GB1091471A - Process and apparatus for heat treating particulate solid material - Google Patents

Abstract

<PICT:1091471/C4-C5/1> A process for heating a particulate carbonaceous material, e.g. anthracite with or without other coals, to make a char for briquetting, comprises heating the material in a vessel to a first temperature for a first time period and entraining the heated particles in a gaseous stream where they are heated to a second, higher, temperature for a time which is less than the first time period. Respective temperatures and times are: (a) 200 DEG to 450 DEG C. for 5 minutes to several hours, and (b) 350 DEG to 650 DEG C. For not more than 15 seconds. The first heating may use a fluidized bed technique, heating being by contact with fluidizing gases, by reaction, or by external heaters, and the heated particles are delivered by a gas transfer line 5 to a vessel 12, which may act as a cyclone separator, as shown. The second stage heating is in two parts, namely: (a) by reaction with air or oxygen jets delivered to a duct 10 or by means of a burner 18 supplied with fuel at 20 and air at 21, 32, and (b) in the vessel 12. The heated particles are delivered tangentially to the duct 10 at 6 and are thoroughly mixed with the burner flame in a duct 11 of restricted radius, heating being completed and separation of char and gases being made in the vessel 12 to which the solid/gas stream is tangentially delivered. The burner construction is shown in more detail in Figs. 3, 4 (not shown). A by-pass 7 enables the part (a) of the second stage heating to be omitted, e.g. at start-up, testing, and shut-down.