CIESC Journal ›› 2021, Vol. 72 ›› Issue (5): 2878-2886.DOI: 10.11949/0438-1157.20201426

• Process safety • Previous Articles     Next Articles

Study on the flame shape of gas-solid jet diffusion

NIE Xuan(),ZHOU Kuibin(),WU Yueqiong,HUANG Mengyuan,JIANG Juncheng   

  1. College of Safety Science Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
  • Received:2020-10-12 Revised:2020-12-22 Online:2021-05-05 Published:2021-05-05
  • Contact: ZHOU Kuibin

气固射流扩散火焰形态研究

聂璇(),周魁斌(),吴月琼,黄梦源,蒋军成   

  1. 南京工业大学安全科学与工程学院,江苏 南京 211816
  • 通讯作者: 周魁斌
  • 作者简介:聂璇(1995—),女,硕士研究生,229477685@qq.com
  • 基金资助:
    国家重点研发计划项目(2016YFC0800100);国家自然科学基金项目(51876088);江苏省第十六批“六大人才高峰”高层次人才项目(XNYQC-005);江苏省研究生科研与实践创新计划项目(SJCX20_0385)

Abstract:

This study investigates the flame geometrical features of the gas-solid jet diffusion flame (GSJDF). A new facility is designed and built using the Venturi effect, by which the jet diffusion flame can entrain the micron-sized solid particles at constantrate. The uniform white quartz sands of 147 μm and 178 μm in diameters were used for test, respectively. In particular, the gas jet diffusion flame (gas jet fire) formed by closing the side sand inlet is compared with it. Theoretical analysis and experimental result make sense that the addition of sand reduces the flame temperature, and then increases the flame height and the lift-off height by increasing the flame Froude number and decreasing the flame burning speed, respectively. The GSJDF of 147 μm sand has a higher flame height and lift-off height than that of 178 μm sand, for the total mass of 147 μm sand entrained into the flame is larger and so leads to a less flame temperature. In addition, the GSJDF holds a larger trend to produce the lift-off phenomena and a higher flame height than the jet diffusion flame, which also indicates the role of sand in the flame temperature reduction.

Key words: gas-solid mixtures, jet diffusion flame, flame temperature, lift-off height, flame height

摘要:

利用文丘里效应,自行设计气固射流扩散火焰(气固喷射火)实验装置,分别采用147 μm和178 μm两种粒径均匀的白色石英砂以近似恒定速率卷吸入火焰中,来研究固体颗粒对火焰形态的影响,特别地,通过关闭侧面进砂口所形成的气态射流扩散火焰(气态喷射火)与之相比较。理论分析和实验结果表明,砂子进入火焰中会降低火焰温度,并且粒径为147 μm的砂子进入火焰的质量大于178 μm砂子,导致小粒径气固喷射火具有更低的火焰温度,从而具有更低的层流燃烧速度和更大的火焰Froude数,最终使其具有更高的推举高度和火焰高度。对比分析气固喷射火和气态喷射火实验结果,也表明固体颗粒对火焰温度的冷却作用导致气固喷射火更容易产生推举现象并具有更高的火焰高度。

关键词: 气固混合物, 喷射火, 火焰温度, 火焰高度, 推举高度

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