Patent ID: 8997376
Filing Date: 2015-04-07
Classification: C10B,C10L,F26B

Abstract:
1. A dryer for use in drying moisture containing material comprising aggregates of brown coal having a tendency to create dust when dried, whereby the process minimizes generation of the dust, the process including the steps of: providing the material in a heated chamber having a steam containing atmosphere at a temperature above the dewpoint of the steam, recirculating a hot gas including a portion of the steam through said chamber in order to evaporate moisture from the material to a predetermined level of dryness, and controlling the relative humidity by venting excess steam from the chamber when the steam content exceeds a threshold value, wherein the chamber receives and continuously conveys the moisture containing material therethrough; the dryer further including a heater for heating the chamber to a temperature sufficient to evaporate moisture from the material and generate steam to maintain the steam above its dewpoint; an inlet and an outlet through which a recirculating stream of hot gas including a portion of the steam passes into and out of said chamber; recirculating means for recirculating the hot gas stream through the chamber; and a vent which is operable to control the relative humidity in the chamber by releasing a portion of the hot gas stream from the chamber when the concentration of steam in the chamber exceeds a threshold value.