动力波湿式洗涤器的液体喷射高度及阻力损失的计算

1、动力波湿式洗涤器的液体喷射高度及阻力损失的计算李秋萍邵国兴(上海化工研究院200062)摘要 通过理论分析及试验研究 ,得出了动力波湿式洗涤器的液体喷射高度及阻力损失的计算式 ,且计算值与实测值非常接近 ,为动力波湿式洗涤器的设计及放大提供可靠依据 。关键词 动力波 湿式洗涤器 喷射高度 阻力损失湿式洗涤器是以液体 ( 通 常 为 水) 作 为 洗 涤液 ,通过气液两相的接触实现两相间的传热和传 质过程 ,以满足气体的净化 ( 除尘或吸收) 、冷却 、 增湿等要求 。70 年代美国杜邦公司成功地开发了“动力波 泡沫洗涤器”,第一套工业应用装置于 1986 年建成投产 ,目前已有数百套装置被用于

2、废酸回收 、煅 烧炉 、二氧化钛酸解槽 、硫代硫酸铵 、发烟硫酸 、硫 酸转鼓式浓缩器 、粉煤锅炉 、硅卤化物 、hcl 和氯 化镍回收等 40 多个不同的生产场合1 。上海化 工研究院于 1995 年成功地开发出了一种新型高效的 带 混 合 元 件 的 动 力 波 湿 式 洗 涤 器 , 并 在 复 (混) 肥生产系统的尾气净化及苯乙酸流化造粒系 统上取得了令人满意的应用效果 。1作用原理及结构特点动力波湿式洗涤器采用了一种独特的洗涤方图 1 带混合元件动力波湿式洗涤器结构示意1 . 水槽 2 . 混合元件 3 . 喷嘴 4 . 动力波洗涤管5 . 气体出口管 6 . 液沫分离器式 ,气体自

3、上向下高速进入洗涤管 ,洗涤液通过特殊结构的喷嘴自下向上逆向喷入气流中 ,气液两 相高速 逆 向 对 撞 。当 气 液 两 相 的 动 量 达 到 平 衡 时 ,形成一个高度湍动的泡沫区 ,气液相之间呈高速湍流状态 ,接触表面积大 ,而且接触表面不断地 更新 ,从而具有高效的洗涤效果 。带混合元件的 动力波洗涤器是在其泡沫区下部的适当位置增设 一个顺流混合元件 ,使气液两相再一次进行湍流 混合 ,起到顺流洗涤的作用 。这就在一机内实现了两级串联洗涤 ,使设备更紧凑 ,除尘效率高 ( 通 常在 99 %以上) ,且能耗低 ,其阻力损失仅为文丘 里洗涤器的一半 , 是一种新型高效湿式洗涤器 。 其

4、作用原理和结构见图 1 。26液体喷射高度的计算确定液体喷射高度是设计动力波湿式洗涤器 装置高度的主要依据 。动力波湿式洗涤器的液体喷射方式属于垂直向上的非淹没射流 。文献3 提 出了液体 (水) 从圆形断面喷嘴垂直向上射入大气 时的喷射高度的经验计算式 :2he = h/ (1 + h)(1)设射流在喷嘴出口处的总水头为 h ,射出后所能达到的喷射高度为 he ,如图 2 所示 。射流为 了克服气流阻力 , 有一部分水头损失 h 。参照 管流水头损失的公式 ,可写出 :第 28 卷化肥工业第 6 期表 1 液体的喷射高度与液体喷射速度的关系v gdov lhe实测he计算 (m/ s) (m

5、) (m/ s) (m) (m) 14. 214. 214. 214. 214. 214. 20 . 0070 . 0070 . 0070 . 0070 . 0070 . 0071 . 42 . 22 . 93 . 64 . 35 . 10. 110. 240. 320. 350. 470. 580 . 080 . 180 . 280 . 380 . 480 . 60表 2液体的喷射高度与气相速度的关系v l(m/ s)do(m)v g(m/ s)he实测(m)he计算(m)图 22he = k hev 4 . 34 . 34 . 30 . 0070 . 0070 . 0078 . 411.

6、314. 20. 660. 640. 470 . 650 . 560 . 48 h = h -(2)do 2g由于本文的喷射液体不是直接射入大气中 ,而是与气体作高速逆向对撞 ,因此上式中的 v 应 为 :表 3液体的喷射高度与喷射口直径的关系do(m)v g(m/ s)v l(m/ s)he实测(m)he计算(m)v = v l + v g(3)v20 . 00714. 25 . 80. 530 . 68l因2 g = h ,代入式 (2) 可得 : 0 . 010 14 . 2 5 . 8 0 . 88 0 . 85 v2 he v2l2g = he + k d装置的阻力损失是确定动力消耗

7、的主要依据之一 。为了正确地描述带混合元件的动力波洗涤 器的阻力损失 ,将阻力分成两部分进行分析 。先由进口至水槽 ,即冲击泡沫段及混合元件的阻力 ,用 p 表示 。其次由水槽至出口管 ,即液滴分离 器的阻力 ,用 p 表示 。因此 ,带混合元件的动力波洗涤器的阻力损失可简单地表示为 :2 go整理后得 :v22v llhe =(4)2g + kv2/ do 2g + v2式中 = k/ do ,为一系数 ,由实验确定 ,亦可按经验式进行计算 。文献3 提出的经验式如下 :0. 000 25k = =(5)p = p + p(7)do3dodo + 1 000先测定无洗涤水条件下的气流阻力 ,

8、得出 :由实验将上式修正为 : p 3 = 0. 27 gv g2/ 2(8)(9)0 . 000 25 = 0. 33 v1. 08(6) p 3 = 1. 19 v 2/ 2ldo3do + 1 000g g式 (4) 和式 (6) 即为动力波湿式洗涤器液体喷射高度的计算式 。由式 (4) 可以看出 ,液体的喷射 高度与液体喷射速度 、气相速度及喷射口直径等参数有关 。由表 1 可以看出 ,当气相速度和喷射口直径保持不变时 ,液体的喷射高度随液体喷射 速度的增大而增大 。由表 2 可以看出 ,当液体喷 射速度和喷射口直径保持不变时 ,液体的喷射高度随气相速度的增大而减小 。由表 3 可以看

9、出 ,当气相速度和液体喷射速度保持不变时 ,液体的 喷射高度随喷射口直径增大而增大 。在喷入 洗 涤 水 后 , 气 流 的 阻 力 也 随 之 增 加 。由于水槽至出口管这一段气流中仅夹带着极少量 的液沫 ,因 此 其 阻 力 损 失 为 纯 气 流 时 的 1 . 4 倍 , 即 :p = 1. 67 gv g2/ 2(10)而 p 由于洗涤水的喷入并与气流冲击形成湍流混合区 ,使阻力损失明显上升 。通过实测 数据回归分析 ,得知 p 与气流速度 、液体喷射速度以及液气比有关 ,可近似地表示为 :p = 0. 23 ( ql / qg) 0. 7 v l0. 8 v g2. 2(11)上式

10、的计算值与实测值相比非常接近 ,详见表 4 。27阻力损失的计算3 1994-2013 china academic journal electronic publishing house. all rights reserved. 第 28 卷化肥工业第 6 期表 4 p 实测值与计算结果的比较力波湿式洗涤器与喷淋塔洗涤器相比 ,具有结构紧凑 、造价低 、占地面积小等优点 。其阻力损失虽 比喷淋塔洗涤器略大 ,但其除尘效率要高得多 ,且 液沫夹带量少 ,洗涤液可以循环使用 ,减少了污水 处理量 。ql/ q g(l/ m3)v g(m/ s)v l(m/ s) p 实测(m) p 计算(m)

11、5. 008. 003. 002. 004. 005. 003. 755. 006. 675. 881. 1114. 214. 214. 214. 214. 211. 311. 38 . 48 . 49 . 819. 03 . 65 . 82 . 21 . 42 . 92 . 92 . 22 . 22 . 95 . 92 . 16771 2953241674903532261472355102946781 379320168488345226142220497291结语本文通过理论分析及实验研究得出的动力波 湿式洗涤器的液 体 喷 射 高 度 及 阻 力 损 失 的 计 算 式 ,其计算值与实

12、测值非常接近 ,可为动力波湿式洗涤器的设计及放大提供可靠依据 。参考文献51中国化工学会无机酸碱盐学会 ,化工部硫酸工业科技情报中心站编译. 孟山都环境化学公司技术交流材料 ,1992 ,10 邵国兴. 带混合元件的动力波洗涤器. 硫酸工业 ,1999 , (2) 闻德荪主编. 工程流体力学 ( 水力学) : 下册. 高等教育出版社 ,1991吴明山 ,王禄宝. 智能化喷浆造粒生产尿基复合肥. 化肥工业 ,2001 , (2) :5254符号说明do 喷射口直径 ,md 洗涤管直径 ,m g 9 . 81 m/ s2h 射流在喷嘴出口处的总水头 ,mhe 液体喷射高度 ,mp 动力波湿式洗涤器

13、的阻力损失 ,pap 动力 波 湿 式 洗 涤 器 的 冲 击 泡 沫 段 5 . 53 17 . 0 9 . 5 2 296 2 349 234应用实例在江苏环太集团公司的 10 万 t/ a 高浓度 npk4尿基复合肥生产系统中 ,尾气净化选用了带混合元件 的 动 力 波 湿 式 洗 涤 器 , 处 理 风 量 为 15 000 m3/ h ,洗涤管直径为 650 ,使用效果良好4 。将上述结果应用于该工业装置的设计 ,其计 算结果如下 :处理风量 qg = 15 000 m3/ h 洗涤管直径 d = 0 . 65 m 液体喷射量 ql = 40 000 l/ h 喷射口直径 do =

14、0 . 045 m 15 000 气流速度 v g =及混合元件的阻力损失 ,pap 动力 波 湿 式 洗 涤 器 的 液 滴 分 离 段的阻力损失 ,pa3 600 0 . 785 0 . 652= 12 . 56 (m/ s)= 40 液体喷射速度 v l3 600 0 . 785 0 . 0452= 7 (m/ s)p 3 、p 3 无洗涤水及无混合元件条件下的冲击泡沫段及液滴分离段的阻力损失 ,paql 液体喷射量 ,l/ hqg 气体流量 ,m3/ hv g 气体 在 进 口 冲 击 管 及 出 口 管 中 的 流 速 ,m/ sv l 液体喷射速度 ,m/ s 系数根据式 (6)

15、得 = 0 . 005根据式 (4) 得 he = 2 . 3 m即液体的喷射高度为 2 . 3 m ( 设计中动力波 洗涤器的洗涤管高度为 4 m) 。由式 (11) 得 pl = 567 pa由式 (10) 得 p = 144 pa则该动力波洗涤器的阻力损失为 :p = p + p = 567 + 144 = 711 ( pa)由上述计算结果可以看出 ,带混合元件的动3g 气体密度 ,kg/ m(收到修改稿日期2001 - 09 - 11)28 1994-2013 china academic journal electronic publishing house. all rights

16、reserved. journal of the chemical fertil izer industryvol . 28no . 62001 ( serial no . 167)technology f or production of ammoniumbicarbonate fertilizerkong xianglinabstract the history of development is viewed in retrospect of the industrial production technology for ammonium bicarbonate from the fi

17、rst demonstration unit prepared for setting up at shanghai research institute of chemical industry in march 1958 , and its contribution to the state andpeople is summarized.of the effect of these process parameters. the suitable process conditions are :reaction temperature of 0 5 , inital ammonia co

18、ncentration of30 %36 % , mass ratio of aqua ammonia to gypsum of about 91 , and mass ratio of kcl to gypsum of 1 . 11 . under these conditions the conver2 sion of cao is close to 90 % , product purity higher than 70 % , and thecrude product may be further purified by crystallization.key words gypsum

19、 aqua ammonia potassium sulfate pocess conditions studysum2key words ammonium bicarbonate production technologyproduction of non2homogeneous urea2ba sedcompound fertilizers by fluidized granulationli tianwen , fei weiyang et al .abstract a brief account is given of the development of a new pro2 cess

20、 for the production of high2analysis non2homogeneous urea2based com2 pound fertilizers by fluidized granulation and the experimental work. the results show that monoammonium phosphate , diammonium phosphate , sin2 gle superphosphate or triple superphosphate may be used as raw materials to produce ur

21、ea2based compound fertilizers and the nutrient content may be adjusted in line with the demand of the users. urea2based compound fer2 tilizers made by spraying molten urea onto single or triple superphosphate granules can prevent hygroscopicity.key words urea2based compound fertilizers fluidized gra

22、nulationnon2homogeneousmaryevaluation of retrof it of large andmedium ammonia plants in china withshell pulverized coal pressurega sif ication technology ( part )l u zhengtaoabstract the reliability is analyzed in the operation of a shell pul2 verized coal gasifier , an explanation is given of the p

23、lans for retrofitting tongting nitrogenous fertilizer plant and liuzhou nitrogenous fertilizer plant with the shell pulverized coal gasification technology , and a compar2 ison is made of the investment in retrofit with the texaco gasification tech2nology.key wordscomparisonpulverized coal gasificat

24、ion technology shell texacodetermination of emission rate of fluorineduring eva poration of acidic ammoniumphosphate slurrytang s hengwei , liu daijun , yingjiankang and liang binabstract a determination is made of the relationship of the emis2 sion rate of fluorine during the evaporation of acidic

25、ammonium phosphate slurry with the degree of neutralization and water content . the results in2 dicate that the emission rate of fluorine increases with a decrease in water content and degree of neutralization. when the degree of neutralization is below 0 . 4 , the emission rate of fluorine is high

26、, so the effect of the de2 gree of neutralization is evident , and when the degree of neutralization ex2 ceeds 0 . 6 , the emission rate is low.key words acidic ammonium phosphate slurry fluorine emissionrate determinationdds desulf urization technology and its usewei xionghui , wang xiangyun and li

27、u xinqiabstract the mechanism is discussed of desulfurization and co2 removal by the dds catalyst , a relevant mathematical model is estab2 lished , and it is verified through experiments that the model can fully guide industrial design. actual operation results indicate that the new technology of d

28、ds desulfurization has been used in a number of ammonia plants with success for the desulfurization of shift effluent gas and semi2 water gas , its desulfurization result and comprehensive economic benefit being better than those of the traditional wet desulfurization technology.key words dds cataly

29、st desulfurization mechanism mathe2matical modelstudy of process conditions of pota ssiumsulfate production by gypsum conversion in concentrated ammonia mediuml u hong , liu daijun , yang linjun et al .abstract an experimental study is made of the regular pattern of the effect of such important para

30、meters as the initial ammonia concentra2 tion , reaction temperature , liquid2solid ratio and ratio of gypsum in excess in the manufacture of potassium sulfate by direct conversion of gypsum and potassium chloride in concentrated ammonia medium , and through linearregressive treatment of the experim

31、ental results a kinetic analysis is madecalculation of height of l iquid sprayfrom dyna mic wave wet scrubber and resistance lossli qiuping and s hao guoxingabstract through theoretical analysis and experimental study a for2 mula is found for the calculation of the height of liquid spray from the dy

32、2 namic wave wet scrubber and the resistance loss , and the calculated value and the measured value are very close , thereby providing a reliable basis for its design and scale2up .59 1994-2013 china academic journal electronic publishing house. all rights reserved. journal of the chemical fertil iz

33、er industryvol . 28no . 62001 ( serial no . 167)key words dynamic wave wet scrubber spray height resis2tance lossmum conditions are found as follows : sample mass 5 g ,heating voltage 220v , and heating time 80 min. this method has the characteristics of conve2 nient operation , quickness , and accu

34、racy , so it is able to act as a timely guidance in production.key words quick moisture apparatus moisture content ammoni2um nitrateinquiry into ne w process f or purif icationand recovery of ta il ga s from yello w phosphorusmanufacturewei xiqun , zheng caiping , zhang jie et al .abstract in connec

35、tion with the present drawbacks of the conven2 tional purification method of tail gas from yellow phosphorus manufacture , a new process flow is proposed , and an experimental study is made of the key steps in the new process.key words yellow phosphorus tail gas purification pressureswing adsorption

36、use of ca pacitance l iquid level indicatorand its reva mpzhou fengabstract the causes for the damage of the capacitance level indi2 cator are analyzed , and in line with its working principle and configuration it is revamped accordingly. then it is put into operation , and it works steadily and acc

37、urately , with good results.key words capacitance liquid level indicator use revampdiscussion on urea interference in determinationof organics in organo2mineralcompound fertilizersfan bin and liu gangabstract in the determination of organics in organo2mineral com2 pound fertilizers by titration with

38、 potassium bichromate , suitable conditions for determination are defined through experimentation so as to overcome urea interference : the concentration of potassium bichromate solution is0 . 8 mol/ l , the quantity used is 5 ml , the quantity of concentrated sulfu2ric acid used is 5 ml , and the d

39、igestion time and temperature are 15 min and 100 , respectively.trial burning of coal briquets ma de withtype z2m adhesiveli yonghengabstract jiangxi no . 2 chemical fertilizer plant burned on trial coal briquets made with type z2m adhesive in its 3 200 coal gasifier and obtained preliminary success

40、 , thereby opening up a new prospect for the use of coal briquets in medium2scale plants. type z2m adhesive is a new type successfully developed recently , and its technical indications in every respect prove its usability and its being at an advanced stage .key words type z2m adhesive coal briquets

41、 technical charac2teristicskey words organic carbonoxidation by potassium bichromateorgano2mineral compound fertilizers interferenceextension of service l ife of wa ste heat boilerin sulf uric acid production and improvement on economic benef it of enterpriseliang jianhai et al .abstract the working

42、 environment for the waste heat boiler in sul2 furic acid production is very poor and the heated tube surface is liable to cause leakage from burst or perforation of the tubes due to corrosion and abrasion. by taking preventive measures to reduce corrosion of the heated tube surface at high and low temperatures , prevent ashes from depositing in the flue and control the p