Jet characteristics of nozzle of pipe grid gas distributor in FCC regenerator

doi:10.11949/j.issn.0438-1157.20170999

Abstract

Abstract:

In the catalytic cracking unit, the bottom of the regenerator is equipped with a pipe grid gas distributor. The gas is distributed into the regenerator bed through the nozzles on the distributor. In the actual operation, there will be problems of uneven distribution of gas and a serious erosion wear phenomenon in the distributor, and they have influences on the distribution effect and life of the distributors. The study on the jet characteristics of the nozzle was carried out in a two-dimensional bed experimental device. The solid material used in the experiment is FCC catalyst particles. In the experiment, the gas flow velocity through the nozzles ranged from 30 m·s^-1 to 70 m·s^-1, and the jet angle of the nozzles was in the range of 0°-67.5°. The jet length of the nozzles and the flow field of the bed near the nozzle were recorded by photogrammetry. The results show that the jet length increases with increasing the nozzle gas velocity and the nozzle angle. During the process when jet gas is turned upwards, swirl vortex appears in the upper part between the two branch pipes. The swirl vortex has a great relationship to the gas velocity and the jet angle. The size of the vortex is related to the size of the dilute phase space. Finally, based on the experimental data, a calculation model about the nozzle jet length was established.

Key words: catalytic cracking, gas distributor, nozzle, jet characteristics, jet length

摘要：

在催化裂化装置中再生器底部通常设置有树枝状管式气体分布器，通过分布器上的喷嘴分布气体。但在实际运行过程中喷嘴常出现布气不均和磨损问题，影响其自身的布气性能和使用寿命。为此，在二维床实验装置上针对喷嘴的射流特性进行了实验研究。实验物料为FCC催化剂颗粒，喷嘴出口气速范围为30～70 m·s^-1，喷嘴喷射角度范围为0°～67.5°。实验用摄影观察法测量喷嘴射流的射流长度和附近的流场流态。实验结果表明射流长度随喷嘴气速和喷射角度的增大而变长。射流气体在向上翻转过程中，在树枝状管式气体分布器两分支管之间产生旋转涡流现象，旋转涡流的大小与喷嘴出口气速和安装角度有密切关系。最后基于实验数据，建立了喷嘴射流长度的计算模型。

关键词: 催化裂化, 气体分布器, 喷嘴, 射流特性, 射流长度

CLC Number:

TQ05

SHI Ruijie, WANG Chuangbo, MA Ling, YAN Chaoyu, WEI Yaodong. Jet characteristics of nozzle of pipe grid gas distributor in FCC regenerator[J]. CIESC Journal, 2018, 69(2): 655-663.

石睿捷, 王创博, 马玲, 严超宇, 魏耀东. 催化裂化再生器树枝状气体分布器喷嘴的射流特性[J]. 化工学报, 2018, 69(2): 655-663.

References 31

[1]	陈俊武. 催化裂化工艺与工程[M]. 北京:中国石化出版社, 2005:548-558. CHEN J W. Catalytic Cracking Process and Engineering[M]. Beijing:China Petrochemical Press, 2005:548-558.
[2]	杨光福, 孙文勇. 重油催化裂化装置再生器主风分布器的磨损及其危害分析[J]. 安全, 2010, 31(10):11-14. YANG G F, SUN W Y. Wear and damage analysis of main wind distributors of regenerator in heavy oil catalytic cracking unit[J]. Safety, 2010, 31(10):11-14.
[3]	李晓曼, 万古军, 魏耀东. FCC装置主风分布管喷嘴磨损的气相流场分析[J]. 炼油技术与工程, 2006, 36(6):13-16. LI X M, WAN G J, WEI Y D. Analysis of the gas-phase flow field for the erosion of nozzle of pipe distribution in FCCU[J]. Petroleum Refinery Engineering, 2006, 36(6):13-16.
[4]	万古军, 魏耀东, 时铭显. 催化裂化再生器树枝状主风分布管磨损的气相流场分析[J]. 炼油技术与工程, 2006, 36(3):21-24. WAN G J, WEI Y D, SHI M X. Analysis of gas-phase flow field for erosion of FCC dendritic main air pipe distributor[J]. Petroleum Refinery Engineering, 2006, 36(3):21-24.
[5]	徐俊, 秦新潮, 李晓曼. 流化床管式分布器内流场模拟和布气性能分析[J]. 化工学报, 2010, 61(9):2280-2286. XU J, QIN X C, LI X M. Flow field simulation and distribution performance analysis of a gas pipe distributor in fluidized bed[J]. CIESC Journal, 2010, 61(9):2280-2286.
[6]	李海滨, 王洋. 流化床中侧向射流穿透深度的研究[J]. 化学反应工程与工艺, 1995, 11(2):198-202. LI H B, WANG Y. Inclined jet penetration length in fluidized bed[J]. Chemical Reaction Engineering and Technology, 1995, 11(2):198-202.
[7]	洪若瑜, 李海滨, 王洋. 气固流化床中侧向射流穿透深度的研究[J]. 化工冶金, 1996, 17(2):132-137. HONG R Y, LI H B, WANG Y. Study on the inclined jet penetration length in a gas-solid fluidized bed[J]. Engineering Chemistry & Metallurgy, 1996, 17(2):132-137.
[8]	唐楠. 喷动流化床流动特性数值模拟[J]. 洁净煤技术, 2012, 18(5):60-64. TANG N. Numerical simulation on flow characteristics of spouted-fluidized bed[J]. Clean Coal Technology, 2012, 18(5):60-64.
[9]	王其威, 裴培, 张锴, 等. 气固流化床内射流特性的研究[J]. 燃料化学学报, 2007, 35(3):354-358. WANG Q W, FEI P, ZHANG K, et al. Numerical simulation of jetting characteristics in a gas-solid fluidized bed[J]. Journal of Fuel Chemistry and Technology, 2007, 35(3):354-358.
[10]	SAURIOL P, CUI H, CHAOUKI J. Gas jet penetration lengths from upward and downward nozzles in dense gas-solid fluidized beds[J]. Powder Technology, 2013, 235(2):42-54.
[11]	AWORINDE S M, HOLLAND D J, DAVIDSON J F. Investigation of a swirling flow nozzle for a fluidized bed gas distributor[J]. Chemical Engineering Science, 2015, 132:22-31.
[12]	周亚明, 沈湘林. 二维流化床内垂直向上射流影响区的试验研究[J]. 煤炭转化, 2001, 24(3):29-32. ZHOU Y M, SHEN X L. Investigation of the jet-influenced area of a vertical jet in two-dimensional fluidized bed[J]. Coal Conversion, 2001, 24(3):29-32.
[13]	周亚明, 沈湘林. 二维流化床内射流深度的试验研究[J]. 锅炉技术, 1999, (4):1-5. ZHOU Y M, SHEN X L. An experimental investigation of the jet penetration depth in a two-dimensional fluidized bed[J]. Boiler Technology, 1999, (4):1-5.
[14]	周亚明, 刘海滨, 沈湘林. 二维流化床内水平射流横向脉动特性的研究[J]. 东南大学学报(自然科学版), 1999, 29(3):120-129. ZHOU Y M, LIU H B, SHEN X L. Research on lateral fluctuations of horizontal jet in a two-dimensional fluidized bed[J]. Journal of Southeast University(Natural Science Edition), 1999, 29(3):120-129.
[15]	GELDART D, BAEYENS J. The design of distributors for gas-fluidized beds[J]. Powder Technology, 1985, 42(1):67-78.
[16]	CUI H, GRACE J, MCKNIGHT C, et al. Jet configuration for improved fluidized bed stripping[J]. Chemical Engineering Journal, 2006, 125(1):1-8.
[17]	陈伟博, 李俊国, 程中虎, 等. 气固流化床中倾斜分布板上射流深度的研究[J]. 化学反应工程与工艺, 2014, 30(1):11-14. CHEN W B, LI J G, CHENG Z H, et al. Study on jet penetration length in a gas-solid fluidized bed with inclined distributor[J]. Chemical Reaction Engineering and Technology, 2014, 30(1):11-14.
[18]	陈永国, 田子平, 缪正清, 等. 图像处理在二维循环流化床瞬态射流长度测量中的应用[J]. 锅炉技术, 2004, 35(3):10-13. CHEN Y G, TIAN Z P, MIAO Z Q, et al. Measure of transient jet length based on image processing in circulating fluidized bed[J]. Boiler Technology, 2004, 35(3):10-13.
[19]	金涌, 俞芷青, 孙竹范, 等. 流化床多管式气流分布器的研究(Ⅱ):分布器设计参数的确定[J]. 化工学报, 1984, 35(3):203-213. JIN Y, YU Z Q, SUN Z F, et al. Investigations on branched pipe distributors for fluidized beds(Ⅱ):Determination of design parameters for branched pipe distributors[J]. Journal of Chemical Industry and Engineering(China), 1984, 35(3):203-213.
[20]	金涌, 夏光. 流化床管式分布器的研究[J]. 过程工程学报, 1982, (3):67-72. JIN Y, XIA G. Investigations on branched pipe distributors for fluidized beds[J]. The Chinese Journal of Process Engineering, 1982, (3):67-72.
[21]	孙竹范, 金涌, 汪展文, 等. 流化床中多管式气体分布器的研究[J]. 食品科学技术学报, 1984, (1):3-10. SUN Z F, JIN Y, WANG Z W, et al. Investigation on branched pipe distributors for fluidized beds[J]. Journal of Beijing Institute of Light Industry, 1984, (1):3-10.
[22]	EMAMI A, BRIENS C. Study of downward gas jets into a liquid[J]. AIChE Journal, 2008, 54(9):2269-2280.
[23]	MERRY J. Penetration of vertical jets into fluidized beds[J]. AIChE Journal, 1975, 21(3):507-510.
[24]	HONG R Y, LI H B, et al. A correlation equation for calculating inclined jet penetration length in a gas-solid fluidized bed[J]. Particuology, 2005, 3(5):279-285.
[25]	郭庆杰, 张济宇, 刘振宇. 流化床射流深度的研究[J]. 煤炭转化, 1999, 22(3):15-21. GUO Q J, ZHANG J Y, LIU Z Y. The penetration depth in the gas-solid fluidized bed[J]. Coal Conversion, 1999, 22(3):15-21.
[26]	郭庆杰, 张济宇, 刘振宇. 双射流流化床流动特性的研究[J]. 燃料化学学报, 1999, 27(6):535-540. GUO Q J, ZHANG J Y, LIU Z Y. Flow characteristics in jetting fluidized bed with double nozzles[J]. Journal of Fuel Chemistry and Technology, 1999, 27(6):535-540.
[27]	司崇殿, 郭庆杰. 不同种类颗粒射流流化床的射流深度[J]. 青岛科技大学学报(自然科学版), 2007, 28(2):129-133. SI C D, GUO Q J. Jet penetration depth in a fluidized bed of different particles[J]. Journal of Qingdao University of Science and Technology(Natural Science Edition), 2007, 28(2):129-133.
[28]	钟文琪, 章名耀. 喷动流化床射流穿透深度试验研究[J]. 东南大学学报(自然科学版), 2005, 35(1):29-34. ZHONG W Q, ZHANG M Y. Experimental investigation on jet penetration depth in spout-fluid bed[J]. Journal of Southeast University(Natural Science Edition), 2005, 35(1):29-34.
[29]	罗国华, 张济宇. 多组分射流床中的射流深度[J]. 化工学报, 1996, 47(1):91-99. LUO G H, ZHANG J Y. The jet penetration depth in a fluidized bed of multi-component particles[J]. Journal of Chemical Industry and Engineering(China), 1996, 47(1):91-99.
[30]	肖卓楠, 赵增武, 武文斐, 等. 循环流化床锅炉风帽射流深度实验研究[J]. 内蒙古科技大学学报, 2010, 29(3):263-266. XIAO Z N, ZHAO Z W, WU W F, et al. Experiment on penetration depth nozzle jets of circulating fluidized bed boiler[J]. Journal of Inner Mongolia University of Science and Technology, 2010, 29(3):263-266.
[31]	陈虎魁. 流化床中下喷射流穿射深度研究[J]. 宝鸡文理学院学报(自然科学版), 1997, 17(3):40-46. CHEN H K. Penetration depth of a downwards jet in fluidized bed[J]. Journal of Baoji College of Arts and Science(Natural Science), 1997, 17(3):40-46.