电袋复合除尘技术在电石渣配料生产线上的应用

<正>我公司3 000t/d和2 500t/d两条100%电石渣配料生产线,2008年建成的窑尾五电场电除尘器,对窑尾废气的处理效果达不到新国标排放标准。为此,公司在2014年5月决定对电除尘器进行技术改造,根据生产工艺特点和电除尘器现有状况,决定改电除尘器为电袋复合除尘器,以有效降低粉尘排放浓度,达到环保标准要求,力尽社会责任。1原电除尘设备的运行状况及技术性能参数电除尘器入口实际烟尘浓度100~150g/m3(标态),出口烟尘浓度30~50mg/m3(标态)。窑尾电除尘     

2000t/d生产线窑尾电除尘器改为电袋复合型除尘器的措施

我公司2 000t/d生产线窑尾30/12.5/3×10/0.4电除尘器原有3个电场,烟气最大处理量450 000m3/h,标态下电除尘器入口粉尘浓度30g/m3。由于窑尾电除尘器标态下粉尘排放浓度〉100mg/m3,达不到国家环保排放要求。为此在2010年4月大修技改时,     

电除尘器技术改造

水泥厂过去的除尘设备排放标准一般为150mg/m3,现在大部分地区都提高到80～100mg/m3。如何使这些老设备提高收尘效率,做到少化钱,物尽其用,是老厂环保设备改造的一大难题,下面结合石家庄水泥厂一台90m2窑尾电除尘器及两台10m2烘干机电除尘器的多次技改,谈一点体会。1 90m2电除尘器的改造 从电除尘器理论公式和运行经验都证明增加收尘面积可提高收尘效率。一般有两条途径,一是增加收尘器     

电除尘器飞灰粒径表征及细颗粒降温团聚

基于50000m³/h实烧烟气中试系统,采用Mastersizer 2000E激光粒度分析仪和电子低压冲击仪（ELPI）,首次对电除尘器飞灰几何粒径和空气动力学粒径进行全面表征。结果表明,电除尘器入口及各电场的飞灰几何粒度分布均呈双峰分布特征,各电场峰值依次右移,但末级旋转电极电场≤ 1μm的颗粒占比略有升高,电除尘器入口及第1～5电场飞灰几何中位径分别为6.607μm、17.378μm、2.884μm、2.577μm、2.460μm、2.480μm;温度降低,电除尘器入口飞灰几何粒度分布的双峰均右移,颗粒团聚现象明显,80℃、90℃、110℃、130℃、150℃时电除尘器入口飞灰几何中位径分别为13.183μm、10.500μm、10.171μm、6.607μm、7.586μm,从130℃降至90℃,电除尘器入口几何粒径≤ 1μm、≤ 2.5μm、≤ 10μm的飞灰占比分别减少了19.8%、19.2%、12.6%;不同温度时,电除尘器对空气动力学粒径0.03～10μm段颗粒的个数浓度、质量浓度均有较高脱除效率,均在75%以上,最高可达99.9%;温度降低,电除尘器进出口空气动力学粒径不同粒径段颗粒个数浓度和质量浓度均有不同程度降低,从130℃降至90℃、80℃,对应电除尘器入口PM_2.5团聚效率分别为46.76%、60.08%,对应电除尘器出口PM₁₀减排分别为59.80%、91.08%,PM_2.5减排分别为45.94%、76.22%,PM1减排分别为40.40%、62.12%。     

回转窑电除尘器事故分析及改造

永新水泥厂Φ 4. 5m× 100m湿法回转窑电除尘器 (型号 PTPK- 100),因壳体强度不足以承受壳体内部负压,投用后不久即发生事故. 2002年 5月 11日壳体框架立柱严重弯曲变形,致使除尘器内部短路,无法正常工作,给生产造成很大损失.后经采取措施,使除尘器恢复了运行.经分析,认为电除尘器实际运行负压超出了设计值是造成此次事故的主要原因.     

烘干机除尘器耐腐蚀改造

巢湖水泥厂Φ2.4m×18m矿渣烘干机原采用SZ17m2电除尘器,使用初期效果较好,由于工艺系统的缺陷,烘干机的废气温度与露点温度相差甚小,当废气温度降至露点温度或低于露点温度时,废气与粉尘发生反应,对电除尘器的配件产生电化学腐蚀。因此电除尘器配件的使用寿命较短,一般在1～1.5年,最短时仅10个月。针对存在问题,2002年对其进行改造,取得了良好的效果。1腐蚀的产生及危害1)由于烘干机应用了新型扬料板和新式热风炉技术,其热效率不断提高,产量由原先的18t/h提高到30t/h,从而使进入电除尘器的烟气量和含尘浓度增大,加大了电除尘器的负荷,造成…     

湿法短窑立式电除尘器的改造

我厂３号窑为Φ３．５m／４．０m×６９m窑尾带Φ４．５m×３．８m卧式蒸发机的湿法短窑，出蒸发机废气经旋风除尘器和５０m２立式电除尘器进行二级收尘。该生产线自１９７４年投产以来窑尾废气一直超标排放，虽经改造并对电除尘器进行了彻底大修，但仅能维持在三类区６００mg／m３（标况）的达标线上。１原立式电除尘器参数及存在问题１．１原立式电除尘器设计及工况参数见表１～３表１原立式电除尘器设计参数电场断面５０m２电场风速１～１．２７m／s电场数量并联二电场处理能力１８００００～２２８０００m３／h同极距３５０mm极板型式郁…     

CLX电除尘器的技术改造

我厂Φ2.4×7m磨机的CLX电除尘器自1995年建成投产以来,效果一直不理想,针对这一现状,我厂组织实施了对该电除尘器的技术改造,改造后电除尘器运行良好,收尘效果显著。1 对CLX卧式电除尘器1、2电场的改造 改造前存在的问题如下(改造前电除尘器1、2电场如图1)。     

老立式电除尘器的技术改造

我公司Φ 3. 5m/3. 3m/3. 0m/3. 3m× 118m的老湿法回转窑系统,窑尾 E40m2立式两电场电除尘器于 1957年建成投产,经过 40多年的超负荷运转,技术性能下降,导致污染较为严重。 1994年投资约 490多万元技改了 1台 70m2卧式电除尘器,投入运行后其效果一直不理想。针对这一现状,展开了对 1号窑 E40m2立式电除尘器的试验性技术改造。 1原收尘系统 1. 1收尘系统工艺流程 (见图 1)图 1除尘系统工艺流程 1. 2 E40m2立式电除尘器设计参数 　　有效断面积 40m2,最大废气处理能力 120 000m3/h,标况下允许最大入口含尘浓度 40g/m3,要求电场风…     

电除尘器阳极板及阴极吊挂积灰问题的解决

江苏盐城天辰水泥厂2500t/d生产线,窑尾采用型号为KDW180-3&#215;4.0电除尘器,该电除尘器的横截面积180m2,采用3个电场。自电除尘器投入运行一年来,阳极板积灰严重,极板下部有开裂;阴极吊挂积     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。