伞板形液体布膜装置结构及布膜性能研究

对适用于垂直管降膜蒸发器的伞板形液体布膜装置的结构进行了介绍,给出了伞板形液体布膜装置与换热管内壁之间的环隙的计算公式。并对其成膜性能进行了实验研究,得到了液体雷诺数、液体布膜装置的结构与液体成膜不均匀度系数之间的关系。     

新型液体管外降膜布膜装置的实验研究

在吸收器内改善换热管的布膜效果,可以显著提高吸收器的传热传质系数。基于此提出了一种新型垂直管外布膜装置,并进行了实验研究和理论分析。考察了液体布膜装置的环隙内径,螺旋沟槽通道的数目、结构参数的选择,及其对布膜效果的影响。实验结果表明:液体布膜装置的最佳环隙间距为0.6—1.0 mm,螺旋沟槽的数目3—5个,螺旋沟槽的横截面积根据管径的大小和壁厚在1—4 mm2中选择,可以快速均匀地布膜。利用实验数据回归了液体在螺旋沟槽通道内的流量系数和雷诺数的关联式。     

液体管外降膜的实验

在实验的基础上探讨了液体在垂直管外降膜的流动特性,分析了影响液体管外成膜均匀性和润湿性的影响因素,提出了布膜装置的环隙在0.5～2.0mm有一最佳值,喷淋密度在250～700kg/(m·h)之间有一最佳值,布膜装置的进液采用单管沿壁面旋转270°切向流的进液方式,并对液体管外降膜装置的设计提出了建议。     

二氯苯大型双降膜结晶器结构设计

介绍精制对二氯苯装置核心设备双降膜分步式结晶器的工作原理、选材及关键结构设计等。由于物料中含有一定量的稀盐酸,故设备中与物料接触部分材料选N06600或316L;通过合理设计管内布膜器,提高产品收率和质量;优化结晶器管外布膜器,提高换热能量的利用效率;合理设计管板结构减少设备造价。     

降膜蒸发器布膜器的设计

布膜器是降膜蒸发器的关键部件，它对降膜蒸发器的性能影响是至关重要的。本文介绍了一种布膜器的结构，参数选择及计算方法，并在生产实践中取得了良好的应用效果，对降膜蒸发器的设计是很有益处的。     

降膜蒸发器布膜器的设计

降膜蒸发器蒸发性能的好坏取决于换热管内液膜的厚度及其稳定性。布膜器是决定液膜厚度和稳定性的关键部件。对布膜器结构、分布盘筛板孔的分布方式、结构参数和工艺参数进行了考察、分析,并在此基础上对某布膜器重新进行了设计计算。     

外环状弹性壁布膜器及超薄降膜厚度

研发了竖直管外环状弹性壁降膜分布器,可以产生微米量级厚度均匀的超薄降膜流动。由弹性薄壁轴对称变形协调性决定,该布膜器具有均匀性和稳定性内在机理。理论分析导出了初始膜厚及布膜流量与布膜器内液柱高度的线性关系,并通过布膜器操作参数及降膜流量等实验数据进行了验证。实验结果表明,该布膜器对降膜管壁的润湿性能已经达到由固液界面性质决定的最小润湿流率。     

大型管外降膜蒸发器多层淋降式分布器的设计

本文针对管外降膜蒸发的特点,考虑工业化生产的实际需要,提出了一种切实可行的大型竖直降膜蒸发器布液装置的结构方案,并对关键的结构参数进行了分析,提出了设计、计算依据。     

大型管外降膜蒸发器多层淋降式分布器的设计

本文针对管外降膜蒸发的特点 ,考虑工业化生产的实际需要 ,提出了一种切实可行的大型竖直降膜蒸发器布液装置的结构方案 ,并对关键的结构参数进行了分析 ,提出了设计、计算依据。     

伞板型布膜器对降膜蒸发性能的影响

引　言降膜蒸发器是一种高效、节能的蒸发设备 ,具有传热系数高、温差损失小、汽化表面大、物料停留时间短等特点 ,适于热敏性物料蒸发 ,易于实现多效操作 ,广泛应用于化工、轻工、食品加工、海水淡化等领域[1].由降膜蒸发器的工作原理可知 ,降膜蒸发器能否高效运行主要取决于料液在换热管间的均布及其在换热管内壁成膜的均匀程度 .在降膜蒸发器换热管上端安装布膜器是一种有效的方法 .溢流型布膜器结构简单 ,但加工、安装精度要求高 ;目前常用的插件型布膜器成膜较好 ,但结构复杂 ,安装和检修都不方便 ,而且阻力相对来说比较大 .针对这一情…     

Ultrathin carbon film from carbonization of spin-cast polyacrylonitrile film

Here we present ultrathin carbon films derived from polyacrylonitrile precursor film. Subsequent carbonization was investigated to examine the optical and electrical properties of resulting carbon films. The precursor PAN solution was carefully prepared and heated in order to have thin and uniform PAN film, and X-ray reflectivity of the precursor film and the carbon film shows uniformity. X-ray diffraction pattern of the carbon film indicated that the obtained carbon films possess low crystallinity. It was also found that the thickness for ultrathin carbon film from PAN layer showed counterbalanced optical and electrical performance in the range of experiment.     

干膜用聚酯薄膜产生疵点的原因

详细介绍并分析了干膜用聚酯薄膜疵点的分类和产生原因。大疵点形成的原因为煳料造成的内部杂质和外来杂质造成的表面杂质,小疵点形成的原因为添加剂粒子团聚造成的内部原因和辊筒烙印造成的表面原因。     

PET薄膜在干膜生产中的应用

PET薄膜为干膜光阻层的载体,起保护作用,主要是隔绝氧气、分层和避免机械划伤,在曝光之后显影之前除去。其厚度呈现逐渐变薄的趋势,主要为15~19μm。     

Modeling and control of film porosity in thin film deposition

Systematic methodologies are developed for modeling and control of film porosity in thin film deposition. The deposition process is modeled via kinetic Monte Carlo (kMC) simulation on a triangular lattice. The microscopic events involve atom adsorption and migration and allow for vacancies and overhangs to develop. Appropriate definitions of film site occupancy ratio (SOR), i.e., fraction of film sites occupied by particles over total number of film sites, and its fluctuations are introduced to describe film porosity. Deterministic and stochastic ordinary differential equation (ODE) models are also derived to describe the time evolution of film SOR and its fluctuation. The coefficients of the ODE models are estimated on the basis of data obtained from the kMC simulator of the deposition process using least-square methods and their dependence on substrate temperature is determined. The developed ODE models are used as the basis for the design of model predictive control (MPC) algorithms that include penalty on the film SOR and its variance to regulate the expected value of film SOR at a desired level and reduce run-to-run fluctuations. Simulation results demonstrate the applicability and effectiveness of the proposed film porosity modeling and control methods in the context of the deposition process under consideration.     

有机释放膜上铝膜的溶解与粉碎

镜面铝浆由于其优越的镜面效果得到广泛的应用。采用有别于传统球磨法的全新工艺——有机释放膜过渡法制备了镜面型铝银浆。结果发现,通过丙酮溶解丙烯酸树脂基有机释放膜,可获得厚度十分均匀的铝膜或铝鳞片。超声振荡可加快薄膜溶解速度。通过超声振荡和强力机械搅拌可粉碎铝膜。制得的镜面铝浆平均粒度(d_(50))为11.9μm,粒度分布宽度为1.22。     

Dielectric elastomer film with anisotropic actuation deformation on film plane

A new dielectric elastomer (DE) film, which was able to show anisotropic large plane deformation actuated by an external electric field, was designed and synthesized. Specifically, an asymmetric di-vinyl monomer cyclohex-3-enylmethyl acrylate (CEA) was incorporated into the middle block of poly(styrene-b-butyl acrylate-b-styrene) as potential crosslinking points. By widely used UV curing technique through a mask, the DE films could be locally hardened any area one selected. This could break the symmetry of the actuation deformation on the DE film plane, maximizing the deformation in a given direction while the actuation area strain remained unchanged. The actuation strain_y/strain_x reached 2.3, strain in x direction was 10.3% while in y direction was 23%, when the DE film of S(BA-ran-CEA)S with 2.5 mol % CEA incorporated was locally hardened in the form of soft and hard belt of 1 mm width alternatively along y direction. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48795.     

Biodegradable film. IV. Printability study on biodegradable film

A starch‐based biodegradable (BD) low density polyethylene (LDPE) film can be directly printable without any corona treatment, unlike virgin LDPE film. Such a film shows poor adhesion and nail scratch resistance of the ink on the printed area of the film. In order to increase the adhesion and nail scratch resistance of the ink on the printed BD film, grafting of acrylonitrile onto the BD film is carried out. The polyacrylonitrile grafted BD film shows better adhesion, nail scratch resistance, and printability. The printability of the polyacrylonitrile grafted BD film is comparable to the conventional corona treated LDPE film. The extent of printability is a function of the surface smoothness, as well as the optimum percentage of grafting on the biodegradable film. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1273–1277, 2001     

油酸对壳聚糖/玉米醇溶蛋白复合膜液流变及膜性能的影响

为了提高壳聚糖/玉米醇溶蛋白膜的机械性能，将壳聚糖液与玉米醇溶蛋白液共混，向其中加入0%、15%、30%、45%（w/w）的油酸改性，研究膜液的粒径、zeta电位、静态和动态流变特性；然后，分析油酸添加量对膜阻隔性能，机械性能和相容性的影响。结果表明：添加油酸后，膜液体系粒径增大、分散均匀，添加30%油酸的膜液分散性更好，PDI为0.34，粒径为1307.5nm。随着油酸含量增大，膜液粘度减小，流动指数增大，弹性模量和粘性模量增加。OA-30膜机械性能较好，抗拉强度达到36.37MPa，断裂延伸率达到22.32%。膜的阻隔性增强，水蒸气、氧气透过率分别降低了44.21%和66.52%。复合膜中壳聚糖与玉米醇溶蛋白分子相容性好，表面光滑平整。综上所述，油酸改性改善了壳聚糖/玉米醇溶蛋白复合膜性能。     

High‐performance bismaleimide resin film for resin film infusion

A novel high‐performance resin film, coded 4508B, suitable for the resin film infusion (RFI) process, was developed. It was prepared from 4,4′‐bismaleimidodiphenylmethane (BDM), o,o′‐diallylbisphenol A (BA), polyethersulfone (PES), and polyimide (PI). The resin and its composite, reinforced by glass fiber cloth, were prepared and characterized in detail. The results showed that the resin film was stable at room temperature, its infusion temperature was 120°C, and the pot life was more than 60 min. In addition, the cured resin and the composite prepared by the RFI process had good thermal and mechanical properties and hot‐wet resistance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2918–2922, 2001