立式压滤机在4A沸石生产中的应用

介绍了立式自动压滤机在4A沸石生产线上与原有的设备进行了对比,认为其性能和应用情况均优于传统设备,值得在相关行业推广。     

Anisokinetic Shrouded Nozzle System for Constant Low-Flow Rate Aerosol Sampling from Turbulent Duct Flow

An anisokinetic shrouded nozzle system was designed for sampling particles at a constant low flow rate from a ventilation duct to an aerodynamic particle sizer (APS). Shrouded anisokinetic nozzles are a means for sampling from a moving airstream with higher particle transmission than with unshrouded isokinetic nozzles. This shrouded nozzle sampling system was evaluated in an experimental ventilation duct system. Aspiration and transport efficiency measurements were made for five particle sizes in the range 1–13 μm at each of three duct air speeds in the range 2.2–8.8 m/s. Under these conditions, the shrouded nozzle system showed improved performance compared to buttonhook isokinetic nozzles, especially for larger particles and higher air speeds. Measured transmission efficiencies through the shrouded nozzle sampling system were generally higher and more reliably predictable than those through buttonhook isokinetic nozzles. Model predictions of transport and aspiration efficiencies of the shrouded nozzle system showed good agreement with measurements over the entire range of experimental conditions. The shrouded nozzle sampling system could be used to measure concentrations in ventilation ducts with an APS for particles in the diameter range 1–13 μm.

Copyright 2014 American Association for Aerosol Research     

Mechanics of Constant-Rate Filter Pressing of Highly Flocculated Slurries

The growth of a powder compact from a highly flocculated slurry has been simulated by a computer program that models non-steady-state Darcian flow. Computer simulations have been compared with filter-pressing experiments. Constant-rate filter-pressing experiments are divided into two regimes of piston stress—displacement behavior: an initial, almost-linear, but concave-up, regime during cake growth, followed by a second region of rapidly increasing piston stress when the piston comes into contact with the cake. Linear piston stress—displacement behavior is expected, from theory based on a uniform cake model. Highly flocculated slurries show highly nonlinear behavior. Nonlinear behavior is shown to be consistent with nonuniform growth of the cake. The permeability and consolidation behavior of the cake has been determined by a consolidometer experiment. Computer simulations indicate that the particle-packing density profiles during cake build-up are surprisingly similar during cake growth. Conditions for uniform consolidation can be determined from a general equation for non-steady-state Darcian flow. Results are directly applicable to constant-flow-rate pressure casting or slip casting.     

变速滤池处理低浊度水试验

研究开发了一种复合变速滤池,实现了对普通滤池过滤作用的强化.试验结果表明该滤池可有效地去除原水中的浊度和亚硝酸盐氮,其去除率分别为58.82%～86.96%和33.33%～39.51%,保证了出水水质.该滤池采用变速流形式,可充分发挥深层滤料的作用.     

Transparent Hydroxyapatite Prepared by Hot Isostatic Pressing of Filter Cake

Hydroxyapatite powder was synthesized and formed into a compact in an aqueous medium using a filter-cake method. The compact was hot isostatically pressed at 700° to 1000°C and 100 MPa for 2 h. Fully dense, transparent materials were obtained above 800°C. Both forming and densification methods were found to be important in obtaining transparent materials.     

常规过滤器的优化设计

过滤器是保障化工生产系统不受杂质影响,可以正常运行的重要辅助设备。常规的过滤器在杂质含量高时堵塞频繁,投资大,设备占地面积大,泄漏点增加。为了保证系统可靠工作,延长过滤器的使用寿命,对常规过滤器进行了优化设计,使其过滤性能提高,过滤安全得到保障。     

入井流体温度监测规律研究

温度监测与其他井下实时监测方法相比较有很多优势,在近年来的智能井技术中起到很大作用,尤其对超高压井的意义更为重要。井下温度场分布的研究是井温测井的理论基础。充分考虑超高压条件对流体物性的影响,根据能量守恒方程建立了一维温度场数学模型,模拟超高压油井定流量生产时油藏产出流体温度情况。数值模拟结果表明,入井流体温度由于焦耳-汤普森效应和热传递作用而发生温度变化,并且生产压差越大、流量越大时,入井流体温度越高。     

浅谈化学动力学关于速率常数的计算

在化学动力学中,速率常数的计算与化学方程式的书写有关,在具体计算中,速率常数应考虑为k实,若反应物计量系数,v=1则k实＝kn ,若n≠1则kn=uk实,则,其中kn为n级反应的速率常数,它与方程式的书写无关,由实验决定。     

The Behavior of Constant Rate Aerosol Reactors

An aerosol reactor is a gaseous system in which fine particles are formed by chemical reaction in either a batch or flow process. The particle sizes of interest range from less than 10 Å (molecular clusters) to 10μm. Such reactors may be operated to study the aerosol formation process, as in a smog reactor, or to generate a product such as a pigment or a catalytic aerosol. Aerosol reactors can be characterized by three temporal or spatial zones or regions of operation for batch and flow reactors, respectively. In zone I, chemical reaction results in the formation of condensable molecular products which nucleate and form very high concentrations of small particles. The number density depends on the concentration of preexisting aerosol. Zone II is a transition region in which the aerosol number concentration levels off as a result of hetergeneous condensation by the stable aerosol. In zone III coagulation becomes sufficiently rapid to reduce the particle number concentration. There may be a zone IV in which agglomerates form. Chemical reaction may continue to generate condensable material throughout the various zones. This paper deals with reactors in which aerosol material is generated at a constant rate. Design parameters of interest are the particle size distribution, number density, surface area, and mass loadings. For ideal systems composed of spherical coalescing particles, these can be predicted theoretically for certain limiting cases. However, the irregular agglomerates which may form in zone IV are more difficult to characterize theoretically.     

二苯基二甲氧基硅烷反应速率常数求导

采用气相色谱法测定了线性变温条件下二苯基二甲氧基硅烷(DDS)的质量分数,由此通过线性变温动力学方法求出DDS的分解反应活化能E=138.0194 kJ/mol,25℃反应速率常数为1.1469×10-4/d.建立了反应速率常数与温度间关系的方程,由此方程可预测出存放一定时间后DDS的质量分数变化情况,对生产有一定指导意义.     

熔体静电纺热压PET复合过滤材料的制备工艺研究

采用热压技术将熔体静电纺纤维与传统非织造织物在线复合,制备熔体静电纺热压复合过滤材料,探讨热压压力、热压温度和收集速度对复合过滤材料过滤性能、剥离强力与断裂强力的影响。结果表明,熔体静电纺纤维经热压后良好贴附在非织造基材表层;随着热压压力的增加,复合过滤材料的过滤性能得到一定提高,剥离强力随之增大,断裂强力先增大后急剧减小;热压温度对复合过滤材料的过滤性能影响不大,但对其力学性能有较大影响,复合过滤材料的剥离强力和断裂强力随着热压温度的增加而增大;随着收集速度的减小,复合过滤材料的过滤效率、剥离强力和断裂强力均有所提高。     

恒流堵塞器的性能研究

介绍了恒流堵塞器的结构组成和工作原理。给出了恒流堵塞器水嘴与弹簧的设计方法。设计了一个室内性能实验系统,对堵塞器进行了限位实验,分析不同阀芯位移与压差的关系;对所设计的弹簧进行了恒流性能实验,结果表明所设计的弹簧与水嘴匹配较好,误差较小;最后对弹簧刚度适用范围进行了研究。     

Gravity Filtration with Accretion of Slurry at Constant Rate

Abstract

The separation of liquid from solid in many industrial effluents may be described by a physical theory developed originally to describe one-dimensional movement of water in a swelling soil. The theory makes use of measured hydraulic conductivity-liquid content, and liquid content-liquid potential relations. Both these functions have been found to be well defined, as required for their use in the theory.

The process of gravity filtration is explored in terms of this theory for vertical columns of effluent, to the top of which additional effluent is applied continuously at a constant rate, and from the bottom of which the liquid phase escapes through a membrane which prevents escape of the solid phase. The physics of the process is discussed, and illustrative calculations and experimental data are presented for one aspect of the process for which a quasianalytical solution is possible. The calculations are simplified using the flux-concentration relation of Philip.

The approach permits reliable calculation of the liquid-solid profile and the filtration rate for the process.     

V型滤池恒水位控制及滤池自动反冲洗控制方案

众所周知,水是生命之源,随着社会的不断发展,自来水对人民生活及生产业的影响力与日俱增,进而对供水的质量与安全可靠性的要求不断提升。因此加强制水系统工况的监控是一项有效的措施,尤其是加强水处理各个工艺环节的自动监测和控制意义重大。该文主要对V型滤池恒水位控制及滤池自动反冲洗作了论述,供相关设计与运行参考。     

助滤剂增强恒压过滤机生产能力的计算方法

论述了恒压操作预涂助滤剂后,由于介质阻力发生变化对过滤机生产能力的影响,并提出了预涂助滤剂后,过滤介质常数的计算式。     

熔体流动速率测试（二）

充分认识聚合物熔体流动速率（MFR）测试方法的优点和不足,对理解熔体流动速率的测试原理极为重要。聚合物熔体流动速率测试方法按照ASTMD1238进行测试,对应的国际测试标准为ISO1133。这两种测试标准存在一些小的差异,在执行功能基本上是相同的。     

Constant Displacement Rate Method for Testing Epoxy Adhesive Bonds

A constant load-point displacement rate method is used to test double-cantilever-beam specimens of 2024-T3 aluminium alloy bonded with AF126 adhesive. The elastic energy release rate, G_1, was calculated from measured values of load and load-point displacement. Measurements in humid air at 50°C showed that G₁ depended strongly on load-point displacement rate. At high rates, the bond was not degraded and G₁ was equivalent to G_1c. At very low rates, the bond was degraded and G₁ was equivalent to G_1scc. In a region between these extremes, G₁ was sensitive to load-point displacement rate because moisture degraded the bond at a rate similar to the crack velocity. Selection of data where G₁ was unstable with load-point displacement rate leads to a crack velocity, which may be used as a bond durability indicator.     

陶瓷过滤器滤管脉冲反吹过程的流动特性

在由三根陶瓷滤管组成的实验装置上 ,利用热线风速仪对脉冲反吹时滤管外瞬态流场进行了测定 ,分析了喷吹压力、脉冲宽度、过滤气速和喷吹距离对滤管外流场的影响。随着离开滤管距离的增加 ,喷吹速度和回流速度逐渐减小。结果表明 ,回流现象和喷吹气流沿轴向的不均匀性是影响过滤器脉冲反吹性能的重要因素