煤矿井下混合型湿喷工艺影响要素分析

Influence factors analysis on mixed wet spraying process of concrete in coal mine

为了使混合型湿喷工艺更好地在煤矿混凝土支护中得到推广应用,从喷射料准备段、喷射料输送段、喷射料混合段三个方面论述了混合型湿喷法各部分构成,分析了影响混合型湿喷法使用效果的诸多因素,包括输送气体的压力、流量、含水率,输送管道直径、长度,砂石料的粒度、含水率、含泥率等,并结合煤矿实际情况探讨了各因素的相互作用关系。结果表明,通过增设专门的砂石料(含速凝剂)和水泥浆混合装置才能提高喷射面强度,降低回弹率;在煤矿喷射原料准备中,应尽可能地降低砂子的含水率和含泥率以及压缩空气中的水分含量;影响喷射能力和输送距离的关键在混合料输送段,混合料输送段不宜设置太长,以免压缩空气压力和流量损失太大,造成混合段管路堵塞;混合湿喷法彻底消除了喷射过程中水泥扬尘对工作环境的污染,有效保护了作业工人的身体健康。

In order to promote the application of mixed wet spray process in concrete support of coal mine,from the 3stages of spray material preparation,transportation and mixing,this article discusses influence factors of application of the process in coal mines,including gas pressure,gas flow,water content in gas,pipeline diameter,pipeline distance,aggregate particle size,aggregate water content and mud content. Combining with coal mine actual conditions,interact relations between each factor are discussed. The results show that by adding sand stone（ including accelerator） and cement slurry mixing device the spray surface strength can be improved, and the rebound rate reduced; during raw material preparation,the water content of sand,mud rate and the moisture content of compressed air should be reduced as far as possible; the key of spraying capacity and transport distance is in the mixed material transport section,the length,thus,should be controlled,to avoid loss of compressed air pressure and flow,causing pipeline blockage; mixed wet spray method completely eliminates dust pollution in spraying process,which effectively protects the health of workers.