A rotary dryer is a device that uses rotation, gravity and warm gasses to dry a material. These driers range from small household clothes dryers to large industrial systems. Regardless of their size, the majority of rotary dryers work the same way. A drum rotates and moves material while hot gasses quickly dry it out. There are several different gasses used in rotary dryers. In commercial or industrial dryers, nearly any gas can be used, but the more common ones are exhaust fumes and various inert gasses. In these dryers, the main concern is possible contamination of the work material and the maximum heat of the used gas.
The directly heated rotary dryer operates on the principle of lifting and showering the product through a hot gas stream moving either in parallel or counter-flow. In the indirect dryer, which is more suited to fine and dusty materials, there is little or no contact between the product and the drying gases since they are heated from the outside, via a stationary jacket fitted with either multiple burners or other external heat source.
The purpose of this work was to analyze the influence of the flights on the drying rate and to evaluate the validation of an equationing proposed for the prediction of load and length of fall of the particles for two-segment flights. Another purpose was to verify the prediction of some equations in the literature for the residence time of the rotary dryer.
lead powder dryer: