An investigation of the unstable region for dense phase conveying in sliding bed flow

For fine powdered materials, capable of being conveyed in dense phase, a conveying region exists in which instability in flow and pipeline blockage can occur if the pressure gradient available is insufficient to maintain a minimum value of solids loading ratio. A reduction in material flow rate can also lead to pipeline blockage in this region. Conveying trials under-taken with cement are used to illustrate the nature of the problem.     

The effect of welded boundaries on the response of rectangular hot-rolled mild steel plates subjected to localised blast loading

A series of experiments examining the effects of welded boundaries on the localised blast load response of mild steel plates is presented in this short communication. Two types of welding are examined, TIG and MIG welding. The welded boundary response is compared with clamped boundary and straight and chamfer machined boundary responses. The overall trend of midpoint deflection–thickness ratio versus dimensionless damage number for all the plates follows previously reported empirical trends. The tearing threshold (Mode II*) in terms of the damage number is lowest for the machined plates followed by the welded plates with the clamped plates having the highest resistance to tearing.     

门式脚手架在已建高层建筑外装修中的应用

介绍门式脚手架在已建高层建筑外排栅中的整体搭设和应用实例。     

焦化生产中含硫容器自燃氧化倾向性分析

分析了炼焦化工生产过程中硫的分布和存在形态、硫铁化合物自燃的影响因素,提出了防止储罐、管道等设备自燃事故的安全控制方法.     

箕斗卸载状况的检测方法

介绍了箕斗卸载状况检测方法的原理,分析了各种方法的优点和缺点。使用时应根据具体情况选择合理的检测方法。     

爱立信SGSN3．0CPU负荷与容量分析

由于爱立信厂家未能提供用户模型、设备配置和SGSN实际容量之间的内在关系解释以及系统CPU负荷、SGSN实际容量的计算方法,为此,本文主要通过对现网数据进行计算及研究,建立一套行之有效的容量分析、监控预警体系来解决这一问题。     

基于《压缩式垃圾车》(CJ/T 127 2000)行业标准的后装压缩式垃圾车的几点优化建议

后装压缩式垃圾车集自动装填与压缩、密封运输和自卸为一体, 自动化程度高,如在结构减重、推出板有限元分析、液压系统优化、绿色设计及密封优化等方面进行设计优化和改进,将直接使车辆的装载量、密封性、环保性、稳定性、作业可靠性及行驶安全性得以提高.     

乳化炸药混装车水孔爆破的优越性

该文分析了应用袋装炸药装填水孔爆破产生拒爆、"冲天炮"、根底偏高和爆破效果差等问题,然而应用乳化炸药混装车装填水孔可以解决这些问题,并且爆破后具有根底平整、大块率低、毒气少和综合效益高等优点.以三峡永久船闸旁侧泄水箱涵工程和江苏田湾核电站工程为例进行了分析.     

Influence of load and speed on wear characteristics of grey cast iron in dry sliding — selection for minimum wear

The wear of grey cast iron in dry sliding conditions has been studied with the aims of (1) finding the influence of working conditions on the wear rate, and (2) determining the region of speed and load where low wear is accomplished. Grey cast iron with flake and nodular graphite was submitted to investigation using a pin-on-disc machine. The results indicate that the flake graphite cast iron is more suitable for applications at speeds greater than 4 m s⁻¹ and lower loads, while nodular cast iron has greater wear resistance at lower speeds in the range of loads investigated - from 50 N cm⁻² to 200 N cm⁻²     

Crack growth in aluminium alloy sheet material under flight-simulation loading

Crack propagation tests were carried out on 2024-T3 sheet specimens to study the effects of omitting low-amplitude cycles from the gust-dominated TWIST load sequence (MiniTWIST) and the removal of small load ranges from the manoeuvre-dominated FALSTAFF load sequence (short FALSTAFF). In other tests high-amplitude loads of TWIST and MiniTWIST were truncated at different levels. The results are compared with data from similar test programmes, including crack initiation. Attention is paid to unstationary crack growth retardation and a transient retardation during initial crack growth started by an artificial crack.