湿法烟气脱硫喷嘴雾化特性研究

通过大量系统的试验,从喷嘴体积流量、雾化粒径、雾化角、雾化粒度分布等方面对空心锥旋流喷嘴、螺旋喷嘴和实心锥喷嘴的雾化性能进行了详细的比较和分析，为湿法烟气脱硫工作中喷嘴的选型提供了依据。     

脱硫离心喷嘴雾化特性的研究

根据动量守恒原理，分析了脱硫离心喷嘴的结构参数与喷嘴雾化特性(流量系数、喷雾角等)之间的关系。建立了相应的无粘理论计算模型。将理论计算结果与实验数据进行比较，表明该无粘理论计算模型对脱硫喷嘴雾化特性的研究具有一定的参考价值。     

压力式喷嘴在湿法烟气脱硫中的应用

从压力式喷嘴的结构特点、雾化特性及影响因素出发。系统叙述了压力式喷嘴的研究历史与现状。结合湿法脱硫工艺的特点，阐述了压力式喷嘴在湿法脱硫中的应用。并分析了当前的研究状况。     

某燃煤电厂锅炉除尘器“电改袋”后问题的数值模拟分析

针对某燃煤电厂除尘器“电改袋”后运行中出现的设备阻力较高、滤袋破损、收尘灰斗灰量不均匀问题进行分析.采用数值模拟分析方法对除尘器内部的气流组织进行模拟试验研究,结合现场实际设备建立了物理模型,对除尘空间颗粒物沉积进行了理论分析,结果表明进入除尘器的颗粒物(200 μm以下)沉降速度低于1.5 m/s.把含尘气体近似为气相气流,采用Realizable κ-ε紊流模型进行该袋式除尘器除尘空间流场计算,结果表明除尘区中间气流平均上升速度达到1.0 m/s,在该上升气流作用下大部分颗粒物难以自然沉积是造成阻力增大的主要原因之一；采用长流程设计除尘空间会造成袋底下部空间的气流速度较大,前大后小,平均相差达到4倍左右,造成滤袋收尘量后移,它是造成滤袋破损和阻力升高的主要原因；各仓室流量分配相差11％～13％及各仓室滤袋流量分配不均容易造成局部滤袋破损几率增高.     

燃油加热炉布袋除尘器工艺设计及袋室气流分布研究

针对燃油加热炉的冒黑烟问题,开展烟气除尘技术研究.在分析燃油烟气特性的基础上,进行加热炉的袋式除尘器工艺设计.使用计算流体力学软件对除尘器内流场均匀性进行模拟分析,计算出袋室内截面的压力和气流速度分布.结果显示,除尘器内的压力和速度在不同部位显示出明显的非均匀性,袋室内布袋的排列方式和灰斗的结构是影响气流均匀性的重要因素.提出改善袋室内气流分布均匀性的措施.     

烟气脱硫喷淋塔流体力学特性研究

研究了喷淋空塔内烟气流速、液气比和吸收区高度等因素对气相阻力的影响,并在实验研究的基础上建立了喷淋塔流体力学数学模型,讨论了烟气流速、液滴直径等工艺参数对液滴停留时间、吸收区阻力和塔内传质面积的影响。     

陶粒填料生物滴滤塔处理二甲苯废气

以两种不同的陶粒作为生物滴滤床填料净化二甲苯废气,研究了喷淋液量、气体流量、进气负荷、喷淋液中氨氮浓度及填料层高度对净化效率的影响,并对两种填料的使用效果进行了对比。结果表明：二甲苯废气进气流量越小、进气负荷越低,净化效果越好;充足的氮源是高净化率的保证;对于较高浓度的废气,需要适当增加填料层高来达到净化要求;使用具有比表面积大的陶粒作为填料,可以使设备挂膜时间更短、能耗更低,净化效率更高。     

湿式静电除尘器流场的数值模拟与优化设计

湿式静电除尘器流场的分布对烟气深度净化具有重要意义，采用CFD数值模拟方法对某项目600MW燃煤发电机组湿式静电除尘器的内部流场设计进行了研究分析。结果表明，流量分配和气流整流是内部流场的两个关键设计要点。有关流量分配的设计需在确保各电场流量分配均匀的同时不明显增加烟风系统阻力，而气流整流的设计方案可同时运用气流均布板和整流格栅，此设计方案不仅可降低整套整流方案的压损，还有利于整流方案的标准化设计和现场优化调整，提高装置可靠性。     

烟气脱硫系统的吸收塔及停留时间

介绍了烟气脱硫系统中三种主要的吸收塔类型,及烟气在吸收塔中停留时间和喷淋吸收区高度的计算方法。简述了液气比与气速、烟气中SO2含量的关系,并列举了喷淋塔、动力波塔和平流塔等工程实例。     

用生物滴滤塔净化苯乙烯废气

用内部填充有陶粒的生物滴滤塔净化苯乙烯废气，考察了气体流量、液体喷淋量及氮源对苯乙烯废气净化效果的影响。，进口苯乙烯质量浓度为300～4500mg／m^3时，气体流量和进FI苯乙烯质量浓度对苯乙烯的去除率影响显著，当气体流量为0．3m^3／h时，苯乙烯去除率达87％以上。实验结果表明：在气体流量为0．9m^3／h时，液体喷淋量对苯乙烯废气的净化效果影响不明显；降低进口苯乙烯质量浓度和增大生物滴滤塔的有效传质面积，有利于苯乙烯的净化；用浓度为0.0017mol／L的NaNO3作氮源时苯乙烯的去除效果优于用NH4Cl作氮源时苯乙烯的去除效果。     

油田高含盐污水雾化蒸发的数值模拟

基于FLUENT软件,对油田高含盐污水的雾化蒸发过程进行了数值模拟,得到了逆流型雾化蒸发塔内的流场分布特性,对比分析了不同操作参数对蒸发效果的影响。结果表明:液滴蒸发速率沿塔体中心轴线自上而下呈加快趋势;进口空气流速与温度是影响液滴蒸发的关键操作参数,提高流速及温度均可加快液滴的蒸发速率;当进口空气流速达到0.4 m/s后,对蒸发速率的影响减弱;当进口空气温度达到313 K后,对蒸发速率的提高作用不大;喷雾锥角的变化对蒸发速率影响不明显;液滴越细化,蒸发速率越快。     

湿法脱硫技术关键问题研究

针对我国烟气脱硫存在的实际问题,研究了湿法脱硫关键技术,如多孔板环面积、层数、安装角度、孔径及开孔率,喷淋塔压力降特性等。解决了湿法烟气脱硫过程中关键问题,实现了除雾器的国产化,优化了物料分配技术,降低了脱硫石膏含水率,形成了一整套具有自主知识产权的湿式高性能脱硫技术,并成功应用于多个燃煤电厂商用脱硫工程,取得了显著的经济效益和社会效益。     

Field performance of a fan‐driven spray evaporator

An emerging evaporation technology uses a powerful axial fan and high‐pressure spray nozzles to propel a fine mist into the atmosphere at high air and water flow rates. Commercial units have been deployed at several locations in North America and worldwide since the mid‐1990s, typically in arid or semiarid climates. A commercial spray evaporator was field tested at the U.S. Department of Energy's Savannah River Site in South Carolina to develop quantitative performance data under relatively humid conditions. A semiempirical correlation was developed from eight tests from March through August 2003. For a spray rate of 250 L/min (66 gpm) and continuous year‐round operation at the Savannah River Site, the predicted average evaporation rate is 48 L/min (13 gpm). © 2006 Washington Savannah River Company     

冲天炉烟气除尘

采用湿法除尘,在烟气管道内设置喷嘴,使烟气充分加湿和降温后再进入立式文丘里,旋流析除尘器,消除了ＣＯ爆炸危险,在冲天炉上部烟囟顶端设安全２盖板,以保证生产的正常进行;烟气经湿式除尘后达到排放标准。     

Fly ash scrubbing in a novel dual flow scrubber

Scrubbers are used as particulate emission control devices with the increase in stringency of old regulations or promulgation of new regulations. Scrubbing of fly ash in a novel dual flow scrubber, i.e., one water filled bubble section and one section with water-spray, is reported in this article. The presented system included a tapered section in order to achieve the bubble regime. On the other hand, a two-phase critical flow atomizer was used for the generation of spray regime with high degree of spray uniformity. Experiments were carried out for studying the behavior of the system in terms of various pertinent variables. The fly ash removal mechanism was explained in terms of various physical interactions. Electrostatic effect was found to have an insignificant influence on the collection efficiency of fly ash. The removal efficiency was found to decrease with the increase in inlet fly ash loading in the bubble section while it was increased in the spray section. A compromise must, therefore, be struck while operating the scrubber for achieving the desired performance. The effects of other operating variables studied on the removal efficiency remained similar in the regimes under investigation. The combined effect was, however, that the spray regime was dominating. Experimentation also revealed that the bubble section collected particles down to 20 microm size. Detailed experimentation revealed that almost 100% removal efficiency (zero penetration) of fly ash could be achieved in the dual flow scrubber at a QL/QG ratio of 3.0 m3/1000 ACM (actual cubic meter). Almost zero penetration of fly ash particles, clearly demonstrated that the dual flow scrubber with its staging operations met with the stricter emission regulations for particulate matter. Selection of any particulate control device is intrinsically related to the performance as a function of various pertinent variables of the system. Correlations were, therefore, put forward for the prediction of the performances of the bubble and the spray sections in terms of various pertinent variables of the system. The overall removal efficiency achievable in the dual flow scrubber was predicted with the help of these correlations. The predicted values were in excellent agreement with the experimental values (well within +/-5.0% deviation). Comparison of the performance of the present system with the existing systems indicated that the bubble and spray sections either alone or in combination (as in a dual flow scrubber), was energy and efficiency-wise much better than the existing systems. The novelty of the system is also described.     

ART in‐well air stripping—An innovative technology succeeds where other technologies have failed

Accelerated Remediation Technologies LLC (ART) developed a proprietary (patent‐pending) effective remediation technology that is based on verified and established concepts. The ART technology combines in‐situ air stripping, air sparging, soil vapor extraction, enhanced bioremediation/oxidation, and Dynamic Subsurface Circulation^TM in an innovative wellhead system. The system is designed to accommodate a 4‐inch well and is cost‐effective when compared with other remediation technologies. The air‐sparging component results in lifting the water table. This lifting of the water in the well causes a net reduction in head at the well location. Vacuum pressure (the vapor‐extraction component) is applied on top of the well point to extract vapor from the subsurface. The negative pressure from the vacuum extraction results in water suction that creates additional water lifting (mounding). A submersible pump is placed at the bottom of the well to recirculate water to the top for downward discharge through a spray head. The water cascades down the interior of the well similar to what occurs in an air‐stripping tower. Enhanced stripping via air sparging near the bottom of the well occurs simultaneously. In essence, the well acts as a subsurface air‐stripping tower. The pumped‐and‐stripped, highly oxygenated water flows down well annulus and over the “mounded” water back in to the aquifer, which creates a circulation zone around the well to further enhance cleanup. The ART technology has been implemented at several sites nationwide, including industrial laundry facilities, manufacturing plants, and service stations, and has achieved significant reductions in contaminant concentrations. Specifically, a concentration of tetrachloroethene (PCE) decreased from 2,700 to 240 μg/l, in 13 days. In less than three months, the concentrations dropped further to 79 μg/l, which is within the range of background levels. Other sites utilizing the technology have exhibited similar reduction trends in complex subsurface environments. © 2002 Wiley Periodicals, Inc.     

塔式湿法脱硫的工艺比较

对湿法脱硫中的填料塔、鼓泡塔、喷淋塔和液柱塔进行了工艺和结构上的比较，并分析了它们的优缺点。     

Enrichment of PCDDs/PCDFs in the cooling system of municipal solid waste incineration plants

This study measured the levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs), destroyed or formed in combustors and re-synthesized in cooling systems. For the proper control of PCDDs/PCDFs in municipal solid waste (MSW) incinerators, three grate-type MSW incinerators were selected, two of which had boilers, and one of which had a water spray tower (WST) as a cooling system. At the combustor outlets, dusts were in the range of 1640-4270 mg/Sm3 and PCDDs/PCDFs were in the range of 0.103-2.619 ng-TEQ/Sm3, showing the different values according to the grate structure of combustor and the flow direction of flue gas. After the flue gases passed through the cooling system, PCDDs/PCDFs at the waste heat boiler (WHB) outlets were enriched to levels that were 10.8-13.6 times higher than those at the furnace outlets, but PCDDs/PCDFs at the WST outlet was reduced to 5% of the level found at the furnace outlet. The emission patterns, such as the ratio of PCDFs to PCDDs, the ratio of gaseous-phase to particulate-phase PCDDs/PCDFs, and the compositional percentiles of each 2,3,7,8-substituted congener varied according to the types of air pollution control devices (APCDs). Reducing re-synthesis in the cooling system rather than enhancing the removal efficiencies of the APCDs seems to be more effective for lowering the levels of PCDDs/PCDFs in MSW incineration plants.