共查询到19条相似文献,搜索用时 78 毫秒
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文章在喷淋实验塔中,研究了氨法烟气脱硫的特性。将空气和气态二氧化硫按一定比例混合后的气体作为模拟烟气,用氨水作为脱除二氧化硫的吸收剂,对模拟烟气的进气温度、进气浓度、气速、液气比以及吸收液的pH五个因素对脱硫率的影响进行了逐一考察,获得了各因素与脱硫率之间的关系,并得到较适宜的操作参数。实验结果表明:随着液气比和吸收液pH的增大,脱硫率增大。随着模拟烟气进气温度、进气浓度和气速的增大,脱硫率降低。其中温度因素对脱硫率的影响不明显。实验得到适宜的操作参数为:常温下,模拟烟气气速为2.0m/s,液气比为10,pH为6.4时,对浓度为2000mg/m^3的烟气操作,收率可维持在85%以上,并在理论上对各因素和脱硫率之间的内在联系作了理论分析。 相似文献
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近年来氨法脱硫以其低投入,脱硫率高以及有价值的副产物越来越受到重视。今以并流式湿壁塔脱硫实验装置为例,以氨水作为吸收液,在20℃和常压下研究了氨法烟气脱硫的气液传质与化学反应过程,并且在伴有快速的化学反应吸收的双膜理论的基础上,建立了数学模型。利用该模型对并流式湿壁塔氨法脱硫过程进行了模拟,分析了吸收液pH值、液气比、吸收液浓度、烟气流速以及初始SO2浓度对脱硫效率的影响,并与实验结果进行了对比。结果表明:在进气浓度为2500 mg·m·3时,最佳的工艺条件为液气比为2.2~2.8 L·m·3,吸收液pH值为5.8~6.5,烟气流速为1.5~2.5 m·s-1;该模型的计算值与实验数据基本吻合,为氨法烟气脱硫的工业化应用提供了理论参考。 相似文献
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喷淋塔氨法脱硫技术被广泛应用于净化烟气的SO2,传质系数是喷淋吸收塔重要的设计和运行参数,但目前文献中有关氨法脱硫传质系数的报道很少,还有待进一步研究。在喷淋塔中对氨法脱硫SO2吸收传质过程进行了实验研究,结合对液滴和塔壁液膜运动的计算,得到不同实验条件下SO2的吸收传质速率,并建立了氨法脱硫SO2吸收传质系数表达式。该传质系数包含浆液pH、烟气流速ug和液气比L/G等主要参数,能够反映不同pH、ug和L/G条件下SO2在单位气液接触面积上的传质速率。对比验证结果表明,该传质系数计算得到的SO2吸收传质速率与实验值之间的相对误差小于±12%,二者能够较好地吻合。建立的传质系数表达式能够为喷淋塔氨法脱硫的优化设计和运行提供理论参考。 相似文献
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氨法烟气脱硫技术具有脱硫效率高、无二次污染、副产品资源化程度高等优势,而存在的氨损耗和亚铵氧化等问题却长期制约其推广应用。针对这一问题开发的多功能脱硫塔,从设备和工艺两方面综合考虑,基本解决了这一问题,以此为核心的脱硫系统在260 t/h循环流化床锅炉烟气脱硫工程运行三年多表明,该系统脱硫效率达95%~99%,尾气中SO2含量在50~190 mg/m3;副产硫铵满足国家标准。 相似文献
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烟气脱硫喷淋塔的数值模拟 总被引:1,自引:0,他引:1
以计算流体力学为基础,在三维坐标系下采用标准k-ε双方程模型求解动量、能量和组分方程,结合浆滴蒸发模型及简化的浆滴脱硫反应模型,以Eu ler-Lagrange方法建立了喷淋塔内烟气脱硫的数值计算模型,模型计算结果与孔华的试验数据符合较好。模型计算结果表明,对于粒径小的喷淋液滴,其烟气脱硫反应和液滴蒸发主要发生在烟气进口附近,而随着液滴粒径的增大,液滴在塔内蒸发和脱硫反应的过程延长。同时,增加烟气温度、降低烟气中SO2的入口质量浓度以及增加液气比均有利于提高脱硫效率。文中模型相对于一维柱塞流模型,能够直观地显示出喷淋塔内的流场、温度场和组分质量浓度场的空间分布。 相似文献
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Jie Zhu Zhenhua Liu Jie Bai Yunfeng Yang Qin Peng Shichao Ye Mingzhe Chen 《Korean Journal of Chemical Engineering》2016,33(1):63-72
We did an experimental study on ammonia absorption in a spray tower. The kinetic characteristics of droplets were investigated by considering the forces acting on a droplet. The gas-phase mass transfer coefficient was deduced with the Colburn analogy method. A simplified model for predicting NH3 capture with a spray tower has been presented based on mass transfer and ionic equilibrium, which was successfully validated against experimental data. The influences and the sensitivity analysis of main operating parameters on the absorption efficiency were analyzed. As the most sensitive parameter, the mean droplet diameter was obtained by fitting experimental data with an empirical correlation. The distributions of two typical process parameters along the absorber were also simulated. Decreasing the pH value of absorbent is an effective but restrictive way to strengthen the mass transfer rate on account of insufficient liquid-side resistance. 相似文献
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介绍了组合式除雾脱硫塔在烟气脱硫项目中的应用情况.重点介绍了组合式除雾脱硫塔的设备结构和运行优势.该脱硫塔将一段电除雾器通过法兰连接在脱硫塔的上部,通过电除雾器对烟气中的烟尘、酸雾、及砷、铅等有害杂质进行深度净化,以达到满足环保排放指标的目的.该脱硫塔可节约设备占地面积,节省投资成本. 相似文献
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Muzammil Ali Peter John Heggs Mojtaba Ghadiri Andrew Bayly Hossein Ahmadian 《Drying Technology》2017,35(3):281-299
A steady-state, three-dimensional, multiphase computational fluid dynamics (CFD) modeling of a pilot-plant countercurrent spray drying tower is carried out to study the drying behavior of detergent slurry droplets. The software package ANSYS Fluent is employed to solve the heat, mass, and momentum transfer between the hot gas and the polydispersed droplets/particles using the Eulerian–Lagrangian approach. The continuous-phase turbulence is modeled using the differential Reynolds stress model. The drying kinetics is modeled using a single-droplet drying model, which is incorporated into the CFD code using user-defined functions (UDFs). Heat loss from the insulated tower wall to the surrounding is modeled by considering thermal resistances due to deposits on the inside surface, wall, insulation, and outside convective film. For the particle–wall interaction, the restitution coefficient is specified as a constant value as well as a function of particle moisture content. It is found that the variation in the value of restitution coefficient with moisture causes significant changes in the velocity, temperature, and moisture profiles of the gas as well as the particles. Overall, a reasonably good agreement is obtained between the measured and predicted powder temperature, moisture content, and gas temperature at the bottom and top outlets of the tower; considering the complexity of the spray drying process, simplifying assumptions made in both the CFD and droplet drying models and the errors associated with the measurements. 相似文献
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介绍了威顿(中国)达州化工有限责任公司改造后氨水配制的工艺流程和操作方法。改造后,氨水配制过程中氨水槽温度较原工艺降低,内部气压较低,不会发生氨水槽液封被冲破、大量氨逃逸至脱硫塔的现象;中控室远程控制配制氨水,操作人员不用现场操作,避免了因液氨泄漏造成人员伤害事故的发生。 相似文献
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