潜水搅拌器叶轮设计及搅拌流动研究

基于环流理论实现潜水搅拌器叶轮设计,应用Fluent软件对其产生的复杂搅拌流场进行数值求解。结果表明:搅拌器叶轮运行时产生旋向射流,利用体积流来输送液体。通过改变搅拌器叶轮的设计参数,对模拟结果进行对比分析,提出优化设计方案,现场运行效果良好,效益显著。     

大型螺旋桨五轴加工中基于方向包围盒层次树的全局干涉碰撞检测

针对大型螺旋桨五轴加工中重叠区存在的全局干涉碰撞，构建了一种基于动态OBB层次树的检测算法：建立螺旋桨和特殊铣刀头的方向包围盒层次树，利用多刚体系统的运动学理论，获得螺旋桨和特殊铣刀头在每个加工位置处包围盒的动态坐标变换矩阵，根据分离轴理论，实现每个加工位置的全局干涉碰撞检测。通过包围盒分组以及运动趋势判断，提高了全局干涉碰撞检测算法的效率。     

输油泵叶轮流道表面的电解抛光

采用电解抛光的方法可降低叶轮流道表面粗糙度，减少流道表面与流体的摩擦阻力，提高输油泵效率，达到节能的目的。通过ＤＫＳ７５０—５５０输油泵叶轮流道表面的电解抛光试验，提出了电极设计中的抛光余量、电极间隙、电流密度、电解液流速、抛光时间等基本工艺参数的确定和计算方法。介绍了组合电极的制造工艺及安装方法。测试数据对比表明，输油泵叶轮流道表面经电解抛光后，节能效果显著。     

水环真空泵叶轮轮毂工艺改进

2BE1系列水环真空泵叶轮轮毂按德国西门子公司工艺是采用铸造生产的,其铸钢轮毂质量不稳定,生产周期长。为改变这一状况,我们在消化、吸收引进技术的基础上,结合生产实际情况,采用焊接的方法制造轮毂,取得了质量好、成本低、生产周期短的效果。     

多功能大型宽叶搅拌桨

介绍MAXBLEND(MB)、FULLZONE(FZ)、SANMELER(SM)3种多功能大型宽叶搅拌桨的结构形式、在槽内产生的流动状态、混合特性、功率特性,以及液液系、固液系、气液系的分散特性。这些搅拌桨适用粘度10-3—100Pa·s,具有低能耗高效率的特点,在槽内产生的轴向的径向速度分布比较均匀,沿槽内壁轴向的传热系数也比较均匀,传热系数较高;在聚合、晶析操作中,有利于防止结垢,并且容易控制粒径的分布。     

Effect of the attack angle on the roll and trailing vortex structures in an agitated vessel with a paddle impeller

The purpose of the present study is to observe the effect of the blade attack angle on the roll and trailing vortex structures in a stirred vessel via laser-Doppler velocimetry (LDV). In this investigation, four-bladed paddle impellers with four attack angles, which were 45^°, 60^°, 75^° and 90^°, respectively, were used. By synchronizing LDV with a rotary encoder coupled to the impeller shaft, angle-resolved measurements of all three velocity components were performed. This experimental method made it possible to capture the details of the vortical structure both behind the impeller blade and discharge region. Our study on the mean flow structure generated by three types of pitched blade turbines (45^°, 60^°, and 75^°, respectively) found that a single trailing vortex was formed around each turbine blade. Roll-up of the vortex sheet issuing from the blade tip was also observed, which indicated a major roll of trailing vortex generation mechanism for each pitched blade turbine.     

“可控涡”法设计离心叶轮的应用研究

详细介绍了用“可控涡”法设计离心叶轮时叶片涡给定的几种方法，通过编制程序确定了叶片涡rCw在子午流面上的分布。并利用确定的可控涡对一离心叶轮进行了反问题设计。计算结果表明：速度分布合理，满足设计要求。图10参9     

潜油电泵导叶轮流道检测仪的研制

潜油电泵以它特有的深抽、大排液量、经济有效的采油特点成为油田中后期增加产量的重要手段之一。作为潜油电泵重要组成部分的导叶轮，其流道的畅通情况直接决定了潜油电泵的排量。目前，在油田的实际应用中，还没有快速准确地检测导叶轮流道的方法。文章叙述了潜油电泵导叶轮流道检测仪的设计原理、结构及功能，并对检测结果进行了分析。     

乙烯氢酯基化合成丙酸甲酯催化反应动力学研究

采用以三氯化钌为主的催化体系,在高压釜中采用虹吸式涡轮搅拌器消除乙烯在气液两相中的传递因素对反应带来的影响,研究了以甲酸甲酯为原料,通过乙烯氢酯基化反应合成丙酸甲酯的催化反应动力学。探讨了该反应的机理,得到)(β-1)],反应速率常数k1=0 0668mol/(s·L),反应活化能CA/(1-1/β)][1-(CA/CA0反应的动力学数学模型为rp=[k1CM0E=81 363kJ/mol。     

Changes in intracellular sodium and potassium in chemostat-cultivated Escherichia coli

Escherichia coli was continuously cultivated at constant dilution rate for a range of agitation rates, and at constant agitation rate over a range of dilution rates. Mean cell volume increased linearly both with increase in agitation rate (as we have previously found) and with increase in dilution rate. In each case, measurement of intracellular sodium and potassium content after rapid separation of cells from the medium by centrifugation through silicone oil showed these to increase as the mean cell volume increased. In absolute terms, the increase in sodium or potassium per unit cell volume was significantly greater for changes in agitation rate than for changes in dilution rate.