直线式吸烟机罩内风速控制系统的改进与应用研究

摘要

利用flow-simulation软件建立（20+1）孔道直线式吸烟机上的罩内风速模型，基于该模型，认为烟支在燃烧过程中，燃烧起始位置和结束位置间具有较大的气流速度差，可能显著影响烟气捕集结果。为消除这一影响，使吸烟机罩内气流速度达到均匀稳定，本文改进了吸烟机排风装置并在吸烟机的防护罩下端加装整流网。实验结果表明，改造后，当固定位置风速设定200 mm/s时，燃烧起始和结束位置平均风速差由93.0 mm/s降至20.7 mm/s；CM7卷烟烟气常规分析各指标项测定值在组间和孔道间的变异系数显著低于改造前，说明改造后吸烟机捕集主流烟气常规化学成分的均匀性和稳定性得到了提高；CM7卷烟烟气常规分析各指标项测定值明显低于目前使用的常规分析用吸烟机测得的结果，两者之间具有显著性差异。%By establishing an air-flow speed model on a(20+1)channel linear smoking machine through flow-simulation, changing patterns of air-flow speed around cigarettes in smoking process were imitated. At different combustion stages, the gap of air-flow speed between front and rear end of a cigarette caused by air-flow could lead to changes of air-flow speed around cigarettes during smoking process, which then affect smoke trapping. By improving air exhaust device and adding steady flow net to the bottom of the enclosure of smoking machine, air-flow speed became more even and stable: intro-group and intro channel RSDs of the regular smoking indexes determined were significantly decreased and the average gap of air-flow speed between the front and the rear end of the cigarette was reduced from 93.0 mm/s to 20.7 mm/s when the air-flow speed was set at 200 mm/s. It was proved that the average air-flow speed around front and rear end of cigarettes remained about 200 mm/s at every channel during the entire smoking process after the air control system was improved. The influences of air-flow speed and its changing of directions to cigarette combustion and smoke trapping were reduced. Regular smoking indexes of CM7 monitor cigarettes determined are significantly lower using the improved linear smoking machine than original (ordinary) one.