petrolei Sinica(Petroleum Processing Section),2007,23(6):6-12.
[2]卢春喜,时铭显,许克家.一种带有密相环流预汽提器的提升管出口的气固快分方法及设备:1200945A[P].1998-12-09.LU C X,SHI M X,XU K J.With a dense phase circulation in the process of the stripper of gas-solid riser export fast points method and equipment:1200945A[P].1998-12-09.
[3]中国石化总公司催化裂化装置长周期运行调查组.催化裂化装置长周期运行的调查[J].炼油设计,1998,28(2):6-13.Investigation Group of Long Period Running of FCC,SINOPEC.Investigation on long period running of FCC[J].The Refining Design,1998,28(2):6-13.
[4]胡敏,刘为民.催化裂化装置沉降器结焦和防治对策[J].炼油技术与工程,2013,43(6):26-32.HU M,LIU W M.Study on coking in settler of FCCU and prevention countermeasures[J].Petroleum Refinery Engineering,2013,43(6):26-32.
[5]卢春喜,时铭显.国产新型催化裂化提升管出口快分系统[J].石化技术与应用,2007,25(2):142-146.LU C X,SHI M X.Novel catalytic cracking riser term separation devices in China[J].Petrochemical Technology&Application,2007,25(2):142-146.
[6]许克家.催化裂化提升管出口快分系统的稠密相环流式预汽提器的研究[D].北京:中国石油大学.1998.XU K J.Study on dense-phase airlift loop stripper for quick separator of riser of FCC[D].Beijing:China University of Petroleum,1998.
[7]LIU M X,LU C X,SHI M X.Hydrodynamic behavior of a gas-solid air-loop stripper[J].Chinese Journal of Chemical Engineering,2004,12(1):55-59.
[8]刘梦溪,卢春喜,时铭显.单段高料位气-固稠密相环流汽提器的密度分布[J].石油化工,2002,31(10):815-819.LIU M X,LU C X,SHI M X.Particle velocity distribution in a single stage high level gas solid annular flow stripper[J].Petrochemical Technology,2002,31(10):815-819.
[9]刘梦溪,卢春喜.单段高料位气-固稠密相环流汽提器的密度分布[J].石油化工,2001,30(11):850-854.LIU M X,LU C X.Study of new kind of stripper[J].Petrochemical Technology,2001,30(11):850-854.
[10]刘梦溪,卢春喜,时铭显.两段气-固环流反应器流体动力学行为和传质特性的研究[C]//中国颗粒学会2006年年会论文集.2006:591-595.LIU M X,LU C X,SHI M X.Hydrodynamics and mass transfer characteristics of a novel two-stage gas-solid internal airlift loop reactor[C]//The Chinese Society of Particles For 2006.2006:591-595.
[11]刘显成,卢春喜,时铭显.两段气升式气-固环流取热器导流筒壁与床层间的传热特性研究[J].过程工程学报,2004,4(增刊):611-618.LIU X C,LU C X,SHI M X.Study on heat transfer between gas-solids suspension and the surfaces of two draft tubes in an airlift loop heat exchanger[J].The Chinese Journal of Process Engineering,2004,4(suppl.):611-618.
[12]张永民,卢春喜,时铭显.催化剂汽提器内气-固传质特性的研究[J].高校化学工程学报,2004,18(4):409-413.ZHANG Y M,LU C X,SHI M X.Study on the gas-solid mass transfer performance in catalyst stripper[J].Journal of Chemical Engineering of Chinese Universities,2004,18(4):409-413.
[13]张永民,卢春喜,时铭显.催化裂化新型环流汽提器的大型冷模实验[J].高校化学工程学报,2004,18(3):377-380.ZHANG Y M,LU C X,SHI M X.Large-scale cold pilot experiment on a new annular catalyst stripper for FCC units[J].Journal of Chemical Engineering of Chinese Universities,2004,18(3):377-380.
[14]林海波,孔春林.气-固循环流化床提升管颗粒速度和浓度的测量技术[J].四川轻化工学院学报,2002,15(4):28-33.LIN H B,KONG C L.Measurement techniques of solids concentration and solids velocity in circulating fluid beds riser[J].Journal of Sichuan Institute of Light Industry and Chemical Technology,2002,15(4):28-33.
[15]NIEUWLAND J J,MEIJER R,KUIPERS J A M.Measurements of solids concentration and axial solids velocity in gas-solid two-phase flow[J].Powder Technology,1996,87(2):127-139.
[16]刘会娥,余皓,魏飞,等.提升管内颗粒的微观运动行为[J].石油大学学报(自然科学版),2003,27(4):106-109.LIU H E,YU H,WEI F,et al.Micro flow behaviors of particles in riser[J].Journal of the University of Petroleum,2003,27(4):106-109.
[17]鄂承林,卢春喜,高金森,等.气-固两相流中颗粒时均速度的测量新方法[J].过程工程学报,2003,3(6):505-511.E C L,LU C X,GAO J S,et al.A new method for the measurement of solids time-averaged velocity in gas-solid two-phase flow[J].The Chinese Journal of Process Engineering,2003,3(6):505-511.
[18]JEON H J,KIM S D,KIM S J,KONG Y.Solid circulation and gas bypassing characteristics in a square internally circulating fluidized bed with draft tube[J].Chemical Engineering and Processing,2008,47:2351-2360.
[19]钱诗智,陆继东,FLAMANT G.高温气固流化床的临界流态化行为[J].燃烧科学与技术,1996,2(4):315-321.QIAN S Z,LU J D,FLAMANT G.Critical fluidization behavior of gas-solid fluidized bed at elevated temperatures[J].Journal of Combustion Science and Technology,1996,2(4):315-321.
[20]DAVIDSON J F,HARRISON D.Fluidized Particles[M].London:Cambridge University Press,1963.
[21]魏飞,金涌,俞芷青,等.磷光颗粒示踪技术在循环流态化中的应用[J].化工学报,1994,45(2):230-236.WEI F,JIN Y,YU Z Q,et al.Application of phosphor tracer technique to the measurement of solids RTD in circulating fluidized bed[J].Journal of Chemical Industry and Engineering(China),1994,45(2):230-236.
[22]王勤辉,骆仲泱,倪明江,等.循环流化床内颗粒停留时间分布[J].燃烧科学与技术,2001,7(4):221-224.WANG Q H,LUO Z Y,NI M J,et al.Particle residence time distribution in a circulating fluidized bed[J].Journal of Combustion Science and Technology,2001,7(4):221-224.
[2]卢春喜,时铭显,许克家.一种带有密相环流预汽提器的提升管出口的气固快分方法及设备:1200945A[P].1998-12-09.LU C X,SHI M X,XU K J.With a dense phase circulation in the process of the stripper of gas-solid riser export fast points method and equipment:1200945A[P].1998-12-09.
[3]中国石化总公司催化裂化装置长周期运行调查组.催化裂化装置长周期运行的调查[J].炼油设计,1998,28(2):6-13.Investigation Group of Long Period Running of FCC,SINOPEC.Investigation on long period running of FCC[J].The Refining Design,1998,28(2):6-13.
[4]胡敏,刘为民.催化裂化装置沉降器结焦和防治对策[J].炼油技术与工程,2013,43(6):26-32.HU M,LIU W M.Study on coking in settler of FCCU and prevention countermeasures[J].Petroleum Refinery Engineering,2013,43(6):26-32.
[5]卢春喜,时铭显.国产新型催化裂化提升管出口快分系统[J].石化技术与应用,2007,25(2):142-146.LU C X,SHI M X.Novel catalytic cracking riser term separation devices in China[J].Petrochemical Technology&Application,2007,25(2):142-146.
[6]许克家.催化裂化提升管出口快分系统的稠密相环流式预汽提器的研究[D].北京:中国石油大学.1998.XU K J.Study on dense-phase airlift loop stripper for quick separator of riser of FCC[D].Beijing:China University of Petroleum,1998.
[7]LIU M X,LU C X,SHI M X.Hydrodynamic behavior of a gas-solid air-loop stripper[J].Chinese Journal of Chemical Engineering,2004,12(1):55-59.
[8]刘梦溪,卢春喜,时铭显.单段高料位气-固稠密相环流汽提器的密度分布[J].石油化工,2002,31(10):815-819.LIU M X,LU C X,SHI M X.Particle velocity distribution in a single stage high level gas solid annular flow stripper[J].Petrochemical Technology,2002,31(10):815-819.
[9]刘梦溪,卢春喜.单段高料位气-固稠密相环流汽提器的密度分布[J].石油化工,2001,30(11):850-854.LIU M X,LU C X.Study of new kind of stripper[J].Petrochemical Technology,2001,30(11):850-854.
[10]刘梦溪,卢春喜,时铭显.两段气-固环流反应器流体动力学行为和传质特性的研究[C]//中国颗粒学会2006年年会论文集.2006:591-595.LIU M X,LU C X,SHI M X.Hydrodynamics and mass transfer characteristics of a novel two-stage gas-solid internal airlift loop reactor[C]//The Chinese Society of Particles For 2006.2006:591-595.
[11]刘显成,卢春喜,时铭显.两段气升式气-固环流取热器导流筒壁与床层间的传热特性研究[J].过程工程学报,2004,4(增刊):611-618.LIU X C,LU C X,SHI M X.Study on heat transfer between gas-solids suspension and the surfaces of two draft tubes in an airlift loop heat exchanger[J].The Chinese Journal of Process Engineering,2004,4(suppl.):611-618.
[12]张永民,卢春喜,时铭显.催化剂汽提器内气-固传质特性的研究[J].高校化学工程学报,2004,18(4):409-413.ZHANG Y M,LU C X,SHI M X.Study on the gas-solid mass transfer performance in catalyst stripper[J].Journal of Chemical Engineering of Chinese Universities,2004,18(4):409-413.
[13]张永民,卢春喜,时铭显.催化裂化新型环流汽提器的大型冷模实验[J].高校化学工程学报,2004,18(3):377-380.ZHANG Y M,LU C X,SHI M X.Large-scale cold pilot experiment on a new annular catalyst stripper for FCC units[J].Journal of Chemical Engineering of Chinese Universities,2004,18(3):377-380.
[14]林海波,孔春林.气-固循环流化床提升管颗粒速度和浓度的测量技术[J].四川轻化工学院学报,2002,15(4):28-33.LIN H B,KONG C L.Measurement techniques of solids concentration and solids velocity in circulating fluid beds riser[J].Journal of Sichuan Institute of Light Industry and Chemical Technology,2002,15(4):28-33.
[15]NIEUWLAND J J,MEIJER R,KUIPERS J A M.Measurements of solids concentration and axial solids velocity in gas-solid two-phase flow[J].Powder Technology,1996,87(2):127-139.
[16]刘会娥,余皓,魏飞,等.提升管内颗粒的微观运动行为[J].石油大学学报(自然科学版),2003,27(4):106-109.LIU H E,YU H,WEI F,et al.Micro flow behaviors of particles in riser[J].Journal of the University of Petroleum,2003,27(4):106-109.
[17]鄂承林,卢春喜,高金森,等.气-固两相流中颗粒时均速度的测量新方法[J].过程工程学报,2003,3(6):505-511.E C L,LU C X,GAO J S,et al.A new method for the measurement of solids time-averaged velocity in gas-solid two-phase flow[J].The Chinese Journal of Process Engineering,2003,3(6):505-511.
[18]JEON H J,KIM S D,KIM S J,KONG Y.Solid circulation and gas bypassing characteristics in a square internally circulating fluidized bed with draft tube[J].Chemical Engineering and Processing,2008,47:2351-2360.
[19]钱诗智,陆继东,FLAMANT G.高温气固流化床的临界流态化行为[J].燃烧科学与技术,1996,2(4):315-321.QIAN S Z,LU J D,FLAMANT G.Critical fluidization behavior of gas-solid fluidized bed at elevated temperatures[J].Journal of Combustion Science and Technology,1996,2(4):315-321.
[20]DAVIDSON J F,HARRISON D.Fluidized Particles[M].London:Cambridge University Press,1963.
[21]魏飞,金涌,俞芷青,等.磷光颗粒示踪技术在循环流态化中的应用[J].化工学报,1994,45(2):230-236.WEI F,JIN Y,YU Z Q,et al.Application of phosphor tracer technique to the measurement of solids RTD in circulating fluidized bed[J].Journal of Chemical Industry and Engineering(China),1994,45(2):230-236.
[22]王勤辉,骆仲泱,倪明江,等.循环流化床内颗粒停留时间分布[J].燃烧科学与技术,2001,7(4):221-224.WANG Q H,LUO Z Y,NI M J,et al.Particle residence time distribution in a circulating fluidized bed[J].Journal of Combustion Science and Technology,2001,7(4):221-224.