Computational fluid dynamics(CFD)has been used to analyze the mixing process of Asphalt and Rubber(AR)in a stirred tank with a six flat-blade disc turbine(Rushton),a down-pumping 45°pitched-blade turbine(PBTD-6)a...Computational fluid dynamics(CFD)has been used to analyze the mixing process of Asphalt and Rubber(AR)in a stirred tank with a six flat-blade disc turbine(Rushton),a down-pumping 45°pitched-blade turbine(PBTD-6)and a down-pumping propeller(TXL).The two-phase(solid-liquid)flow in the considered stirred tank has been modelled in the framework of an Eulerian-Eulerian approach,a laminar-flow assumption and a multi-reference frame strategy.The following effects have been investigated:The influence of the impeller speed,impeller type,crumb rubber(CR)particle diameter and initial CR particle loading on the quality of the CR particle’s suspension.The outcomes of the numerical simulations have been found to be in good agreement with the experimental results.The most important findings can be summarized as follows.The flow velocity on the lower part of the stirred tank,induced by the Rushton impeller,is the highest for the three considered mixing systems at the same impeller speed.The suspension quality of CR particles increases with the impeller speed.A larger particle diameter and a higher initial CR particle loading lead to an uneven distribution of particles.The degree of homogeneity in the Rushton impeller system is better than that of the PBTD-6 impeller system and the TXL impeller system at the same impeller speed,while the suspension uniformity of the TXL impeller system is the best possible one for the same power consumption.展开更多
基金the Fundamental Research Funds for the Central Universities[300102250112]the Fundamental Research Funds for the Central Universities,CHD[300102251711].
文摘Computational fluid dynamics(CFD)has been used to analyze the mixing process of Asphalt and Rubber(AR)in a stirred tank with a six flat-blade disc turbine(Rushton),a down-pumping 45°pitched-blade turbine(PBTD-6)and a down-pumping propeller(TXL).The two-phase(solid-liquid)flow in the considered stirred tank has been modelled in the framework of an Eulerian-Eulerian approach,a laminar-flow assumption and a multi-reference frame strategy.The following effects have been investigated:The influence of the impeller speed,impeller type,crumb rubber(CR)particle diameter and initial CR particle loading on the quality of the CR particle’s suspension.The outcomes of the numerical simulations have been found to be in good agreement with the experimental results.The most important findings can be summarized as follows.The flow velocity on the lower part of the stirred tank,induced by the Rushton impeller,is the highest for the three considered mixing systems at the same impeller speed.The suspension quality of CR particles increases with the impeller speed.A larger particle diameter and a higher initial CR particle loading lead to an uneven distribution of particles.The degree of homogeneity in the Rushton impeller system is better than that of the PBTD-6 impeller system and the TXL impeller system at the same impeller speed,while the suspension uniformity of the TXL impeller system is the best possible one for the same power consumption.
