Rotary Drums are used for drying and cooling a wide variety of bulk materials depending on the type and arrangement of internals of which wide selection is available.
Simple design, trouble free operaeon, high output and flexibility for capacity are typical of these drums.
A rotary dryer is a type of industrial dryer used to reduce or minimize the moisture content of the material by bringing it into contact with a heated gas. The dryer is made up of a rotating cylinder ("drum" or "shell"), a drive mechanism, and a support structure (commonly concrete posts or a steel frame).
High evaporation rates can be obtained by locating the burner directly in the head of the drum. The product must be insensitive to heat and appropriate internals is provided to ensure uniform distribution of the product in the lining area of the drying drum
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Rotary cooler using air/water as cooling medium are very much like counter flow drying drums. The material to be cooled is fed into one feed end of rotary cooler, liŌed, and cascaded by flights through the cooling air stream as it passes from the feed end to discharge end of the rotary cooler.
Where the rotary cooler is followed by rotary dryer, the hot air from cooler can be used as dilution air in the dryer. Rotary Cooler sometimes uses water indirectly through tube or spraying on shell.
Rotary kilns are used for pareal or complete spilling off and evaporating combined water from hydrates and crystalline products and in the heat treatment of various substances with the purpose of changing their molecular or chemical composieon.
The Rotary Klin is normally direct fired and lined with refractory material to protect the steel shell, reduce radiation losses, and transfer heat to the material.
For reasons of process control and heat economy, the Rotary Kilns are usually combined with other equipment like Drying Drum or Cooler before and after the Kiln
These are similar in Construction to the indirect contact design. The steam tubes placed inside the Rotating shell act as the heat source. Steam is introduced into a header, through a rotary joint, which is also provided with a condensate discharge pipe. The material picks up heat from the steam tubes during passage through the dryer. The drying temperature is readily controlled by controlling the steam pressure.
Air is required only for removal of evaporated moisture. Hence air quantity is minimal, thus reducing duseng problems. As gas quantity required is very small, the system can also be adapted for inert gas operation with solvent recovery. The same passing water inside the tube can be used as cooler design.
These are typically used for Dense Soda Ash. These are rotary equipment prior to supplying to FBD. There are few installations in Soda Ash industry in India.
