Filter media filtration-specific properties

Filter media are characterised by many different chemical and mechanical properties, and the right combination can usually be found for most applications. Purchas (1980) identified some 20 significant properties divided into three major categories (1) machine-orientated properties (Table 2.2), (2) application-orientated properties (Table 2.3) and (3) filtration-specific properties (Table 2.4). These and the characteristics of the feed suspension interact to affect the lifetime of the filter medium, which has implications for the process productivity and economics - as illustrated in Figure 2.1. Although... 

In conclusion, the following experiments on filtration-washing-deliquoring should be performed to produce data (viscosity of liquids, effective solid concentration, specific cake resistance, cake compressibility, etc.) that are necessary to evaluate times of individual steps of filtration at an industrial scale, i.e. to obtain the proper basis for scale-up of filtration processes measure the filtrate volume versus time make marks on your vacuum flask and take down the time when the filtrate level reaches the mark => no more experiments are needed for preliminary evaluations of filtration properties of slurries initially fines pass the filter medium => recirculate them to the slurry,... 

The fiber cloth is the deciding ctor in the success or failure of all press operations. In view of the wide range of process variables involved in the filtration process, it is virtually in ossible to select a filter medium that will satisfy all process requirements and the usual limited time scale available for cloth selection is used to find an acceptable medium, i.e. one that will satisfy most, if not all of the requirements. In this reject, one particular requirement (e.g. filtrate clarity) may have to be relaxed, if other specifications (e.g. filtrate rate, absence of blinding) are to be maximised. Thus the more open weave Mcs will be superior in nonblinding characteristics, but may have poor particle retention. The latter will in rove in the order monofilament < muldfilament < staple fibre. Tabulated information is presented in Tables 4.2,4.3 and 4.4 below on the effect of yam properties, weave patterns, etc. on the processes of cake release, productivity, resistance to blinding, etc.. 

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