高温陶瓷净化生物质气化粗燃气粉尘试验研究

生物质气化得到的粗燃气含有焦油和粉尘杂质,两者形成的混合物在净化装置的高温区易碳化结焦,在低温区容易凝结成团,因此常规的除尘技术并不适用。针对该问题,本文开发了粗燃气高温陶瓷除尘技术,并考察了生物质原料种类、补燃及反吹等工艺条件对除尘室压降和运行温度的影响。试验结果表明:与木片单独气化比较,采用25%成型颗粒燃料+75%木片(质量比)混合气化可导致除尘室阻力上升1200~1500Pa;高温除尘室最佳操作温度为450~550℃,补燃较反吹是降低除尘室压降更有效的手段,当燃气处理量为260~400m3/h时,补燃空气的最佳流量为10~12m~3/h,此条件下可使除尘室压降稳定在1200Pa左右。陶瓷管燃气除尘设备可实现100h连续稳定运行,除尘器出口粉尘浓度为10~40mg/m~3,粉尘脱除率92.3%~99.8%,焦油脱除率为31.0%~92.5%,且补燃除尘后可燃气体组分浓度基本保持不变。     

入口抽滤预团聚提高旋风分离器性能试验研究

分析了旋风分离器对细粉捕集效率低的原因,并提出了对传统旋风分离器的改进方案,即将传统旋风分离器的排气芯管改进为一个过滤筒,并在滤筒内部加装转动清灰刷,这样的设计充分利用了旋风分离器和过滤除尘器各自的优点,使过滤除尘和旋风除尘有机结合在一起,节约了设备空间,提高了其综合性能,实验结果表明除尘总效率一般都在99.94%以上,完全除去了1.6μm以上的细粉尘。     

环流循环除尘系统的开发(Ⅰ)除尘系统的性能

针对亚微米粉尘的除尘开发出了环流循环除尘系统.实验测试了环流循环除尘系统、环流式旋风除尘器、常规型除尘器的效率和压降.结果表明,环流循环除尘系统对分子筛的除尘效率达到了97%以上,分割直径d50为0.33～0.65μm,明显地高于B型和环流式旋风除尘器,压降小于3000Pa,只比B型旋风除尘器的单台压降高60%左右.     

天然气净化用多管旋风分离器的分离性能

为了系统评价天然气净化用多管旋风分离器的分离性能,在线测量了入口气速6~24 m/s、入口颗粒浓度30~2000 mg/m3范围内多管旋风分离器的分离效率和分级效率. 结果表明,多管旋风分离器的分离效率和分级效率都随入口气速和入口颗粒浓度增大而提高. 与单管旋风分离器相比,在相同实验条件下,多管旋风分离器的分离效率下降2%~15%;单管旋风分离器基本能除净粒径大于10 mm的颗粒,而多管旋风分离器只能去除15 mm以上的颗粒. 多管旋风分离器的压降主要是内部单管旋风分离器的压降,占整个压降的80%~90%.     

撞击流除尘技术研究

设计开发了撞击流除尘器,对撞击区中假定为球形的颗粒进行受力分析。根据牛顿第二定律建立颗粒受力平衡方程,推导出除尘临界气速ua,t函数关系式和撞击区宽度l应满足条件。选用自行设计的磷矿粉回收试验装置,对除尘效率与加速管空气速度及粉尘质量浓度间关系进行试验研究,结果表明在加速管空气速度在5～15m/s低速度范围内,最优除尘气速大约为10m/s,除尘效率可达99%;在15～30m/s范围内,该气速约为23m/s,除尘效率也在96%以上;粉尘质量浓度为0.8kg/m3时,除尘效率最高,表明撞击流除尘器适合处理含尘质量浓度较高的物料。     

关于复合肥生产装置干燥尾气二级除尘系统的优化设计

针对10万t/a复合肥生产装置尾气粉尘严重超标的问题,提出了增设二级除尘系统的技术改造方案。介绍了旋风除尘器的工作原理;建立了旋风除尘器效率数学模型及其约束条件;通过对数学模型求解,确定了旋风除尘器的结构尺寸,完成了优化设计。结果表明,尾气粉尘浓度由原来的263.3 mg/m3降低到25.2 mg/m3。     

旋风-颗粒床组合去除PM2.5的试验研究

为增强对微细粉尘的捕集能力,将旋风分离器与颗粒床过滤器串联组合,重点研究该复合式除尘装置对PM2.5的去除效果。试验结果表明,旋风分离器与颗粒床过滤器串联系统的总分离效率可达99.99%,且压降不高于3.5 k Pa。颗粒床出口粉尘d50=0.7μm,d95=1.4~1.7μm。故该装置在较低的能耗下对5μm以下微细粉尘尤其是PM2.5有较高的捕集能力。     

环流式旋风除尘器内颗粒运动的数值模拟

采用CFD软件Fluent提供的雷诺应力模型（RSM）和随机轨道模型,对环流式旋风除尘器内颗粒运动轨迹进行了数值模拟研究。预测了不同粒径颗粒的运动轨迹和分离效率。结果表明：颗粒在环流式旋风除尘器内的运动路径比常规除尘器长;特殊的流路设计,避免了常规旋风除尘器易产生的上灰环和颗粒短路问题,使除尘效率大幅度提高;除尘器内颗粒运动有较强的随机性,尤其对于小颗粒,受气流湍动影响显著。对不同粒径颗粒分离效率的预测表明：环流式旋风除尘器的分割粒径为1．25μm。     

袋除尘技术在PEF600×900破碎机上的应用

秀山水泥厂PEF600×900颚式破碎机除尘原用四管旋风收尘器,使用多年,管道多处磨损修补,收尘效率低。因此,1998年自制了一台外滤式袋除尘器代替原旋风除尘器。这台收尘器安装运行后,取得了满意的效果,本文作一介绍。 1 除尘设备的选型 PEF600×900颚式破碎机在工作时,有一定的粉尘飞扬,由于粉尘颗粒较粗,排尘风量不大于     

离心力场-移动床耦合气固分离装备的研究进展

气固分离装备的发展对于实现高温烟气的高效除尘净化具有重要意义。基于单一气固分离机制的除尘装备难以实现精细除尘的目标。将离心分离和移动床分离耦合在同一装备中，实现两种分离机制的协同强化无疑是一种解决方案。在该耦合装备中，旋风壳体和移动床内气相、捕集颗粒、粉尘的运动较之常规单体旋风分离器、移动床均具有一些独特的特性。通过压降-时间响应曲线发现该新型耦合分离装备具有自清洁功能。该装备对黏附性微细粉尘的捕集效率在95%以上；旋风壳体分离了10μm以上颗粒物，而内置颗粒床捕集到的粉尘粒径在10μm以下，验证了二者在同一装备中的协同强化。但是，强化自清洁效应和提高捕集效率构成了一对矛盾。研究表明，该新型耦合分离装备仍具有很大的性能提升空间。     

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。