Kinetic laws and technological calculation of the process of dedusting gases by granular layers in the refractories industry. 2. Gradual clogging of pores in the granular layer

Kinetic laws of the process of filtering of effluent industrial gases and aspiration emissions by granular layers with gradual clogging of the pores of the filtering partition are considered. The dependences obtained hold true for a relatively low mass concentration of the disperse phase of the aerosol. The previous paper is published in No. 3,1999.     

Kinetic laws and technological calculations of gas dedusting with granular layers in refractory production. 3. Precipitation on the surface of a rotating granular filtering element

The present paper is published as a matter for discussion. Rotating filtering elements with a granular structure are not yet used in the production of refractories despite the obvious maintenance advantages, which is connected with insufficient analysis of the process. The aim of the present publication is to fill the gap. The preceding papers of the series have been published in Nos. 3 and 4 of 1999.     

Study of the Performance of a Novel Hydrocyclone Built in the Configurations of the Classical Families

The performance of classical families of hydrocyclones (Bradley, Rietema, and Demco) has been compared with a novel equipment, the filtering of hydrocyclones. In the filtering of hydrocyclones, the conical section is replaced by a conical filtering wall producing another liquid stream leaving the equipment besides underflow and overflow streams. In the present paper, the influence of the filtering conical wall in the classical geometries was analyzed by experimental and CFD studies. The results showed that the replacement of the conical section of hydrocyclones built with classical geometries by a filtering cone have significantly changed their performance. In general, the separation performance and the capacity can be enhanced with the filtering hydrocyclones.     

基于合成纤维过滤技术的评述

概要评述了国内外合成纤维过滤技术的研究现状和应用前景，从积泥形态学阐述了纤维滤料的过滤机理，比较了纤维滤料与传统石英砂滤料的过滤特性。通过分析滤料形状和过滤器的结构讨论了各类纤维过滤装置的特点。报导了纤维过滤技术在工业给水，地下水，工业废水处理中的应用结果。实践证明；纤维滤料比传统的石英砂滤料具有质地软，强度高，水的阻力小，过滤速度快，截污容量大，易清洗等特点，对今后的研究工作提出了一些建议。     

改进隔膜法烧碱蒸发工艺提高盐碱分离效果

通过改进方法,准确测出碱液中盐的粒径,并得出结论:离心机一级转鼓筛网的过滤间隙及过滤面积是盐碱分离效果的关键,在此基础上进行了生产试验,母液含盐量降低40%以上。     

羟胺催化剂过滤器金属烧结滤芯的再生

主要从过滤精度，流体透过性能，过滤效率，过滤机理等方面结合HPO法生产已内酰胺工艺羟胺反应过滤器金属烧结滤芯的再生问题，通过对金属烧结滤芯一般特性的过滤性能的分析。结合实验数据。提出了一种综合性再生方法，该方法延长了滤芯的使用周期。满足了生产高负荷生产要求，再生效果较好。     

DA863自适应滤料在给水滤池改造中的应用实践

主要介绍了东风汽车总公司自来水厂采用DA863自适应滤料进行滤池改造的工程设计情况.并对以DA863自适应滤料为技术核心的D型滤池的内部结构和配套附属设施等做了进一步的说明.     

Aerodynamic methods for increasing the efficiency of dust catchers in the production of refractories. 3. Efficient distribution of dust-and-gas flows in systems and installations for dust catching

Conditions and methods of efficient distribution of dust-and-gas flows in grain filters are considered. Various designs of distributing devices are suggested. It is shown that separating walls are more advantageous than distributing grids. Various variants of reflecting walls for the uniform distribution of the dust-and-gas flow are recommended for cylindrical porous filtering elements of dust catchers, swirlers that provide a minimum consumption of power are presented. Some design solutions for an efficient distribution of the dust-and-gas flow in electric filters are considered.     

关于多孔材料过滤精度的探讨

从多孔材料过滤精度的定义出发,探讨了过滤精度的评定方法和过滤精度与冒泡孔径间的关系,指出了过滤精度与冒泡孔径间具有一定的数值换算关系及换算注意事项,同时也指出了在过滤器设计使用和滤材选用时要考虑过滤精度评定时的试验条件、要结合工况条件对滤材标定过滤精度值进行修正。     

纤维过滤板质量评价方法的探索

以蚓激酶料液和纯化水为实验介质,探索了过滤板质量的评价指标及检测方法,为建立有效的过滤板质量评价体系奠定了基础.蚓激酶料液实验表明,滤速与过滤板的除杂能力密切相关,滤板滤速越慢,除杂能力越强.0.05 MPa的纯化水实验表明,纤维过滤板滤速受到诸多自身因素影响,滤板重量越大,灰分值越高,紧度越大,滤速越慢,除杂能力也越强.操作压力也是一个影响过滤板滤速及除杂效果的重要参数,操作压力越高,滤液浊度也越大,滤板除杂效率越差,同时纯化水实验结果表明操作压力与过滤板滤速存在近线性关系.     

浆态床FT合成反应器中内部过滤操作研究

在装有金属烧结丝网作为过滤介质的内部过滤元件的浆态鼓泡反应器中,考察了颗粒粒径40—70μm和60—90μm、固相质量分数0—30%、气体流速2—6cm/s、操作温度25—150℃、过滤压降0.1—0.3MPa和反冲洗压差0.4—1.0MPa等操作因素对过滤速率的影响。实验结果表明过滤速率随着颗粒粒径、温度的提高及固相质量分数的降低而增大,并对不同过滤方式进行了考察。     

Hydrodynamic study of the granular flow in the solar dryer

There are a great many drying processes and types of equipment, such as dryers with immersed channels; the main advantage of this type of dryer, and the reason why it is chosen by manufacturers, is the homogeneous distribution of the drying air, made possible by dihedrons. In our work, we have investigated a flow model with a random double dispersion and have finally shown that the dispersion coefficients are not constant but vary depending on the position of the granular material in the column of dihedrons.     

纳米纤维复合材料在污水过滤领域的研究进展

纳米纤维在污水过滤领域是最有发展前途的过滤材料。阐述了静电纺纳米纤维过滤材料对液体的过滤机制,总结了有关静电纺纳米纤维过滤材料对重金属离子和有机污染物及细菌的应用研究现状,简单讨论了纳米复合过滤材料当前存在的问题和挑战,并展望了静电纺纳米纤维过滤材料在污水处理领域的应用。     

滤波法计算三角高程测量大气折光系数

根据湍流场理论,将近地大气层折光系数作为具有先验统计特性的随机参数,按照滤波的方法计算三角高 程测量从测站到目标间的视线上各点的大气垂直折光系数,改善了折光系数的计算精度。     

Liquid‐like wave structure on granular film from granular jet impact

Results in the literature show that a granular film appears from a dense granular jet impacting on a circular target under certain conditions (Cheng X, Varas G, Citron D, Jaeger HM, Nagel SR, Phys Rev Lett. 2007; 99(18):188001). In current study, granular jet impacts are experimentally studied using a high‐speed camera, and interesting liquid‐like wave structures on the granular film are observed with increasing granular jet velocities or decreasing solid fractions of granular jets. Effects of the particle diameter, the granular jet velocity, and the solid fraction of granular jet on the wave structures are investigated. The dynamic characteristics of granular wave such as the wave frequency and velocity are demonstrated and compared with the liquid jet impact. Results reveal that increasing pushing pressure enhances the gas‐particle interaction inside the nozzle, which causes the granular jet instability and further gives rise to the granular wave at lower solid fractions and higher granular jet velocities. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3276–3285, 2017     

On the thermal conductivity of granular materials

Stationary heat transfer in a granular material consisting of a continuous medium containing spherical granules of other substances is considered under the assumption that the spatial distribution of granules is random. The effective thermal conductivity characterizing macroscopic heat transfer in such a material is expressed as a certain function of the conductivities and volume fractions of the medium and dispersed substances.For reasons of mathematical analogy all the results obtained for the thermal conductivity are valid while computing the effective diffusivity of some admixture in granular materials as well as for evaluation of the effective electric conductivity or the mean dielectric and magnetic permeabilities of granular conductors and dielectrics.     

Concentration Analysis of the Saturation of the Working Medium with Material Released from the Processed Product at a Thermal Processing Plant

Problems in the concentration analysis of the process of saturation of the working medium with a material released from the processed product are considered for the reactor of open-cycle, semiclosed-cycle, and closed-cycle systems with and without filtering of the working medium. A general formula for calculating the saturation concentration CF is proposed: C _F = C _RF/(1 – XY), where C _RF is the concentration of the material released and X and Y are the recycling and filtering ratios, respectively.     

The influence of granular flow rate on the performance of a moving bed granular filter

The goal of this study is to evaluate the effect of granular flow rate on the performance of a moving bed granular filter designed for hot gas filtration of fine char particles (dust) produced during fast pyrolysis of biomass. The filter employs a counter-current configuration, in which down-flowing granular material spreads out at the bottom of the filtration vessel to form an interfacial area where the dusty gas enters the granular bed and much of the gas cleaning is hypothesized to occur. This study uses a real-time particle counter to measure the instantaneous filtration efficiency during cold flow tests of the filter. Differential pressure measurements at various locations within the granular bed are used to assess the level of char dust hold-up over time. These experiments reveal a critical granular residence time below which the filter must be operated to achieve filtration efficiencies exceeding 99%. Operating above the critical value causes the filter to “clog” and decrease in efficiency. The clogging is characterized by a critical dust volume fraction as determined through a fixed bed filtration test. The filter is found to accumulate most of the dust at the interfacial region. Also the interfacial region is more efficient than the downcomer section of the granular bed in removing dust. Decreasing residence time of granular material in the filter reduces the hold-up of char dust in the filter, which is expected to mitigate coking reactions of organic vapors when the filter is used to remove char from fast pyrolysis gas streams.     

Effect of a Cylindrical Permeable Wall on the Performance of Hydrocyclones

Hydrocyclones are designed for solid‐liquid separation widely used in industry due to their advantages including high separation efficiency. Depending on the purpose desired by the user, it is possible to enhance the performance of the hydrocyclone through the combined use of other unit operations with the hydrocycloning such as filtration. The incorporation effect of a porous cylinder on a hydrocyclone with optimized geometry was studied experimentally. According to the main results, the filtering cylindrical hydrocyclone showed significant average reductions in energy consumption compared to conventional hydrocyclones of the same geometry. Minor differences in terms of total efficiency of the filtering equipment were observed compared to the conventional one.     

Improved Estimation of the Langmuir Adsorption Isotherm Using Multiscale Filtering

Abstract

Adsorption isotherms play an important role in the design and analysis of adsorption processes. These isotherms are estimated empirically from measurements of adsorption process variables. Unfortunately, these measurements are usually contaminated with errors that degrade the accuracy of estimated isotherms. Therefore, these errors need to be filtered for improved isotherm estimation accuracy. Multiscale wavelet-based filtering has been shown to be a powerful filtering tool. In this work, multiscale filtering is utilized to improve the estimation accuracy of the Langmuir adsorption isotherm in the presence of measurement noise in the data by developing a multiscale isotherm estimation algorithm. The idea behind the algorithm is to use multiscale filtering to filter the data at different scales, use the filtered data from all scales to construct multiple isotherms, and then select among all scales the isotherm that best represent the data based on a cross-validation mean squares error criterion. The developed multiscale isotherm estimation algorithm is shown to outperform the conventional time-domain estimation method through a simulated example.