旋转流强化管式膜微滤的研究评述

浓差极化和膜污染是阻碍微滤广泛应用的关键难题 ,在认识理解颗粒迁移沉积和过滤速率下降的基础上 ,本文对旋转流管式膜微滤进行了一定的探讨分析。     

旋转切向流PA管式膜微滤试验研究

实验研究了旋转切向流聚丙烯PA管式膜微滤。通过建立的旋转切向流强化微滤实验装置系统，测定了旋转直线切向流和旋转圆弧切向流PA管式膜在不同SiO2悬浮液农度和不同流体压力下的膜通量随时间的变化曲线。实验研究结果表明，旋转切向流强化微滤不但节能，而且系统结构简单。     

肇转流强化管式膜微滤过程中分离因数研究

分离因数是影响旋转流强化管式膜微滤过程的关键操作变量之一,本文首先对管式膜分离器内分离因数的分布特征进行了研究,然后,不仅从理论上研究了分离因数对过滤过程行为的影响,而且进行了探讨分离因数对过滤性能的影响的试验研究,结果表明,管式膜分离器内分离因数没轴向从顶部底部呈迅速减小的分布特征;分离因数的增大,可使过滤过程推动力提高,并使外旋流时过滤过程中固相颗粒不易向膜面迁移并沉积,但加剧了内旋流时过滤过     

旋转流强化管式膜微滤过程中分离因数研究

分离因数是影响旋转流强化管式膜微滤过程的关键操作变量之一。本文首先对管式膜分离器内分离因数的分布特征进行了研究,然后,不仅从理论上研究了分离因数对过滤过程行为的影响,而且进行了探讨分离因数对过滤性能影响的试验研究。结果表明,管式膜分离器内分离因数沿轴向从顶部到底部呈迅速减小的分布特征;分离因数的增大,可使过滤过程推动力提高,并使外旋流时过滤过程中固相颗粒不易向膜面迁移并沉积,但加剧了内旋流时过滤过程中固相颗粒向膜面迁移并沉积的趋势;在悬浮液固相浓度保持一定时,过滤通量随分离因数的增大而提高     

膜微滤强化技术国内研究进展

概述了国内膜微滤强化技术研究进展,分析了附加场、设置湍流促进器或脉动进料方法,以及旋转横流强化、旋转动态膜强化、组合强化等方法的特点。     

强化十字流微滤研究进展及评述

膜污染是阻碍十字流微滤广泛应用的关键难题,在认识理解过滤速率下降和颗粒迁移沉积的基础上,本文介绍了近年来国内外在强化十字流微滤方面的研究状况和成果。     

横流微滤技术现状与应用

<正> 横流微滤(CMF)已经成为一种获取纯滤液的过滤技术,它所采取的过滤介质为微孔滤膜,可以截留粒度约0.05μm的颗粒。因此,CMF的使用介于超滤(颗粒粒度约0.5×10~3μm)和普通过滤(颗粒粒度约     

生物强化-微滤澄清设备处理工业园区河道污水

工业园区河道水质复杂,为生活污水、河水和工业废水混合水,其主要污染指标有pH、COD、BOD、氨氮、总磷、总氮等常规指标,废水中含有多种难降解有机污染物。采用高效生物复合强化-微滤澄清一体化设备,处理广州某河道污水,出水可稳定达到城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准。设备的运行成本较低,约为0. 45元/m~3。该工艺具有处理效果稳定、经济可行的特点。     

附加湍流器强化陶瓷膜微滤过程的研究

通过在管式陶瓷膜内设置不同结构形式的湍流器，试验和比较了不同主体流速和膜滤压差等工艺条件下的膜滤速率及能耗，分析了湍流器所产生的强化膜滤过程的效果以及试验条件下的一般规律。     

超声强化多通道陶瓷膜微滤超细TiO2悬浮液

针对超声强化膜分离过程能耗高的问题,提出并设计了一种新型超声强化膜分离操作方式,并进行了超声强化陶瓷膜微滤超细TiO₂颗粒悬浮液的研究。考察了超声场参数、操作时间及溶液环境对多通道陶瓷膜微滤过程的影响规律,并分析了此操作方式强化陶瓷膜微滤颗粒悬浮体系的机理。结果表明,该操作方式能够获得较高膜通量恢复率及平均膜通量,同时超声能量消耗减小了90.0%以上;降低超声频率及提高功率,有利于膜通量恢复,在超声参数45 kHz和0.33 W·cm^-2条件下,膜通量恢复到初始值的94.0%;控制超声辐射时间0.167 min,微滤时间8 min时,平均膜通量提高了61.5%;降低悬浮液颗粒浓度及提高料液温度都有利于超声场强化陶瓷膜微滤过程。     

Removal of Moisture from the Ultra Fine Particles Using Both High Centrifugal Force and Air Pressure

Abstract

A newly developed centrifugal batch dewatering unit was developed and used to remove the moisture contents of ultra fine particles (e.g., kaolin clay, silica, talc, and precipitated calcium carbonate). In the present method, air pressure was applied into the vessel of a conventional centrifuge to improve the efficiency of the dewatering. The experimental results showed that the moisture reductions of the samples could be enhanced more than 50% depending on dewatering conditions (i.e., G-force, spin time, applied pressure, cake thickness, particle size, surface hydrophobicity, and particle agglomeration). As a result, when the new centrifuge modification is used for the fine particle dewatering, cost and environmental concerns of thermal dryers could be considerably reduced and the handleability of the filter cakes could be significantly increased.     

离心泵轴向力分析和平衡方法探讨

离心泵工作时,其转子会受到一个与轴心线相平行的轴向推力。如果该力得不到有效的控制,在其作用下转子可能会出现一种轴向窜动的情况,这时就会引发转动部件以及固定部件之间直接接触,当这种情况发生就会引发泵零部件非正常运行。对离心泵的轴向力产生和平衡方法作了详细的叙述,希望可以起到一定的作用。     

陶瓷微滤膜回收钛白粉水洗液中TiO_2颗粒中试与现场考核

对陶瓷微滤膜回收钛白粉水洗液中二氧化钛粒子进行了中试实验和现场考核 ,考察了错流速度、浓度对渗透通量的影响及湍流促进器对微滤过程的强化效果 ;建立了日处理 15 0t废水的陶瓷膜回收钛白粉成套装置 ,并对该装置进行了现场运行性能考察和经济核算。实验结果表明 ,采用陶瓷膜微滤技术回收钛白粉水洗液中二氧化钛粒子不仅在技术上是可行的 ,在经济上也是合理的。     

Improving Suction Performance of Centrifugal Pumps by Using Jetting Device

Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.     

用引射技术提高离心泵的汽蚀性能

Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.     

采用普通陶瓷原料制备低成本多通道堇青石质陶瓷微滤膜

采用高岭土、铝矾土、滑石等普通天然原料,利用挤压成型法和浸渍提拉法制备了低成本多通道堇青石质陶瓷微滤膜。同时采用扫描电子显微镜、X射线衍射仪等对膜样品的显微结构及性能进行表征。结果表明,在1200℃下烧成,可成功制备孔隙率为28.2%的多通道堇青石质陶瓷微滤膜载体。然后通过浸渍提拉法,在固含量为25 wt%、浸渍时间为10s的工艺下,制备了厚度约为80μm的堇青石质顶膜。同时,实验制备的微滤膜还具备热膨胀系数低、结构均匀无缺陷和耐碱性能良好等优点。     

陶瓷微滤膜处理钛白粉水洗液的过程强化研究

本文采用湍流促进器和反冲对陶瓷膜处理钛白粉水洗液的微滤过程进行了强化研究。实验和以上两种方法均不同程度地提高了渗透通量,降低了能耗。考察卫湍流促进器结构参数和反冲持续时间、压力、周期对强化效果的影响,确定了合适的湍流促进器结构参数和反冲条件,并对反冲的重复性进行了实验考察。     

Flux Enhancement in a Helical Microfiltration Module with Gas Injection

Abstract

A helical flow module with an inner rod mounted membrane was designed and built to reduce gel layer deposit and membrane fouling during microfiltration. Controlled centrifugal instabilities resulting from flow in a helically grooved channel, as well as the leakage flow between adjacent grooves, generated secondary vortex flows. The permeation fluxes for helical modules with Dean vortex flow were compared with flat crossflow modules at different operating pressures, concentrations, and feed flow rates. The permeation flux of the helical module for a feed solution containing 0.3 wt% kaolin solution at 1.2 bar was 57% higher than that of the flat module. Moreover, in addition to secondary vortex flow, compressed air was introduced to the membrane module. The increase in flux for the helical module with air injection was significant: the flux enhancements at 1.3 bar, 2 L‐solution/min and 1.3 L‐air/min for 0.1 wt% solutions of kaolin and bentonite were 47 and 73%, respectively.     

陶瓷微滤膜澄清钛白废酸研究

针对钛白废酸的资源化 ,采用陶瓷膜微滤澄清钛白废酸 ,为进一步扩散渗析回收硫酸提供预处理。研究了操作条件如压力、流速、质量浓度、温度等对过程的影响。研究表明陶瓷膜过滤钛白废酸具有很好的澄清效果 ,渗透液浊度小于 0 .5NTU ;废酸中较高质量浓度的硫酸亚铁使温度对过滤的影响复杂化 ,温度降低会使其在膜孔内发生结晶 ,产生难以恢复的堵塞 ;采用 5mg/kg以下的改性聚丙烯酰胺絮凝可以使膜通量有所提高 ,过多的絮凝剂会使膜产生吸附污染而降低通量。其他过程参数对膜通量有一定的影响     

Microfiltration of Emulsified Oil Wastewater

Hydrophilic polyvinylidenefluoride (PVDF) membranes were employed for emulsified oil wastewater treatment. The best operating conditions for optimum flux of water, which penetrates through the membrane and rejection (prevention of oil droplets from passing though the membrane) were obtained. Concentration and pH effects on flux and rejection were determined. Increase of weight concentration caused flux decline due to the formation of a thick layer on the membrane surface. However increasing the concentration increased rejection. The pH effects were complex. By increasing the acidity of the feed, rejection was reduced.