基于空气纤维膜的模块化制氮充氮设备设计与应用

氮气因化学性质稳定，常作为现代导弹贮运发射箱(筒)内部的保护气，为箱(筒)内产品提供温度干燥的气氛环境。目前，列装部队常采用标准氮气瓶直接充装，但在战术阵地等交通受限的边远地区，不具备氮气瓶充装条件。基于上述需求，设计一种模块化制氮充氮设备。该设备采用中空纤维膜渗透原理制备氮气，所制备氮气纯度大于99.95%,露点小于-60℃,优于标准氮气瓶。该设备各项制氮指标均优于标准要求，能够满足贮运发射筒氮气充填的需要。     

用于可控气氛热处理的新的制氮法

美国道氏(Dow)化工公司研究成功了以中空纤维膜技术从压缩空气中分离氮的新方法。这种称之为琴纳龙(Generon)的制氮装置已在Torring-ton Shiloh热处理厂投入使用,并取得了经验。中空纤维膜制氮法的原理 Generon这种制氮装置是制氮技术上的一大新进展。它以中空纤维膜技术使其最先成为一种体积小、能方便地自行就地停放的很有竞争力的氮气发生器。这种装置(见图2)(略)可由一个或数个空气分离罐组件构成,并有它自己配套的压缩空气源,或简     

氮基气氛热处理技术进展

介绍了氮在热处理气氛中的作用和氮基气氛的成分以及制氮方法，同时对氮气源的几种供氮方式作了比较。     

中空纤维膜分离制氮

中空纤维膜分离制氮天津凯德科学仪器有限公司（天津３００１９０）韩光瑶中空纤维膜分离制氮的膜组是一个圆筒状的高分子材料制成的中空纤维膜束，每束象列管式换热器一样包含上百万根中空纤维，以提供最大限度的分离面积。每根纤维直径约几十微米，就象人的头发丝一样细...     

氮基气氛热处理氮气源评述

介绍了氮在热处理气氛中的作用,评述了不同的供氮方式和制氮方法,讨论了PSA制氮装置的稳定性,提出了PSA制氮目前乃是我国氨基气氛热处理氮气源的适宜方案。     

氮化锰的微波合成

以74μm锰粉为原料,在氢气和氮气的混合气、750℃以及保温2 h的条件下于微波反应器中合成氮含量为7.75%(质量分数)的氮化锰。研究了粉末粒度、合成温度、合成保温时间及合成气氛对合成产物氮含量的影响。结果表明:氮化气氛需要氢气和氮气的混合气体,氮化气氛中少量的氢促进了原料氮化和除去杂质氧。微波高温合成技术的合成温度和合成时间较传统工艺具有明显的优势。     

罩式控制气氛渗氮炉的调试

在传统的气体渗氮炉中渗氮的工件,由于渗氮气氛的氮势难以精确控制,工件的白色化合物层往往超出技术要求。罩式控制气氛渗氮炉配备了可精确控制渗氮气氛氮势的氢探头、质量流量计等精密仪器,解决了上述渗氮的质量问题,已成功地应用于风电机齿圈的渗氮。     

氮基气氛热处理氮气源评述

介绍了氮在热处理气氛中的作用，评述了不同的供氮方式和制氮方法，讨论了ＰＳＡ制氮装置的稳定性，提出了ＰＳＡ制氮目前乃是我国氮基氢气热处理氮气源的适宜方案。     

技术信息

山西省煤炭化学研究所于一九八六年五月二十六日至五月二十九日在上海市农委招待所举行“氮基气氛热处理技术交流会”。全国各地约一百多位代表参加了这次会议。这次会议介绍了该所最近通过冶金部鉴定的“七五”期间国家科委的攻关项目——低温甲醇裂解催化剂,低温甲醇裂解机,氮气净化催化剂(除氧)。用甲醇裂解气和氮气配制的氮基气氛可用于有色金属退火;碳钢、合金钢淬火,退火;碳纤维保护气氛烧结等等。该所研制的低温甲醇裂解机已在上海614厂(上海造币厂),上钢五厂,上海合成纤维研究所等单位得到应用,性能稳定。     

在含氮气氛中氮的吸收

所有的钢在氮气或含氮气氛中700℃以上热处理时,都发生吸氮现象。一般来说,吸氮现象导致材料的强度增加,韧性下降。当吸氮给后序加工带来困难时(冷加工开裂),就不希望有吸氮现象(如线状、片状等钢材的退火)。在这些情况下,应在其它气体中,如氩气或在真空条件下处理工件。据报导,含铝镇静钢在含氮气氛中渗碳时的吸氮现象,增加了细小晶粒的尺寸稳定性。控制某些金属(锰、铬)及其铁合金和高合金钢在氮气或含氮气氛中热处理时的吸氮量,能赋予材料特殊的物理性能。     

Porous and dense Ni hollow fibre membranes

Nickel hollow fibre membranes were prepared by extruding a polymer solution containing suspended nickel (Ni) powder to green hollow fibres, which were then sintered at elevated temperature under an argon atmosphere. The hollow fibres were characterized by a scanning electron microscope (SEM), X-ray diffractometer (XRD), mercury porosimeter, gas permeation test and conductance measurements. Porous Ni hollow fibres with micron-sized pore structures can be obtained directly by sintering the green fibre at relatively lower temperatures. Heated at a higher temperature (i.e., 950 °C), the Ni hollow fibres became gas-tight membranes which are of great interest for hydrogen separation.     

空心阴极真空电弧焊接的引弧机理

空心阴极真空电弧焊接（Hollow Cathode Vacuum Arc Welding,HCVAW)技术是一项新型、独特的技术,在航空,航天等工业部门有着巨大的应用潜力,本文介绍了空心阴极真空电弧焊接技术的特点及其放电机理,讨论了低气压下空心阴极电弧放电与常规电弧和电的不同特点,根据电离气体中性化条件,初步探讨了在低气压下空心阴极电弧放电的引弧过程,分析了影响低气压下空心阴极电弧放电引弧电压的因素。     

Effect of Atmosphere on Synthesizing Hollow Ceramic Microspheres by Self-reactive Flame Quenching Technology

In order to obtain high comprehensive performance hollow ceramic microspheres (HCMs), used Al-Cr2O3 as the main reaction system, HCMs were prepared by Self-reactive flame quenching technology in Ar2 and N2 atmosphere respectively. Effects of the two different atmospheres on synthesizing HCMs were studied. Results show that in Ar2 atmosphere, because of incomplete reaction of agglomerate powders, porous particles with hollow structure and smooth-faced HCMs constitute the products. However in N2 atmosphere, because agglomerate powders react completely, all of them become smooth-faced HCMs. Results above show that experiment atmosphere is a important parameter to synthesize HCMs and to a great extent influences reaction process of agglomerate powders in the flame field.     

Modeling of formation of binary-phase hollow nanospheres from metallic solid nanospheres

Spontaneous formation of binary-phase hollow nanospheres by reaction of a metallic nanosphere with a non-metallic component in the surrounding atmosphere is observed for many systems. The kinetic model describing this phenomenon is derived by application of the thermodynamic extremal principle. The necessary condition of formation of the binary-phase hollow nanospheres is that the diffusion coefficient of the metallic component in the binary phase is higher than that of the non-metallic component (Kirkendall effect occurs in the correct direction). The model predictions of the time to formation of the binary-phase hollow nanospheres agree with the experimental observations.     

Phenomena in GTA and GHTA welding in Mars-like atmosphere

NASA is advancing the project of manned Mars exploration. In the future, Martian outposts and structures will be constructed. To realize this, welding technology is expected to be applied. The main atmospheric component of Mars is carbon dioxide, and the atmospheric pressure is approximately 700 Pa. In this study, welding experiments were carried out in a simulated Mars atmosphere of 99.5% carbon dioxide and a pressure of 700 Pa. Conventional gas tungsten arc (GTA) welding and gas hollow tungsten arc (GHTA) welding, in which arc operating gas is allowed only to flow out from the electrode tip of a hollow tungsten electrode, were investigated. The arc discharge behaviour and the melting characteristics in the simulated Mars atmosphere were studied. As a result, it was shown that GTA welding and GHTA welding might be applicable even in the Mars atmosphere.     

Biomorphic synthesis of long ZnO hollow fibers with porous walls

Long biomorphic ZnO hollow fibers with porous walls have been fabricated using cotton fibers as bio-templates. Cotton fibers are infiltrated with zinc acetate aqueous solution and subsequently calcinated in an air atmosphere at high temperatures to remove cotton templates. The as-prepared hollow fibers are as long as several centimeters and replicate not only macroscopic structure of the cotton fibers, but also microscopic morphologies. The calcinating temperatures in the fabrication process have great effects on the surface roughness and wall quality.     

单晶空心涡轮叶片精确控形技术的研究进展

针对航空发动机单晶空心涡轮叶片的精确控形技术,结合国内外相关工作的研究状况,从空心涡轮叶片复杂陶瓷型芯精密成形技术、单晶高温合金叶片近净形熔模精密铸造技术及叶片精铸过程尺寸精度控制方法等方面,对单晶空心涡轮叶片精确控形技术领域取得的研究成果进行了总结和分析。重点介绍单晶空心涡轮叶片精确控形技术领域内取得的研究成果,论述了我国单晶空心涡轮叶片精确控形技术的未来研究重点。     

大型空腔铸件铸造工艺研究

以下凸模铸件为例,详细研究大型空腔铸件的铸造工艺.通过改进铸造工艺,解决了大型空腔铸件铸造过程中的漂芯、排气等问题,获得高质量的铸件产品.     

G1膜片精密级进模设计与技术创新

分析了G1膜片级进模的设计难点,总结了以往同类模具的设计经验,对中华映管G1膜片级进模进行了设计和技术改造创新,并对相应的技术难点加以解决,优化了模具结构及性能,取得了更佳的生产效果。     

生物模板法结合溶胶-凝胶技术制备二氧化硅中空微球材料(英文)

生物模板法与溶胶凝胶技术的结合是实现无机中空微球材料快捷、高效制备的有效途径。本研究利用油菜花粉为模板,以正硅酸四乙酯为前驱体,通过溶胶-凝胶包裹的方法制备了二氧化硅中空微球。通过将二氧化硅溶胶吸附到花粉颗粒表面形成包裹层,再经过烧结处理将花粉模板去除的方法,可以方便地制备表面有一定特殊形貌的二氧化硅中空微球材料。利用扫描电子显微镜,电子能谱仪以及傅里叶变换红外光谱对花粉颗粒和所制备的二氧化硅中空微球进行表征。结果表明:利用花粉颗粒为模板,结合溶胶-凝胶方法可以成功制备具有特殊表面结构的无机中空微球材料,在这一过程中,物理吸附作用是主要的影响因素。