Reed W R, Klima S, Shahan M, Ross G J H, Singh K, Cross R, Grounds T
CDC NIOSH, Pittsburgh Mining Research Division, Pittsburgh, PA 15236, USA.
Fletcher & Co., Huntington, WV 25705, USA.
Int J Min Sci Technol. 2019 Sep;29(5):711-720. doi: 10.1016/j.ijmst.2019.02.005.
A 2nd generation roof bolter canopy air curtain (CAC) design was tested by National Institute for Occupational Safety and Health (NIOSH) at a Midwestern underground coal mine. During the study, the roof bolter never operated downwind of the continuous miner. Using a combination of personal Data Rams (pDR) and gravimetric samplers, the dust control efficiency of the roof bolter CAC was ascertained. Performance evaluation was determined using three methods: (1) comparing roof bolter operator concentrations underneath the CAC to roof bolter concentrations outside the CAC, (2) comparing roof bolter operator concentrations underneath the CAC to the concentrations at the rear of the bolter, and finally, (3) using the gravimetric data directly underneath the CAC to correct roof bolter operator concentrations underneath the CAC and comparing them to the concentrations at the rear of the bolter. Method 1 dust control efficiencies ranged from -53.9% to 60.4%. Method 2 efficiencies ranged from -150.5% to 52.2%, and Method 3 efficiencies ranged from 40.7% to 91%. Reasons for negative and low dust control efficiencies are provided in this paper and include: incorrect sampling locations, large distance between CAC and operator, and contamination of intake air from line curtain. Low dust concentrations encountered during the testing made it difficult to discern whether differences in concentrations were due to the CAC or due to variances inherent in experimental dust measurement. However, the analyses, especially the Method 3 analysis, show that the CAC can be an effective dust control device.
美国国家职业安全与健康研究所（NIOSH）在中西部的一个地下煤矿对第二代锚杆钻机的机棚气幕（CAC）设计进行了测试。在研究过程中，锚杆钻机从未在连续采煤机的下风侧作业。通过结合使用个人数据采样器（pDR）和重量采样器，确定了锚杆钻机CAC的降尘效率。使用三种方法进行性能评估：（1）将CAC下方锚杆钻机操作员处的粉尘浓度与CAC外部锚杆钻机处的粉尘浓度进行比较；（2）将CAC下方锚杆钻机操作员处的粉尘浓度与锚杆钻机后部的粉尘浓度进行比较；最后，（3）使用CAC正下方的重量数据来校正CAC下方锚杆钻机操作员处的粉尘浓度，并将其与锚杆钻机后部的粉尘浓度进行比较。方法1的降尘效率在-53.9%至60.4%之间。方法2的效率在-150.5%至52.2%之间，方法3的效率在40.7%至91%之间。本文给出了降尘效率为负或较低的原因，包括：采样位置不正确、CAC与操作员之间距离过大以及来自线帘的进风受到污染。测试过程中遇到的低粉尘浓度使得难以辨别浓度差异是由于CAC还是实验粉尘测量中固有的差异。然而，分析结果，尤其是方法3的分析结果表明，CAC可以是一种有效的降尘装置。
