过滤材料声学性能的实验研究*

为探讨纤维过滤材料的吸声效果,扩展吸声材料的选择范围,并为噪声粉尘一体化控制提供指导,通过实验分析不同等级一般通风用纤维层滤料的过滤性能和吸声性能,研究叠加方式及空腔设置等对滤料吸声性能的影响。研究结果表明:一定条件下,滤料的过滤效率越高吸声性能越好;单层滤料吸声效果较差,通过多层叠加,可显著提升吸声效果,达到吸声材料水平;不同等级滤料组合叠加,按过滤效率降序排列整体吸声性能更好。滤料作为吸声材料应用时,在其后侧设置空腔可明显增强吸声效果;兼顾过滤和降噪时,考虑粗效对中效滤料的保护作用,可在粗效加中效滤料后再附加粗效滤料,达到在不显著增加阻力的同时改善吸声性能的目标。     

水雾荷电振弦纤维栅除尘器除尘性能影响因素的实验研究

为研究除尘系统结构最优配置,实验采用新型高效水雾荷电振弦栅除尘方法,以除尘效率及阻力损失为参照结果,选定纤维栅板数量、纤维栅与喷嘴间距、纤维栅材料和间隙4个因素进行单因素试验,针对各因素对纤维栅除尘效率的影响进行了分析研究,结果表明多块纤维栅除尘效果明显优于单块纤维栅,正常处理风速时3块纤维栅的除尘效率最高,纤维栅阻力与其数量呈正比;纤维栅除尘效率随间距增大而先增后减,间距为230 mm时除尘效率最高;塑胶纤维栅除尘效果明显优于其他材料,各阻力值排序为:塑胶＞涤纶＞不锈钢＞尼龙;纤维栅除尘效率随纤维间隙增大而降低,其阻力随间隙增大而减小;利用SPSS软件进行4因素三水平正交试验分析,在特定条件下除尘效率显著性排序为:纤维栅数=纤维栅间隙＞纤维材料＞纤维栅与喷嘴间距;阻力损失显著性排序为:纤维栅数=纤维栅间隙=纤维材料=纤维栅与喷嘴间距;试验最佳配置为3块间隙0.6 mm尼龙纤维栅板,且纤维栅板距喷嘴最小间距为185 mm。     

金属丝棉结构在电焊烟尘处理中的过滤性能研究

电焊烟尘对人危害极大,必须加以净化才能排放到空气中.然而电焊作业烟尘量极大,由于过滤效率低,导致小型移动式电焊除尘器应用受到限制.为了更好地利用移动式除尘器净化电焊烟尘,研究高效过滤材料变得非常重要.通过数值模拟金属丝绵的除尘效率、过滤压力损失及残余压降等影响过滤性能的因素,将金属丝绵应用于移动式除尘器.为了更好地发挥...     

抛光打磨车间便携式除尘器本体设计与试验

基于气旋分离和滤筒过滤的除尘原理,采用气旋分离作为一级除尘分离大颗粒粉尘,滤筒过滤作为二级除尘去除细颗粒物,设计并构建了适用于抛光打磨车间的便携式除尘器试验模型,并对其运行性能参数进行测试。结果表明：除尘器处理风量为117～179 m³/h,漏风率和设备阻力随处理风量的增加而升高,漏风率控制在3.52%以内,设备阻力最小为163 Pa,最大为393 Pa;除尘效率随风量的增大而发生轻微降低,该便携式除尘器的最高除尘效率达99.63%。     

脉冲滤筒除尘器对超细粉体净化的实验研究

随着工业的快速发展,空气中颗粒污染物的含量和种类越来越多,不仅对人体健康造成危害,颗粒污染还对能见度、气候、动植物均有影响,寻找合适的除尘设备,提高对微细粉尘的除尘效率,对安全和环境保护有着重要而深远的意义。该文利用脉冲滤筒除尘器对粒径分布为0.5-5μm的超细粉体进行净化实验。测试了除尘器净化效率、除尘器阻力及过滤风速等主要性能参数。实验结果说明:脉冲滤筒除尘器对于粒径为0.5-5μm超细粉体,在过滤风速为0.8-1.25m/min时,除尘器阻力小于300Pa,净化效率达99.9999%。得到结论:滤筒除尘器具有高除尘效率,低阻力损失,节约除尘系统的动力消耗的优点,有利于在超细粉体净化工艺中的应用。     

掘进巷道粉尘控制技术的研究

针对掘进巷道的特点,研制了一种高效实用的自激式水浴水膜除尘器,并对其结构、除尘过程和与掘进机相配套的方式进行了研究分析。还对掘进巷道中的产尘源进行了调查和分析,认为掘进巷道的防尘方法：应先采用掘进机头的内外喷雾,然后采用长压短抽的通风除尘系统和利用除尘器将含尘空气进行净化;对转载点除尘采用简易闭密罩加喷雾;对巷道周壁的粉尘采用喷洒粘尘剂固尘,才能有效地降低整个巷道的粉尘浓度。     

A Contribution to the Study of the Antidust Respirators’ Real Performance

In most industrial enterprises, hazardous factors are present in quantities exceeding permissible levels. Such a situation requires using antidust respiratory protection. It has been suggested, however, that filters for respirators are not assessed properly and that lab results might not be related to real filtering efficiency in industry. This article contains test results of some commercially available filtering half-masks, including the effect of loading with real dust, high humidity, high temperature, and a combination of loading with dust and high humidity on the half-masks’ performance. The results show that the effect of these factors is considerable and that a combination of loading with silica dust and exposing to high humidity can cause a complete loss of performance.     

中小型燃煤锅炉烟气脱硫除尘一体化技术的研究与应用

燃煤所造成的酸雨污染和颗粒物污染已成为制约我国经济和社会可持续发展的一个重要因素.除尘脱硫的一体化技术研究已成为我国锅炉烟气污染控制的一个热点.主要从干法、半干法、湿法3个方面介绍了SSX式、湍流塔板式、旋流板式、SHG式、吸附过滤和等离子体等国内应用得比较普遍的几种锅炉烟气脱硫除尘一体化技术.对其优缺点做了比较,结合我国国情,提出了应重点发展湿法脱硫除尘一体化技术.     

覆膜滤料过滤性能分析

覆膜滤料以其高效低阻、透气性好等特点备受关注。选取4种典型的覆膜滤料,通过静态和动态过滤实验分析其阻力和效率特性,进而对覆膜滤料的过滤性能进行综合分析。结果表明:在清洁阶段,4种覆膜滤料的喷吹周期和残余阻力差异较大,粉尘剥离率平均值为83.2174%,最大偏差为2.32%;在稳定阶段,4种覆膜滤料的清灰周期、残余阻力差异减小且趋于稳定,残余阻力增长率接近且偏差均在5%以内,剥离率平均值为95.4485%,最大偏差仅0.55%。可以看出,稳定阶段覆膜滤料的种类对于阻力增长率和粉尘剥离率影响不大。通过细颗粒物过滤实验可知,评价覆膜滤料对PM2.5的过滤效果需要综合考察滤料清洁阶段和稳定阶段,可为覆膜滤料应用和评价提供指导。     

Investigation of Blended Fibre Filtering Materials

Five variants of mixtures of different synthetic fibres at different area ratios were manufactured into needled nonwovens intended to be used as a filtering material for respiratory protection. Two variants were produced according to an earlier patent, and the contents of the other three was completely new. Samples of the nonwovens were tested for sodium chloride particles penetration and for breathing resistance. The results showed that one variant of a nonwoven, designated PP/PPFM, had very valuable filtering properties and that those properties were stable in time.     

粉尘监视仪在全干式除尘中的应用

粉尘监视仪在干式布袋除尘工艺中起着至关重要的作用,能够及时反映出干式布袋的运行状况,起到保护除尘设备和监控煤气粉尘含量的作用.同时粉尘监视仪还可广泛地用于环保型工业生产中.     

综采工作面粉尘运移和粉尘浓度三维分布的数值模拟研究

分析了综采工作面流场及粉尘分布的特点 ,视工作面含尘风流为气 粒两相流 ,建立了描述综采工作面风流中粉尘运动和浓度分布的数学模型。采用计算流体力学的有限容积法求解 ,编制了模拟计算综采工作面三维空间内风速和粉尘浓度分布的计算机程序     

工业防尘技术新进展

介绍了我国工业防尘技术的现状和新进展。着重讲述了屋顶除尘器、抑尘剂、移动通风槽分别是二次烟尘治理、开放性扬尘抑制、移动尘源控制的新技术措施,风量调节与控制、气力输灰技术将在除尘系统中广泛应用;在除尘设备方面,长袋低压脉冲袋式除尘技术和“表面过滤”技术成为袋式除尘新技术,设备大型化将成为方向。     

捕尘过滤材料清洗再生实验研究

空气颗粒物过滤材料作为一次性使用的耗材,在阻力升高至一定值时就被更换并抛弃,不仅使过滤系统成本增加,而且会产生二次污染,不利于生态环保。通过实验探究滤料清洗再生的方法,研究了MES表面活性剂浓度、温度、清洗时间对清洗效果的影响。结果表明:温度为25℃、MES溶液质量分数为0.7%、清洗时间为30 min时的清洗效果最佳,清洁度可达97%,结合超声波辅助时可使清洁度增至99.2%,经过4次清洗再生后,滤料的阻力、效率与纤维力学性能未发生明显变化,证明了该方法在工业应用中的可能性。     

旋风除尘器灰环磨损与锥体角度关系的研究

提出在普通锥体型旋风除尘器中,回转性灰环是造成锥体部位磨损的重要原因之一.通过对锥体内粉尘颗粒的受力分析,从理论上推导出了减低灰环磨损的锥体角度的表达式.通过对理论分析提出了旋风除尘器锥体设计中应注意的问题,为旋风除尘器的设计提供一定的参考依据.     

湿式旋流弦切除尘器性能实验研究

旋流弦切除尘器作为一种新型湿式除尘器,具有良好的特性。本文在所建立的实验系统上,按湿式除尘性能测试的相关规范,研究了除尘风速、弦切速度与除尘器效率和压力损失间的关系。实验结果显示:在液气比为定值时(0.05 L/m~3),在实验风速范围内,除尘效率存在极值;压力损失符合流体力学的局部阻力规律,并拟合出了除尘器的局部阻力系数。     

Friction spark generation and incendivity of several metal alloys

When metal alloys are used as mechanical equipment or tools in explosive atmospheres, the occurrence and incendivity of mechanically generated sparks as ignition sources should be taken into consideration. The formation of mechanically generated sparks was investigated for seven metals, including Q235 steel, 304 stainless steel, TC4 titanium alloy, 6061 aluminum alloy, H62 bronze alloy, AMAK3 zinc alloy, and AZ31B magnesium alloy. The relationship between the physical-chemical properties and generation and incendivity of friction sparks was evaluated. For 6061 aluminum alloy, H62 bronze alloy, AMAK3 zinc alloy, and AZ31B magnesium alloy, no bright friction sparks were observed in the maximum friction velocity of 12 m/s and maximum surface pressure of 3.75 N/mm², because of low hardness, high thermal conductivity, low melting point, and the absence of carbon content. Ignition testing indicated that nano titanium dust layers with MIEL (minimum ignition energy of dust layer) of 1 mJ were not ignited by friction particles from the four metal alloys. However, bright particles were clearly observed for 304 stainless steel, Q235 steel, and TC4 titanium alloy. Friction sparks at the maximum power densities showed incendivity with micro titanium layers having an MIEL of 17.5–25 mJ but not with PMMA, corn starch, and wood dust having MIELs greater than 1 J. Two different particle burning behaviors with different fragmentation mechanisms during the friction process were determined, namely the micro explosion phenomenon for TC4 titanium alloy and particle burst for Q235 steel. Results indicate that the physical-chemical properties of friction metal rods are useful for preliminary evaluation of spark generation. Powder layers with known MIEL can be considered as indicator testing materials to evaluate spark incendivity.     

钢铁窑炉烟尘PM_(2.5)控制技术与装备

简述了国家863课题"钢铁窑炉烟尘PM_(2.5)控制技术与装备"的目的、意义和研究成果,介绍了细颗粒物预荷电技术、基于海岛纤维的表面超细过滤材料、预荷电袋滤器、"一阀多喷"清灰等技术的最新进展,通过示范工程的成功运行,验证了成果的先进性和实用性。研究成果将为工业窑炉烟尘细颗粒物深度净化提供技术和装备支撑,适用于新建除尘项目和除尘项目改造。     

The effect of admixed material on the flaming and smouldering combustion of dust layers

The rate of propagation of flame and the rate of propagation of smouldering in still air, have been investigated for several particle sizes, mixtures of coarse and fine dusts of the same material, and mixtures containing partially coarse dusts of limestone. Wood sawdust and grass dust were used as the industrial materials. Measurements were made by using a mold of acceptable dimensions. The results obtained indicated that the flaming and smouldering rates are dependent on the particle size and the depth of the layer and the values of the smouldering rates were found to be about 20% of the values obtained with flaming. Also, an admixture of fine dust of 50% of the same material to coarse dust for a 0.5 cm layer of both materials is sufficient to increase the values of the flaming rate by 61% for wood sawdust and the smouldering rate by 88% and 52% for wood sawdust and grass dust, respectively. The admixture of limestone as low as 10% was sufficient to produce zero propagation for both types of burning.     

卧式滤筒除尘器的气流组织模拟研究

为了研究卧式滤筒除尘器内部气流的不均匀性问题,采用计算流体动力学软件Fluent对卧式滤筒除尘器内部气流组织进行数值模拟研究。参考目前市面上常见卧式除尘器,设计有、无挡板的2种卧式滤筒除尘器模型,通过分析2种模型下过滤过程的速度分布和滤筒流量分配情况得出:在无挡板模型下存在射流冲刷、气流分布不均等问题,而在进风口加设挡板能解决气流冲刷问题,滤筒流量分配得到明显改善;在相同滤室高度下分别对挡板角度为150°,160°,165°,170°,175°,180°对比发现,挡板角度在165°~170°时其内部气流组织能达到均匀标准。