Laboratory study on the swell and contraction characteristics of lumpy raw coal pyrolysis coking process
Depending on self developed visual testing instrument for coal pyrolysis coking process,influence of volatile matter and particle size on the swell and contraction behavior of some typical lumpy raw coals was investigated under uniform heating temperature.The results indicated that for the same coal,the swell and contraction curves of pyrolysis were different with different particle sizes,however,the curve change law with the temperature was similar regardless of the particle size.The shrinkage of lumpy raw coal had two peak stages,one was active decomposition stage at 400-550 ℃ and the other was secondary degassing stage after 550 ℃.The swell rate of pulverized coal of the same coal was smaller than that of lump coal.The shrinkage characteristic of pulverized coal was more obvious than that of lump coal.Compared with pulverized coal,the swell rate and contraction rate of lump coal were faster.The swell and contraction characteristics of lump coal were not only related to its volatile matter but also related to the coal type and its own structure.With the increase of lumpy raw coal volume,both the maximum expansion rate and the final shrinkage rate increased first and then decreased.
coal pyrolysislumpy raw coalparticle sizeswell and contraction
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