催化裂化油浆结垢原因及解决措施

讨论了催化裂化油浆系统的结垢原因及减少其结垢的措施。介绍了近年来国内外催化裂化油浆的发展状况和应用效果。针对我国的实际情况提出了一些设想和建议。     

半固态挤压成型的研究现状

半固态挤压成型是集半固态加工与挤压成型为一体,利用半固态合金浆料的流变性能进行充型,并在压力作用下凝固成型的一种材料加工新技术。介绍了半固态挤压成型的原理及特点,阐述了半固态挤压成型在挤压合金方面的研究现状及其发展前景。     

MEASUREMENT OF SOLID SLURRY FLOW VIA CORRELATION OF ELECTROMAGNETIC FLOW METER,ELECTRICAL RESISTANCE TOMOGRAPHY AND MECHANISTIC MODELLING

The study presented here was carried out to obtain the actual solids flow rate by the combination of electrical resistance tomography and electromagnetic flow meter. A new in-situ measurement method based on measurements of the Electromagnetic Flow Meters (EFM) and Electrical Resistance Tomography (ERT) to study the flow rates of individual phases in a vertical flow was proposed. The study was based on laboratory experiments that were carried out with a 50 mm vertical flow rig for a number of sand concentrations and different mixture velocities. A range of sand slurries with median particle size from 212 μm to 355 μm was tested. The solid concentration by volume covered was 5% and 15%, and the corresponding density of 5% was 1078 kg/m³ and of 15% was 1238 kg/m³. The flow velocity was between 1.5 m/s and 3.0 m/s. A total of 6 experimental tests were conducted. The equivalent liquid model was adopted to validate in-situ volumetric solids fraction and calculate the slip velocity. The results show that the ERT technique can be used in conjunction with an electromagnetic flow meter as a way of measurement of slurry flow rate in a vertical pipe flow. However it should be emphasized that the EFM results must be treated with reservation when the flow pattern at the EFM mounting position is a non-homogenous flow. The flow rate obtained by the EFM should be corrected considering the slip velocity and the flow pattern.     

考虑浆体黏度的泥石流流速计算方法

泥石流浆体黏度通过影响泥石流内、外部的阻力特征影响泥石流的糙率系数,泥石流糙率系数与浆体黏度之间的关系还没有基于观测数据的定量表述。通过对云南东川蒋家沟泥石流观测资料的分析,研究泥石流糙率系数与浆体黏度之间的关系,并通过回归分析得到考虑浆体黏度的泥石流糙率系数计算公式,最后基于此构建了考虑浆体黏度的泥石流流速计算公式。结果表明,随着泥石流浆体黏度的增加,泥石流糙率系数逐渐增加,浆体黏度在宏观上表现为增阻作用,考虑浆体黏度的泥石流流速计算公式改进了现有公式在计算浆体黏度较高的泥石流流速中的不足。研究结果可为进一步研究浆体黏度对泥石流运动阻力的影响提供参考,也为工程实践中的流速计算和增阻消能设计提供新的思路。     

Settlement prediction model of slurry suspension based on sedimentation rate attenuation

This paper introduces a slurry suspension settlement prediction model for cohesive sediment in a still water environment. With no sediment input and a still water environment condition, control forces between settling particles are significantly different in the process of sedimentation rate attenuation, and the settlement process includes the free sedimentation stage, the log-linear attenuation stage, and the stable consolidation stage according to sedimentation rate attenuation. Settlement equations for sedimentation height and time were established based on sedimentation rate attenuation properties of different sedimentation stages. Finally, a slurry suspension settlement prediction model based on slurry parameters was set up with a foundation being that the model parameters were determined by the basic parameters of slurry. The results of the settlement prediction model show good agreement with those of the settlement column experiment and reflect the main characteristics of cohesive sediment. The model can be applied to the prediction of cohesive soil settlement in still water environments.     

塑性混凝土防渗墙在武都水库围堰工程中的应用

塑性混凝土防渗墙由于其本身的特性,已经被广泛的应用到工程的除险和围堰的防渗处理中。防渗墙施工属于地下隐蔽工程,质量检测只能在工程完工后进行,故应当在施工过程中加强质量控制。结合武都水库围堰工程,探讨了塑性混凝土防渗墙的施工工艺及施工难点,指出了在施工过程中质量控制的关键,在一定程度上可为类似工程提供参考。     

超深全岩地质复合接力钻孔灌注桩施工

本文介绍了流溪河特大桥钻孔灌注桩施工的实例,并针对钻孔过程中出现的护筒底口漏浆,超深全岩地质孔垂直度易超标,基岩过硬对钻具破坏严重,直径2.5m超深桩灌注等问题进行了探讨。     

提高管道输沙效率方法的探讨

随着黄河标准化堤防工程进一步开展，淤背固堤泥沙输送距离不断增加。目前，排距超过3000m的越来越多，部分淤背固堤工程排距甚至超过10000m。随着排距的增加，接力输送方式的使用，机械设备的选择与配套、接力站安设位置准确与否对系统的生产效率和生产成本都起着决定性的作用。本文通过对淤背固堤工程分析研究，提出以提高泥浆浓度、泥沙输送效率的手段。提高系统的生产效率。并利用水力学水头计算理论，结合生产实践论述如何进行设备配套以及接力站位置确定。     

池体混凝土漏水点处理

混凝土蓄水池属于薄壁结构，容易出现漏水、渗水、本文主要介绍了对此问题的补救措施，即速凝水泥浆堵漏法，效果显著，值得推广。     

坝前淤泥对闸门启门力影响的模拟相似性及方法

水库泥沙淤积在闸门前，会增大闸门启门力。如何通过模型试验确定有泥沙淤积时闸门启门力，本文对此进行了探讨。认为淤积在坝前的细颗粒泥沙多数情况下可当做宾汉体泥浆，根据坝前淤泥受力平衡条件，导出淤泥相似准则，并论述了模拟试验方法。