Through-circulation dryers

TABLE 12-16 Performance Data for Continuous Through-Circulation Dryers ... 

Examine the continuous through-circulation dryer problem posed by Luus and Jaakola (1973) ... 

Through-circulation dryers, 9 120, 148 Through driers, 2 149 Throwing power, 9 773 Thujopsene, 24 543-544 Thulium (Tm), 14 631t, 635t electronic configuration, l 474t Thyme, 23 171... 

Through circulation dryers employ perforated or open screen bottom tray construction and have baffles that force the air through the bed. Superficial velocities of 150 ft/min are usual, with pressure drops of 1 in. or so of water. If it is not naturally granular, the material may be preformed by extrusion, pelleting, or briquetting so that it can be dried in this way. Drying rates are greater than in cross flow. Rates of 0.2-2 lb/(hr)(sqft tray area) and thermal efficiencies of 50% are realized. Table 9.7(d) has performance data. 

Through-circulation Dryers. Material is supported on a conveying screen that moves continuously. Hoi gases from below or above conveyor pass through the material and pick up moisture. 

Through-circulation Dryers. Materia is placed on trays with screen bottoms. Hoi gases are blown from below- through material. 

Design Methods for Continuous Tunnel Dryers In actual practice, design of a continuous through-circulation dryer is best based upon data taken in pilot-plant tests. Loading and distribution of solids on the screen are rarely as nearly uniform in commercial installations as in test dryers 50 to 100 percent may be added to the test drying time for commercial design. 

Through circulation dryers employ perforated or open screen bottom tray construction and have baffles that force the air through the bed. Superficial velocities of 150ft/min are usual. 

Chemical Engineers Handbook, McGraw-Hill, New York, 1984, p. 20.23, Table 20.8). (d) Through Circulation Dryers... 

Particles and powders below 1 mm are effectively dried in dispersion or contact dryers, but most through-circulation units are unsuitable. Conversely, for particles of several millimeters or above, through-circulation dryers, rotary dryers, and spouted beds are very suitable. 

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