Electrostatically Enhanced Granular Bed Filters

A mathematical model for the filtration of dust in granular filters under the influence of a Coulombic force is developed. The paper considers the effect of filter porosity and external field orientation on the filtration efficiency of inertialess, inertial, and diffusional aerosols. Calculated filtration efficiencies may be used to design electrostatically enhanced granular filters.     

聚结式过滤器处理含油污水实验研究

研究采用聚结式过滤器处理含油污水,选取润滑油配制含油污水,研究了初始含油量、流量、静置时间以及乳化程度等参数对分离效果的影响.实验结果表明,初始含油量越高、乳化程度越小、除油效果越好.针对开发的聚结式含油污水过滤器,对其操作工艺参数进行了优化,流量应控制在600L/h左右,静置时间以30min为宜.     

Performance Evaluation of Electrostatically Augmented Air Filters Coupled with a Corona Precharger

An experimental study of electrostatically augmented air (EAA) filters coupled with a corona precharger has been conducted using Arizona road dusts and tobacco smoke. The measurements of filter efficiency and pressure drop across the EAA filter have been made using an ASHRAE 52.1-1992 filter test system and an opacity meter to measure the particle concentration upstream and downstream of the test filter. The two-stage EAA filter unit consists of the positive corona precharger upstream of a filter, to precharge particles with the electrical strength of 4.7 kV/cm, and an electrified filter collector, which has folded media with meshy metal separators, in the upstream and downstream side gaps. DC voltage of +1,000 V (1.4 kV/cm) is applied between the upstream and downstream separators to produce an electric field between the separators and media as well as across the media in a polarity so that most of the precharged particulates are collected on the upstream filter collector. A conventional filter was measured and had 70.0% efficiency with dusts of 1.96 w m in mass median diameter and 2.5 m/s face velocity, while the EAA filter had 92.9% efficiency. An electrical effect on the EAA filter was evaluated to both improve the filter efficiency and reduce the pressure drop across the filter. Also, the performance evaluation of the EAA filter using an air handling chamber system in occupied space was investigated with tobacco smoke particles.     

强化生物除磷系统中好氧颗粒污泥形成与研究

好氧颗粒是一种大型的生物聚集体,内部结构紧凑,可用于高效的废水处理。通过好氧颗粒化工艺的发展、颗粒化机理、强化生物除磷(enhanced biological phosphorus removal,EBPR)系统中颗粒污泥形成研究、颗粒污泥菌群结构研究和颗粒稳定性等方面进行了新的综述。     

磷铵—氯化铵—氯化钾系复混肥造粒过程正交实验研究

采用正交实验方法对磷铵—氯化铵—氯化钾系复混肥盘式造粒特性进行了研究 ,通过方差分析及显著性校验 ,确定了过程的适宜工艺条件。     

Modeling of Droplet Separation Kinetics in Granular Bed Filters Based on MRI Measurements

In droplet separation by granular bed filters, the transient loading regime plays an important role because, for gases with low droplet concentrations, steady state will be reached only after a long time. A mathematical model describing this transient loading regime as well as steady state was developed. It is based on differential balances for the dispersed droplets and for the separated liquid. The time‐dependent and spatially resolved liquid loading is calculated and compared with data obtained by magnetic resonance imaging (MRI), a noninvasive measuring technique. The good agreement between simulated and measured loading curves proves the general applicability of the model.     

Experimental Study on the Loading Characteristics of Needlefelt Filters with Micrometer-Sized Monodisperse Aerosols

In this work, three types of needlefelt filters, made of Polyester (PE), Ryton Sulfar (RS), and Polyaramid (PA), were tested to in- vestigate the aerosol loading characteristics of fabric filters when challenged with micrometer-sized monodisperse potassium sodium tartrate (PST) particles. A fibrous filter with packing density of 9%, thickness of 0.38 mm, and fiber diameter of 5.1 θ m was included for comparison. A vibrating orifice monodisperse aerosol generator was used to produce three different sizes (5, 10, and 20 θ m) of PST particles for aerosol loading experiment. An ultrasonic atomizing nozzle and a TSI constant output nebulizer were used to generate polydisperse PST particles for the aerosol penetration test. The aerosol penetration of submicrometer-sized particles through the filters was measured by using a Scanning Mobility Particle Sizer. An Aerodynamic Particle Sizer was used to measure the penetration fraction of aerosol particles larger than 0.8 θ m. The pressure drop across the filter was monitored by using pressure transducers, which were calibrated against an inclined manometer. Airflows of 5, 10 , 20, and 30 cm/s were used to study the flow dependency. The aerosol penetration results showed that the particles larger than 3 θ m did not penetrate the clean fabric filters tested in the present study. The loading curves (plots of pressure drop against sampling time) displayed three regions: an initial region of fast increase, a transition region, and a final linear region after the dust formation point. After the formation point of the dust cake, both fabric and fibrous filters shared the same slope (of the loading curves). The slope of different regions of the loading curves was determined by many factors, such as size of challenge aerosol, face found to be critical to the performance of the fabric filters. In order lower porosity, which caused an extra rise in pressure drop across velocity, surface treatment, and the compressibility of the dust cake forming on the filter. The method of final surface treatment was to avoid the unnecessary rise in air resistance, the melting clumps formed during final surface treatment should be as thin and narrow as possible, just enough to support the filter bag cleaning. From the standpoint of filter quality and energy consumption, the low filtration velocity has to be adopted whenever possible, because high filtration velocity not only led to lower filter quality (in particular for submicrometer-sized particles) but also created dust cake of lower porosity, which caused an extra rise in pressure drop across thet dust cake.     

CO_2泡沫封窜提高采收率实验研究

三维人造岩心可模拟油藏非均质性,如韵律性、渗透率极差、大孔道等,可以较为真实地模拟地层情况。泡沫是一种有效的封窜手段,通过不同注入时机下CO_2泡沫封窜提高采收率室内模拟实验,得出了以下结论 :气交替见效最快,泡沫驱提高采收率能力最强,但泡沫用量最大,在现场开发过程中针对气窜,前期选用CO_2/水交替注入方式延缓气体窜逸,气窜后选用泡沫封窜。     

管内置梯形波带强化传热实验研究

设计了3种梯形波带内插件并对其强化换热特性进行实验研究,得出管内插入梯形波带扰流组件的传热系数h提高率为126%～220%,并对扰流组件引起的管程阻力进行了分析。通过传热性能评价准则(PEC)对插入梯形波带后的换热管进行传热的综合评价,证明梯形波带内插件确实是一种良好的加强换热能力的组件,并对实验数据线性回归拟合出了传热关系型。     

袋式过滤器过滤初期阶段滤袋压力特性的实验研究

针对袋式过滤器过滤初期阶段的压力特性,选用高密度聚乙烯粉料进行了实验分析,主要考察过滤速度和入口浓度对滤袋压降的影响。实验结果表明,在过滤初期阶段滤袋的压降上升趋势很明显,这种压降的增大主要来自于残余压降;滞留在滤料内的粉尘改变了滤料内部的流道结构,从而导致了滤袋残余压降的不断升高;过滤速度和入口浓度的增加均可使残余压降增大。最后通过压降组成的分析,提出了滤袋总压降的计算模型。     

组合式滤清器阻力特性研究

为考察由惯性级、网垫级组成的三级滤清器的阻力特性,采用了对三级滤清器进行整体数值模拟的研究方法。该方法改进了对惯性级、网垫级各级阻力叠加来获得组合滤清器的阻力特性的方法,能够较真实地反映流场的流动特性,为分析研究滤清器性能及优化设计提供合理的依据。通过实验获得的不同工况下三级滤清器的阻力特性曲线与数值模拟结果的对比验证了整体模拟方法的高精度。     

颗粒斜槽流的实验研究与数值模拟

从实验和理论两个方面对颗粒慢速斜槽流进行了研究。建立颗粒慢速斜槽流的实验装置 ,采用示踪颗粒法测定表面速度 ;通过测量表面速度和流层厚度 ,初步分析了流率及壁面状况对流动的影响。用有限元法对粗糙表面上的慢速斜槽流进行了数值模拟     

带有内置过滤元件的流化床颗粒层形成和保持影响因素的实验研究

整体煤气化联合循环 (IGCC)、增压流化床联合循环 (PFBC)等新型、高效的能源清洁转换系统都需要一套运行可靠、高效、维护简单的高温或常温煤气净化装置。该文利用光导纤维对一个实验规模的带有内置过滤元件的三维流化床的颗粒浓度特性进行了实验研究。研究表明 ,L阀、卸料口的位置及局部颗粒浓度对过滤元件颗粒层的形成和保持有重要影响。颗粒浓度功率谱显示床内气 固混合以低频为主 ,混合良好     

电化学法再生颗粒活性炭的研究

研究了一种新的颗粒活性炭再生方法。研究了再生时溶液的pH值、盐类的投加量和作用时间对活性炭再生的影响;研讨了电化学再生活性炭对不同种类有机吸附物的作用。实验结果显示:电化学方法在颗粒活性炭的再生上是有效的,同时具有低能耗、低炭耗和设备简单等优点。     

改性纤维球过滤器的应用性研究

介绍了过滤器的结构和亲水憎油改性纤维球滤料 ,根据来水水质情况可以采用压紧式或非压紧式纤维球过滤器的结构。在大庆油田进行现场应用性试验 ,结果表明 ,改性纤维球过滤器具有滤速高、处理量大的特点 ,适用于聚驱油田含油污水深度处理 ,出水达到低渗透层注水水质标准     

缝洞型油藏沥青质增强凝胶聚合物体系的堵水性能试验研究

基于缝洞型油藏的特点,针对水解聚丙烯酰胺HPAM交联聚乙烯亚胺PEI凝胶-聚合物体系以及沥青质增强凝胶聚合物体系在缝洞型油藏中的堵水性能开展研究.通过静态实验对比研究了两种聚合物体系在凝胶时间、凝胶强度和稳定性方面的差别,并基于缝洞微模型进行了动态实验,研究了物理裂缝特征和孔隙形状几何特征等因素的影响规律.结果表明:沥青质增强凝胶聚合物体系比凝胶聚合物体系具有更高的最终采收率和更晚的见水时间.凝胶聚合物和沥青质增强凝胶聚合物的注水性能也与孔隙形状和裂缝物理性质有关.研究结果为凝胶聚合物提高缝洞型油藏采收率工艺参数优化提供支撑.     

单室不锈钢阳极微生物燃料电池强化反硝化的研究

采用碳布阴极,不锈钢阳极构建了以葡萄糖为唯一电子供体、硝酸盐作为电子受体管状单室微生物燃料电池(MFC),研究MFC的COD、NO3-去除情况和强化反硝化性能。在室温下,初始COD为595 mg/L,外接电阻100、1000Ω时,该MFC去除率为62%、56%,比厌氧对照组高10%~15%,NO3-去除率为60%、58%,比厌氧对照组高10%。表明该MFC在能良好降低COD的同时,也能够很好的去除硝酸盐,并且强化了反硝化过程,是一种很高效的去除硝酸盐的方法。给我们在MFC的研究和硝酸盐的降解中提供了一个新的方向,对加深理解MFC机理,推动MFC技术发展和降解硝酸盐的水处理的应用具有理论与实际意义。     

齿边穿孔扭带对管内强化传热的实验研究

研究新型扰流元件--齿边穿孔扭带插入换热管中强化传热的情况,考察影响传热效果的三个因素:孔径、孔距、扭矩。并通过对比实验,分析在换热管中分别插入齿边穿孔扭带、穿孔扭带与无孔扭带时,强化传热的效果。     

化学氧化强化三元复合驱污水混凝处理实验研究

为进一步提高原油采收率,国内多数油田开展了三次采油技术的研究和应用。三元复合驱采油废水中残留了大量的聚丙烯酰胺、表面活性剂和碱,油田污水处理常采用混凝处理,由于采出水中含有一定浓度的聚合物,导致采出水的粘度增加,油、水、泥的分离难度增大,常规混凝效果不好,为此需要采取措施强化混凝。本实验采用静态烧杯试验得出,在最佳实验条件:聚合硫酸铁投量为2 500 mg/L、温度为45℃、pH值为6、快速搅拌(200 r/min)2 min后慢速搅拌(80 r/min)5 min、沉淀时间30 min后,水样含油量去除率达64%左右。通过混凝前投加氧化剂强化混凝实验得出:高锰酸钾投量在0.5 mg/L时,除油率提高8%。双氧水投量在5 mmol/L时,除油率提高17%。芬顿试剂中双氧水投量为5 mmol/L,二价铁离子投量在1.5 mmol/L时,除油率提高25%,效果最好。