發(fā)布時(shí)間：2018-09-17 17:14

【摘要】：木粉是木材加工而成,也是木材加工行業(yè)的伴生粉體,生產(chǎn)場(chǎng)所的木粉對(duì)人和設(shè)備有不良影響,并且木粉遇到熱表面被點(diǎn)燃存在燃燒爆炸的危險(xiǎn)。研究木粉的最小著火溫度,對(duì)于木粉的安全生產(chǎn)意義重大。主要利用粉塵云和粉塵層最小著火溫度測(cè)試儀分別測(cè)定懸浮和堆積狀態(tài)下木粉粉塵的最小著火溫度,并研究木粉著火的影響因素,最后提出木粉產(chǎn)生場(chǎng)所安全控制措施。具體結(jié)論如下:(1)擴(kuò)散壓力、粉塵濃度、惰性介質(zhì)對(duì)木粉粉塵云的最小著火溫度都有影響。對(duì)于質(zhì)量30、50、100、200、300、500 mg的木粉最合適的擴(kuò)散壓力分別為0.1、0.1、0.1、0.1、0.2、0.3 bar,隨著質(zhì)量的增大,最合適的擴(kuò)散壓力呈上升趨勢(shì)。(2)木粉塵云的最小著火溫度隨著木粉塵濃度的增加先減小后增大,但增大幅度不大。木粉粉塵云著火時(shí)有最敏感的濃度和擴(kuò)散壓力分別為1.363 kg.m-3和0.2 bar,此條件下,最小著火溫度為430℃。(3)當(dāng)惰性粉體加入量少時(shí),抑制作用較弱,隨著惰性粉體的增加,惰性粉體抑制作用增強(qiáng)。質(zhì)量分?jǐn)?shù)相同時(shí),NaCl的抑制作用最弱,NH4H2PO4的抑制作用強(qiáng)于CaCO3,但伴隨惰性粉體質(zhì)量分?jǐn)?shù)的增加,NH4H2PO4的抑制作用弱于CaCO3。(4)在金屬加熱板作用下,木粉粉塵層的燃燒主要包括兩個(gè)階段:燃燒的引發(fā)階段和持續(xù)階段。當(dāng)木粉塵層厚度由5 mm增加到27.5 mm,最小著火溫度由320℃減小到270℃,即在此厚度范圍內(nèi),粉塵層堆積厚度增加,木粉的最小著火溫度降低。借助Origin進(jìn)行數(shù)值擬合,得到當(dāng)堆積厚度為44 mm時(shí),木粉粉塵層的著火溫度最小為260℃。堆積厚度和木粉粉塵層的最高溫度之間沒(méi)有明顯的關(guān)系,并且在相同的條件下,測(cè)得木粉粉塵層的最高著火溫度也不相同,跨度較大。(5)木粉粉塵云和粉塵層的最小著火溫度分別為430℃和260℃。盡管木粉堆積時(shí)不會(huì)發(fā)生爆炸事故,但是燃燒的木粉粉塵層其溫度可高達(dá)540℃,可以作為點(diǎn)火源引燃懸浮狀態(tài)的木粉粉塵云引發(fā)爆炸事故,因此,有木粉堆積或沉積的生產(chǎn)場(chǎng)所其生產(chǎn)設(shè)備或管道熱表面的溫度不能超過(guò)260℃。生產(chǎn)場(chǎng)所的木粉對(duì)人的健康和設(shè)備都有不良影響,并且存在爆炸的危險(xiǎn),通過(guò)安全工程技術(shù)、安全管理和安全培訓(xùn)來(lái)確保安全生產(chǎn)。
[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，

本文編號(hào)：2246578