COAL GASIFICATION AND PRODUCTION OF BY-PRODUCT SUPERHEATED STEAM

摘要

COAL GASIFICATION AND PRODUCTIONOF BY-PRODUCT SUPERHEATED STEAM(D#76,476-1-F)ABSTRACTCoal or other high ash containing carbonaceous solidfuel is reacted with a free-oxygen containing gas, with orwithout a temperature moderator, in a down-flow partialoxidation gas generator to produce a stream of raw synthesisgas, fuel gas, or reducing gas. A large portion of thecombustion residue, i.e. molten slag and/or particulatesolids that is entrained in the down-flowing generated gasstream is removed by gravity when the gas stream is passedthrough a diversion chamber. The separated solid materialand molten slag pass down through an outlet in the bottom ofthe diversion chamber and into a pool of quench water below.Preferably, a small portion of the hot gas stream to pre-vent plugging. The main gas stream leaving the diversionchamber through the side outlet passes upward through asolids separation zone, optionally including gas-gas quenchcooling, cyclones, filters, impingement separators, orcombinations thereof. Next, most of the sensible heat inthe gas stream is recovered by indirect heat exchange withboiler feed water and steam. Saturated and superheatedsteam are produced. In the main gas cooling zone, the hotgas stream with a substantially reduced solids content ispassed serially through the tubes of two or more communi-cating shell-and-straight fire tube gas coolers. Saturatedsteam, which is produced in one, or more of said gas cool-ers, is superheated in another of said gas coolers. Eachgas cooler may have one or more passes on the shell and tubesides and is preferably in an upright position with fixedtube sheets.