移动电极电除尘器除尘效率的计算

移动电极静电除尘器通过清灰刷除掉阳极板上收集的粉尘,阳极系统为移动电极（即作回转运动的集尘极）阳极板呈带条状,固定在链条上,随链轮转动。移动电极静电除尘器有效克服了困扰常规电除尘器对高比电阻粉尘的反电晕及振打二次扬尘等问题,大幅度提高了除尘效率。提供常规固定电极除尘区与移动电极除尘区联合使用的除尘器除尘效率计算公式。     

旋转电极式电除尘器技术研究

简要阐述了旋转电极式电除尘器的原理、结构、应用及特点，并总结出其除尘效率计算公式。研究结果表明：该技术能最大限度的减少二次扬尘，显著降低电除尘器出口排放浓度，对高比电阻粉尘有很好的收尘效果。与其他除尘器比较，旋转电极式电除尘器节省场地、空间和能源，性价比高，具有较广阔的应用前景。     

动态与信息

新型电除尘装置目前,国外出现了一种新型的干式电除尘装置,即移动电极型电除尘器。移动电极型 EP 与振打式的固定电极 EP 的主要区别是:(1)集尘极是移动的;(2)用电刷使集尘极捕集的粉尘剥落。移动电极型 EP 的主要构造如图1所示。集尘极被短栅状的部件分开,由不锈钢板和补强材料构     

电袋除尘器改造在半干法烟气脱硫中的应用

介绍了包头第二热电厂200MW机组半干法脱硫系统配套电除尘器的情况，由于燃用煤质的改变及环保要求的提高，原电除尘器出口粉尘浓度无法满足排放要求，需要对其进行改造。通过经济、技术对比分析，确定采用电袋除尘器改造方案。改造后粉尘排放浓度降至30mg／m^3。满足环保要求。     

旋转电极式电除尘器在大型火电机组上的应用

简述了旋转电极式电除尘器的工作原理和特点,重点介绍了大型火电厂330 MW机组旋转电极式电除尘器改造,详细分析了其采用旋转电极式电除尘器、电袋复合除尘器改造的技术经济性.大型火电厂330MW机组电除尘器改造后运行良好,出口粉尘浓度在30 mg/m3以下,并具有较好的经济性.     

600 MW机组除尘器升级改造及效益评价

元宝山发电有限责任公司2号600 MW机组配套电除尘器由于设计效率低、燃烧煤种变化、设备老化等多方面原因，除尘效率下降，除尘器出口烟尘排放浓度超标严重。为了满足新的《火电厂大气污染物排放标准》的要求，对元宝山发电有限责任公司2号机组配套电除尘器进行升级改造，将原有的4台四电场静电除尘器增效改造为4台电袋复合式除尘器。通过电除尘器的改造，降低了除尘器出口粉尘排放浓度，提高了除尘效率，保证了2号机组电除尘器的安全稳定运行。     

循环半干法工艺在高硫煤脱硫中的应用分析

通过对荆门热电厂4号炉循环半干法脱硫的试验分析,讨论了Ca/S、脱硫操作温度对脱硫效率及电除尘器出口粉尘排放浓度的影响,为循环半干法工艺在高硫煤脱硫中的实际应用提供参考.     

电除尘器内部粒子运动及分布数学模型仿真研究

对电除尘器除尘过程中粉尘粒子运动及其分布规律进行研究，用数学的方法构建了一个比较完整的数学模型。通过设定合适的边界条件，采用差分法对所建立的数学模型进行求解，并借助功能强大的数值计算和绘图工具软件Matlab将电除尘器中复杂的粉尘粒子运动进行数值仿真，力求清晰地描述除尘过程中粒子的运动状态和分布规律。研究表明，电除尘器中粉尘粒子在横断面上的浓度分布大致符合指数函数的分布规律，靠近收尘极板的浓度值高于电晕线附近的浓度值，这说明数学模型能够真实地反映电除尘中粉尘粒子的运动规律。     

适应低排放的电除尘技术探讨

针对高标准的排放要求以及将进一步提高的排放标准,对电除尘器是否能满足目前的排放标准和低排放要求进行了研究。通过对国内110个机组配套电除尘器实际应用情况调查和国外燃煤机组电除尘器应用分析,客观地评价了电除尘器对国内煤种的适应性,指出移动电极式电除尘器、双极异距电流体微粒聚合器、烟气调质、湿式电除尘器、低低温电除尘器等新技术的发展和综合应用是满足30mg/m3低排放标要求的最佳选择。     

基于GPRS技术电除尘器高频电源智能监测系统研究

电除尘器是火电厂重要环保设备，其运行的稳定性和参数合理性直接影响粉尘排放浓度。针对上述问题，详述利用ARM微处理器和GPRS网络相结合，开发电除尘器高频电源智能监测系统设备，在远距离处可以获得现场的实时数据，实现对高频电源远程监控和诊断。     

Performance evaluation of material separation from spent fluorescent lamps using the thermal end-cutting method

The recovery of valuable materials such as aluminum, phosphor powder, and glass from spent fluorescent lamps (SFLs) is part of the overall recycling process of lamps. In the end-cutting process, an SFL is separated into a base cap and a glass part using thermal shock caused by the temperature difference between the heating unit and the cooling unit. The separation efficiency of the end-cutting system is estimated by measuring the mass of the parts of the SFL. The optimum condition of the end-cutting process with thermal shock was determined to have a temperature difference of 600 °C and moving speed of 2 cm/s. At optimum conditions, the separation efficiency of glass and the end cap from an SFL using the end-cutting method is estimated to be more than about 97 %. In an air injection system, however, the separation efficiency of phosphor powder from glass is less than 50 %. Separation efficiency in the end-cutting system is increased by decreasing the moving speed of the SFL and increasing the temperature difference between the heating unit and the cooling unit. From the results of experiments, it was found that the end-cutting unit has very high performance because the overall separation efficiency is more than 95 %.     

Effectiveness of gutter brushes in removing street sweeping waste

Litter on roadways has to be removed for hygiene and to reduce pollution, amongst other reasons. Therefore, the effective operation of street sweepers is important in the collection of solid waste. In this article, the effectiveness of gutter brushes of street sweepers in removing different debris types, namely medium-size gravel, small and fine particles, and wet thin debris is studied by means of sweeping tests using a brushing test rig. Two types of gutter brushes, cutting and F128, are tested under a variety of operating conditions. The experimental tests provide a means of identifying suitable ranges of brush penetration for the different debris types under defined operating parameters such as brush angle of attack, brush rotational speed, and sweeper velocity. These ranges may provide sufficiently high removal forces and avoid the occurrence of sweeping problems such as backward sweeping and inappropriate bristle–surface contact. Optimum operating parameters for the three debris types studied, as well as a mixture of all of them, are determined. Lastly, the results indicate that, as far as the sweeping effectiveness is concerned, the F128 brush is the preferred one for the cases studied.     

Converting moving-grate incineration from combustion to gasification - numerical simulation of the burning characteristics

Waste incineration is a politically sensitive issue in the UK. The major current technology is based on direct combustion of wastes in a moving-grate furnace. However, general public opinion prefers non-direct burning technologies. Waste gasification is one of those nearest technologies available. By reducing the primary air-flow rate through the grate of a packed-bed system, operation of the existing solid-waste incineration equipment can be easily converted from combustion mode to gasification mode without major modification of the hardware. The potential advantages of this are lower dust carry-over in the flue gases, lower bed temperature (and therefore lower NO(x) formation in the bed), simplified gas-treatment procedures and lower running cost, among other benefits. The major disadvantages are, however, reduced throughput of the wastes and possibly higher carbon in the ash at exit. In this study, numerical simulation of both combustion and gasification of municipal solid wastes in a full-scale moving grate furnace is carried out employing advanced mathematical models. Burning characteristics, including burning rate, gas composition, temperature and burning efficiency as a function of operating parameters are investigated. Detailed comparisons between the combustion mode and gasification mode are made. The study helps to explore new incineration technology and optimise furnace operating conditions.     

Evaluation of the effect of automotive bumper recycling by life-cycle inventory analysis

This paper describes a case study of the application of life-cycle inventory analysis to automotive bumper recycling. Two scenarios of bumper recycling are compared. One is “bumper-to-bumper recycling,” in which we recycle bumpers into more bumpers. The other is “cascade recycling,” in which bumpers are recycled into different parts of a car with a lower function. Inventory analysis is applied to both these recycling scenarios by analyzing the stages of acquiring natural resources, manufacturing materials, and parts, disposal, and recycling. We chose air emission, solid waste, and fossil fuel resources as items of the inventory analysis. We quantified the effect of reductions in the environmental load by recycling bumpers, and found that reductions in the environmental load were larger with cascade recycling than with bumper-to-bumper recycling based on current conditions. Received: February 2, 2000 / Accepted: April 21, 2000     

Removal of PCDD/F from flue gases in fixed or moving bed adsorbers

Whereas the PCDD/F-abatement in MSWIs is mostly achieved through entrained-phase adsorption upon activated carbon, the other thermal processes are more bending towards fixed/moving bed adsorption or catalytic destruction. The treatment of entrained-phase adsorption has been previously dealt with. The present paper focuses upon fixed/moving bed adsorption as abatement alternative. The characteristics of granular carbonaceous adsorbents are reviewed and commented upon, and stress some advantages of the fixed/moving bed operation. The equilibrium adsorption characteristics are expressed in terms of the number of active sites of the adsorbent and its saturation capacity. The breakthrough calculations for a fixed/moving bed adsorber are based upon these adsorption characteristics and expressed in terms of the relevant operating parameters of the flue gases to be treated. Although detailed literature data on these adsorbers are scarce, application of the design equations predicts meaningful results, thus demonstrating the predictive capacity of the design method.     

End-of-life flows of multiple cycle consumer products

Explicit expressions for the end-of-life flows (EOL) of single and multiple cycle products (MCPs) are presented, including deterministic and stochastic EOL exit. The expressions are given in terms of the physical parameters (maximum lifetime, T, annual cycling frequency, f, number of cycles, N, and early discard or usage loss). EOL flows are also obtained for hi-tech products, which are rapidly renewed and thus may not attain steady state (e.g. electronic products, passenger cars). A ten-step recursive procedure for obtaining the dynamic EOL flow evolution is proposed. Applications of the EOL expressions and the ten-step procedure are given for electric household appliances, industrial machinery, tyres, vehicles and buildings, both for deterministic and stochastic EOL exit, (normal, Weibull and uniform exit distributions). The effect of the physical parameters and the stochastic characteristics on the EOL flow is investigated in the examples: it is shown that the EOL flow profile is determined primarily by the early discard dynamics; it also depends strongly on longevity and cycling frequency: higher lifetime or early discard/loss imply lower dynamic and steady state EOL flows. The stochastic exit shapes the overall EOL dynamic profile: Under symmetric EOL exit distribution, as the variance of the distribution increases (uniform to normal to deterministic) the initial EOL flow rise becomes steeper but the steady state or maximum EOL flow level is lower. The steepest EOL flow profile, featuring the highest steady state or maximum level, as well, corresponds to skew, earlier shifted EOL exit (e.g. Weibull). Since the EOL flow of returned products consists the sink of the reuse/remanufacturing cycle (sink to recycle) the results may be used in closed loop product lifecycle management operations for scheduling and sizing reverse manufacturing and for planning recycle logistics. Decoupling and quantification of both the full age EOL and of the early discard flows is useful, the latter being the target of enacted legislation aiming at increasing reuse.     

机组负荷对SCR系统运行影响研究

对SCR烟气脱硝系统的性能检测指标进行分析,阐述了严格控制SCR系统出口氨逃逸率和定期冲洗空预器装置的重要性,建议可以通过加设省煤器小旁路来调节烟气温度,以保证SCR系统在低负荷下正常运行。     

Research on the recycling industry development model for typical exterior plastic components of end-of-life passenger vehicle based on the SWOT method

In-depth studies on the recycling of typical automotive exterior plastic parts are significant and beneficial for environmental protection, energy conservation, and sustainable development of China. In the current study, several methods were used to analyze the recycling industry model for typical exterior parts of passenger vehicles in China. The strengths, weaknesses, opportunities, and challenges of the current recycling industry for typical exterior parts of passenger vehicles were analyzed comprehensively based on the SWOT method. The internal factor evaluation matrix and external factor evaluation matrix were used to evaluate the internal and external factors of the recycling industry. The recycling industry was found to respond well to all the factors and it was found to face good developing opportunities. Then, the cross-link strategies analysis for the typical exterior parts of the passenger car industry of China was conducted based on the SWOT analysis strategies and established SWOT matrix. Finally, based on the aforementioned research, the recycling industry model led by automobile manufacturers was promoted.     

用移动床生物膜反应器处理石化废水

采用悬浮填料移动床生物膜反应器处理石化废水,在水力停留时间大于6h、反应器填料投加率为50％的条件下,出水COD、NH3－N、SS、浊度等均达到国家排放标准,在水力停留时间大于8h时,能达到良好的硝化效果。