| The asphalt warm foaming device is a mechanical equipment developed with the technology of warm mix asphalt,which can be used on asphalt mixing equipment.The device can produce different kinds of foam asphalt,reduce the viscosity of asphalt,and realize the production of mixed asphalt mixture,which has the characteristics of energy conservation,environmental protection and low production cost.The current domestic study of foamed asphalt cold technology,temperature of foam asphalt mixing technology research has focused on foam asphalt and mixture parameters,performance,but the structure and parameters of asphalt warm foaming device is less research.Based on the analysis of the principle of asphalt foaming,the evaluation index of foam asphalt and the factors influencing the foaming of asphalt are studied.It is considered that the asphalt foaming device is the key component of the foaming effect of asphalt.Through analyzing of the structure and working principle of two kinds of asphalt foaming devices FB100 and GFAT1,the working parameters of the asphalt foaming device are calculated by combining engineering application.Based on the principle of asphalt foaming and the structural characteristics of asphalt foaming chamber,the foaming process of asphalt is simulated by CFD(computational fluid dynamics software ANSYS FLUENT,and the structure of the foaming chamber is designed based on the theory of fluid mechanics.The simulation process of asphalt foaming process is carried out by ANSYS FLUENT.According to the simulation results of the asphalt foaming chamber and relevant simulation data,the influence law of asphalt jet inlet and foam asphalt outlet on the expansion rate and half-life is analyzed,and there will obtain good foaming effect that the size of asphalt jet inlet is φ4mm and the size of foam asphalt outlet is φ8mm.The comparison experiments of cylindrical and elliptical foaming chambers show that the asphalt foaming half-life of the cylinder foam chamber is longer and suitable for the temperature mixing technology.The ellipsoid foam chamber has a larger expansion rate and is suitable for cold mixing technology.The cylindrical foam chamber for 70# and 90# asphalt foaming experiment is carried out,the results show that the optimum foaming water for 70# and 90# asphalt is 2%,the best foamed asphalt temperature is between 150℃~160℃.In order to guarantee the performance of the foam asphalt,specific of asphalt foaming test of different grade asphalt should be carried out,and the asphalt temperature and foaming water consumption should also be determined.In the field engineering,the industrial application test is carried out for the cylindrical foaming cavity of the development design.The performance of SBS modified asphalt foaming test and the temperature mixing asphalt mixture are analyzed respectively,and the results are verified finally. |
