助滤剂在高黏度可压缩物料过滤中的应用

对于高黏度、高可压缩、固相浓度低、以澄清液相为产品的过滤过程,通常采用加入助滤剂的强化过滤技术进行液固两相分离。在进行助过滤时,应该根据待分离物料的不同物性,选择不同种类的助滤剂,且保证助滤剂的添加量适当,才能起到助过滤的效果,减小滤饼阻力、加快过滤速度、确保滤液澄清。     

液体燃料合成浆态反应器内部过滤的研究

在液体燃料合成浆态搅拌反应器中设置了以金属烧结板为过滤介质的内过滤器,实现固液分离。研究了压降、温度、搅拌转速、固含率、过滤介质孔径及颗粒粒径对过滤速率的影响。实验结果表明:在浆态反应器中进行内过滤可以得到澄清稳定的滤液;随着操作进行,滤饼厚度达到动态平衡,过滤速率最终趋于稳定;过滤速率随着压降、温度、过滤介质孔径、颗粒粒径的增大及搅拌转速、固含率的减小而增大。应用因次分析法建立过滤模型,通过麦夸特算法对实验数据进行最优拟合得到模型的参数值,统计检验以及模型计算值与实验值的比较表明该模型可靠。     

生产无机盐的主要过程及设备——过滤(概述)

<正>过滤是一种分离悬浮在液体或气体中的固体颗粒的操作,现仅讨论悬浮液的过滤。悬浮液称为滤浆,滤浆中的固体颗粒称为滤渣,积聚在过滤介质上的滤渣称为滤饼,透过滤饼和过滤介质的澄清液体称为滤液。评价过滤操作优异的标志之一是过滤速度,影响过滤速度的因素主要有压力差、过滤面积、滤饼的阻力、滤液的黏度、过滤介质和最初滤饼层的     

用动态旋叶压滤机澄清菠萝汁的实验研究

动态过滤技术与膜技术相结合是目前固液分离领域的研究热点。采用澄清剂法澄清菠萝汁,存在缺陷。本文在动态旋叶压滤机中,研究了无机Ni膜和聚砜膜用于菠萝汁澄清过程的过滤特性。研究表明,无机Ni膜和聚砜膜澄清菠萝汁的膜通量分别是按指数和乘幂关系衰减的;果汁浓度和剪切速度的交互作用对膜通量有较大影响;无机Ni膜的通量显著高于聚砜膜的通量(3￣4倍),且无机Ni膜的稳定过滤时间比聚砜膜的稳定过滤时间长得多。     

旋叶压滤机的动态过滤理论及其主要性能参数的研究

本文以动态过滤阻力理论，建立了膜滤速率的数学模型，分析了旋对压滤机械室内的速度分布及其影响因素，提出了旋叶压滤机主要性能参数：过滤速率，过滤速率衰减、功率消耗、滤饼厚度的计算公式，为今后设计和选用旋叶后滤机提供了理论依据和计算方法。     

动态微孔膜过滤特性研究

以旋叶膜滤机作为过滤设备对光合细菌发酵液为过滤物料进行了动态微孔膜过滤特性的研究。将膜技术与动态过滤技术相结合是膜分离技术的一个热点,集二者各自的优点,对其进行研究和开发,既有理论意义,又有实用价值。在实验中研究了操作条件如转速、压力、浓度对微孔膜过滤速率的影响。过滤速率的衰减基本可分为2个阶段,即速率下降阶段和稳态过滤阶段。     

动态膜滤速率特性的研究

以旋叶膜滤机作为过滤设备对光合细菌发酵液为过滤物料进行了动态微孔膜膜过滤特性的研究.将膜技术与动态过滤技术相结合是膜分离技术的一个热点,集两者各自的优点,对其进行研究和开发,既有理论意义,又有其实用价值.作者在实验中研究了操作条件如转速、压力、浓度对微孔膜过滤速率的影响.过滤速率的衰减基本可分为两个阶段,即速率下降阶段和稳态过滤阶段.     

包膜缓释肥料养分释放速率评价方法的探讨

将巴氏滤液管置于直径２ｃｍ、高２０ｃｍ的圆柱状玻璃管中,制成一个封闭式的自动连续过滤系统,将肥料置于该系统中,使上端进水,下端收集滤液,检测各瞬间滤液中养分的浓度,即可得到时间与养分释放速率的相关曲线。Ｈａｕｋｅ描述的包膜缓释肥料养分释放的第二阶段可进一步划分为三个阶段,可望在短时间内完成定量检测包膜肥料质量。     

横向流动过滤特性的研究及其应用

横向流动过滤的特点是料浆平行于过滤面高速流动,因而它的固体颗粒和滤液的流动方向和一般滤饼过滤有显著区别。在滤饼过滤过程中固体颗粒和滤液的流动方向一致,滤饼随着过滤时间的持续而不断增厚,过滤速率随之下降。在横向流动过滤过程中,固体颗粒的运     

对旋叶压滤机过滤速率与生产能力的探讨

本文介绍了动态旋叶压滤机的过滤特性,讨论了过滤介质阻力和滤饼阻力等因素对计算旋叶压滤机过滤速率的影响。提出了考虑原位清洗后平均生产能力的计算方法。     

Effects of filter additives on cake filtration performance

Effects of various additives, such as diatomaceous earth, inorganic adsorbent, and polymeric flocculant, on cake filtration performance were evaluated. By performing the standard vacuum filtration experiments under a constant pressure condition, we quantified their ability to reduce cake compressibility and to remove fine particulate matters. From the flux decline curves obtained, we used modified Ruth equation to determine the cake compressibility index. The filtrate clarity was quantified by measuring its turbidity spectrophotometrically. Diatomaceous earth filter aid was very effective in reducing the compressibility thereby improving filtrate flux. Calcium phosphate adsorbent was more effective in clarity improvement than in flux enhancement, whereas an anionic flocculant was effective in both aspects. When these additives were used together, the expected additive, synergic effect was not realized. However, about 3.5 times higher initial flux and 6-fold improved clarity were obtained as compared to the control experiment. Experimentally obtained flux decline curves were perfectly fitted into one of the Hermia’s blocking filtration law equations. Also, it was experimentally observed that the compressibility reduction improved filtrate clarity in a linear fashion. This type of approach is useful to quantitatively determine each additive’s characteristics and thus to maximize the performance of cake filtration operations.     

Relating quality,capacity and energy consumption of oil filters

In the theoretical part of the paper a simple theory is presented relating filtrate clarity, filter capacity and energy consumption. The particle size distribution is subdivided in coarse, intermediate and fine particles. The key role play the intermediate particles who can enter and clog the filter medium. This combined with a layered cake model selects complete blocking as the filtration mechanism for the intermediate particles. In the experimental part results are given on the Multipass flat cell filtration of SAE 5–80 test dust in oil, monitoring upstream and downstream pressure and particle concentration as a function of time. For the chosen filter media and within the experimental range of flow and concentration the simple theory can be applied successfully to these SAE oil filtration experiments.     

Particle Classification by Multishaft Disk Separator

Particle classification by sieving filtration using rotating disk filters mounted on single and double hollow shafts was investigated. The shaft and disks were enclosed in a stainless steel housing. Parameters such as particle concentration, feed flow rate and rotation speed of the filter disk were investigated to study their influence on the filtrate flux rate and particle classification. The filtrate flux rate was not affected by increasing the particle concentration. The analyzed particle size distributions were found to be narrow when the particle concentration increased. Increasing the rotation speed of the shaft produced a narrow particle size distribution. Increasing the feed flow rate (enhanced filtration pressure difference) resulted in a wider particle size distribution, but beyond a certain point a cake will form.     

发酵液预处理工艺特性

研究了抗生素发酵液提取过程中的预处理工艺特性 ,考察了各种因素对过滤速度和滤液效价的影响 ,并以螺旋霉素 (SPM )为例进行了详细研究 .实验发现 ,SPM过滤滤液效价随过滤 pH值的不同而变化 ,在 pH =5 5时有一最佳峰值 .同时 ,在溶液中存在蛋白质的溶解平衡 ,在过酸过碱时蛋白质会变性沉淀 .而SPM在蛋白质沉淀等固形物上存在吸附平衡 ,许多外加物质可以产生竞争吸附而影响过滤收率 .对以上实验结果用修正的Langmuir吸附理论提出合理的解释 ,建立了理论模型 ,并推导出了数学公式 .     

INVESTIGATION INTO OPTIMAL CONDITIONS FOR CROSS -FLOW FILTRATION OF HIGH-LEVEL NUCLEAR WASTE

ABSTRACT

The Savannah River Site has 23 Type III high-level radioactive waste tanks, each with a storage capacity of 1.3 million gallons. These tanks contain nearly 9 million gallons of precipitated salt. To immobilize the waste, the salt is dissolved through water addition, followed by precipitation of the radionuclides through the addition of sodium tetraphenylborate. This precipitate is then concentrated and washed to remove sodium through cross-flow filtration. This waste pretreatment process started radioactive operation in late 1995. During the normal plant operation, the cross-flow filtration system (consisting of two 216-square-foot filter elements) maintains a constant filtrate production rate. This Objective is achieved by allowing the operating pressure to increase to maintain a constant filtrate production rate. A maximum pressure differential limit of 40 psig has been imposed on this system. When this maximum is approached, a high-energy backpulse of filtrate removes foulant from the surface of the filter, thereby restoring the filter flux.

This laboratory work examined two key aspects of the anticipated facility operating conditions: the efficacy of using pressure differential to control filtrate production rates and the risk posed to filter performance associated with pore plugging of the filter immediately following the backpulse. Tests used simulated tetraphenylborate precipitate and a bench-scale cross-flow filtration unit consisting of two parallel filter units each 4 feet in length. Tests used slurries containing between 1 and 10 wt % tetraphenylborate to cover the anticipated range of operation. Data collected included both initial flux-decline measurements and steady-state filtrate production measurements. Analysis of these data indicates, for the more dilute slurries, pressure was an effective tool in controlling filtrate flux. However, as the slurry became more concentrated, the ability to manipulate filtrate flux by pressure greatly diminished. Analysis of the initial filtrate decline data using first- principle models indicates that the primary mechanism for decreasing filter flux involved development of a surface cake. Given the operating constraints of the facility, these results provide guidance for future filtration operation.     

内旋转子过滤离心机

介绍一种新式过滤离心机,它包含一套轻型内旋针轮转子和一套固定过滤器。针轮由小及大逐渐向浆液传递动量,启动旋流,产生离心过滤压力。物料在离心力分量的作用下滑出过滤器。针轮能够自我调节动平衡、启动快、负荷小,振动、噪声也比转鼓过滤离心机低。本技术可以实现连续作业。     

含锌高浓度氨氮废水治理研究

分析了高浓度氨氮废水的成份 ,将其含硫废水进行一定的调配调解后 ,使其中重金属污染物 Zn2 沉淀过滤出来 ,Zn2 的去除率达 99.99% ;其过滤液作为汽提原料 ,汽提可除去大部分硫化物与氨氮     

往复旋转管式陶瓷膜超滤脱脂奶水溶液的研究

往复旋转管式陶瓷膜过滤系统通过膜组件往复旋转在膜表面反复产生高剪切率,达到减缓膜污染的效果。在相同操作条件下,与单向旋转过滤和死端过滤相比较,往复旋转过滤具有更好的减缓膜污染的作用。本实验利用往复旋转膜过滤装置超滤脱脂奶水溶液,考察了各种参数对该膜系统过滤特性的影响。实验结果表明,料液浓度增大,膜通量减小;过高的操作压差将会抑制膜通量增加;旋转速度增大,膜表面剪切强化作用增强,膜通量相应增大;膜稳态通量随往复旋转周期增大呈现先增大后减小的趋势。当料液速度达到膜组件转速时,瞬时反方向旋转膜组件,膜表面产生最大的剪切率,膜稳态通量也达到最大值。能耗分析表明,往复旋转过滤较单向旋转过滤单位通量能耗低。     

动态过滤条件下核孔膜分级截留率的研究

利用旋叶压滤机与核孔膜的理想组合，通过实验验证与理论分析研究了在高分散物系情况下核孔膜对具有不同形状、一定粒度分布的悬浮液的分级截留特性。给出原料液、滤液的粒度分布规律，定义了颗粒截留率的概念，最后对膜的堵塞问题进行了讨论并提出初步建议。     

微孔陶瓷膜过滤(三)——陶瓷膜的使用寿命、再生方法、预敷操作及其与有机膜的对比

以平板陶瓷膜为过滤介质的动态旋叶压滤机进行微滤实验，对陶瓷膜的使用寿命、阻塞情况、再生效率、预敷效果等进行了探讨，提出了有效的再生方法，并与有机膜进行了对比实验，得到了对工程实际有指导意义的一些初步结论，显示了用陶瓷膜作为动态旋叶压滤机过滤介质的优越性。