井下转载破碎点粉尘分布特征及降尘系统研究

Dust distribution characteristics and dust removal system at underground transfer and crushing location

为了改善综放工作面转载破碎区域的工作环境,结合粉尘分散度分析和现场实测得出转载机机头前1 m处、破碎机处及前刮板机和后刮板机处是四个主要的产尘位置。其中,转载机机头前1 m处持续不断地产生呼吸性粉尘,其PM5占比高达85.19%,原因在于煤块与带式输送机猛烈撞击后产生大量呼吸性粉尘;破碎机处也产生大量呼吸性粉尘,但积累呼尘的速率相对较慢,其PM10占比可达98%,这些粉尘主要来源于两防护罩间由于连接不吻合而产生的缝隙;前刮板机和后刮板机处可吸入粉尘占比相对稳定且比例较高,粉尘粒度分布相对均匀,这是由于此处煤块普遍较大且携带较高的势能,下落后产生大量微细粉尘。并根据每个产尘点的特性采用不同的喷雾降尘技术并设计相应的降尘系统:转载点喷雾形成全断面喷雾抑尘,破碎机喷雾将粉尘封闭在破碎机内部并沉降,前后刮板机喷雾利用雾群将粉尘完全覆盖。最后通过现场检验,PM5和PM10粉尘的降尘率都达到85%左右,降尘效果良好。

To improve working conditions of transfer and crushing zone at fully mechanized caving faces,the four main dust producing locations are at 1m from the reversed loader head,the crusher and the front and back scrapers,in terms of in situ dust dispersion analysis and measurement.Respirable dust is continuously generated at 1m from the reversed loader head,and the PM5 of the dust accounts for 85.19%.The reason is that a large amount of respirable dust is produced after the coal collides with the belt conveyor violently.A large amount of respirable dust is also produced at the crusher,but the accumulation rate of dust is relatively slow,and the PM10 ratio will reach 98%.The dust mainly comes from the gap between the two protective covers due to mismatch.The proportion of inhalable dust at the front and back scrapers is relatively stable and high,and the distribution of dust particle size is relatively uniform.This is because the coal here is generally large and carries high potential energy,resulting in a large amount of fine dust fall.Then according to the characteristics of each dust production point,different dust removal spray techniques are selected to design the corresponding dust removal systems.At the transfer location,spray system forms a full-section dust suppression;the crusher spray system seals the dust in it and settles them down;and the front and back scrapers spraying system completely covers the dust.It turned out the in situ dust removal rates of PM5 and PM10 reach about 85%,and the dust removal effect is favorable.