Porous Solids—Batch Operations

The use of small affinity adsorbent particles immobilized in hydrogel beads has been investigated for whole broth processing (1). The adsorbent particles can contain biospecific ligands covalently attached to a porous solid support. A mathematical model was developed to study bioproduct adsorption using immobilized affinity adsorbent beads in batch operation. 

High-pressure conditions favour a smaller bubble size and narrower bubble-size distribution, and therefore lead to higher gas hold-up in BSCR, except in systems operated with porous plate distributors and at low gas velocities. For design purposes in BSCR at high pressure, where the liquids operate in the batch mode, Luo et al. [31] proposed the following formula for the calculation of the gas hold-up, based on their proper experimental data and those of many other authors [1,26,31-34] for various systems of gas, liquid and solids ... 

Other than the fiber aid, to form a highly porous and uniform filter cake. The suqiension to be filtered is then introduced onto the filter. Clarification by filtration results by the action of the filter aid trapping the suspended solids within the filter aid cake, by the techniques described in Section 6.1. Only a thin layer of cake is usually considered to be inq>ortant in this operation. If the filtration equipment is continuous by nature, e.g. a rotary vacuiuu filter, a thick filter aid cake may be enployed as the top layer contaminated with the material filtered during the clarification can be scraped off and discarded. The layers below the surface are then exposed for fiuther filtration and, therefore, economically viable rates of filtration ensue. Alternatively, if the filtration is conducted in a batch vessel thinner filter aid cakes are usually employed, with more frequent cleaning required. 

Various designs are used to achieve either a clarification of liquors, or a significant increase in solids concentration resulting in the production of a wet solid filter cake of minimal moisture content. This can be driven by either an applied pressure to the substrate over a porous filter medium (i.e. pressure filtration), or a vacuum applied behind the filter medium (vacuum filtration). The process can be on a batch basis, or via a continuous operation where, by a mechanical rotary means, new filtration areas are offered to the substrate. Chemical conditioning, including flocculation and coagulation, can be used to increase throughput, cake solids or fines capture. 

Batch Filtration Filtration involves separation of solids from liquid using a porous medium or screen. A mechanical separation process, this unit operation involves less energy than drying. 

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