Experimental study on ash-returned reactor of CFB atmospheric air gasifier

Abstract

In an attempt to improve the gasification efficiency and decrease the carbon content in fly ash of atmospheric air CFB gasifiers, an innovatory equipment by name ash-returned reactor is put forward by SKLCC. Ash-returned reactor is an ash-returned apparatus on line of ash circulation, typically like "U"type valve in CFB boilers, with additional function of some extent combustion of residual carbon and increase the furnace inlet temperature of returning ash, and hence the coal conversion of gasifiers is enhanced. As to its configuration compared to conventional "U"type valve, ash-returned rector has two distinguished features of several times of height scale of fluidizing transportation region to meet the combustion reaction time need and appropriate heat transfer tube bundles arranged in the region to moderate the local temperature so as to avoid slagging. And hence, corresponding to the structure renovation, the material transportation and regulation performance of ash-returned reactor is primarily investigated through a series of experiments in a cold lab-scale facility in this paper. The heat transfer characteristic of the tube bundles is then researched and its influential factors are further discussed. These works lay a foundation on the following study of hot state experiments and industrial applications.