Rotary dryers have been a part of the thermal processing industry for over a century, and have earned their reputation as the industry workhorse for industrial dryers. They have become a staple in industries such as agriculture and mineral processing, and are often chosen for their high efficiency. One aspect that contributes to this efficiency is the engineering and implementation of rotary dryer flights.
Rotary dryer flights are fin-like structures affixed to the interior of the rotating cylinder, used to help increase efficiency of heat transfer between the material and the gas stream. As shown in the diagram, these flights scoop up the material from the bed, and then shower the material through the stream of hot gas. This is known as creating a “curtain” of material. Ideally, the curtain will span the width of the interior of the drum, evenly falling from one side to the other. While this might sound easy, creating the right curtain boils down to a science behind specific material attributes that allow a flight to be engineered to work in combination with the material to produce the best curtain.
An ideal curtain is created by having the optimum volume of material flowing through the rotary dryer, in combination with the most efficient flight design. Not only does the design of the flight itself play a part, but so does the flight pattern, or where the flights are welded into the dryer. Flights can be staggered, or they may line up flush with each other.
FEECO has been engineering custom rotary dryers for over 60 years. Our material database as well as our knowledge of thermal processing, allows us to engineer a rotary dryer that fits the needs of our customers.
For more information on FEECO’s rotary dryers, contact us today!