一种异型封头成型方法的研究与实践

本文介绍了制造薄壁封头的一种新思路、新方法,付诸实施后取得了满意的效果。     

内压薄壁碟形封头的简易计算方法

给出一种计算内压薄壁碟形封头不失稳壁厚的简易计算方法。按该法设计碟形封头比其它方法更为优越，且经实践证明其安全系数至少在１．５以上，其计算公式应用范围也较宽。     

内压薄壁椭圆封头的简易计算方法

本文给出了一种计算内压薄壁椭圆封头不失稳壁厚的简易计算方法。按该法设计椭圆形封头比其它方法更优越,且所给出的公式是建立在实验基础上的经验公式,具有足够的安全可靠性。同时本文公式应用范围也比较宽。     

内压薄壁椭圆封头的简易计算方法

本文给出了一种计算内压薄壁椭圆封头不失稳壁厚的简易计算方法。按该法设计椭圆形封头比其它方法更优越，且所给出的公式是建立在实验基础上的经验公式，具有足够的安全可靠性。同时本文公式应用范围也比较宽。     

超大型薄壁压力容器(BYD反应器)制造技术

介绍了丁炔二醇(BYD)反应器的构造,从封头、筒体的组焊,盘管的制造,耐压试验和总装5个方面阐述了大型薄壁压力容器的制造过程。     

钢制薄壁内压短圆筒承载能力的试验研究

通过试验对16 MnR钢制薄壁内压短圆筒的承载能力进行了研究;建立了薄壁短圆筒屈服强度和爆破强度的经验公式;得到了区分内压长短圆筒的临界长度计算公式;分析了封头结构对16 MnR钢制薄壁短圆筒屈服强度和爆破强度的加强程度和加强范围的影响。结果表明:标准椭圆封头对短圆筒爆破强度的加强范围比屈服强度的广;碟形封头对短圆筒爆破强度和屈服强度的加强范围基本无差异;标准椭圆封头对16MnR钢制薄壁内压短圆筒屈服强度和爆破强度的加强作用比采用碟形封头的大,其加强范围也比采用碟形封头的广。     

封头相邻焊缝间距小于3倍壁厚的检测分析和后续措施

某制造厂生产的封头不相交拼缝中心线间距小于钢材厚度的3倍,不满足GB 150.4第6.4.1条要求。针对这一问题对封头进行了金相检验和残余应力测试。检测结果表明,该封头可以开展后续制造,并提出了改进措施。     

薄壁圆筒平封头环焊缝的应力与变形

通过对薄壁圆筒环向对接焊缝建立适当的力学模型，再利用柱似计算方法，导出了薄壁圆筒平封头环向焊缝应力与变形的分析解答。     

GB／T25198-2010《压力容器封头》出版发行

该标准规定了钢制以及铝、钛、铜、镍及镍合金制压力容器用封头的制造、检验与验收要求，以及常用的封头型式与基本参数。该标准适用于整板、拼板采用冲压、旋压、卷制以及分瓣成形的压力容器用半球形、椭圆形、碟形、球冠形、平底形和锥形封头。常压容器及其他承压设备用封头的制造、检验与验收要求亦可参照该标准执行。     

封头制造加工技术两例

介绍了大型封头制造加工技术两例。第一例介绍了锥形封头无缝锥顶段的加工制作工艺,该工艺简单,加工件质量优良。第二例分析了在大型凸形封头上组焊大口径管件引起封头变形的原因,提出了加工中防止封头变形的工艺要求。     

奥氏体不锈钢薄壁压力容器焊缝返修

介绍了奥氏体不锈钢薄壁压力容器焊接过程中容易产生的问题及应对措施。通过实例,介绍了奥氏体不锈钢薄壁压力容器焊缝的返修方法和工艺。结果表明,焊缝返修完全可行,产品质量符合相关标准要求。     

Optimal process conditions of shrinkage and warpage of thin‐wall parts

Optimal process conditions of thin‐wall injection molding of a cellular phone cover were investigated with the consideration of interaction effects between process parameters. L₂₇ experimental tests based on Taguchi's method were performed, and then Cyclone Scanner, PolyCAD and PolyWorks were used to measure the shrinkage and warpage of the thin‐wall injected parts to determine the optimal process conditions. Based on the results of the analysis of variables and the F‐test, interaction effects for each observed factor were determined. The results indicated that the packing pressure was the most important process parameter affecting the shrinkage and warpage of the thin‐wall part. The optimal process conditions were different for the shrinkage and the warpage. This was because during the injection process, the mechanisms affecting shrinkage or warpage were different. Compared with the results obtained with simplified thin‐wall parts in the literature, it was found that the geometry of a real commercial part did affect the optimal process conditions and the order of influence of process parameters. The optimal process conditions determined by Taguchi's method for reducing the shrinkage and warpage were verified experimentally in this work. Polym. Eng. Sci. 44:917–928, 2004. © 2004 Society of Plastics Engineers.     

A physical model for predicting the minimum stable slug length

A physical model for the prediction of the minimum stable slug length in vertical and horizontal slug flows is presented. The model is based on a new concept of recurrent relaxation of the wall boundary-layer at the slug front and its redevelopment at the slug back. Due to the overlapping process in the developing region the probable average stable slug lengths should range between the predicted minimum stable slug length and twice this value. Comparisons with experimental data is satisfactory.The prediction of the slug length provides an improved method to effect closure for previously existing models for this flow pattern.     

裂解炉横跨管联箱的结构设计探讨

介绍了横跨管联箱的组成、壁厚计算及端部结构,并结合具体工程,对支管连接的方法、补强计算等方面进行了探讨。     

钢制薄壁圆筒形压力容器的可靠性安全系数

应用可靠性设计方法中的强度—载荷干涉模型,考虑设计、制造、检验、操作及安全监察等因素的影响,建立了分析初始可靠度的力学模型,对钢制薄壁内压圆筒的静强度和钢制薄壁外压圆筒临界失稳强度大于实际最大栽荷的初始可靠度进行了研究,提出了按所要求的初始可靠度确定静强度安全系数与临界失稳强度稳定系数的方法。     

纤维增强薄壁环氧玻璃钢绝缘管在线编织-拉挤成型制造技术

提出一种不同于纤维缠绕、拉绕等现有方法的连续RTM法在线编织成管,再在模内浸渍树脂,经拉挤成型薄壁环氧玻璃钢管的工艺方法。     

基于屈服失效准则的薄壁容器试验压力系数

应用基于概率统计理论的可靠性设计方法,根据屈服失效准则,分析了在最苛刻的试验压力条件下,按标准设计的薄壁内压容器可接受的屈服强度初始可靠度范围。从控制薄壁内压容器在不同工况下最小初始可靠度的角度,对其试验压力系数进行了探索。     

不锈钢薄板焊接方法的探讨

随着我国不锈钢市场的不断扩大,不锈钢板的消费量也逐年增加,薄壁不锈钢板也已经深入到各种生产制造领域中,因此薄壁不锈钢板的焊接也就成为生产制造中一个重要工序,由薄壁不锈钢板自身的焊接工艺特点决定了其焊接存在的难度,本文着重介绍薄壁不锈钢板的焊接工艺及其特点。     

Crossflow Gradients in Thin Channels for Separation by Hyperlayer FFF,SPLITT Cells,Elutriation, and Related Methods

Abstract

The formation and use of thin equilibrium layers or hyperlayers in separations are discussed and the advantages of developing such hyperlayers along the transverse coordinate of thin channels is described. It is shown how a new method for establishing crossflow gradients in thin permeable-wall channels can be combined with sedimentation or electrical forces to generate transverse hyperlayers free of gradient-forming materials. The sedimentation case is shown to be equivalent to elutriation, but with the advantages of increased speed and of flow uniformity and thus of improved resolution. A general theory describing the form of the transverse flow gradient is developed. This theory is applied to the special case of hyperlayer formation in a thin channel with one permeable and one impermeable wall.     

薄壁尼龙零件常规铣切方法研究

尼龙是一种具有优良机械性能的热塑性工程塑料,但它刚度低、热变形温度低、吸湿性大、蠕变较大、热敏性能等缺点使其在薄壁零件的常规铣切加工中易产生变形,而且无法定位。本文对薄壁尼龙零件铣切加工中存在的问题进行了分析和研究,找到了常规铣切加工薄壁尼龙零件的定位方法和加工工艺参数