Kiln dryer

Air Drying Equipment. Tunnel kiln dryers (70) are long furnaces comprised of several zones of different temperature, humidity, and air flow through which the ware travels on a moving car or belt. These kilns afford continuous processing. Periodic kiln cross-circulation dryers (70) are box furnaces in which ware is stacked on permanent racks or on a car that can be shuttled in and out of the furnace. Fans or jets are used to circulate heat uniformly through the ware. The process is not continuous, but production rates can be enhanced by shuttling multiple cars. 

Control of particulate matter emissions from the kilns, dryers, grinders, etc. is by means of standard devices and systems (1) multiple cyclones (80% efficiency), (2) ESPs (95% -I- efficiency), (3) multiple cyclones followed by ESPs (97.5% efficiency), and (4) baghouses (99.8% efficiency). 

Kilns Dryers, grinders, etc. Kilns Dryers, grinders, etc. 

Nodulizing Mixture of ore fines and fuel, or simply of fusible fines, is passed through a rotary kiln or dryer and agglomerates form by partial fusion, chemical reaction, etc. as the temperature is raised Granulation, calcining Rotary kiln, dryer... 

Gas Generation. This is the simplest application for the fluid bed technology. The gas can be used as a substitute for natural gas in an existing boiler or for the drying of wood products in a kiln dryer etc. 

Rotary cascading kiln dryer heat transfer coefficient (/ , = 0.1 W/kg solids °C for coarse materials and 0.4 W/kg °C for fine materials. 

FIGURE 14.52 Simplified scheme of an automatically controlled lumber kiln dryer. 

FIGURE 43.15 Fluidized bed dryers (a) with heating tubes (b) with superheated steam heating, 1—screw conveyor 2—stationary hlade 3—cylinder 4—side cyclone 5—ejector 6—stationary vanes 7—superheater, 8— impeller, 9—top outlet 10—screw conveyor (Courtesy of Niro A/S) (c) rotary kiln dryer using sands heated in a fluidized hed humer. (Adapted from Isheim, M.C., US Patent 4,248,164, 1981.)... 

Rotary kiln/dryer hot air indirect (continuous, indirect convection) hot air, c/s including solids feeder, motor, drive, shell and flights and heating equipment instrumentation. FOB cost 590000 at peripheral surface area = 100 m with n = 1.00 for the range 10-400. L-rM = 2.2-3. L/M = 0.4. Alloy cost factors c/s, X 1.00 s/s, X 2.5. 

Kiln dryers for lumpy, flat and solids pieces are also chamber dryers with huge chambers, from the point of view of process engineering. The product is spread on immovable or moving trays, or turned and moved over the trays using wipers or blades. 

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