多中段高溜井卸矿口气流分布及影响因素

Air distribution and influencing factors at unloading port in multiple level of high ore pass

为了治理多中段高溜井卸矿后由气流变化造成的粉尘污染,采用量纲分析法分类推演影响气流分布的因素,建立多中段高溜井卸矿的相似实验模型,研究多中段高溜井卸矿口的压差、气流速度及其影响因素。研究结果表明:卸矿后,一、二中段以诱导气流为主,而三、四中段以冲击气流为主;随着卸矿流量增加,各中段卸矿口的最大风速先增大后减小,其中,在各流量下,最大风速出现在卸矿流量为1.0 kg/s时;当卸矿流量增加到1.2 kg/s时,各中段卸矿口的最大风速下降,并且对二、四中段的最大风速影响较明显;二、四中段卸矿口最大风速分别降低26.0%和22.7%;各中段卸矿口最大风速随着矿石粒径和含水率增加而降低,但矿石粒径对二中段卸矿口最大风速的影响较明显;一、二、四中段卸矿口最大风速随着卸矿高度增加而增大,而三中段卸矿口的最大风速随着卸矿高度增加先增大后减小。

To prevent and control the dust pollution caused by the change of air flow after ore unloading in multiple level of high ore pass,the dimensionality analysis method was used to classify and deduce the influencing factors of airflow distribution.A similar experimental model of multiple level of high ore-pass was established,and differential pressure,airflow velocity and its influencing factors of unloading port in multiple level of high orepass were studied.The results show that after unloading,the first and second level are dominated by induced airflow,while the third and fourth level are dominated by the impact air flow.With the increase of the unloading flow rate,the maximum wind speed of unloading port in each level increases firstly and then decreases.At each flow rate,the maximum wind speed appears at the unloading flow rate of 1.0 kg/s.When the unloading ore flow rate increases to 1.2 kg/s,the maximum wind speed decreases,and it has obvious influence on the maximum wind speed of the unloading port in the second and fourth level,which decrease by 26.0%and 22.7%respectively.The increase of ore size and moisture content can reduce the maximum wind speed at each unloading port,but the effect of the ore size on the maximum wind speed at the unloading port in the second level is more obvious.The maximum wind speed at the unloading port in the level of the first,second and fourth increases with the increase of ore unloading height,while the maximum wind speed at the unloading port in the level of the third increases firstly and then decreases with the increase of ore unloading height.