木粉最小着火温度及其安全生产对策的研究
发布时间：2018-09-17 17:14
【摘要】：木粉是木材加工而成,也是木材加工行业的伴生粉体,生产场所的木粉对人和设备有不良影响,并且木粉遇到热表面被点燃存在燃烧爆炸的危险。研究木粉的最小着火温度,对于木粉的安全生产意义重大。主要利用粉尘云和粉尘层最小着火温度测试仪分别测定悬浮和堆积状态下木粉粉尘的最小着火温度,并研究木粉着火的影响因素,最后提出木粉产生场所安全控制措施。具体结论如下:(1)扩散压力、粉尘浓度、惰性介质对木粉粉尘云的最小着火温度都有影响。对于质量30、50、100、200、300、500 mg的木粉最合适的扩散压力分别为0.1、0.1、0.1、0.1、0.2、0.3 bar,随着质量的增大,最合适的扩散压力呈上升趋势。(2)木粉尘云的最小着火温度随着木粉尘浓度的增加先减小后增大,但增大幅度不大。木粉粉尘云着火时有最敏感的浓度和扩散压力分别为1.363 kg.m-3和0.2 bar,此条件下,最小着火温度为430℃。(3)当惰性粉体加入量少时,抑制作用较弱,随着惰性粉体的增加,惰性粉体抑制作用增强。质量分数相同时,NaCl的抑制作用最弱,NH4H2PO4的抑制作用强于CaCO3,但伴随惰性粉体质量分数的增加,NH4H2PO4的抑制作用弱于CaCO3。(4)在金属加热板作用下,木粉粉尘层的燃烧主要包括两个阶段:燃烧的引发阶段和持续阶段。当木粉尘层厚度由5 mm增加到27.5 mm,最小着火温度由320℃减小到270℃,即在此厚度范围内,粉尘层堆积厚度增加,木粉的最小着火温度降低。借助Origin进行数值拟合,得到当堆积厚度为44 mm时,木粉粉尘层的着火温度最小为260℃。堆积厚度和木粉粉尘层的最高温度之间没有明显的关系,并且在相同的条件下,测得木粉粉尘层的最高着火温度也不相同,跨度较大。(5)木粉粉尘云和粉尘层的最小着火温度分别为430℃和260℃。尽管木粉堆积时不会发生爆炸事故,但是燃烧的木粉粉尘层其温度可高达540℃,可以作为点火源引燃悬浮状态的木粉粉尘云引发爆炸事故,因此,有木粉堆积或沉积的生产场所其生产设备或管道热表面的温度不能超过260℃。生产场所的木粉对人的健康和设备都有不良影响,并且存在爆炸的危险,通过安全工程技术、安全管理和安全培训来确保安全生产。
[Abstract]:Wood flour is a kind of wood processing powder, which is also the accompanying powder of wood processing industry. The wood powder in the production place has a bad effect on people and equipment, and the wood flour is in danger of burning and exploding when the hot surface is ignited. It is of great significance to study the minimum ignition temperature of wood flour for the safe production of wood flour. The minimum ignition temperature of wood powder dust was measured by dust cloud and dust layer minimum ignition temperature tester, and the influencing factors of wood powder ignition were studied. Finally, the safety control measures of wood powder production site were put forward. The main conclusions are as follows: (1) Diffusion pressure, dust concentration and inert medium all affect the minimum ignition temperature of wood dust cloud. The most suitable diffusion pressure for wood flour with a mass of 30 ~ 50100200300500 mg is 0.1g / 0.1g 0.1g / 0.20.3mol / min, respectively. With the increase of mass, the most suitable diffusion pressure tends to increase. (2) the minimum ignition temperature of wood dust cloud decreases first and then increases with the increase of wood dust concentration. But the increase is small. The most sensitive concentration and diffusion pressure of wood dust cloud were 1.363 kg.m-3 and 0.2 bar, respectively, and the minimum ignition temperature was 430 鈩，
本文编号：2246578
[Abstract]:Wood flour is a kind of wood processing powder, which is also the accompanying powder of wood processing industry. The wood powder in the production place has a bad effect on people and equipment, and the wood flour is in danger of burning and exploding when the hot surface is ignited. It is of great significance to study the minimum ignition temperature of wood flour for the safe production of wood flour. The minimum ignition temperature of wood powder dust was measured by dust cloud and dust layer minimum ignition temperature tester, and the influencing factors of wood powder ignition were studied. Finally, the safety control measures of wood powder production site were put forward. The main conclusions are as follows: (1) Diffusion pressure, dust concentration and inert medium all affect the minimum ignition temperature of wood dust cloud. The most suitable diffusion pressure for wood flour with a mass of 30 ~ 50100200300500 mg is 0.1g / 0.1g 0.1g / 0.20.3mol / min, respectively. With the increase of mass, the most suitable diffusion pressure tends to increase. (2) the minimum ignition temperature of wood dust cloud decreases first and then increases with the increase of wood dust concentration. But the increase is small. The most sensitive concentration and diffusion pressure of wood dust cloud were 1.363 kg.m-3 and 0.2 bar, respectively, and the minimum ignition temperature was 430 鈩，
本文编号：2246578
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