硫冷凝冷却器换热管与管板的焊接技术研究

硫冷凝冷却器是硫磺回收装置的核心设备,其换热管与管板的焊接是制造关键工序。本台产品设计换热管和管板与常规换热器相比,采用了J形坡口结构,大大增加了焊接难度。通过不同的焊接方法组合试验,从中优选出了手工钨极氩弧焊M-GTAW打底焊+脉冲TIG相结合的焊接工艺,试验结果表明,焊缝中气孔极少,突破了单边V形坡口根部未焊透的瓶颈,同时亦改善了根部的应力集中状况。该焊接技术具有较高的研究价值和较广的市场应用前景。

Preparation of Hierarchically Trimodal-Porous ZSM-5 Composites through Steam-assisted Conversion of Macroporous Aluminosilica Gel with Two Different Quaternary Ammonium Hydroxides

This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.

Synthesis of Waterborne Polyurethane Modified by Nano-SiO_2 Silicone and Properties of the WPU Coated RDX

A series of nano silica/silicone modified waterborne polyurethane(WPU) have been synthesized from polytetramethylene glycol and isophorone diisocyanate, dihydroxymethyl propionic acid and triethylamine, ethylenediamine, trimethylolpropane, nano-SiO2 and the silane coupling agent KH550. The effect of the dosage of nano-SiO2 on the WPU-Si membrane and the coated RDX(cyclotrimethylenetrinitramine) particles have been studied in terms of their surface properties, mechanical properties, and thermal stability. The results showed that with the increase of Si content, the stability of the emulsion reduced gradually. The material with more Si content displayed an increased thermodynamic stability, an increased high temperature resistance, an increased tensile strength and a decreased elongation at break. With the increase of Si content, the surface tension of the material decreased, the bibulous rate reduced, and the contact angle increased gradually, so that the surface tension of the polyurethane and RDX are close to each other which could improve the performance of coating.

Physicochemical Properties and Catalytic Performance of a Novel Aluminosilicate Composite Zeolite for Hydrocarbon Cracking Reaction

A novel micro-micro/mesoporous aluminosilicate ZSM-5-Y/MCM-41 composite molecular sieve with a MCM-41 type structure was synthesized through a novel process of the self-assembly of CTAB surfactant micellae with silica-alumina source originated from alkaline treatment of ZSM-5 zeolite. The physical properties of the ZSM-5- Y/MCM-41 composite molecular sieve were characterized by XRD, Py-FTIR and N2 adsorption-desorption techniques. Different kinds of molecular sieves including ZSM-5, Y zeolite, AI-MCM-41, ZSM-5/MCM-41 and ZSM-5-Y/MCM- 41 as cracking catalysts were investigated, using 1,3,5-triisopropylbenzene （1,3,5-TIPB） as the probe molecule. Catalytic tests showed that the ZSM-5-Y/MCM-41 composite molecular sieve exhibited higher catalytic activity compared with the microporous ZSM-5 zeolite, Y zeolite, mesoporous A1-MCM-41 molecular sieve and ZSM-5/MCM-41 composite molecular sieve under the same conditions. The remarkable catalytic activity was mainly attributed to the presence of the hierarchical pore structure and proper acidity in the ZSM-5-Y/MCM-41 composite catalyst. Meanwhile, a carbcnium ion mechanism was put forward for the cracking of 1,3,5-TIPB.

Synthesis of Hierarchically Porous FAU/γ-Al2O3 Composites with Different Morphologies via Directing Agent Induced Method

Zeolite FAU composites with a macro/meso-microporous hierarchical structure were hydrothermally synthesized using macro-mesoporous γ-Al_2O_3 monolith as the substrate by means of the liquid crystallization directing agent(LCDA) induced method. No template was needed throughout the synthesis processes. The structure and porosity of zeolite composites were analyzed by means of X-ray powder diffraction(XRD), scanning electron microscopy(SEM) and N_2adsorption-desorption isotherms. The results showed that the supported zeolite composites with varied zeolitic crystalline phases and different morphologies can be obtained by adjusting the crystallization parameters, such as the crystallization temperature, the composition and the alkalinity of the precursor solution. The presence of LCDA was defined as a determinant for synthesizing the zeolite composites. The mechanisms for formation of the hierarchically porous FAU zeolite composites in the LCDA induced synthesis process were discussed. The resulting monolithic zeolite with a trimodal-porous hierarchical structure shows potential applicability where facile diffusion is required.

TDS智能选矸系统在滨湖煤矿井下的应用

针对煤炭含矸率高、主井矸石提升量大的问题,滨湖煤矿结合井下煤流、煤仓、巷道位置及落差等因素,在井下建设了TDS智能选矸系统。生产实践表明,TDS智能选矸系统的投用有效释放了主井提升能力,不仅提高了升井煤炭的质量,而且简化了地面原煤生产系统,降低了后续选煤作业生产成本,取得了较好的经济效益和社会效益,为实现煤炭的绿色开采提供了助力。

Factors Influencing Droplet Size of Silicone Oil Emulsion with High Solid Content

A silicone oil emulsion with 60% of solid content was prepared with methyl silicone oil used as the main material by means of the emulsifier-in-oil method.The influence of emulsification conditions on the droplet diameter of silicone oil emulsion was discussed.The experimental results showed that the emulsification method,including the quantity of the emulsifier,the time and temperature of emulsification,the emulsifying water dosage,and the stirring speed,had significant impact on the droplet size.The optimal conditions were identified to achieve a smallest droplet diameter of the emulsion at an emulsifier dosage of 6%,an emulsification temperature of 70 ℃,an emulsification time of 30 min,and a stirring speed of 1100 r/min,with water added in two portions at a ratio of 1:1.The high-solid content silicone oil emulsion with a mean droplet diameter of 2.731 μm was prepared under these conditions that could ensure absence of stratification and floating oil under centrifuging at a speed of 3000 r/min for 30 min.

改性端羟基聚丁二烯-三异氰酸酯基网状聚氨酯合成及性能

将端羟基聚丁二烯(HTPB)用4种中间体改性后,与三异氰酸酯通过聚合交联反应制备改性端羟基聚丁二烯-三异氰酸酯基网状聚氨酯。改性后网状聚氨酯性能均有所提高,拉伸强度提高了1.05~2.83 MPa,断裂伸长率增加了4.9%~69.77%,软段玻璃化转变温度(T_(gs))和硬段玻璃化转变温度(T_(gh))均提高。认为是改性后结构中—NO2或三嗪环—C=N基团与氨基甲酸酯中—NH2形成氢键,产生超分子交联。其中PU-1-氯-2,4-二硝基苯(DNCB)-4,4′,4″–三苯甲烷三异氰酸酯(TTI)的力学性能和热性能最优,拉伸强度为5.67 MPa,断裂伸长率为174.83%,认为是由于产生氢键和TTI本身结构对称;T_(gs)和T_(gh)分别为–67.28℃和172.23℃,认为是TTI中苯环使分子刚性、极性增强,相分离度降低。

Hierarchically Structured Monolithic ZSM-5 through Macroporous Silica Gel Zeolitization

The hierarchically structured ZSM-5 monolith was prepared through transforming the skeletons of the macroporous silica gel into ZSM-5 by the steam-assisted conversion method. The morphology and monolithic shapes of macroporous silica gel were well preserved. The hierarchically structured ZSM-5 monolith exhibited the hierarchical porosity, with mesopores and macropores existing inside the macroporous silica gel, and micropores formed by the ZSM-5. The products have been characterized properly by using the XRD, SEM and N2 adsorption–desorption methods.

Fabrication of Hierarchically Porous FAU/α-Al_(2)O_(3) Monoliths via Gel Pre-aging Routes Using Seed Gel as Directing Agent

Hierarchically porous FAU monoliths were synthesized via the gel pre-aging route using seed gel as directing agent andα-Al2O3 as monolithic carrier.The as-synthesized samples were characterized by means of the Fourier transform infrared spectroscopy(FT-IR),X-ray powder diffraction(XRD),scanning electron microscopy(SEM),and N2 adsorption techniques.The effects of seed gel,gel pre-treatment,and gel pre-aging step were determined,while the possible mechanism for formation of alumina composites via different synthesis processes were discussed.The results showed that the crystal size,the shape,and the loading of the supported FAU could be readily tuned by varying the composition of the crystallization gel without notably changing the structure ofα-Al2O3.The proposed seed gel pre-treating and gel pre-aging route are simple,reproducible,and practically easy to integrate triple porous structures into large-dimension monoliths,which are proved to be very effective in depositing pure FAU crystals on theα-Al2O3 skeleton surface and strengthening the interfacial interaction between them.Moreover,it may provide inspiration to the synthesis of other hierarchical zeolites.

Hydrothermal Synthesis and Mechanism for Formation of Novel Micro-Micro-Mesoporous Aluminosilicate Composite Zeolite

A novel micro-micro-mesoporous aluminosilicate LS-BFMZ （low-silica-BEA（beta）-faujasite （Y）-mesoporous） composite zeolite with the MCM-41 type structure was synthesized through a novel process involving the self- assembly of CTAB surfactant micellae with silica-alumina source originated from alkaline treatment of the beta zeolite. The physical properties of the LS-BFMZ composite zeolite were characterized using various techniques, including XRD, IR and SEM techniques. Meanwhile, a possible mechanism regarding the formation of the LS-BFMZ composite zeolite was proposed.

Excellent Cracking Performance of Macroporous Amorphous Aluminosilicate Catalyst

Micrometer-scale macroporous aluminosilicate catalyst was prepared via the sol-gel process. Results of catalytic cracking of 1, 3, 5-triisopropylbenzene showed that the synthesized aluminosilicate catalyst exhibited much higher activity than traditional ZSM-5 zeolite under the same condition. It is worth mentioning that the polymer product selectivity of aluminosilicate was much lower than that of ZSM-5, which might be useful for implementing the catalytic cracking process. The unique structure of macroporous aluminosilicate with interconnected-macropores and continuous skeletons was believed to be responsible for its excellent catalytic activity and low polymer product selectivity. Detailed discussion on the reaction pathway was also conducted.

Preparation and Analysis of Thermal and Mechanical Properties of HTPB-type Polyurethane Elastomer Containing Paraffin Microcapsules

Two microcapsules with different paraffin phase changes were prepared using styrene-divinylbenzene copolymer and melamine resin as the capsule wall and paraffin(with a melting point of 50°C)as the capsule core.The microcapsules were directly added to the hydroxyl terminated polybutadiene(HTPB)-polyurethane elastomer system to fabricate the polyurethane elastomer composites.The thermodynamic stability and mechanical properties of the material were then studied.The results show that the thermal stability of the polyurethane elastomer does not decrease after adding paraffin phase change microcapsules,and the thermal stability of the polyurethane elastomer with melamine resin as the wall increases.Tensile strength increased from 367 kPa to 797 kPa,and compression strength increased from 245.9 N to 344.7 N.In addition,capsule walls comprised different monomers/paraffin microcapsules of the copolymer of styrene and divinylbenzene.The optimal mechanical property was obtained at a monomer/paraffin ratio of 1:1.The compression strength increased and the tensile strength decreased.The tensile strength of the microcapsule with melamine resin capsule wall and the compression strength of the microcapsule with polystyrene capsule wall were considerably improved.

Method for Control of Particle Size and Morphology of Paraffin/Polystyrene-Divinylbenzene Microcapsules

Microencapsulation of phase change materials(Micro PCMs) has been paid special attention because of their extensive applications in saving and releasing energy. Micro PCMs containing paraffin with a melting point of 55 ℃ in polystyrene-divinylbenzene(P(St-DVB)) were prepared by suspension-like polymerization. The characterization of microcapsules by FTIR, DSC and TG proved that paraffin had been successfully encapsulated and the proportion of encapsulated paraffin was 49.8%—58.5%. The effects of polyvinylpyrrolidone(PVP) with different molecular weights serving as the suspension stabilizer were investigated in detail. The results illustrated that the type of PVP had a significant influence on the particle size of Micro PCMs. The average diameter of Micro PCMs decreased with an increasing molecular weight of PVP. Moreover, the crosslinker-postaddition method was adopted in this study to improve the morphology of P(St-DVB) Micro PCMs. SEM images showed that when the DVB was added at the 2nd hour of polymerization the morphology of obtained P(St-DVB) Micro PCMs exhibited good sphericity since it could avoid the influence of cross-linker agent during the nucleation period.

白石湖煤加氢液化过程含氮化合物转化行为研究

对煤加氢液化过程中含氮化合物的转化行为及在气、液、固三相产物中的赋存形态进行研究,可为低阶煤的高效洁净利用奠定理论基础。在0.01 t/d连续试验装置完成新疆白石湖煤加氢液化连续试验,采用微量硫氮分析仪、氮化学发光气相色谱仪(GC-NCD)、电喷雾电离(ESI)傅里叶变换离子回旋共振质谱(FT-ICR MS)和X射线光电子能谱(XPS)对液化油及残渣中的含氮化合物进行分子识别表征。结果表明,原煤中含量较多的季氮,在液化条件下转化为NH3,迁移到气相产物中,液化残渣中以稠环形态的吡啶氮和吡咯氮为主。氮在气体、低分油、高分油、残渣的比例分别为35.21%、24.41%、19.79%、20.59%。小于170℃液化油馏分含氮化合物含量由高到低排序为:苯胺类>吲哚类>喹啉类>脂肪胺类。大于170℃液化油馏分含氮化合物从N_(1)到N_(X)O_(X)(X=1-2)均存在,主要是苯并咔唑带环烷侧链和苯并咔唑带环烷醚链两类含氮化合物。

Synthesis of ZSM-5 Monoliths with Hierarchical Porosity

A new route to synthesize ZSM-5 monoliths with hierarchical pore structure has been referred to in this study. The successful incorporation of the macropores and mesopores within the ZSM-5 struc- ture was achieved through transforming the skeleton of the macroporous silica gel into zeolite ZSM-5 using carbon materials as the transitional template. The ZSM-5 crystal covered part of the macroporous material, and provided micropores to the macroporous silica gel. The structure of carbon monolith was studied after dissolving the silica contained in the carbon/silica composite.

苯乙烯-丁二烯-苯乙烯嵌段共聚物/石墨烯/石蜡定型相变材料的制备与性能研究

采用高温炼制法,以苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)及多层石墨烯(MLG)为支撑材料,对石蜡(PW)进行封装,制备了SBS/MLG/PW三元复合定型相变材料(SSPCMs)。利用扫描电子显微镜、傅里叶红外光谱、差式扫描量热和热失重等手段来表征定型相变材料的微观结构及热物性。结果表明:定型相变材料各组分之间属于物理混合;石蜡含量为89%的样品综合性能最优,滴点高达176.3℃,钢网分油率低至0%,相变焓值为157.7J/g,表现出良好的热稳定性、胶体稳定性及储能性能;经过50次相变循环后,定型相变材料的储能性能仍然保持稳定,循环使用性能良好;在100℃的高温环境下仍能保持稳定的形状,显著减小了石蜡渗漏率;定型相变材料的热导率较纯石蜡提高了20.51%。

蒋庄煤矿选煤厂浮选系统次生泡沫的综合治理

蒋庄煤矿选煤厂在浮选系统运行之后,为了彻底解决浮选系统次生泡沫造成的系统紊乱等问题,通过一系列的技术举措和经验摸索,逐步形成了以工艺优化为主,固定设施改造为辅的技术手段进行综合治理。对于细粒煤泥分选效果更佳的浮选柱作为系统优化的研究,以减少超细颗粒粘附在泡沫而导致泡沫难以破碎的现状;对于能够有效提高煤泥弧形筛透筛性设备进行探索应用,增加筛面气动击打装置;对于煤泥水输送环节影响因素进行研究,将直管道改造为转折溜槽配以喷淋,在料筒(池)和浓缩池增设喷淋,以提高输送环节和终端环节的消泡效果。结果表明,通过综合治理技术举措,浮选系统各环节泡沫积聚逐步减少,有效促进了工艺及系统运行稳定,取得了良好的应用效果,在洗选工艺系统管理工作具有积极的推广利用价值。

High activity in catalytic cracking of large molecules over micro-mesoporous silicoaluminophosphate with controlled morphology

A novel micro-mesoporous silicoaluminophosphate(MUS-5) with controlled morphology has been first synthesized in a two-step route.The physical properties of the silicoaluminophosphate were characterized using XRD,SEM,TEM,nitrogen adsorption-desorption and NH3-TPD techniques.When the pH value of the solution system was varied in the range from 2.0 to 5.0,three different morphologies of silicoaluminophosphate including chain-like,flower-like and barrel-like morphology were obtained.Catalytic tests showed that the silicoaluminophosphate exhibited higher catalytic activity compared with the conventional microporous SAPO-5 under the same conditions for catalytic cracking of 1,3,5-triisopropylbenzene heavy aromatics.The remarkable catalytic reactivity was mainly attributed to the presence of the hierarchical porosity in the silicoaluminophosphate catalyst.