泛比电阻电除尘器伏安特性的理论及实验研究

粉尘比电阻是影响电除尘器收尘效率的一个重要因素,为扩展电除尘器对粉尘比电阻的适应范围,提高对泛比电阻粉尘的收尘效率,提出一种具有辅助电极和交错平板收尘极的新型电除尘器,并对其伏安特性进行了研究。结果表明,泛比电阻电除尘器的收尘场强比普通的线-板式电除尘器高,而且更均匀,辅助电极对电晕电流具有明显的抑制作用。     

电除尘器提效节能除尘效率公式的研究

依据理论驱进速度和我国电除尘器(EP)的运行现状,以及提效节能型高压供电设备的开发成功与推广,分析研究了反映高压供电提效节能智能优化控制特性的EP除尘效率公式。公式指出,有效驱进速度和EP除尘效率与提效节能工作方式下的二次电压峰值及最小值成正比,与火花整定工作方式下的二次电压峰值及最小值之比成正比。该公式可为EP高压供电等设备的优化研究开发和提效节能运行提供参考依据。     

纵横复合收尘极板电除尘器除尘性能研究

常规电除尘器体积大,成本高,限制了其应用.本文提出了一种新型电除尘器--纵横复合收尘极板电除尘器.通试验,比较了纵横复合收尘极板电除尘器和常规电除尘器的一些影响因素,即极板电流密度的大小和均匀性,流场分布均匀性,不同电压和不同电场风速下的除尘效率等.试验结果表明,在相同条件下,纵横复合收尘极板电除尘器的极板电流密度及流场分布更均匀,除尘效率明显高于常规电除尘器.本研究对减小电除尘器体积、降低电除尘器成本和推进电除尘技术的发展有较大的现实意义.     

矿山粉尘的湿式纤维层过滤阻力类比研究

为提高矿山粉尘收集效率,对除尘器湿式过滤层纤维丝过滤阻力进行理论分析,建立粉尘粒子通过除尘器湿式纤维丝时的阻力理论模型,自行设计了湿式纤维层过滤实验模拟系统,模拟矿山粉尘特点进行了实验研究,对理论模型参数进行了无量纲修正,进一步完善粉尘湿式过滤的阻力理论公式.实验表明,该理论在实际应用中具有较高的准确性.经修正后的理论曲线不仅与实验曲线的趋势保持一致,同时数值上也基本吻合,具有良好的代表性.     

Voltammetric study on the interaction of the heavy metals Cd(II) and Mn(II) with transfer‐RNA,DNA and other polynucleotides

Small amounts of bivalent cations, usually provided by Mg²⁺, are in the living cell necessary for the biological activity of t‐RNA as these bivalent cations influence the tertiary and secondary structure of this globular polynucleotide.

In context with the discussed possibility of carcinogenic actions of ingested Cd it is of particular interest to check whether there exist specific strong interactions of this toxic heavy metal with nucleic acids.

Therefore, the binding of the toxic heavy metal ion Cd²⁺ and the essential heavy metal ion Mn²⁺ to t‐RNA and for comparison to DNA and the polynucleotides poly‐U, poly‐A and poly‐A‐poly‐U has been studied. Free metal ion concentrations have been determined by differential pulse polararography. Association constants and the number of binding sites have been evaluated by the Scatchard method and alternatively according to a simple electrostatic model of the polyelectrolytes. With the Scatchard method for t‐RNA and all polynucleotides with helical structure two different binding sites of different strength are observed. Those with higher association constants are assigned to the helical parts of t‐RNA. Interaction sites with low association constants correspond to the parts with no ordered tertiary structure, as their exclusive occurrence for poly‐U, having a completely stochastic coil structure, reflects. The values of the association constants for the stronger and weaker association sites are in the respective polynucleotides for both investigated bivalent metal ions of comparable magnitude. This emphasizes that the interaction is essentially of electrostatic nature and depends primarily on the charge of the interacting species.

Thus the specific strong interaction of Cd by the intercalation into the tertiary structure of nucleic acids or by chelation of their base units can be ruled out as one possibility for carcinogenity of Cd.

Moreover, under physiological conditions the high excess of competitive Mg²⁺ will suppress the interaction of Cd based on electrostatic forces.     

电除尘器对烧结灰除尘性能影响的试验研究

在电场断面面积为0.3 m 2(600m× 500 m)的电除尘器(ESP)实验系统上,采用正交试验法,确定电晕线型式、含尘浓度、电压值和风量(电场风速)4个试验因子,总除尘效率为指标值,进行电除尘器对烧结灰除尘性能的试验研究.研究结果表明,当气流含尘浓度从15g/m3提高到25g/m3时,ESP的总除尘效率η从96.87%降至87.55%;当电源电压值由85 kV增至96 kV后,ESP的总除尘效率从98.16%降至87.55%;当ESP的电场风速由0.62 m/s增至0.79 m/s,总除尘效率由96.87%降至92.46%;星型线ESP的除尘效率相对较低;尖端放电可改善ESP用于高比电阻粉尘时的操作性能,芒刺线、锯齿线ESP的除尘效率分别高达99.46%和99.55%.     

Characteristics and hazards of electrostatic discharges in air

In the assessment of electrostatic hazards in the process industries, a great deal of emphasis has been placed on the determination of energies in spark discharges. There are, however, other electrostatic discharge phenomena where this approach has severe limitations. The purpose of this paper is to describe the state-of-the-art with respect to electrostatic discharges in gases (air). An in depth review of the literature has been made, and the various types of discharges are tabulated and discussed.     

粉料无尘装车技术及其在电除尘器、大布袋除尘器输灰系统中的应用

传统电除尘器、大布袋除尘器输灰系统存在工艺繁杂、能耗大、输送速度慢、系统难于维护及二次扬尘问题,电除尘器、大布袋除尘器输灰系统采用粉料无尘装车技术可有效简化工艺、提高生产速度和系统运行、维护可靠性,很大程度减少能耗并彻底根除二次扬尘。     

高压静电分选Ag与PET的实验研究

为了提高高压静电分选Ag与聚对苯二甲酸乙二醇酯(polyethylene terephthalate,简称PET)的效率,寻求可产生较佳分选效率的电压、转速、极间距和电晕线角度。采用自制的线辊式静电分选机,通过单因素实验和部分因子实验,研究了不同条件下Ag与PET的分选效率。结果表明:将Ag与PET从二者混合物中有效分选出来的电压为25~30k V、转速为60~75 r/min、极间距为60~70 mm、电晕极角度为50~60°;当电压为30 k V、转速为75 r/min、电晕极距离为70 mm和电晕极角度为60°时,Ag的分选效率达到了最大值为99.60%,PET的分选效率也达到了最大值为99.98%,为线辊式静电分选机结构设计与参数优化提供了参考。     

烟道中同极性荷电粉尘的凝并研究

针对目前电除尘器对微小颗粒粉尘捕集效率低、本体体积庞大的问题,突破传统预荷电装置的应用模式,将预荷电装置安装于电除尘器模拟烟道中,进行了高压电场荷电凝并研究,考察了凝并电场频率、电场强度以及电场类型对粉尘凝并效果的影响。实验结果表明:可以大幅度降低粒径在0.3~0.5μm的粉尘百分比;有效增加粒径>1μm的粉尘百分比;可以有效提高模拟电除尘器对细小颗粒粉尘的捕集效率,有望减少电除尘器的本体体积。