Drum rotational speed

Increase mixer impeller or drum rotation speed or fliiid-hed gas velocity. 

Decrease load to reduce wear Lower-formulation density. Decrease hed-agitation and compaction forces (e.g., mixer impeller speed, fliiid-hed height, bed weight, fluid-hed excess gas velocity, drum rotation speed). 

Increase collision frequency subsection.) Increase binder distribution. Increase mixer impeller or drum rotation speed or fluid-bed gas velocity. 

Rate of growth (low deformability) Increase rate of nuclei formation. Increase collision frequency. Increase residence time. Improve wetting properties. (See Wetting subsection.) Increase binder distribution. Increase spray rate and number of drops. Increase mixer impeller or drum rotation speed or fluid-bed gas velocity. Increase batch time or lower feed rate. 

Extent of growth Increase binder viscosity. Decrease agitation intensity. Decrease particle density. Increase liquid loading. Increase binder concentration, change binder, or add diluents and polymers as thickeners. Increase operating temperature for systems with simultaneous drying. Otherwise decrease temperature. Decrease mixer impeller or drum rotation speed or fluid-bed gas velocity. Extent observed to increase linearly with moisture. 

The drum dryer is a highly flexible equipment because its operational variables like the steam pressure, the drum rotational speed, the nip width, and the ratio of drum rotational speeds can be regulated independently. The steam pressure ranges from 2 to 7 bar, the drum rotational speed varies from 2 to 30 rpm, the nip width ranges from 0.05 to 0.5 mm, and the ratio of drum rotational speeds is from unity to 5. The feed can be pre-concentrated and preheated to reduce the drying load but there is a limit to the feed concentration beyond which the sheet may not form well. ... 

Agitation of the melt, as near to the drum as possible, appears to have a marked effect on the efficiency, as does the drum rotational speed. The optimum drum speed must be found by trial and error. Decreasing the speed offers two advantages increased contact time which gives a closer approach to equilibrium and hence improved separation, and better drainage of impure mother liquor off the drum as it emerges from the melt. Decreases in the speed, however, reduce the production rate, so a compromise must be reached. 

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