Rotary drum furnaces, kilns, incinerators, dryers

Inclined rotary drum furnaces, kilns, incinerators, and dryers often use long type F or type G flames (fig. 6.2). If drying is involved, substantially more excess air than normal may be justified to provide greater moisture pickup ability. (See fig. 1.10.)... 

Fig. 1.10. Rotary drum dryer/kiln/furnace for drying, calcining, refining, incinerating granular materials such as ores, minerals, cements, aggregates, and wastes. Gravity moves material cocurrent with gases. (See fig. 4.3 for counterflow.)...

Continuous dryers, ovens, incinerators, and furnaces take any of a variety of forms such as rotary drum, tower, shaft, tunnel oven, multihearth (Herreshoff) kiln, and fluidized bed. As with all continuous furnaces, their design is very dependent on how the load(s) can be moved through the furnace (or occasionally, how the furnace can be moved over the loads). 

Fig. 4.3. A rotary drum dryer, kiln, incinerator, or furnace transports granular loads left to right) by gravity and rotation, counterflow to the burner gases and induced air. Parallel flow orco-current flow (fig. 1.10) can be used with some load materials and processes.

---