...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Combustion and Flame >The ignition and combustion of mixtures of a gaseous hydrocarbon fuel in air when fluidising a bed of sand
【24h】

The ignition and combustion of mixtures of a gaseous hydrocarbon fuel in air when fluidising a bed of sand

机译：The ignition and combustion of mixtures of a gaseous hydrocarbon fuel in air when fluidising a bed of sand

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相关主题

摘要

Previous work has been examined here to arrive at a proper criterion for when a mixture of a hydrocarbon gas and air ignites, when it is used to fluidise a bed of e.g. silica sand. It was concluded that, even when the bed has been warmed up to AP; 900 DEG;C, combustion of such a mixture of gases is usually prevented in the bed's particulate phase, i.e. in the gas moving interstitially between particles of sand. This is caused by free radicals recombining on the surfaces of the fluidised particles. As for the bubble phase, combustion in a bubble of a hydrocarbon gas, pre-mixed with air, is inevitably delayed by the chemistry involving a sequence of straight and branched chain reactions. Also, there can be a toroidal motion of gas inside a bubble; this enhances the transport of heat and radicals from the torus to the sand and so inhibits ignition of a bubble's contents. The result is that for a stoichiometric mixture of propane and air at atmospheric pressure, ignition occurs when a bubble's diameter has grown by coalescence to:d(b) similar to 3 U-mf t(ig) similar to nbsp;2.7 x 10(-9) U-mf exp (158 kJ mol(-1)/RT) nbsp;Here U-mf is the superficial velocity of the fluidising gas for incipient fluidisation; t(ig) is the autoignition delay for the particular fluidising gas mixture. This approximate statement is for both slow and fast bubbles; it is very similar to a criterion deduced previously by a different route. The above relationship is based on ignition occurring in a bubble, whenever the residence time in the gas passing up through the bubble along its vertical axis exceeds the ignition delay. (c) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved. nbsp; nbsp;

著录项

获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号