随着科学技术的进步和社会生产力的发展，人类文明进程得到前所未有的发展，但是与此同时，人类社会也面临着一系列重大环境与发展问题。因此，发展环境工程意义重大。下文是我为大家搜集整理的关于环境工程5000字 毕业 论文的内容，欢迎大家阅读参考!
浅谈环境工程中的工艺 方法
摘 要：环境工程作为一种现代城市建设的工程，不仅对城市的环境有着非常重要的影响，还关系到城市居民的健康问题。所以，在城市环境工程的建设过程中，有关部门应该加强对工艺方法的选择和研究。
关键词：环境工程工艺;工程法;类比法;对称法;应用分析
随着我国经济的发展，我国的城市环境也有了明显的改善，这种情况下无论是环境工程的质量还是规模都有所变化，所以，为了更好的实现对环境工程的管理，有关部门应该加强对环境工程的工艺和方式的研究，以便更好的实现对现阶段的环境工程的优化。下文中笔者将结合现阶段几种常见的环境工程的施工工艺和技术，对该问题进行分析。
1 价值工程法的现实应用和分析
目前来看，在环境工程的施工过程中，价值工程作为一种非常重要的常见工程技术，对于环境工程的施工质量和效果有着非常重要的影响。尤其是在环境工程的经济效益实现的过程中以及相关的环境工程的产品设计形式的表达上，有着非常重要的作用。一般来说，这些作用可以概括为以下几点：
1.1 环境工程中的价值工程法可以有效的在工程中避免功能过剩的问题。即在现代的环境工程的施工过程中，有关部门可以通过对工程的价值的比较和分析，来实现对环境工程的有效评估，所以，有关部门可以通过价值工程法来实现对环境工程的各种职能的优化和删除，这样就可以将环境工程最大的合理化控制，有助于环境工程的价值的发挥和实现。
1.2 环境工程的价值工程法可以有效的避免价值短缺的现象，也就是说在环境工程的价值分析的过程中，可以根据现有工程的实际情况，对工程的总体成本进行控制，可以有效的平衡工程的成本，避免不必要的功能支出导致的成本增加，因为环境工程的复杂性决定了各种职能之间可能存在相互冲突的状况。所以，采用价值工程法可以有效的规避这种问题。
2 类比法的实际应用和分析
所谓类比法，就是指在环境工程的过程中，对现有的环境工程的各种 实施方案 进行类别，也就是说对有共同点的各种环境工程质检的前提和方式进行分析，这样就可以更好的实现对环境工程的各种具体项目的判断。一般来说，我国的环境工程的类比法的应用主要体现在以下几个方面：
2.1 环境工程中的废气/废水处理工艺类比，指的是在环境工程的开发过程中，应该对各种工程中的废水和废气进行类比，也就是说要实现对其成分和处理的方法进行严格的控制。一般来说，主要体现在以下几个方面：①膜分离技术分析：即在对现有的环境工程的废水和废气进行处理的过程中，要对现有的膜分离技术进行全面的分析，不仅要对其进行盐水淡化处理，还要对其进行严格的废水除盐等技术的使用。这种方式的最大的特点在于能够实现对能源的节约，可以实现施工过程中的有效环保，还能够实现对各种相变反应的有效控制。②吸附技术分析：即在对现有的环境工程进行管理和控制的过程中，还应该要通过类比法来实现对一些特定的流体和固体的分离，也就是说在工程过程中，可以根据具体的环境需要对环境进行有效的处理，这种方式广泛的应用在石油工业废水处理以及相关的大气污染处理中，因为在这种环境工程的操作过程中，会运用到相关的分离性比较高的设备。
2.2 环境工程中垃圾预测的类比法运用：
在环境工程中，常会遇到对生活垃圾的处理问题，因为城市的生活垃圾产生的环境影响是不容忽视的，由于城市生活垃圾的产生量是非常大的，所以如果可以对生活垃圾进行一个全面的预测，就可以事前做好相关的处理方案的设计。一般来说，在采用类比法对现有的环境工程中的垃圾预测时，应该注意以下几个方面的问题：①类比指标的选取：即选择合适的环境工程的对比方案，对现有的各种城市生活垃圾产生的因素进行对比分析，以便更好的实现对该区域的地域性的垃圾产生问题进行分析。②类比城市的选取：在对城市垃圾的预测分析的过程中，应该注意的是要选择一些具有典型的可参考数据的城市作为类比对象和参考对象。③类比方法的实施：即对类比城市生活垃圾人均日产生量的变化发展规律作出合理研究与分析，进而对其进行有效预测。
3 环境工程中的对称法应用分析
对称法可以说是研究环境工程工艺的最基本性方法，它能够针对客观事物的基本属性及性质、结构运动特征，在事物内部构件一一对应的交互关系，从而在相类似事物当中找到相似点所在。从其在环境工程工艺中的应用角度上来说，对称法的应用可以分为内部对称与外部对称这两个方面，具体而言可作如下归纳。
3.1 内部对称法在环境工程中的应用分析：在当前技术条件支持下，内部对称法在环境工程中的应用价值主要体现在以下几个方面：①首先，是氧化与还原反应。我们可利用还原剂自身的还原特性对固体废弃物进行处置作业，并对城市工业建设中所产生的各类废气与废水进行净化处理;与此同时，我们还可以借助于氧化剂自身的氧化特性同样实现上述相关处理目的，以此缓解环境压力;②其次，是上浮与沉淀反应。
我们知道，大部分存在于废水水体当中的杂质在密度分布与大小参数上均有着较为显著的差异，对于那部分密度部分高于水体且尺寸较大的杂质而言，我们可采取重力沉降的方式对其进行去除处理，而对于那部分密度低于水体且尺寸较小的杂质而言，可利用杂质本身的上浮反应达到去除杂质的目的。现阶段上浮处理工艺方法广泛应用于餐饮废水的处理以及污泥原材的浓缩工作当中，而沉淀处理工艺方法则多适用于工业及生活污水/废水的处理工作当中;③最后，是好氧与厌氧反应。好氧微生物与厌氧微生物差异性的反应特征决定了其在环境工程中不同的应用价值。对于好氧微生物而言，其在氧气含量充分的条件下发挥处理特性，在氧化分解与沉淀处理的配合作用之下将废水/污水中大量的有机污染物物质进行去除处理。
3.2 外部对称法在环境工程中的应用分析：在现阶段技术条件支持下，外部对称法在环境工程中的应用价值主要体现在以下几个方面：①旋风除尘器及沉砂池装置：物体在高速旋转的过程当中会产生一定的离心力，进而导致物体气固相分离。上述两种装置基于流体力学对称性特征进行应用，除尘效果显著;②生物法：现阶段城市工业废水及生活污水的处理多以生物法方式进行，配合相应的脱硫与脱氮技术确保环境工程质量的稳定性。
4 结束语
综上所述，环境工程不仅关系到城市的发展和建设，也对城市居民的健康和城市的定位和规划问题有着非常重要的影响。环境工程的核心在于防治环境污染，提高环境质量。在人类活动不断深化发展的背景作用之下，环境污染形势的日益研究要求环境工程对其做出控制与改善。如何将环境工程相关职能发挥到最大限度，确保环境质量提升的高效性与稳定性，已成为现阶段相关工作人员最亟待解决的问题之一。
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试论房屋建筑工程施工与环境保护
摘要：随着科学技术的进步和社会生产力的发展，人类文明进程得到前所未有的发展，但是与此同时，人类社会也面临着一系列重大环境与发展问题。人口剧增、资源过度消耗、气候变异、环境污染和生态破坏等问题威胁着人类的生存与发展。在严峻的现实面前，人们逐渐认识到，人类本身是自然系统的一部分，与环境息息相关。在房屋建筑工程施工过程中，我们必须优先考虑生态环境问题，并将其置于与经济和社会同等重要的地位上才能实现社会繁荣。
关键词：建筑工程 施工与环保 环保 措施
现代建筑是一种过分依赖有限能源的建筑。能源对于那些大量使用人工照明和机械空调的建筑意味着生命，而高能耗、低效率的建筑，不仅是导致能源紧张的重要因素，并且是使之成为制造大气污染的元凶。为了减少对不可再生资源的消耗，环保建筑主张调整或改变现行的设计观念和方式，使建筑由高能耗方式向低能耗方向转化，依靠节能技术，提高能源使用效率以及开发新能源，使建筑逐步摆脱对传统能源的过分依赖，实现一定程度上能源使用的自给自足。
1 房屋建筑施工的技术组织措施
1.1 平面管理
总平面管理是针对整个施工现场监理的管理，其最终要求是：严格按照各施工阶段的施工平面布置图规划和管理，具体表现在：
①施工平面图规划具有科学性、方便性、施工现场严格按照文明施工的有关规定管理。
②在明显的地方设置工程概况、施工进度计划、施工总平面图、现场管理制度、防火安全保卫制度等标牌。
③供电、给水、排水等系统的设置严格遵循平面图的布置。
④所有的材料堆场、小型机构的布设均按平面图要求布置，如有调整将征得现场监理或业主的同意。
⑤在做好总平面管理工作的同时，经常检查执行情况，坚持合理的施工顺序，不打乱仗，力求均衡生产。
1.2 文明施工管理
1.2.1 在过往行人和车辆密集的路口施工时，与当地交警部门协商制定交通示意图，并做好公示与交通疏导，交通疏导距离一般不少于50m。封闭交通施工的路段，留有特种车辆和沿线单位车辆通行的通道和人行通道。
1.2.2 因施工造成沿街居民出行不便的，设置安全的便道、便桥;施工中产生的沟、井、槽、坑应设置防护装置和警示标志及夜间警示灯。如遇恶劣天气应设专人值班，确保行人及车辆安全。
1.2.3 在进行地下工程挖掘前，向施工班组进行详细交底。施工过程中，与管线产权单位提前联系，要求该单位在施工现场设专人做好施工监护。并采取有效措施，确保地下管线及地下设施安全。
如因施工需要停水、停电、停气、中断交通时，采取相应的措施，并提前告之沿线单位及居民，以减少影响和损失。
2 房屋建筑工程施工环境保护措施
为了保护和改善施工现场的生活环境，防止由于建筑施工造成的作业污染，保障施工现场施工过程的良好生活环境是十分重要的。切实做好建筑施工现场的环境保护工作，主要采取以下措施：
2.1 建筑垃圾及粉尘控制的技术措施
①对施工现场场地进行硬化和绿化，并经常洒水和浇水，以减少粉尘污染。
②装卸有粉尘的材料时，要洒水湿润或在仓库内进行。
③建筑物外脚手架全封闭，防止粉尘外漏。
④严禁向建筑物外抛掷垃圾，所有垃圾装袋运出。现场主出入口外设有洗车台位，运输车辆必须冲洗干净后方能离场上路行驶;对装运建筑材料、土石方、建筑垃圾及工程渣土的车辆，派专人负责清扫及冲洗，保证行驶途中不污梁道路和环境。
⑤严格执行工程所在地有关运输车辆管理的规定。
2.2 噪音控制的技术措施
①施工中采用低噪音的工艺和施工方法。
②建立定期噪音监测制度，发现噪音超标，立即查找原因，及时进行整改。
③建筑施工作业的噪音可能超过建筑施工现场的噪音限值时，应在开工前向建设行政主管部门和环保部门申报，核准后再施工。
④调整作业时间，混凝土搅拌及浇筑等噪音较大的工序禁止夜晚作业。
2.3 施工期间振动污染的防治措施
①在可供选择的施工方案中尽量选用振动小的施工艺及施工机械。
②将振动较大的机械设备布置在运离施工红线的位置，减少对施工红线外振动的影响。
③对振动较大的施工机械，在中午(12时~14时)及夜间(20时~次日7时)休息时间内停机，以免影响附近居民休息。
2.4 施工期间水污染(废水)的防治措施
①加强对施工机械的维修保养，防止机械使用的油类渗漏进入地下水中或市政下水道。
②施工人员集中居住点的生活污水、生活垃圾(特别是粪便)要集中处理防治污染水源，厕所需设化粪池。③冲洗集料或含有沉淀物的操作用水，应采取过滤沉淀池处理或其他措施，使沉淀物不超过施工前河流、湖泊的随水排入的沉淀物量。
2.5 施工期间固体废物的防治措施
①注意环境卫生，施工项目用地范围内的生活垃圾应倾倒至围墙内的指定堆放点，不得在围墙外堆放或随意倾倒，最后交环保部门集中处理。
②对施工期间的固体废弃物应分类定点堆放，分类处理。
③施工期间产生的废钢材、木材，塑料等固体废料应予回收利用。
④严禁将有害废弃物用作土方回填料。
2.6 施工现场周围的环境保护
施工过程中积极对现场周围的环境进行保护。在整个工程的施工过程中特别是土方工程施工阶段对进出现场的车辆进行冲洗，严防污染路面。施工时如果现场出现古树、文物等阻碍施工情况时，应立即停止施工并采取隔离措施，报有关单位治理完后再恢复施工。
2.7 其他环保措施
①建立环境保护管理小组，由项目经理主管，成员由专业骨干组成，做好日常环境管理，并建立环保管理资料。
②建立健全环境工作管理条例，施工组织设计中应有相应环保内容。
③对地下管线应妥善保护，不明管线应事先探明，不允许野蛮施工作业。施工中如发现文物应及时停工，采取有效封闭保护措施，并及时报请业主处理，任何人不得隐瞒或私自占有。
④建立公众投诉电话，主动接受群众监督。
⑤施工期间应防止水土流失，做好废料石的处理，做到统筹规划、合理布置、综合治理、化害为利。
3 房屋建筑施工环境保护的意义
3.1 保护和改善施工环境是保证人们身体健康和社会文明的需要
采取专项措施防止粉尘、噪声和水源污染，保护好作业现场及其周围的环境，是保证职工和相关人员身体健康、体现社会总体文明的一项利国利民的重要工作。
3.2 保护和改善施工现场环境是消除对外部干扰保证施工顺利进行的需要
随着人们的法制观念和自我保护意识的增强，尤其在城市中，施工扰民问题反映突出，应及时采取防治措施，减少对环境的污染和对市民的干扰，也是施工生产顺利进行的基本条件。
3.3 保护和改善施工环境是现代化大生产的客观要求
现代化施工广泛应用新设备、新技术、新的生产工艺，对环境质量要求很高，如果粉尘、振动超标就可能损坏设备、影响功能发挥，使设备难以发挥作用。
3.4 节约能源、保护人类生存环境、保证社会和企业可持续发展的需要
人类社会即将面临环境污染和能源危机的挑战。为了保护子孙后代赖以生存的环境条件，每个公民和企业都有责任和义务来保护环境。良好的环境和生存条件，也是企业发展的基础和动力。
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百度 河北除尘机械设备公司 有个技术文章和除尘技术 看这里面内容自己写吧
Abstract
Now, environmental issues have become the iron and steel enterprises have to face challenges. In the iron and steel production, from mining of raw materials preparation, coking, sintering, ironmaking, steelmaking, and so on until the finishing line, smoke and dust exist in almost all of the production line, is not only one of the main sources of pollution, but also a waste of resources, the impact of physical and mental health workers, iron and steel enterprises is the main task of environmental governance.
Through the dust on the domestic iron and steel enterprises governance Shougang iron works with the status of dust control analysis, we can understand that in the dust control Shougang has invested huge in this area, but also to take a lot of advanced dust removal technology, compared treatment results significantly. Especially in the application of airtight cover. However, there are some inadequacies, such as the choice of the collector is still lagging behind.
Therefore, this research paper will be mainly on the 3rd Shougang blast furnace iron works and a silo hopper dust removal equipment of the transformation, including the working principle of electrostatic precipitator, bag filter, as well as the working principle of a long bag ESP transform low-voltage pulse bag filter. There are 3 high-rise silo hopper and a dust of new technologies and practical management of research, namely, the implementation of the dust source or single-double sealed airtight cover and dust vents mobile devices. More convenient in operation and maintenance, the dust concentration to achieve less than posts lOmg/m3, the concentration of precipitator emissions standard of less than 50mg/m3.
The above research and analysis will help future blast furnace of Shougang No. 1,2,4 hopper dust pollution, etc., so that Shougang iron works to improve the environmental quality.
Key words iron works, dust, sealed enclosures, ESP
Experimental study of electrostatic precipitator
performance and comparison with existing
theoretical prediction models
S.H. Kim, K.W. Lee*
Kwangju Institute of Science and Technology, Department of Environmental Science and Engineering,
1 Oryong-dong, Puk-gu, Kwangju 500-712, South Korea
Received 1 February 1999; received in revised form 21 May 1999; accepted 2 June 1999
Abstract
A laboratory-scale single-stage electrostatic precipitator (ESP) was designed, built and
operated in a wind tunnel. As a "rst step, a series of experiments were conducted to seek the
operating conditions for increasing the particle collection e$ciency by varying basic operating
parameters including the wire-to-plate spacing, the wire radius, the air velocity, the turbulence
intensity and the applied voltage. As the diameter of the discharging wires and the wire-toplate
spacing are set smaller, the higher collection e$ciency has been obtained. In the
single-stage multiwire ESP, there exists an optimum wire-to-wire spacing which provides
maximum particle collection e$ciency. As the air velocity increases, the particle collection
e$ciency decreases. The turbulent #ow is found to play an important role in the relatively low
electric "eld region. In the high electric "eld region, however, particles can be deposited on the
collection plates readily regardless of the turbulence intensity. The experimental results were
compared with existing theories and Zhibin and Guoquan (Aerosol Sci. Technol. 20 (1994)
169}176) was identi"ed to be the best model for predicting the ESP performance. As the second
step, the in#uence of particle contamination at the discharging electrode and at the collection
plates were experimentally measured. The methods were sought for keeping the high collection
e$ciency of ESP over elapsed time by varying the magnitude of rapping acceleration, the time
interval between raps, the types of rapping system (hammer/vibrator) and the particle reentrainment.
The rapping e$ciency and the particle re-entrainment were increased with
increasing magnitude of rapping acceleration and time interval between raps. However, when
the thickness of deposited #y ash layer is su$ciently high, the concentration of re-entrained
particles starts decreasing abruptly due to the agglomeration force which can interact among
0304-3886/99/$ - see front matter ( 1999 Elsevier Science B.V. All rights reserved.
PII: S 0 3 0 4 - 3 8 8 6 ( 9 9 ) 0 0 0 4 4 - 3
deposited particles. The combined rapping system is found more e!ective for removing
deposited particles than the hammer rapping system only. ( 1999 Elsevier Science B.V. All
rights reserved.
Keywords: Electrostatic precipitation; Turbulent #ow; Rapping; Particle re-entrainment; Collection e$-
ciency; Negative corona
1. Introduction
Electrostatic precipitators (ESPs) are one of the most commonly employed
particulate control devices for collecting #y ash emissions from boilers, incinerators
and from many other industrial processes. They can operate in a wide range of
gas temperatures achieving high particle collection e$ciency compared with mechanical
devices such as cyclones and bag "lters. The electrostatic precipitation process
involves several complicated and interrelated physical mechanisms: creation
of a non-uniform electric "eld and ionic current in a corona discharge, ionic
and electronic charging of particles moving in combined electro- and hydrodynamic
"elds, and turbulent transport of charged particles to a collection
surface.
Generally, the collection e$ciency of ESP decreases as the discharging electrode
and collection plates are contaminated with particulates. Thus, a rapping system is
needed for removing the collected particulates periodically. While there have been
numerous theoretical and experimental studies on particle collection characteristics of
electrostatic precipitators, a relatively small number of the studies addressed the
e!ects of particle accumulation both at the discharging electrodes and at the collection
plates. Both phenomena are known to in#uence adversely the performance of
electrostatic precipitators. Many researchers, such as Deutsch [1], Cooperman [2],
Leonard et al. [3], Khim et al. [4], Zhibin and Guoquan [5], and Kallio and Stock
[6], conducted particle collection measurements of ESP. However, they concentrated
mostly on the e!ects of both turbulent mixing and secondary wind in multiwire
single-stage electrostatic precipitators. Speci"cally, Cooperman [2] considered reentrainment
and longitudinal turbulent mixing e!ects, Leonard et al. [3] the "nite
di!usivity, and Zhibin and Guoquan [7] the non-uniform air velocity pro"le. Among
them, only Zhibin and Guoquan [7] measured the collection e$ciency of a singlestage
ESP covering a wide particle size range. Even though their experimental data
are considered to be practical and useful, their experimental conditions were not
identi"ed clearly.
In the present study, well-de"ned collection e$ciency data for an ESP are presented
covering the particle size range of 0.1}100 lm. The particles used in the present study
came from the Bo-Ryung power plant in Korea. In addition, the ESP performance
was evaluated in terms of optimum operating conditions. Finally, the optimum
rapping conditions were sought under which the rapping e$ciency increases and the
particle re-entrainment decreases.
4 S.H. Kim, K.W. Lee / Journal of Electrostatics 48 (1999) 3}25
Fig. 1. Schematic diagram of the wind tunnel for the eight wired single-stage ESP performance test.
2. Review of theoretical models
2.1. Particle charging
Fig. 1 shows the laboratory-scale electrostatic precipitator. The particle charging
system consists of discharge wires with diameter (D8) and two grounded parallel
plates of length (¸). A high negative voltage (<8) is applied to the corona discharge
wires, and suspended particles of diameter (d1) #ow with air between the plates at
a velocity (;) in the y-direction. In the whole range of particle sizes, both "eld
charging and di!usion charging mechanisms contribute to signi"cant charges [8,9].
In these theoretical analyses, it is nearly correct to sum the rates of charging from the
two mechanisms and then solve for the particle charging as follows:
dq1
dt
"q4
q A1!q
q4B2#d21
eN
0
4 S8k¹p
m
expA! 2qe
d1k¹B (1)
where q1 is the particle charge, q4 is the saturation charge,N
0 is the average number of
molecules per unit volume, e is the electronic charge ("1.6]10~19 C), b is the ion
mobility ("1.4]10~4 m2/V s), e0 is the permittivity of free space ("8.85]
10~12 F/m), d1 is the diameter of particle, k is the Boltzmann constant ("1.38]
10~23 J/K), ¹ is the absolute temperature ("293 K), m is the mass of a particle
("(p/6)d31
o1), and o1 is the particle density ("2.25]103 kg/m3).
2.2. Theoretical models of particle collection ezciency
Theoretical models of ESPs were provided by Deutsch [1], Cooperman [2],
Leonard et al. [3], Zhibin and Guoquan [7] and others. The Deutsch model for
S.H. Kim, K.W. Lee / Journal of Electrostatics 48 (1999) 3}25 5
calculating the particle collection in an ESP assumes complete mixing by turbulent
#ow and thereby uniform concentration pro"les. In order to improve the drastic
assumption of in"nite di!usivity in the Deutsch model, many researchers tried to
develop "nite di!usivity models by dealing with the convective-di!usion equation
with various boundary conditions.
Cooperman [2] developed a theory which modi"es the Deutsch model to account
for the e!ects of turbulence and particle turbulent di!usion. The major limitations of
the Cooperman model lie absence of a general method to estimate the re-entrainment
factor and the particle di!usivity. Leonard et al. [3] developed a more complicated
two-dimensional model using the method of the separation of variables from the
convective-di!usion equation. He assumed uniformity of velocity components of
charged particles and particle di!usivity. This assumption fails to adequately describe
the particle di!usivity near the collection plates, where it is governed mainly by the
molecular transport and, therefore, the di!usivity near the wall is signi"cantly lower
than the di!usivity in the turbulent core. Zhibin and Guoquan [7] suggested a new
model for the single-stage ESP which takes into account the e!ect of turbulence
mixing by electric wind. Predicted collection e$ciencies of the above theoretical
models are summarized as follows:
gDe"1!exp(!De), (2)
gCoo"1!expC;¸
2D
!SG A;¸
2DB2#(1!R)PeA¸
=B2HD, (3)
gLeo"1!P1
0
PA m!De
J2De/PeBdm, (4)
gZhi"1!S Pe
4pDeP1
0
expC!Pe
4De
(m!De)2Ddm, (5)
where <t is the migration velocity ("q1EC#/3pkd1), C# is the slip correction factor
("1#(2/Pd1)[6.32#2.01 exp(!0.1095Pd1)]), P is the absolute pressure
("76 cm Hg), E is the electric "eld intensity ("<8/=),= is the width of wire-toplate,
De is the Deutsch number ("<t¸/;=), Pe is the electric Peclet number
("<t=/D1), D1 is the particle di!usivity, and P(z) in Eq. (4) is the Gaussian probability
distribution function given by
P(z)" 1
J2pPz
~=
expA!B2
2 BdB. (6)
In order to evaluate the particle di!usivity for the calculation of De and Pe, the #ow
is assumed to be a fully developed turbulent channel #ow. The related physical
quantities are speci"ed like below [10]
1
f 1@2
"!1.8 log10A6.9
ReB, ;q
"Sf;2
8
,
D5"0.12;q=, DB"k¹C#
3pkd1
, D1"D5#DB (7)
6 S.H. Kim, K.W. Lee / Journal of Electrostatics 48 (1999) 3}25
Fig. 2. Comparison of measured fractional number of particles with existing theoretical predictions.
Experimental conditions: D8"1 mm, <8"50 kV, Sx"150 mm, Sy"37.5 mm, ;"1 m/s, ¹6"12%.
where f is the friction factor, Re is the Reynolds number ("2;=/v), ;q is the friction
velocity, D5 is the turbulent di!usivity, and D
B is the Brownian di!usivity.
With the measured data of fractional number of particles at the inlet of the
single-stage ESP, measured fractional number of particles at the outlet of the singlestage
ESP was compared with calculated results of each theoretical prediction model
as shown in Fig. 2. The grade e$ciency is computed over the particle size range
0.1}100 lm, and then integrated the grade e$ciency to obtain the overall mass
e$ciency, where the particle size distribution function is assumed to be lognormal.
The size distribution of most polydisperse aerosols is found very close to the lognormal
distribution. Thus, this assumption is quite reasonable. The lognormal particle
size distribution function is given by Herdan [11]:
f (d)" 1
d ln p'(2p)0.5
expC!(ln d!ln d')2
2 ln2 p' D (8)
where :=
0
f (d)dd"1, the geometric mean diameter d'"5.03 lm and the geometric
standard deviation p'"1.73 from the measured data. The fraction number of each
particle size at the outlet of ESP can be described by this particle size distribution
function. Finally, the theoretical overall collection e$ciency is calculated for comparison
with the experimental results.
S.H. Kim, K.W. Lee / Journal of Electrostatics 48 (1999) 3}25 7
Table 1
The dimensions and operating conditions for the present eight wire single-stage ESP
Dimensions and operating conditions Values
Diameter of discharge wire, D8 (mm) 1, 2, 3, 4
Wire-to-plate spacing, Sx (mm) 50}200
Wire-to-wire spacing, Sy (mm) 12.5}50
Length of collection plate, ¸ (m) 0.75
Height of collection plate, H (m) 0.3
Air #ow velocity, ; (m/s) 0.8}2.5
Applied voltage on wires, <8 (kV) 10}70
Turbulence intensity, ¹6 (%) 12, 15, 18
Air temperature, ¹ (K) 293
Air pressure, P (atm) 1
3. Experimental procedure
The experimental apparatus used in this study consisted of six components: an
aerosol generation system, a wind tunnel, a laboratory-scale ESP, a rapping system,
an aerosol sampling system, and a particle concentration measurement system. The
ESP was 30 mm (=)]500 mm (H)]750 mm (¸) in size and was equipped with eight
discharge wires. The schematic diagram of the ESP is shown in Fig. 1. The basic
operating conditions of the ESP and the parameters used are shown in Table 1. The
single-lane wind tunnel was made of plexiglas and operated at the ambient temperature.
It can provide air velocities ranging from 0.1 to 6 m/s. A thermo-anemometer
(Model 8525, Alnor Instrument Company) was used to measure the air velocity. The
air "ltered with a high e$ciency particulate "lter (HEPA) was supplied with a turbulence
intensity of about 12% and at a "xed mean velocity of 1 m/s. The #y ash
particles which came from the Bo-Ryung electric power plant in Korea were dispersed
using a microdust feeder (Model MF-2, Sibata Scienti"c Technology Ltd.). The #y ash
was analyzed using chemical, physical and electrical methods and the analysis results
are shown in Table 2. The microdust feeder utilizes a variable-speed turntable to
transport #y ash at a constant rate to the test section in the wind tunnel. The
laboratory-scale single-stage ESP described previously was installed in the test section
as shown in Fig. 1. For aerosol sampling, an isokinetic sampling tube was used to
measure the concentration and the size distribution of the #y ash particles. The
measuring points were positioned at the center of the cross-sectional area of the wind
tunnel. Measurements of the particle concentrations upstream and downstream were
made by Aerosizer (Model Mach II and LD, API) which is capable of measuring
individually the size of particles in the range of 0.2}200 lm regardless of the particle
shapes. Finally, the overall collection e$ciency, g%91, was evaluated with the mass
loading of the particles measured at inlet and outlet of the ESP:
g%91"[(m)*/-%5!(m)065-%5]
(m)*/-%5
, (9)
8 S.H. Kim, K.W. Lee / Journal of Electrostatics 48 (1999) 3}25
Table 2
Results of chemical, physical, and electrical analysis of #y ash
Classi"cation Values
Chemcial components of #y ash SiO2 (46.47 wt%)
Al
2
O
3
(24.48 wt%)
Fe2O3 (15.28 wt%)
CaO (4.06 wt%)
MgO (1.56 wt%)
Na2O (0.35 wt%)
K2O (1.17 wt%)
SO
3
(4.20 wt%)
TiO2 (1.18 wt%)
Measurement of particle size distribution GMD 5.03 m
GSD 1.73
d1)4.23 lm
d1'4.23 lm
Electrical resistivity 4.3]109 () m)
where (m)*/-%5 is the mass loading of particles at the ESP inlet. (m)065-%5 is the mass
loading of particles at the ESP outlet.
Presently, two philosophies are prevalent with regard to removal and transfer of the
particulate from the collection plates.
授之以鱼不如授之以渔！蛋卷是某大学国际贸易学系学生，很高兴能帮上你。其实有个很好的办法可以让你迅速拿到这样的文献。我们一般找中英文的文献和论文都是用这样的办法。上google，然后收索你要的作品名称或者重点词汇在后面加.pdf.例如 “农村文化建设调查.pdf”或者“风景旅游区环境质量调查.doc” 这样。你要找什么论文或者文献就重点词+.pdf 或者重点词+.doc 蛋卷用这个办法屡试不爽，你可以多找几篇，看看论文的架构和作者的思路，并且适当参考。希望蛋卷的回答对你有帮助。
