The fluidization behaviour of ignimbrite at high temperature and with mechanical agitation
The fluidization behaviour of ignimbrite at high temperature and with mechanical agitation
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DOI：
10.1029/2003gl018593
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发表时间：
2004-01-23
影响因子：
5.2
通讯作者：
Yates, JG
中科院分区：
文献类型：
--
作者：
Druitt, TH;Bruni, G;Yates, JG
通过实验研究了高温和机械搅拌条件下烟灰煤的流态化行为。当材料从松散堆积状态受到不断增加的气体流动（无搅拌）时，在565℃以下发生格尔达特C族行为。相比之下，即使是温和的机械搅拌也会抑制通道，导致a族的行为，均匀（无气泡）膨胀高达30 - 40%。床崩试验显示室温下的c族行为，200 - 565℃时的a族行为，55℃时的过渡行为。温度的升高和机械搅拌都大大提高了烟灰煤的流化性。推测高温和剪切作用将促进火山碎屑流中的Geldart群a行为。
Experiments were carried out to study the fluidization behaviour of ignimbrite at high temperature and while being mechanically agitated. Geldart group C behaviour occurs up to 565 degreesC when the material is subjected to increasing gas flow ( without agitation) from the loosely packed state. In contrast, even gentle mechanical agitation inhibits channelling and results in group-A type behaviour with homogeneous (non-bubbling) expansions of up to 30 - 40%. Bed collapse tests exhibit group-C behaviour at room temperature, group-A behaviour at 200 - 565 degreesC, and transitional behaviour at 55 degreesC. Both elevated temperature and mechanical agitation greatly increase the fluidizability of ignimbrite. It is inferred that a combination of high temperature and shear during transport will promote Geldart group A behaviour in pyroclastic flows.