为研究受限空间内玉米淀粉燃烧火焰结构以及火焰传播特性,在小尺寸开口竖直管道内进行不同质量浓度下玉米淀粉火焰传播试验。采用高速摄像拍摄火焰传播过程,并用微细热电偶记录试验过程中的火焰温度。试验结果表明:燃烧过程中火焰锋面形状不规则;在低质量浓度下,火焰温度和传播速度随粉尘质量浓度的增加而增大,存在一个最佳粉尘浓度使二者均达到最大值,超过此浓度值后,随着浓度增加二者开始缓慢下降。不同质量浓度粉尘对应的最高火焰温度和最大火焰传播速度呈线性关系。
To explore the structures of flame of corn starch in limited space,flame propagation experiments were carried out in a vertical tube with a small opening. Images of flame propagation were obtained by using high-speed video technique. Temperature profiles were obtained by using micro-thermocouples.The results show that under the experimental conditions,the flame front has a less regular shape,both the flame propagation velocity and temperature increase with the increase of dust cloud concentration at lower concentration,which reach the maximum values at an appropriate concentration,and then decrease slightly at higher concentration,for a given dust concentration,the maximum flame temperature has a linear relationship with its maximum propagation velocity.