Fragmentation ashing process

The product is called water glass, because when solid, it actually is a glass but unlike lime-soda glass (ordinary window glass), it is soluble in water. The process is carried out in large tank furnaces similar to window glass furnaces. The materials are introduced in at intervals, but the products may be drawn off continuously if desired. A mixture of salt cake and coal may replace a portion of the soda ash. As the melt leaves the furnace, a stream of cold water shatters it into fragments. These are dissolved with superheated steam in tall, narrow steel cylinders with false bottoms,14 and the product liquor is clarified.15 Sodium silicates are sold as solutions that vary from the most viscous, 69°Be, to the thinner solu-... 

Applications include coal and trash combustion, coal and biomass gasification, and chemical, including polymer, synthesis. Both particles and the fluidizing gas stream change properties during the process. Coal is converted to ash, carbon dioxide, and carbon monoxide. The coal particle can also become fragmented. Coal and steam can yield hydrogen and carbon monoxide. 

The hot char [300 to 1000 C as measured by infrared pyrometry (44)] and ash provide surfaces which can catalyze secondary thermal reactions of the reactive fragments of the escaping volatiles. The char can also be consumed by them as suggested by Lewellyn et al. However, both processes occur at temperatures lower than the effective plasma temperature and degradation is not as severe. 

There are four kinds of materials used in paste-like filling, which are fragmentized coal gangue, fly ash, special cement and water. The process of filling is as follows (Sun Henghu, et al. 2002) ... 

Mineral matter in coal, during combustion, transforms into fly ash, and results in the buildup of ash deposits on heat transfer surfaces in PC-fired boilers. The ash formation process determines the ash character, that is, its particle size distribution and variation in chemistry. There are two models that can be used to represent ash formation from mineral matter (1) coalescence of included mineral grains and (2) fragmentation of excluded mineral grains during combustion. 

The ability to produce catalyst supports that could fragment led to the development of high-productivity catalysts and processes in which de-ashing of the polymer was unnecessary. 

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