Rotational beds

Fig. 19. TVA-type ammoniator—granulator incorporating a pipe cross reactor. 1, ammonia sparger, located at the 4 o clock position 11.4 cm from granulation shell with holes facing the rotating stream 2, phosphoric acid sparger, located to discharge phosphoric acid onto the top and near the center of the rotating bed of materials 3, pipe cross reactor 4, scmbber Hquor distributor, located above the bed in granulator to dribble scmbber Hquor onto bed.

The area inside the curve represents possible conditions of operation. In these expressions, the ratios pg/pl and pl/Pw have been introduced so that the relationship can be applied for a wide range of liquids and gases. It may be noted that, if the effective value of g is increased by using a rotating bed, then higher flowrates can be achieved before the onset of flooding. 

Absorption of hypochlorous acid into water, a liquid-side mass transfer-limited process, showed HTU values as low as 4 cm, with a strong dependence on liquid-flow rate. Heat of absorption removal was identified as a potential issue with absorption in rotating beds (9). 

Keyvani M, Gardner NC. Operating characteristics of rotating beds. Chem Engr Prog 1989 85(9) 48-52. 

Zheng C, Guo K, Feng Y, Yang C, Gardner NC. Pressure drop of centripetal gas flow through rotating beds. Ind Eng Chem Res 2000 39 829-834. 

Gardner N, Keyvani M, Coskundeniz A. Flue gas desulfurization by rotating beds. U.S. Department of Energy, DOE DE-FG22-87PC 79924, 1993. 

Kroger, D. G., Levy, E. K. and Chen, J. C. (1979). Flow Characteristics in Packed and Fluidized Rotating Beds. Power Tech., 24,9. 

In is likely the above has formed the basis for the use of rotating avalanche testers, where the size and frequency of avalanches formed on the sliding, rotating bed are analyzed as a deviation of the time between avalanches, as well as strange attractor diagrams. This... 

T., and Kasper, C. (2006) Cultivation of MC3T3-E1 cells on a newly developed material (Sponceram ) using a rotating bed system bioreactor. J. Biomed. Mater. Res., 80 (2), 268-275. 

The fines fraction in ROK lime from rotary kilns also contains enhanced levels of impurities. It does not, however, contain a significant amount of over-burned lime, as the fines tend to concentrate at the centre of the rotating bed and are insulated by the larger particles. This enables the % CaCOs in the coarser fractions to be reduced to low levels without over-burning. 

When the active ingredient is in a solid form (solid particles), encapsulation can also be achieved by spraying a coating solution onto the particles surface, by many different processes that will keep the particles in motion (e.g., agitated particles bed in a fluid bed or pan rotating bed), followed by a consecutive step of stabilization of the coating by solidification or membrane formation. 

One of the major limitations of classical vibro-fluidized bed dryers is the potential for mechanical problans and increased energy consumption due to large inertia of the dryer, which must be accelerated. An interesting design allowing vibration of the bed exclusively is the vibro-rotational bed (VRB) in which the oscillatory motion of particles is generated by rotation of a mechanical mixer of special design immersed in the bed. 

Nikitin, V.S. and Puchkov, G.F. 1983. Hydrodynamics of vibro-rotational bed. In Heat and Mass Transfer in Dispersed Systems, Minsk, AN BSSR, pp. 116-123 (in Russian). 

Figure 5.24 Rotating bed reactor concept for CLC as proposed in Refs. [67, 68]. (Source Reproduced from Refs. [67, 68], with permission from Elsevier)...

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