The Simulation Study on Pipeline Dynamic Characteristics of Asphalt Foaming System

Abstract

During the process of asphalt foaming, the control of spraying synchronism and fluid ratio of asphalt and water is the key to the quality of foamed asphalt. Newtonian fluid and non- Newtonian fluid's pipeline dynamic characteristics are studied by utilizing the sectional concentrated parameters modeling which including the dynamic friction item. To spraying water and asphalt in different pipes, the time cost is different. The asphalt viscosity also affects the flow in pipeline. These factors can provide theoretical instruction for developing asphalt foaming system. They can also guide the accurate measurement and control of asphalt and water. A new method of flow matching between varied viscosity fluids is also presented. Foamed asphalt is called green stabilizer because of its extraordinary performance like energy conservation and pollution free. It plays a more and more important role in the road fast rebuilding field. Hot asphalt and cold water with certain ratio are sprayed into the foaming chamber at the same time, then the water phase changes and transforms into vast volume of water vapor. When the vapor is pushed into the asphalt continuous phase, the micro asphalt foams are created. At last, the micro foams are sprayed out the chamber and expands quickly to big foams, thus the foamed asphalt is produced. The viscosity of foamed asphalt is pretty low so that it can bundle the aggregate easily as good binding agglomerant. The spray synchronism and ratio control of hot asphalt and cold water are the key points of the foamed asphalt producing. Water is a typical Newtonian fluid while asphalt is a typical non-Newtonian fluid. The flow of water and asphalt in the pipe is very different. To discover the time and flow difference between water and asphalt in pipes can provide theoretical support to the foaming instrument design. Based on the bond graph method and variant dynamic liquid resistance, the Newtonian fluid and non-Newtonian fluid's pipeline dynamic characteristics are studied by utilizing the sectional concentrated parameters modeling method. Thus it can be adopted to solve the different flow matching problem between varied viscosity fluids and pipeline optimization design problem.