Dryers, belt plate

Agitated/Monoplate Nutsche Filter/Dryer Horizontal Plate Filter/Dryer Continuous Equipment Rotary Drum Filter Centrifugal Filter Horizontal Belt Filter... 

BD Belt dryer DD Drum dryer FB Fluidized-bed dryer CD Conveying dryer BLD Blade dryer PT Plate dryer FFD Falling-film dryer + suitable/good/less + — limited suitability... 

Active Dry Yeast (ADY). The production of active dry yeast is very similar to the production of compressed yeast. However, a different strain of yeast is used and the nitrogen content is reduced to 7% of soHds compared with 8—9% for compressed yeast. The press cake made with the active dry yeast strain is extmded through a perforated plate in the form of thin strands with a diameter of 2—3 mm and a length of 3—10 mm. The strands are dried on endless belts of steel mesh in drying chambers (a continuous process) or in roto-louvre dryers (a batch process), with the temperature kept below 40°C. Drying time in drying chambers is 3—4 h and in roto-louvre dryers is 6 h or more. The final moisture level attained is 7.5—8%. 

Figure 9.8. Rotary tray, through-circulation belt conveyor, and heated screw conveyor dryers, (a) Rotary tray dryer. Wyssmont Co.), (b) Action of a rotating tray and wiper assembly. Wyssmont Co.), (c) Krauss Maffei plate dryer, (d) A single conveyor belt with air upflow in wet zone and downflow in dry. Proctor and Schwartz Inc), (e) A two-stage straight-through belt conveyor dryer, (f) A three-belt conveyor dryer as the material becomes dryer, the loading becomes deeper and the belt longer. Proctor and Schwartz Inc.). (g) Screw conveyor dryer with heated hollow screw (Bepex Corp). (Walas, 1988).

If the material to be extruded is very moist and/or sticky the cutting device would lump the strands into globs of wet material and the discharge plate with wiper bar would further aggravate this situation. A special design is available in which the main shaft is driven from the top. Then, the wet strands fall directly into a dryer or on a belt, thus minimizing aggregation (Fig. 8.60). 

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