液体粘度,表面张力与管径对池式两相流型的影响

在不同直径的垂直玻璃管中盛装着不同物性(粘度与表面张力)的液体,空气经分配器注入静止的液体中,对两相流型的变化进行了观察研究。流型的确定采用了高速录相机系统,也同时进行肉眼观察,并测量了不同流型的空隙度。实验表明:空气-高粘性液体和空气-起泡液体的气、液两相流型与通常的空气-水系统的流型极不相同。其空隙度也在较广泛范围内变化。     

INTERNAL THERMOSYPHON REBOILER

A very serious problem of instability that arises in the vertical thermosyphon reboilers can be solved by a newly developed equipment called internal thermosyphon reboiler. Experiments were carried out in both quartz tube and copper tube with the same geometrical dimensions. The former allowed better visual observation and the latter gave more quantitative informations. Water, sulfuric acid, triethanol-amine, heavy oil, ethanol-water, methanol-ethanol, ethanol-propanol and some other mixtures were used as working media. Particles of polypropene with density very close to water were used as the tracer in water system for investigating the flow characteristics. Rate of circulation, flow patterns, rate of heat transfer and fouling in this equipment were studied. A flow model and a design method were proposed. The results calculated could predict the characteristics of two-phase flow and heat transfer inside this boiling equipment.     

PI膜厚控制方法分析

以凸版印刷机、膜厚测试仪为基础，研究了PI液固含量、PI液补加滴数、印刷速度、Doctor轮压入量等几个因素对PI膜厚的影响，为实际生产中稳定控制PI膜厚提供了依据。     

THE EFFECT OF LIQUID PHYSICAL PROPERTIES ON DRIFT VELOCITY

Drift velocity is a very important paramcter for predictirg the pool volumetric void fraction. Two-phase system of gas and high viscous liquids pool is encountered in various engineering applications. A review of the literature shows no data for explaining the effect of highly viscous liquids on the drift velocity. This paper's analysis shows that there is a considerable influence. It is shown that the foaming behaviour of liquids is dependent on the surface properties. For some highly viscous liquids at a given superficial gas velocity, the viscosity changes with time. The effect of "foam" and "time" on drift velocity is clearly elucidated.     

内热虹吸式再沸器

立式热虹吸再沸器内的流动不稳定性是一个严重问题.本文作者最近研制的内热虹吸再沸器能够解决上述问题.采用相同几何尺寸的石英管及铜管进行实验,前者有利于观察研究,后者则能提供更多的定量结果.工作介质为水、硫酸、三乙醇胺 重油、乙醇-水、甲醇-乙醇、乙醇-丙醇及其他一些混合物.在观察水在管内的流动特性试验中,用聚丙烯颗粒作为示踪粒子,其密度与水非常相近.研究的内容包括循环速率、流型、传热速率及结垢等问题.提出了一个流动模型及设计方法.计算结果可用来推算此沸腾设备内的两相流及传热特性.     

智能型免补水干式防泄漏煤气管道自动排水器研究与应用

针对智能型免补水干式煤气管道排水器安全性、可靠性、经济效益及环保效益进行研究,重点阐述了其工艺技术、工作原理、结构特点、主要功能及优点。     

两相流及传热(五) 流动沸腾传热

沸腾传热是指液体通过传热相变为蒸气的过程。 沸腾型式有两种,即大容积沸腾(或称池式沸腾)和流动沸腾(或称对流沸腾)。 大容积沸腾是指浸没在液体池里的加热面上发生的沸腾。当加热器表面温度超过液体饱和温度一定值时,在加热器表面上形成许多气泡。由于气泡的成核,长大和脱离,同时,由于自然对流的作用,形成了复杂的流体运动。     

稀油密封干式煤气柜集油箱的改进

文中对稀油密封干式煤气柜集油箱设计的合理性进行了探讨，提出了改进集油箱的办法，介绍了改进后的效果。     

一种迟滞结构的高精度USB-PD驱动芯片

为了解决PD驱动电路的可靠性问题,在传统电路基础上设计并实现了一种迟滞结构的高精度PD驱动电路。采用对称双路结构,分别调节信号的上升、下降边沿时间,每一路使用迟滞导通的分段控制方式,提高了控制精度。采用限流方式,解决了因寄生效应而产生的振荡现象,提高了通信的可靠性。采用TSMC 0.18 μm CMOS工艺设计驱动电路并流片。测试结果表明,在BMC方波外的接频率为300 kHz时,线缆上电压信号的上下边沿时间都为340 ns,无明显振荡。该电路的静态功耗小于400 μA,具有较好的实用价值。     

罩式炉尾气回收氢气再利用的研究

针对全氢罩式炉尾气对外直排的现状,对回收全氢罩式炉尾气中的氢气再利用安全性、可靠性、经济效益及环保效益进行了研究与阐述。