滤饼过滤过程的计算机模拟研究

利用自行设计的计算机模拟程序 ,对物料粒度、浆体浓度、过滤压差对过滤脱水的影响以及滤饼分层现象进行了计算机模拟 ,并通过实验进行了验证。结果表明 ,模拟结果虽然在数值上与实验结果有一定差距 ,但定性方面能够很好地与实验结果相吻合。     

滤饼过滤过程的计算机模拟程序设计

详细介绍了滤饼过滤过程中各物理量的计算公式、计算机模拟程序的设计 ,为滤饼过滤过程的研究提供了一种新的研究方法     

恒压过滤滤饼孔隙率分布

在解过滤偏微分方程的基础上导出了滤饼孔隙率分布，对影响孔隙率分布的因素进行了讨论，指出恒压过滤时滤饼孔隙率分布不仅与物料的可压缩性有关，还与料浆浓度及操作条件有关，孔隙率分布的实测结果与理论预测值吻合较好。     

纤维过滤滤饼孔隙率计算机模拟

基于受限扩散模型,建立纤维介质表面粉尘颗粒沉积形成滤饼的模拟模型。粉尘颗粒在远离过滤介质的控制面上释放,假设对流扩散运动为颗粒输送和沉积的主要机理。定义Pe数为颗粒对流作用与扩散运动的比值,讨论不同Pe数对滤饼孔隙率的影响。对Pe数范围为0.25~1600进行模拟计算结果表明,Pe数对滤饼的孔隙率影响显著。当颗粒的扩散运动强于对流运动,颗粒沉积形成的滤饼为较为松散的结构,当Pe数较大时,颗粒沉积形成的滤饼为较为紧密的堆积结构。此外,考虑到实际过滤过程中粉尘颗粒大多为非等径粒子,也对多分散粒子对滤饼形成及孔隙率的影响作了分析。     

过滤介质滤饼可剥落性研究

本文通过实验研究，考察了滤饼的颗粒性质、饱和度、厚度、操作压差、滤布性质等因素对这过滤介质卸饼性能的影响，提出了评定过滤介质滤饼可剥落性实验方法的建议。     

滤饼过滤理论与实践:过去、现在和未来

本文综了当前滤饼过滤理论的发展过程,包括Ｒｕｔｈ＆Ｃａｒｍａｎ的早期工作。Ｔｉｌｅｒ－Ｓｈｉｒａｔｏ过滤方程以及日前一些行之有效的理论观点,着重强调了滤饼沉积过程中逐层分析的概念及相关的计算方法,同时对这些理论运用于实践中的可行性进行了评述。     

离心过滤中滤饼含液量影响因素的研究

本文对离心过滤中影响滤饼含液量的主要因素进行分析。选择细粒级的五种物料，在三足式过滤离心机上做脱液实验，获得的脱水和动力学试验数据，经因次分析，计算机处理，得到实验条件下滤饼含液量Ｗｔ的准数方程：研究结果表明：影响滤饼含液量的因素，首先是物料的物理性质：固体密度ρｓ，颗粒表面积体积平均粒径ｄｓｖ和悬浮液粘度μｓｕｓｐ；其次是操作参数：转鼓角速度ω，脱液时间ｔ和滤饼厚度ｈ。实验条件：Ｆｒ＝１０４８～１５１０，ｄｓｖ＝１．２９～２４．８μｍ，μｓｕｓｐ＝１～１０ｍＰａ·ｓ     

气压过滤的成饼动力学及其滤饼的分形结构

用自制的实验室型气压过滤机并结合滤饼内部结构的测试,研究了气压过滤的成饼动力学及其滤饼结构的分形特征。结果表明,气压过滤条件下,虽然过滤压差较大,但成饼阶段仍遵循Darcy定律;气压过滤的滤饼结构为一分段Sierpinski分形,其分维数值介于1.775～1.885之间。     

关于过滤理论与滤饼可压缩性的探讨

This paper gives a study on the ratesof filtration and cake formation and filter cakes permeability and compressiblity．Anew calculating equation of filter cakes special resistance is advanced,It indicatesthat the permeability of filter cake is not only related with slurry concentration and itssettling velocity,but also related with the pretreatment and chemical environment ofslurry．     

关于过滤理论与滤饼可压缩性的探讨——第二部分 滤饼的可压缩性及比阻

从料浆沉降和过滤成饼两个角度同时研究过滤速率和成饼速率以及滤饼的渗透率和可压缩性,提出了更为全面的滤饼比阻关系式,证明滤饼渗透率首先和料浆的浓度及沉降速度有关,因此和料浆的预处理及料浆的化学环境密切相关。明确了滤饼都是可压缩的,其可压缩性分为两大类：滤饼中颗粒的位移、迁移和团聚颗粒的变形,由于它们的被压缩的机理不同,所以和有关因素的相关关系也不同,分析和论述了主要的关系。全文分为两大部分,相对独立     

滤饼孔隙率的模拟研究

采用计算机模拟方法,对滤饼中颗粒的凝聚机理进行简化,将所过滤的物料外形形态简化为球形颗粒,进行计算机程序设计,模拟物料在纤维过滤介质中过滤形成滤饼的过程,模拟得出滤饼结构,并进行孔隙率计算,在简化模型的基础上,分析滤饼孔隙率,滤饼厚度以及固体颗粒粒径的相关关系,探索滤饼结构研究的新方法及新途径。     

粉尘沉积形成滤饼结构的分形研究

粉尘在过滤过程中,随过滤时间的增加,在过滤介质内部不断沉积形成滤饼,目前人们还主要从过滤的整体行为的角度去研究过滤问题,由于测试手段和研究方法的限制,对直接决定过滤行为的滤饼结构则研究很少。然而,要想深化对过滤机理的认识,揭示滤饼中粉尘颗粒之间的相互作用力与形成滤饼孔隙率的关系,了解滤饼中"尘滤尘"的机理,以提出提高粉尘捕集效率,减少过滤阻力,寻求强化清灰的措施,就必须对滤饼的内部结构进行研究。通过对滤饼结构进行分形研究,寻求滤饼结构分形维数与物料的比表面积及各操作条件的关系,探索滤饼孔隙率、滤饼厚度及粉尘颗粒直径、粒径分布与滤饼分形维数的关系。     

Cake properties of nanocolloid evaluated by variable pressure filtration associated with reduction in cake surface area

A potential method has been developed for evaluating simultaneously both the average specific resistance and average porosity of the filter cake formed in unstirred dead‐end ultrafiltration of nanocolloids such as bovine serum albumin solution and silica sol. The method consists of variable pressure filtration followed by constant pressure filtration. The relation between the average specific cake resistance and the pressure drop across the cake was determined from the evolution of the filtration rate with time in the course of the variable pressure filtration period, based on the compressible cake filtration model. The average porosity was evaluated from the significant flux decline caused by a sudden reduction in the cake surface area in the middle of the constant pressure filtration period. The pressure dependences of both the average specific cake resistance and average cake porosity were obtained from only two runs which differed from each other in the pressure profiles. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3869–3877, 2014     

成饼过滤中过滤介质阻力与堵塞研究的进展

过滤介质是过滤作业的基本部件,由于在过程中不断地被堵塞,介质阻力不断增加,过滤性能逐渐下降,以致于不能再继续使用。因此研究其被堵塞的机理和降低、减少堵塞的措施就成为改善过滤作业的重要课题。综合了26篇有关文献,介绍了成饼过滤介质堵塞的机理、被堵塞过滤介质阻力的大小、影响过滤介质堵塞的主要因素等几方面的近期研究进展。     

陶瓷过滤管表面粉尘层清除过程的图像分析

Based on the analysis of high-speed video images, the detachment behavior of dust cake from the ceramic candle filter surface during pulse cleaning process is investigated. The influences of the dust cake loading,the reservoir pressure, and the filtration velocity on the cleaning effectiveness are analyzed. Experimental results show that there exists an optimum dust cake thickness for pulse-cleaning process. For thin dust cake, the patchy cleaning exists and the cleaning efficiency is low; if the dust cake is too thick, the pressure drop across the dust cake becomes higher and a higher reservoir pressure may be needed. At the same time there also exists an optimum reservoir pressure for a given filtration condition.     

Ultrafine Dust Filtration Using Precoat Materials Considering the Influence of Filter Media

Ultrafine dust separation from different sources like industry, traffic, or private households has become increasingly important in the last decade. A compact baghouse filter system has been developed which is suitable for pellet heaters. For filtration, a precoat material is required to prevent clogging of the filter media by the ultrafine dust particles. In order to ensure the best performance of this filter system, different combinations of filter media and precoat materials, e.g., grade efficiencies and the cake area load for the various filter media, were investigated in a special test rig. With this highly efficient technology, extremely high separation efficiencies of > 99 % and ultrafine dust concentrations of > 1 mg cm^?3 could be reached in a long‐term stable process.     

Parameter Estimation for Incompressible Cake Filtration: Advantages of a Modified Fitting Method

There is a widely used linear strategy to determine the parameters specific cake resistance and filter medium resistance in incompressible cake filtration. In this article, it is intended to demonstrate that this strategy has some disadvantages and should be replaced by an alternative nonlinear approach which yields more exact results. Even though the gains in precision are small for most cases, the nonlinear strategy is favored because it involves no extra effort and is grounded in the same physical theory as the original approach. This claim is based on a broad simulation study using noisy data with known parameter values to compare both fitting strategies and judge their accuracies.