Precoated handling

Diatomaceous Earth Filtration System Design Diatomaceous Earth Filtration System Operation Diatomaceous Earth Filtration System Maintenance Types of Precoat Filters Auxiliary Parts and Equipment Bulk Filter Aid Handling... 

In this Chapter we describe methods of handling precoated layers and also how to apply and dry samples before development. 

In addition, precoated tiibes such as those used in the Abbot Australian Kit and resin filled syringes such as those commonly found in T-3 and T-4 kits may also be readily handled by the gamma vial adapters. These kits, which require specialized test tubes, may not be counted with either the "microfuge or special cocktail techniques."... 

A special type of leaf filter sometimes appears in this application. The elements are horizontal discs that spin on demand to remove the dry cake. The Funda filter is an example. Another special feature sometimes is shuffling of the cake. After the wash with hot water, the isolated filter simply sits idle for some time (1-1.5 hr). TTie mercury during this time penetrates the active carbon, opening the structure of the hed so that the pressure drop will be lower upon restart. This can be done several times before it is necessary to remove the carbon. This technique reduces the consumption and cost of precoat and also the volume of material that must be handled for mercury recovery. 

Paper pulp s disadvantage lies in its preparation. Soda or sulfate pulp, most commonly used, must be disintegrated and kept in suspension by agitation before precoating. This requires considerable auxiliary equipment. Diatomaceous eardis, vdiile they should be kept in suspension, are very easy to handle and do not undergo disintegration. 

Thin-layer chromatography today is a dynamically developing modem analytic method. Areas of progress include increase of the spectrum of selectivity, improvement of efficiency, and in certain cases simplification of handling. The discussion of bulk sorbents and precoated layers above is not a complete enumeration of all possibilities e.g., the different carriers for the layers (glass plates, aluminum, or plastic sheets) are not shown explicitly. In addition, special plates with very restricted applicability are not discussed. 

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