High-Temperature Processing with Calciners

Rotary calciners provide efficient high temperature processing and high heat transfer rates for bulk solid materials.Used to heat fine and dusty, oxidation-sensitive, flammable, explosive, potentially polluting or heat-sensitive materials, the rotary calciner isolates the material to be processed in a high-temperature chamber.The indirect heat source design of the calciner ensures that the heat source is completely separated from the product during processing.In applications ranging from catalyst manufacturing, hydrocarbon processing and wood biomass torrefaction to chemical manufacturing and precious metal recovery, as companies look for materials with finer grain size and uniform quality, rotary calciners provide the performance needed.A rotary calciner consists of an alloy steel cylinder that rotates within an electric or gas heated furnace.

The feeder continuously introduces the product into the cylinder, which is turned by an external drive mechanism.As the cylinder rotates, the material enters the heated furnace, and the atmosphere inside the furnace is always kept under controlled predetermined conditions.To close the ends of the cylinders, fixed casings are used.The upstream enclosure allows the manufacturer to connect product feed equipment and the downstream enclosure provides connections for exhaust cleaning equipment to collect and treat product exhaust vapors. After leaving the furnace, the product can enter a cooling section as required. Finally, it exits the calciner through the downstream housing.

The calciner performs all high-temperature processing in the range of 1,000 to 2,100°F (538 to 1,149°C) in its controlled atmosphere.It enables chamber control to the precise atmosphere requirements of any type of material.With this capability, the calciner can provide enhanced characteristics to the finished product.The heat source for the calciner is a resistance wire or a fuel burner.The heat source heats the surface of the cylinder. In turn, the barrel heats the material through radiative heat transfer, indirect heat transfer, and direct contact of the product with the hot surface of the barrel.