CXS(Ⅱ)型高温袋式除尘器在3000t/d生产线的应用

我公司3 000t/d生产线窑尾与生料磨共用1台双系列CXS(Ⅱ)1000-2×7(F)型高温袋式除尘器,自2004年4月份投产使用以来,曾反复出现过运行阻力大、系统冒灰,甚至直排的不正常现象.经过多次分析论证,认为是配用的高温袋式除尘器过滤面积小、过滤风速高,导致除尘器阻力超过允许范围,影响了整个窑系统的正常运行.2006年3月初在原除尘器的基础上并联1台与原除尘器结构相同的单排(即原除尘器的一半)高温袋式除尘器,收尘袋室由14个增加到21个,并改用普通玻纤滤布.经改造,过滤面积增加了8 566.4m2,过滤风速由0.583m/min降到0.363m/min,系统阻力由2 000Pa左右降为1 200Pa以下,随窑系统运转率达到100%.     

贵州瓮福80万吨／年重钙装置改产DAP的技改及运行情况

介绍瓮福磷肥厂重钙装置改产磷铵 (DAP)时 ,对造粒机氨分布器、溜槽、旋风除尘器、产品筛分机等的技改情况。讨论瓮福磷肥厂及国内某 DAP生产厂造粒机主要参数与美国 TVA氨化造粒机设计推荐参数的对比 ,瓮福磷肥厂造粒物料圆度差、细粒较多 ,外观差、返料偏高的原因是 :物料停留时间短 (仅 1m in,TVA推荐值 2～ 7min) ;物料装载系数低 (5 %～ 2 % ,TVA 推荐值 2 0 %～ 30 % ) ;筒体内空气流速低 (0 . 82 m/ s,TVA 推荐值 1.2 2 m/ s)。     

MAP料浆管式反应器氨化法生产DAP可行性分析

为降低DAP生产对磷矿质量的过高要求,结合料浆浓缩法生产MAP的技术优点,论证在料浆浓缩法生产MAP装置的基础上,用浓缩后的MAP料浆通过管式反应器和氨化造粒机进一步氨化生产DAP的可行性。通过物热衡算,说明可生产(13-18-0)品级DAP,如磷矿中MgO从3.23%降至1.57%,则DAP可达15-42-0优等品级。     

粒状磷酸一铵(GMAP)开发生产技术总结

介绍了100 kt/a磷酸二铵/复混肥(DAP/NPK)装置开发生产粒状磷酸一铵(GMAP)的工艺流程、生产控制、产品性能、管式反应器加转鼓氨化造粒技术以及产品的外观质量,分析了生产过程中出现的问题及采取的优化措施。优化后的工艺参数:洗涤液密度(1 550±10)kg/m3,中和度0.40±0.05,造粒机出口物料中和度1.05~1.10,一次氨占总氨质量分数85%~90%,二次氨占总氨质量分数10%~15%,返料比(4~5)∶1,造粒温度110~115℃,干燥尾气温度90~95℃。     

240kt／a磷铵装置扩能技改情况分析

240 kt/a磷铵装置,原采用预中和-转鼓氨化工艺,为将生产能力提高到29万t/a DAP或30万t/aNPK,引进单管技术.介绍技改前后造粒、干燥、冷却、除尘的流程和设备情况;技改取得的效果(产量提高,环境改善等);及技改过程中如氨逸出率超标,产品水分达不到技改目标值等的原因分析及解决方法.     

外环流氨化反应技术在磷酸二铵生产中的应用

原外环流氨化反应器应用于生产磷酸一铵 ,介绍安徽六国化工股份有限公司应用外环流氨化反应技术生产磷酸二铵所采取的若干技术 ,使外环流氨化反应装置实现了长周期稳定运行生产 DAP,生产强度比原中和槽提高 10倍 ,达 4 .5 t/ (m3· h) ,无需搅拌 ,每年节约大修及维修费 2 8万元 ,向大气排放氨每年减少 18.9t     

240kt／aDAP装置运行情况

介绍安徽六国化工股份有限公司24万t/a DAP的工艺概况及试车、运行、技改情况.针对2001年7月试车初期出现的问题,例如中和槽到氨化粒化器料浆泵送管线及泵易堵,造粒机管梁定位设计缺陷、氨分布器角度设置不合理等进行了整改.并对中和造粒尾气洗涤系统和磷铵产品外观质量提出了改进意见.     

预中和-单管二次氨化技术生产DAP/NPK复合肥工艺

分析常压两步中和喷浆造粒工艺、预中和-转鼓氨化工艺、管式反应器工艺生产DAP/NPK的弱点,介绍为克服这些弱点而研究开发的预中和-单管二次氨化技术的主要工艺过程及该工艺的技术特点和比较优势.提供了贵溪化肥厂的试生产及其效益情况,若月产NPK产品2.5万吨,每月可增加经济效益140万元.     

国外磷复肥发展的新动态(下)

<正> (四)西班牙ERT/ESPINDES人低返料DAP流程 1.本流程是西班牙威瓦(Hue/va)的ERT造粒工厂开发的PCR新流程,1983年开发成功。装置生产能力DAP 600吨/日,NPKS 1300吨/日。第二套装置计划建在东土耳其Ceihan,由Toros Gubre公司承包,现已进入初步设计阶段。 2.ERT/E低返料DAP流程是根据关于一种特殊的安装在造粒器内的PCR的专利设计的。     

150t/h循环流化床锅炉返料风系统的改进

正1改进前状况2台150 t/h高温、高压循环流化床锅炉2011年10月投产,每台锅炉配置2台75 k W的返料罗茨机,1开1备。投运后,存在返料风压过高,风机出口气体压力30 k Pa(额定全压29 k Pa),返料罗茨风机电流高、超负荷,现场噪音(90 d B)严重超标问题。同时,由于风压过高,造成返料风帽磨损、磨穿,过大的返料松动风又对旋风分离器内的气流造成扰动,影响分离器的收集效率,最终影响锅炉的带负荷能力。运行初期,锅炉负荷只能达130 t/h。     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

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.