浅谈洁净室用静电防护鞋的耗散特性

从静电防护鞋的防护机理入手,介绍和对比了国内外静电防护鞋的相关检测指标与测试方法,并对其防静电性能和耗散特性的评价方法提出了一些建议。为解决静电防护鞋的低电阻、持久性和稳定性问题,一方面需要开发高效持久的抗静电鞋材,另一方面还可以从产品测试标准与方法着手,对相关标准和方法进一步改进完善。建议与国际标准接轨,综合考虑鞋/地系统的电阻(人体综合电阻)、行走电压,提高产品的竞争力,促进电子工业、石油工业、纺织工业、橡胶工业以及军事兵器工业等领域的快速发展。     

静电油烟净化器对餐饮油烟中醛酮类VOCs的去除

利用2,4-二硝基苯肼（DNPH）硅胶管采集了9家餐饮企业静电油烟净化装置处理前后的醛酮类VOCs样品,并采用高效液相色谱（HPLC）进行分析.结果表明,9家餐饮企业处理前后的油烟中醛酮类VOCs浓度范围分别为419.5~3372,415.8~2934μg/m³,经过基准风量折算后的浓度分别为783.4~3761和541.7~2997μg/m³,VOCs排放浓度与烹饪方式、实际使用灶头数和排风量有关.从排放的醛酮类VOCs的种类来看,C1~C3化合物的浓度占检测到的总羰基的66%以上,且甲醛占比最高,其次是乙醛;C4~C8化合物的含量相对较低.静电式油烟净化器对醛酮类VOCs的平均净化效率为31.82%,最高可达69.14%,其中对甲醛的净化效果最佳,平均为35.21%,最高达80.10%.复合式静电油烟净化器的净化效果要稍好于单一静电油烟净化器.     

电除尘器的运行与维护

基于越来越多的火力发电厂都采用高效电除尘技术的现状，为了保证电除尘器长期、高效、稳定运行，结合多年的运行工作实践，对电除尘器的运行、维护、检修提出建议。     

铜矿酸性废水氧化钙中和处理装置的改造

介绍了用氧化钙二次中和沉淀法处理铜矿酸性废水的工艺流程、主要设备和处理效果。针对矿山不断开采带来的废水水质变化和处理装置存在的新问题 ,对工艺路线、斜板沉淀池、石灰消和机等进行了改造。改造后的运行结果表明 ,出水水质达到GB8978— 1996二级排放标准 ,节约运行费用 15万元 /a ,沉淀池大修期从 4a延长到 6a ,减少石灰用量 8% ,增加废水处理量 1.5× 10 5m3 /a。     

用电捕焦油法净化炭素焙烧炉烟气

论述了静电捕焦油器净化炭素厂焙烧炉烟气的工艺流程及技术参数 ,提出了确保系统正常运行的技术措施。使用静电捕焦油器后沥青烟排放浓度低于 5 0mg/m3 ,粉尘排放浓度降到 2 6mg/m3 。     

转炉煤气电除尘器气流分布数值模拟

电除尘器电场进出口气流分布的均匀性是影响电除尘器除尘效率的重要因素。基于计算流体力学(CFD)技术,采用fluent软件平台,通过对方形和圆筒形两种外形转炉煤气用电除尘器的气流分布进行数值模拟计算,比较了两种外形电除尘器的气流分布差异,说明了圆筒形电除尘器较方形电除尘器气流分布状态的优越性。     

静电过滤除尘机组性能的现场测试

JDPL型静电过滤除尘机组是我们根据多年来的理论及实验研究成果而设计的。其在实际运行中的测试结果表明,该机组较普通机组效率提高,阻力降低,清灰效果好。     

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%.     

高温烟气中颗粒静电脱除特性的实验研究

研究温度90~450℃条件下静电除尘器的放电特性及除尘特性,分析温度、工作电压、烟气流速及颗粒浓度等关键参数对于颗粒静电脱除效率的影响.结果表明,当温度从90℃上升至450℃,在比收尘面积为46.5m²/(m³·s^-1),粉尘初始浓度约为750mg/Nm³的工况下,颗粒脱除效率均可达到98%以上.随着电压升高,除尘效率不断提高,但其升高趋势逐渐变缓.在相同电压下,随着温度的上升,电晕电流显著增大,强化颗粒荷电,颗粒的脱除效率提高;而在相同电流下,高温下较低的空间场强使得颗粒的驱进速度减小,导致颗粒脱除效率下降.烟气流速提高降低了颗粒的脱除效率,PM_1.0受烟气流速的影响较PM₁₀更为明显.颗粒初始浓度的上升增强了颗粒的碰撞及团聚作用,在一定程度上有利于增强颗粒的脱除效果.     

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.