Study on the System for Separating Sulfurfrom Flue Gas and Dust

This paper describes the structure of the system for separating sulfur from flue gas and dust. In the paper, the velocities of turbulent flow and laminar flow inside the tower, the total of liquid membrance, and the additional flow of rotation fogged fluid are calculated, and the separation of rotation air-solid affected by tower is analyzed. The velocity distribution in quasi free vortex area is obtained from experiment. The minimum separated particle diameter is computed. The paper also studies the chemical reactions of flue gas containing sulfide with the dynamic fogged sulfur separating agent and discusses the main factors related to the effect of separating sulfur and dust. At last, the applications of separating sulfur in industrial stove and collecting dust in environmental engineering are introduced.

Research on Performance of U Separator in Sand and Dust Test System

Sand/dust test is one of the key projects to examine the environmental adaptability of ordnance equipment.In order to decrease the abrasion of test facility caused by the sand/dust particles,the particles contained in the airflowneed to be reclaimed effectively.Amathematical model of Useparator is established.The flowfield and the trajectories of particles inside the separator are obtained using a numerical simulation method,and the separation efficiency and pressure drop of separator with different rows of separate components are also obtained at various flowvelocities.The simulation results indicate that the efficiency of U inertia separator is affected by the flowvelocity evidently,and a reasonably designed separator can meet the requirement of the separation efficiency in particular situation.The results can be use as reference for the design and test of sand/dust separate systems.

Contributions of the Secondary Jet to the Tangential Velocity Distribution and to the Collection Efficiency of the Fixed Guide Vane Type Axial Flow Cyclone Dust Collector

In order to control the maximum tangential velocity V?m(m/s)of the turbulent rotational air flow and the collection efficiencyηc(%)using the fly ash of the mean diameter X R50=5.57?m,two secondary jet nozzles were installed to the body of the axial flow cyclone dust collector with the body diameter D1=99mm.Then in order to estimate V?m(m/s),the conservation theory of the angular momentum flux with Ogawa combined vortex model was applied.The comparisons of the estimated results of V?m(m/s)with the measured results by the cylindrical Pitot-tube were shown in good agreement.And also the estimated collection efficienciesηcth(%)basing upon the cut-size Xc(?m)which was calculated by using the estimated V?m(m/s)and also the particle size distribution R(Xp)were shown a little higher values than the experimental results due to the re-entrainment of the collected dust.The best method for adjustment ofηc(%)related to the contribution of the secondary jet flow is principally to apply the centrifugal effect?c(1).Above stated results are described in detail.

Application of Mechanical Similarity Laws to the Collection Efficiencies of Geometrically Types of Uni-Flow Cyclone Dust Collectors

From the mechanical similarity point of view,the centrifugal effect,Ar,and the Stokes number,St,as well as the Reynolds number,Rec for the motion of solid particles in the cyclone are the relevant parameters.In order to apply these similarty laws for the prediction of the Characteristics of the collection efficiency,ηc,geometrically similar types of uni-flow cyclones were used.The body diameters of the cyclones were D1=30,50,69 and 99mm,respectively.The feed particle concentration of the fly-ash particles was up to Co=60 g/m^3,from the experimental results:(1) the pressure drop,ΔPc,in the cyclones was a function of not only the Reynods number,Rec.but also the body diameter,D1;(2)the collection efficiency,ηc,did not always increase with decreasing body diameter but there existed an optimal body size;(3)application of the mechanical similarity laws to the collection efficiency was not always sufficient for estimating the collection efficiency,since the feed particle concentration was an additional important factor;(4)a new parameter which was the ratio,Epf,of the apparent separation energy,Wp,of the solid particles to the energy loss,Ee,of the gas flow in the cyclone was introduced for discussing the collection efficiency;(5) Fuchs theory,used to estimate the collection efficiency,was examined.Fuchs theory may be applied for high feed particle concentration.

Estimation of Collection Efficiency Depended on FeedParticle Concentration for Axial Flow Cyclone DustCollector

INTRODUCTIONCyclonedustcollectorisappliedinmanyindustries.Especiallytheaxialflowcycloneisthemostsimpleconstructionanditkeepsthehighreliabilityforthecyclonemaintenance.Thereforetheaxialflowcycloneisveryeasytoarrangewithvariouspipelinesofthepneumatictr...

超大型侧吹熔池熔炼余热锅炉烟气流动及烟尘黏附研究

富氧侧吹熔池熔炼广泛应用于铜、铅、锌等有色金属的提取,其后端的余热锅炉承载着余热回收利用、沉降烟尘的重要作用。但在实际生产过程中,炉内烟气流场混乱,烟尘易黏附积灰,炉壁与部件磨损严重等,导致了余热回收效率降低,低负荷运行甚至被迫停机。针对上述问题,采用多相网格质点方法,对年处理150万t精矿超大型富氧侧吹熔池熔炼余热锅炉内烟气流动特性、烟尘沉降与黏附开展数值模拟研究。结果表明:炉内的烟气涡旋会导致烟尘回流至入口烟道;挡板前移会导致挡板受击与堵塞情况加剧;增大挡板间距能有效减小挡板的堵塞;增大辐射室空间能大幅度减小挡板受到的冲击。

结构参数对闭口体系新型激波吹灰器工作特性的影响研究

锅炉吹灰器可以有效实现清除锅炉内部的积灰,提高锅炉运行效率,对锅炉安全运行具有重要意义。SPG型激波吹灰器是在传统激波吹灰器基础上发展而来的闭口体系新型高性能吹灰器,使用数值方法对该装置的可行性进行验证,并分析工作特性,可以为实际应用与改进提供参考。基于CFD技术,将SPG型激波吹灰器作为研究对象,使用动网格技术对设备内活塞的真实运动过程进行仿真模拟,利用Fluent软件模拟计算SPG型激波吹灰器内部流场的连续变化这一动态过程,并通过调整喷管、燃烧室以及压力蓄能器的结构参数,在出口处监测得到各部件结构参数变化对排气特性的影响规律,获取其工作特性。结果表明:喷管的长径比从2增加到4时,出口参数峰值出现滞后现象,但压力峰值与速度峰值获得显著提升,且喷管的扩张段改为直管可以降低膨胀损失,适当增加喷管长径比并直接连接直管是一种较好的方案;燃烧室径向和轴向壁面之间的间距缩短均可使出口压力峰值提高,但轴向距离缩短压力峰值增加幅度更大;在压力蓄能器中,去除阻尼装置压力提升较少,且无法减缓活塞复位,使排出气体减少,去除限位器后喷管出口压力大幅提高,但其峰值持续时间变短。

一种基于直流式风洞的火星尘暴模拟装置

为了研究火星表面尘暴环境对探测器及人类活动的影响,研制了一种基于低密度直流式风洞的火星尘暴环境模拟装置:采用超声速引射器作为风洞动力源,结合具备多工况动态调节能力的大抽气量真空系统,实现了引射气量精准调控,可模拟100~1500 Pa低气压下的5~100 m/s大跨度风速;针对低气压下沙尘浓度难以精确控制的问题,采用振动式喂料、逆向螺旋式喷嘴设计以及大周期滞后串级调节方式,实现了0.1~1 g/m^(3)的沙尘浓度精确控制。该装置可用于研究火星尘暴环境对材料和机构的影响,同时还可用于火星气动力研究。

低阻文丘里振弦栅除尘系统内流场模拟研究

为探究除尘系统流场分布情况以及粉尘与液滴颗粒对除尘系统性能的影响,运用Fluent模拟研究气态单相流、气固两相流和气固液三相流的流场分布情况,分析除尘器在不同工况条件下压力与流场分布规律以及颗粒的运动情况。结果表明:除尘系统流场主要受除尘器结构的影响,受粉尘颗粒的影响较小;液滴颗粒的存在会提高系统的除尘效率;加入液滴颗粒后,粉尘运动凌乱度增强,与液滴碰撞作用加强,促进了细微粉尘的凝聚,但同时会影响除尘器流场稳定性,增加除尘系统阻力损失。

滤筒除尘器喷吹孔孔径的优化

【目的】为控制各个喷吹管气流量的均匀性,对喷吹管上的喷吹孔径进行优化,提高滤筒除尘器清灰效果。【方法】自制高压脉冲喷吹气流量测量装置对现有喷吹管气流量进行测定,采用光纤传感分析仪测试除尘器滤筒各部分的侧壁压力峰值,分析各滤筒清灰效果不均匀的原因;以滤筒各部位侧壁压力峰值作为清灰均匀性效果评估指标,优化喷吹孔径。【结果】优化前4个喷吹孔径均为19 mm,喷吹孔的气流量依次为13.69、 14.78、 16.03、 16.93 L,对应4个滤筒上、中、下部侧壁压力峰值的最小值分别为最大值的37%、 26%、 20%,气流量均匀度标准差为1.41;优化后4个喷吹孔径分别为23、 20、 18、 17 mm,喷吹气流量依次为14.05、 15.08、 15.87、 16.13 L,对应4个滤筒上、中、下部测壁压力峰值的最小值为最大值的56%、 56%、 53%,气流量均匀度标准差降为0.93。【结论】优化后的喷吹管气流量均匀化程度提高,可实现滤筒除尘器的均匀清灰。

基于CFD的某商用车扬尘污染仿真优化分析

针对某新型商用车在泥土路面低速行驶工况中,易扬起地面尘土造成局部空气污染问题。建立商用车CFD仿真分析模型,进行实验对标以验证仿真模型的精确性。将DPM离散相模型分析方法与离散动力学相结合,对商用车外流场中多相流进行数值仿真,揭示了扬尘污染的产生机理。由此制定不同的扬尘治理方案,结合HyperStudy软件进行优化分析,寻求最佳扬尘治理方案,并开展实验验证。研究结果表明:通过优化风扇位置,更换“U型”护风罩并优化导风板尺寸的改进方案,扬尘颗粒数相较原车减少了44.67%,在保证散热性能的前提下,明显改善了扬尘污染现象。

高寒地区平板热管式太阳能集热系统热性能研究

基于呼和浩特地区高寒气候条件,搭建两组完全一致的平板热管式太阳能集热系统,通过实验对比分析太阳辐射强度、传热工质流量、集热板表面积尘等因素对集热器瞬时集热效率以及系统热性能的影响。结果表明,在同等外界条件下,集热器的集热效率随着工质流量的增加而增大,集热效率与太阳辐射强度变化趋势相近,随积尘密度的增加,集热板表面积尘导致系统的得热量减少,集热性能下降。

助流气碟在布袋除尘器下料中的应用

布袋除尘器是粉尘物料制备系统中的重要设备之一,其作用是截留捕获干燥后的物料颗粒并将其均匀输送到高温焙烧反应区,因此其运行效果直接影响物料生产的质量和产能。本文提出了一种对布袋除尘器的箱体增加助流气碟的改造方法,在投入较小的前提下实现了布袋除尘器下料方式的优化,同时避免了目前常用的机械式振打器对湿涩物料振打作用差以及造成料斗裂纹的情况,改造后的布袋除尘器积料和架桥周期大幅增加,产品质量和装置产能都实现了提高。

Fieldline现场总线在袋式除尘器清灰控制系统中的应用

简要介绍工业企业烟气排放控制的重要性及除尘器的作用,详细描述袋式除尘器清灰系统工艺流程,分析现有清灰控制方式的劣势,有针对性地提出了基于Fieldline现场总线的清灰控制系统解决方案。

Determination of optimal blowing-to-suction flow ratio in mechanized excavation face with wall-mounted swirling ventilation using numerical simulations

Wall-mounted swirling ventilation is a new type of system in mechanized excavation faces with a dust sup-pression performance that is closely related to the blowing-to-suction flow ratio.Physical and simulation models were developed according to the No.C103 mechanized excavation face in the Nahe Coal Mine of the Baise Mining Bureau,Guangxi Province to optimize the blowing-to-suction flow ratio for wall-mounted swirling ventilation.Both the k-εturbulence model and the discrete phase model were utilized to simulate airflow field structures and dust concentration distribution patterns at various blowing-to-suction flow ratios.The results suggest that higher blowing-to-suction flow ratios increase the airflow field disturbance around the working face and weaken the intensity of the axial air curtain.On the other hand,both the intensity of the radial air curtain and the dust suppression effect are enhanced.At a blowing-to-suction flow ratio of 0.8,the wall-mounted swirling ventilation system achieved the most favorable dust suppression performance.Both the total dust and respirable dust had their lowest concentrations with maximum efficiencies of reducing both types at 90.33%and 87.16%,respectively.

物理脱碳气化灰渣对水泥胶砂性能影响

气化渣是煤气化过程中产生的一种含碳量较高的固体废弃物,目前主要通过填埋方式处理,不仅占用大量土地,污染土壤和水体,同时造成能源浪费。榆林气化渣经物理分选后得到精碳、惰性渣及细粒尾渣产品,精碳产品干基高位热值可达25.12 MJ/kg;惰性渣产品包括脱碳粗尾矿及脱碳细尾矿,所采集2种尾矿样品成分均以SiO_(2)、Al_(2)O_(3)、CaO、Fe_(2)O_(3)为主,烧失量分别为1.53%、1.20%。对2种尾矿样品磨细后在不同掺量下制备水泥胶砂,强度活性指数分别达75%、79%;15%掺量下,2种脱碳尾矿胶砂的抗折强度、抗压强度与纯水泥胶砂较接近,该掺量条件下,2种脱碳尾矿可替代部分水泥进行建材化综合利用。纯水泥胶砂及掺尾矿胶砂在3 d龄期时均发生水化反应,生成片状结构及针状条。110 d龄期时,纯水泥胶砂水化产物针状条更加致密,互相交错;而掺配脱碳尾矿的水化产物中针状条基本消失,颗粒之间逐渐形成统一整体。

干式钻孔除尘旋风分离技术数值模拟研究

以旋风除尘器为研究对象,建立几何模型,通过FLUENT数值模拟软件对旋风除尘器粉尘收集率进行分析,得到旋风除尘器的筒体高度、阻力、入口风速与粉尘收集率的关系。以数值模拟的结果为依据,设计旋风除尘器样机,并对其各个参数与过滤效率之间的关系进行验证,最终得到旋风除尘器工艺参数。结果表明:最佳筒体高度为1.5倍的筒体直径,入口风速为15 m/s,此时模拟的粉尘收集率为82.47%,阻力为500.76 Pa。实验旋风除尘器过滤效率为80.22%,阻力为494.6 Pa,与数值模拟的结果相近。

综掘工作面内外双旋流风幕发生装置设计与控尘效果研究

针对煤矿综掘工作面粉尘浓度超限的问题,设计了一种新型内外双旋流风幕发生装置,通过数值模拟和相似试验分析了装置应用前后综掘工作面的风流流场特性和粉尘扩散规律。结果表明:司机位置粉尘质量浓度随风幕发生装置射流出口风速的增大呈先降低后增大的变化趋势,有效控尘临界风速为35 m/s;风幕发生装置可以形成阻挡粉尘向外扩散的漏斗状旋流风幕,并将综掘工作面分成粉尘控制区和工作区2部分;旋流风幕将粉尘颗粒的扩散速度降低了84%,且对5μm以下呼吸性粉尘控尘效率更优;新型风幕发生装置应用后司机位置处的粉尘质量浓度由337 mg/m^(3)降到38 mg/m^(3),控尘效率为88.7%。

SCC型湿式除尘器除尘区域流场分析及结构优化

对SCC型湿式除尘器除尘区域流场流动进行分析,基于FLUENT软件采用气-固两相流和气-液-固三相流进行数值模拟研究,对不同时刻金属颗粒和液滴颗粒分布图、金属颗粒物轨迹、速度矢量进行对比,发现加入液滴颗粒后,除尘效率明显上升。通过正交试验研究了导流板长度、导流板倾角、导流板间距对被壁面及导流板捕集金属颗粒所占总数比例的影响,结果显示:各因素对被壁面及导流板捕集金属颗粒所占总数比例的影响主次顺序为导流板长度、导流板倾角、导流板间距,其最佳参数组合是A2B2C2,即导流板长度L=650 mm、导流板倾角θ=22.5°、导流板间距H=450 mm。显著性分析结果表明:导流板长度L对综合除尘效率有一定影响,导流板倾角θ和导流板间距H对综合除尘效率无明显影响。

基于Fluent的某型APU进气管道的流场数值分析

APU进气管道的流场特性研究是APU进气系统设计中的关键部分,针对某型民用飞机APU进气管道外形对APU进气系统性能的影响进行了研究,为了分析APU进气管道及进气风门对进气系统总压力、压力恢复、进气畸变的影响,以某型宽体客机的APU进气管道和进气风门为例,利用CATIA软件构建了三维模型并利用Design Modeler进行流体模型填充和前处理,然后把模型导入至Fluent软件中进行流场的仿真计算,仿真过程中简化了进气管道和飞机尾椎的模型,选取了合理的边界条件,分析不同工况条件下进气管道的气动性能,仿真结果表明所设计的进气管道能够较好满足APU进气系统的需求,确定出了最优的进气管道结构尺寸,为后续的产品设计提供理论支撑。