采用实地模拟试验,研究不同复垦机械在不同填充材料下不同的碾压次数对土壤物理性状的影响,并采用winner2000激光颗粒仪对其土壤颗粒组成进行了量测分析,研究不同机械不同填充材料复垦对物理性状的影响。结果表明:(1)经过3次碾压后,各...采用实地模拟试验,研究不同复垦机械在不同填充材料下不同的碾压次数对土壤物理性状的影响,并采用winner2000激光颗粒仪对其土壤颗粒组成进行了量测分析,研究不同机械不同填充材料复垦对物理性状的影响。结果表明:(1)经过3次碾压后,各复垦地块土壤容重变化趋势趋于平稳,但从碾压7次到碾压9次这个过程,是复垦过程中的一个敏感碾压区,碾压7次后土壤容重会有明显的上升,且在煤矸石、建筑垃圾和粉煤灰三种填充材料中,粉煤灰充填复垦地块在碾压5次后,容重明显高于煤矸石和建筑垃圾充填地块。(2)自卸汽车复垦过程碾压超过3次,其容重即超过1.5 g cm-3,碾压9次容重达到1.76 g cm-3,使土壤质地板结;履带式推土机碾压7次,其容重仍在1.44 g cm-3以下,适于作物生长。(3)经不同程度的碾压后,履带式复垦地块中,建筑垃圾、粉煤灰和煤矸石充填地块"物理性黏粒"含量的最大值分别为25.29%、26.66%和36.89%;自卸汽车复垦的地块中,建筑垃圾、粉煤灰和煤矸石填充的地块总含量的最大值分别为36.23%、32.11%和51.73%。展开更多
Awareness of dust explosion hazards during silo filling operation is important for safety measures. Thus, information on particles-air flow field is required to assess the likelihood of the hazard. Flow field visualiz...Awareness of dust explosion hazards during silo filling operation is important for safety measures. Thus, information on particles-air flow field is required to assess the likelihood of the hazard. Flow field visualization via experimental investigation associated with difficulties and risks. Hence, in the present study, a modeling formulation using commercial computational fluid dynamics (CFD) code, FLUENT software was employed to predict an insight of flow field distribution, in terms of mean and root mean square (RMS) velocities vectors in cylindrical silo during axial filling. According to the simulation results, predicted flow field has a great influence to the silo height and distance to the silo wall due to gravitational force and movement of fugitive dust and re-circulation of air. The results showed that the predicted data were in very good agreement with experimental data obtained from the literature. The maximum error was around 10%. The study has gone some way towards enhancing our understanding of the particles-air behavior inside industrial equipments during filling operation.展开更多
文摘采用实地模拟试验,研究不同复垦机械在不同填充材料下不同的碾压次数对土壤物理性状的影响,并采用winner2000激光颗粒仪对其土壤颗粒组成进行了量测分析,研究不同机械不同填充材料复垦对物理性状的影响。结果表明:(1)经过3次碾压后,各复垦地块土壤容重变化趋势趋于平稳,但从碾压7次到碾压9次这个过程,是复垦过程中的一个敏感碾压区,碾压7次后土壤容重会有明显的上升,且在煤矸石、建筑垃圾和粉煤灰三种填充材料中,粉煤灰充填复垦地块在碾压5次后,容重明显高于煤矸石和建筑垃圾充填地块。(2)自卸汽车复垦过程碾压超过3次,其容重即超过1.5 g cm-3,碾压9次容重达到1.76 g cm-3,使土壤质地板结;履带式推土机碾压7次,其容重仍在1.44 g cm-3以下,适于作物生长。(3)经不同程度的碾压后,履带式复垦地块中,建筑垃圾、粉煤灰和煤矸石充填地块"物理性黏粒"含量的最大值分别为25.29%、26.66%和36.89%;自卸汽车复垦的地块中,建筑垃圾、粉煤灰和煤矸石填充的地块总含量的最大值分别为36.23%、32.11%和51.73%。
文摘Awareness of dust explosion hazards during silo filling operation is important for safety measures. Thus, information on particles-air flow field is required to assess the likelihood of the hazard. Flow field visualization via experimental investigation associated with difficulties and risks. Hence, in the present study, a modeling formulation using commercial computational fluid dynamics (CFD) code, FLUENT software was employed to predict an insight of flow field distribution, in terms of mean and root mean square (RMS) velocities vectors in cylindrical silo during axial filling. According to the simulation results, predicted flow field has a great influence to the silo height and distance to the silo wall due to gravitational force and movement of fugitive dust and re-circulation of air. The results showed that the predicted data were in very good agreement with experimental data obtained from the literature. The maximum error was around 10%. The study has gone some way towards enhancing our understanding of the particles-air behavior inside industrial equipments during filling operation.
