VD406纺丝机冷却成形装置的改造与应用

介绍浙江德清化纤厂将原VD406纺丝机的高压高阻尼密闭式环吹装置,改造成为低压低阻尼半封闭式环吹小车装置的结构。经投料运转考核表明,此项改造设计是成功的,装置性能良好,各项指标都达到设计要求。     

涤纶短丝装置增量改造的关键技术

在消化吸收引进线的基础上,采用自行开发的工艺技术,实施对８０年代直接纺短丝装置进行改造,主要技术关键是纺丝采用低阻尼中心环吹,后处理采用独立变频传动等,使生产能力增加９０%以上,改造的投资仅为引进线的２５%。     

浅析长丝环吹冷却改造装置的特点

分析了内环吹和外环吹两种长丝冷却改造装置的工作原理,并研究了改造后喷丝板的设计。通过对环吹装置两种冷却方式在生产实践中的分析,探讨了两种冷却装置的优缺点。     

BN100环吹装置的应用

测试了BN100环吹装置风速的均匀性,通过分析其结构特点,说明了其优良性能的原因,介绍了控制原理及风量的计算,并总结了环吹安装和运行应注意的问题。     

涤纶短纤维环吹风工艺优化

介绍了1.8万t/a涤纶短纤维装置的“风速测试法”。克服了仪表风量盘控制的某些缺陷,选用合理的环吹工艺,使之满足纺丝工艺条件,提高主风道压力,提高了环吹风抵御外界风速变化的能力,使风速更加稳定和均匀,找到了适合新疆地区的环吹工艺参数,提高了原丝品质。     

涤纶长丝纺丝环吹冷却方式的讨论

纺丝环吹冷却技术可使丝条冷却更均匀、纺丝更稳定、能耗更低,同时有利于多孔细旦产品的研发。环吹冷却技术对环吹风筒的过滤精度和冷却风的清洁程度要求较高。为解决生产粗旦品种因冷却不够,产品存在品质问题等缺陷,通过试验确立了用环吹冷却方式所能生产优质涤沦长丝品种的范围,以及通过风筒长度、喷丝板板径、喷丝板丝孔排布圈数、风温和风压的合理搭配来提升和优化环吹冷却生产产品的品质,为合理运用环吹冷却技术提升产品的品质提供参考依据。     

热风炉的热态观测和修补方法

在热风炉等大型密闭式炉中，通过将CCD照相和其它光源配合使用，可以通过热态观测确定破损部位和推测残余寿命。并将这种热态观测装置和修补技术相结合，在热风出口管道处对破损部位进行修补。     

吹风气回收装置积灰问题分析与处理

通过对吹风气回收装置增加吹风气的集中除尘器、增加余热锅炉系统的吹灰器及进行必要的工艺调整,解决了装置因积灰导致的换热效率低、蒸发量低、热损失大的问题,使装置基本达产、达效。     

大型热管吹风气潜热回收装置运行总结

为满足生产能力不断扩大的需要,在国内率先使用了大型热管吹风气潜热回收装置,并在运行中不断加以完善,该装置不仅能满足小氮肥企业同时回收６￣８台φ２４００／２６００造气炉吹风气的需要,也能满足中氮肥企业同时回收３￣４台φ３６００造气炉吹风气的需要。     

再生纺环吹系统VOCs的产生和减量技术的研讨

再生聚酯熔融纺丝过程中,由于环吹风装置与纺丝箱装配不密封产生的挥发性有机物(VOCs)容易排放至空气中,这是再生聚酯生产过程中产生VOCs的重要组成部分。再生聚酯在环吹阶段产生的挥发性有机物主要为乙醛、甲醛、苯、甲苯、苯甲醛、二甲苯等物质。其中乙醛是最主要的成分,占总挥发性物质的64%。通过优化环吹系统,在回风前使用过滤—水洗—预浓缩—焚烧工艺,废气综合处理率可达78.4%。在生产线上加置PID检测器,实现了VOCs浓度在线监控,进一步形成了环吹VOCs在线监控-高效处理技术,为实现绿色制造提供了借鉴作用。     

螺杆温度与环吹风速对中空纤维稳态纺丝与牵伸性能及纤维结构性能的影响

三维卷曲涤纶中空纤维生产 ,可以通过调节无油丝粘度 ,提高环吹风速 ,来强化不对称冷却吹风效果。借助于 WA XD、分子质量及分子质量分布等测试分析手段对风速调整前后纤维的结构变化进行了对比测试。结果表明 ,粘度是影响生产稳定运行的关键指标之一 ,提高螺杆温度 ,降低熔体粘度 ,相应提高环吹风速 ,强化不对称冷却吹风效果 ,可以提高产品质量和成品结晶度。     

Simulation of polyester melt spinning with axial quench for increasing productivity

Production of polyester filament involves melt spinning into partially oriented yarn (POY), followed by drawing to enhance the bulk and mechanical properties. The industrial demand of increasing productivity is generally met by increasing POY melt spinning speeds, which is limited by increasing polymer chain orientation (and reducing residual drawability) in the POY produced at higher spinning speeds. Modification of the quench geometry during melt spinning is claimed to allow reduction of air drag and polymer chain orientation, permitting an increase in productivity during melt spinning into POY. We present a simple way for modeling the quenching of molten filaments under the modified (axial) air flow. Numerical simulations of the melt spinning are developed to demonstrate the influence of the quench geometry modification as we compare the process with the conventional cross‐flow quench and the modified axial quench. We find that increasing quench air flow reduces the polymer chain orientation, in contrast to the well known effect in cross‐flow quench. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

杜邦公司涤纶短纤维生产技术特点分析

介绍了杜邦公司涤纶短纤维装置工艺技术特点及生产运行特点 ,重点叙述了其纺丝机结构紧凑、纺丝压力高、上环下侧的冷却吹风方式、卷绕丝束采用空气喂入、室温空气中干法拉伸等工艺特点 ,分析杜邦公司工艺对熔体质量及工艺控制的特殊要求 ,认为杜邦技术生产的涤纶短纤维成品丝质量好 ,装置能耗低     

涤纶细旦FDY的生产

对在国产纺丝设备与进口卷绕设备嫁接的生产线上生产涤纶细旦FDY的工艺条件进行探讨 ,论述了切片干燥纺丝温度 ,侧吹风冷却等工艺条件对成品质量的影响。     

Efficient Exciton Quenching by Hole Polarons in the Conjugated Polymer MEH-PPV

Recently published near field scanning optical measurements (NSOM) on the conjugated polymer MEH-PPV exhibited a strong dependence of the photoluminescence intensity on the applied electric fields at the NSOM tip. The observed effect is apparently due to exciton quenching by hole polarons. In the present paper, a model “single carrier” electro-modulated-photoluminescence device is used to further explore the exciton quenching effect of hole polarons in MEH-PPV. Hole polarons, created by charge injection from an ITO electrode, are observed to dramatically quench the photoluminescence intensity of MEH-PPV. The Stern-Volmer quenching efficiency of a hole polaron in conjugated polymer thin films was measured to be 390 nm³. This value, and other data presented herein, are consistent with the published NSOM photoluminescence modulation measurements and offer further evidence that hole polarons are efficient photoluminescence quenchers in MEH-PPV.     

Review of thermo-physical properties, wetting and heat transfer characteristics of nanofluids and their applicability in industrial quench heat treatment

The success of quenching process during industrial heat treatment mainly depends on the heat transfer characteristics of the quenching medium. In the case of quenching, the scope for redesigning the system or operational parameters for enhancing the heat transfer is very much limited and the emphasis should be on designing quench media with enhanced heat transfer characteristics. Recent studies on nanofluids have shown that these fluids offer improved wetting and heat transfer characteristics. Further water-based nanofluids are environment friendly as compared to mineral oil quench media. These potential advantages have led to the development of nanofluid-based quench media for heat treatment practices. In this article, thermo-physical properties, wetting and boiling heat transfer characteristics of nanofluids are reviewed and discussed. The unique thermal and heat transfer characteristics of nanofluids would be extremely useful for exploiting them as quench media for industrial heat treatment.     

侧吹风对FDY条干均匀度的影响

通过侧吹风对熔体直纺FDY的作用,探讨了侧吹风对单丝根数较多的品种333dtex/144fFDY丝的影响,从而优化侧吹风工艺,使产品条干均匀度达到最佳。     

Computer‐aided mathematical modeling and numerical simulation and theoretical analysis of the polypropylene polymer air drawing in spunbonding nonwoven process

In this article, as a nonlinear mathematical problem, the air‐drawing model and the air jet flow field model of the polymer during spunbonding process are also presented, because the continuous filament fiber not always occurs in the spunbonding process, therefore, there exists the filament fiber breakage, the broken fibers occur in the flow field of spunbonding process is a two‐phase flow problem, we suggested a new model called the sphere–spring model that can best described the broken fibers movement features. At the same time, the air‐drawing model of the polypropylene polymer in a spunbonding process is presented and solved by introducing the numerical computation results of the air jet flow field of aerodynamic device. The model's predictions of the filament fiber diameters, crystallinities, and birefringences are coincided well with the experimental data. The effects of the processing parameters on the filament fiber diameter are discussed. A lower polymer throughput rate, lower quench air temperature, higher polymer melt initial temperature, higher air initial temperature, higher air initial speed, medium smaller venturi gap, higher air suction speed, higher quench air pressure, higher air suction speed, higher extrusion temperature, higher quench air pressure, higher cooling air temperature, and so on can all produce finer filament fiber. The results show great prospects for this research in the field of computer‐assisted design of spunbonding technology. POLYM. ENG. SCI., 54:481–492, 2014. © 2013 Society of Plastics Engineers     

涤纶长丝侧吹风过程控制

依据空气焓湿图，按送风目标状态对侧吹风空调各功能段的空气焓值状态进行逆向分析，得到喷淋功能段前的目标温度计算模型。将新风温度与此模型计算值进行比较，得到３种不同控制手段的正确选择。在送风目标的约束范围内，通过冷热能源的非交替控制和变频调速控制，使侧吹风过程能源消耗最低。利用ＭＯＤＣＥＬＬ２０００多回路处理器实现了侧吹风空调的优化节能控制。