Design External-burning Drum For Heating Mixture And Heat Energy Utilization Study

With the quantities of asphalt pavement maintenance on the increase, the asphaltpavement maintenance machinery, especially hot-reclaimed maintenance vehicle, is widelyused and has been further promoted. The burning drum, as one of the most importantcomponents of maintenance vehicle, has a variety of functions such as storage, transportation,heating and so on. The performance and quality of the drum not only decide the maintenancequality, but also constitute the important factors of energy consumption and maintenance cost.So, based on the hot-reclaimed technology of domestic asphalt pavement, considering thequality and efficiency of heating asphalt mixture, combining the structure and heating methodof drum of domestic existing maintenance vehicle, this paper, from the point of view ofenhancing heat efficiency and saving energy, does further study on the structure and heatingmethod of the drum, and comes up with some improvement measures to improve the wholestructure of the drum, optimize the blade structure, arrange combustion-gas stream route,recycle the burnt gas. The main study works are as following:1. Recycling burnt gas to improve the thermal efficiency. To enhance the temperaturearound the drum, heat insulation technology is adopted to protect the combustion chamber ofburning drum. The high temperature gas is produced after the outside wall of drum is heatedby the heating plates. To ensure that the gas can enter the drum smoothly and heat the asphaltmixture again, the structure of the drum is changed. Finally, the purpose of making full use ofburnt gas and improving heat efficiency is achieved.2. In order to increase heat exchange area between high temperature gas and asphaltmixture, the structure of helical blade is improved. The improved blades make it better to liftmixture and form materials shade when the drum is rotating.3. Considering the effect and difference in mixing, lifting mixture and forming materialsshade, the existing and improved blades are researched by means of simulation method, thus,providing the basis of improving the blade structure.4. With the help of simulation method, the relationship between the helix lead angle ofblade and the movement velocity of mixture is researched and the optimization is carried out. The movement velocity of asphalt mixture inside burning drum is figured out by dynamicequation. Based on Fluent software of ANSYS Workbench, the optimized value of helix leadangle of blade is discovered through internal flow field simulation of external-burning drum.Based on the survey of multiple maintenance vehicles both at home and abroad, thestructure and heating system of burning drum are analyzed. Some improvement measures areput forward. Optimization design of the drum is performed. According to the above statement,What has been done will play an important role in improving the mixing quality of asphaltmixture, saving the fuel and enhancing energy efficiency, also has an important academicsignificance and engineering practical value.