Patent ID: 7992319

Claim:
A dryer for drying pellets containing brown coal, comprising at least one substantially vertical elongate container having: an open upper inlet for receiving a charge of moisture and brown coal containing pellets; an open lower outlet for discharging dried brown coal containing pellets, whereby said pellets travel under the influence of gravity from said open upper inlet to said open lower outlet in a substantially continuous manner; two substantially vertical and opposed gas permeable walls through which a drying gas at temperatures from about 15° C. to about 80° C. can pass to contact said pellets; wherein the gas permeable walls comprise a substantially continuous corrugated plate, wherein each corrugation comprises a generally vertically oriented impervious supporting leg and an adjacent generally horizontally oriented permeable leg angled with respect to each other, the permeable leg having spaced openings for the passage of the drying gas; said dryer also comprising at least a first and a second plenums on exterior surfaces of said gas permeable walls, wherein the plenums are divided into zones of differing air stream properties, said air stream properties selected from the properties consisting of velocity, and pressure, said first and second plenums being connected to allow the recycling of the drying gas.