Industrial applications fluidised beds

In the Netherlands only few stand-alone bubbling fluidised bed combustion applications are in operation to process specific wood, sludge and industrial waste streams. The wood- fired bio-energy-plant at Cuyk represents the cunent state of the art of BFBC, handling fresh wood, saw residues, park-/garden residues with steam parameters of 100 bar and 520°C. Stand-alone FBC, like the one at Cuyk, offers approximately 30% (net) electrical efficiency. This value does not offer the energetic advantage (40% electrical efficiency) co-combustion does,... 

Highley, J. and Kaye, W.G., 1983, Fluidised bed industrial boilers and furnaces, in Howard, J.R. ed. Fluidised Beds Combustion and Applications. Applied Science Publishers, London. 

Thermoplastic resins, such as vinyl chlorides, vinyl acetates and polyamides are employed, particularly in the water industry, on buried pipes and fittings. To provide both internal and external coating, application may be by one of these principle techniques dipping in a plastisol, fluidised beds or electrostatic spray. 

Details are given of the development of energy and material recycling processes for thermosetting polymer composites. Applications in the cement industry and in coal fired fluidised bed combustion plants are discussed. 3 refs. 

Table 7 Some industrial applications of fluidised beds...

Entrainment may be defined as the carryover of ejected particles, while selective entrainment of finer or less dense particles is often referred to as elutriation. In most industrial processes, neither entrainment nor elutriation are desirable, which is in sharp contrast to this particular application. Consequently, there is very little research aimed specifically at enhancing the selective removal of less dense material from fluidised beds. Most research on entrainment is based on dimensional analysis applied to experimental data either with no or very limited consideration of the underlying physics Predictions made from these correlations are limited to very simple geometries. They may vary widely even for reactor airangements close to the experimental conditions they are based on, and are often completely unreliable when conditions are markedly different. In several intemal studies they have been found inadequate for entrainment and elutriation predictions in the fluidised bed system under investigation. The problem is too complex to be adequately represented by a small number of ordinary equations that would simply require substitution of a few parameters to obtain the rales of entrainment of the different particle size ftactions. 

Early applications were related to industrial processes and focussed on the sampling of metal ions in natural waters [96], the determination of phenylalanine using in-line ion-exchange [97], modelling of heavy metal adsorption [98], use of pulsed flows for nickel removal from acidic solutions [99], investigation of properties inherent to fluidised beds and transport reactors [100], and treatment of radioactive wastes [101]. The characteristics, limitations and applications of fluidised beads are provided elsewhere [102—104],... 

The technique of passing a gas into a solid which is in the form of tiny granules and thus making the solid behave as if it were a dense, viscous liquid. Fluidised materials may be easily piped from place to place, but a particular application in the rubber industry is the vulcanisation of extruded sections. See Fluid Bed Vulcanisation. Fluorinated Elastomers... 

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