Section 5.13 Filtering Centrifuge

Any of the particle sols prepared above may be used to adsorb macromolecules to create gold probes. To concentrate the suspensions, the solutions may be filtered through a small-pore filter. Centrifugation also may be done. Each protein-gold complexation should be optimized for the proper amount of protein to add to maintain stability of the colloid. This can be done according to the method described in Section 1. 

Centrifuge Dryers Usually they are batch or continuous filtering centrifuges (Sec. 18, "Liquid-Solid Operations and Equipment ) with hot air being blown over the solids in the discharge section. Manufacturers include Heinkel and Bird-Humboldt. 

Effect of recovery on the choice To recover liquid in the order of preference of filters. Section 5.14 and filtering centrifuges. Section 5.13 deep bed, horizontal vacuum, pressure leaf, gravity flat table cartridge, precoat drum and plate and... 

For dry soUds consider the following filtering centrifuges. Section 5.13 basket, basket automatic constant speed vertical, basket automatic variable speed horizontal continuous conical with scroll conveyor, oscillating conical screen cylindrical screen with pusher conveyor or horizontal solid-screen scroll conveyor. 

More detailea descriptions of small-scale sedimentation and filtration tests are presented in other parts of this section. Interpretation of the results and their conversion into preliminary estimates of such quantities as thickener size, centrifuge capacity, filter area, sludge density, cake diyness, and wash requirements also are discussed. Both the tests and the data treatment must be in experienced hands if error is to be avoided. 

Centrifugal filters use centrifugal force to drive the filtrate through the filter cake. The equipment used is described in the next section. 

The factor C and the exponent y must be determined by experiments with pilot settlers. These terms combine all the unknown parameters. The cross-sectional area, S, of the settler should be chosen in such a way that the superficial velocity, of the dispersed phase does not exceed 5-9mms . Often aids for coalescing (e.g., packages of inclined plates or filter cartridges made of metal or plastic) (Fig. 9.23) are used. There are several ways of predetermining coalescence [31-33]. Furthermore, in special cases electrical fields and centrifuges are used to support coalescence [34]. 

Dilute the reaction mixture by adding 4 volumes of H20. Remove unreacted BMCC-biotin through a 30kDaMWCO filter (Millipore) by centrifugation for 8 min at 11 000 x g. Repeat this step to ensure that all unreacted BMCC has been removed before proceeding to the partitioning step (Section 8.3.6). 

All water samples are filtered prior to extraction, and the filtered liquid and the particulates are extracted separately (see Section 9.S). If a water sample contains significant amounts of suspended particulates, centrifuge the sample and decant the water from the particulates before filtering (Paragraph 8.4.7). 

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