Natural Rubber Drying Process

The energy consumption of natural rubber drying is large, which is the key link of cost control in the production process, at the same time, the drying process selection directly affects the quality of the rubber products. At present, hot air drying is the most commonly way in the natural rubber processing, the airflow through the rubber layer is hindered largely determines the resistance of the entire drying process, uniformity of airflow distribution also directly affects the quality of the products of rubber drying, based on the knowledge of fluid dynamics, heat and mass transfer theory and so on, combined with the previous research in the natural rubber drying process fluid temperature and humidity distribution, the further research on the problems of resistance distribution, air distribution, and the heat recovery was carried out in this paper.First of all, on the fundamental theory of dry, the rubber drying process fluid parameters such as temperature, humidity calculation method were determined. Drying technical parameters of typical system glue factory, old and new drying system and the simulation results researched by Wang Weimin were briefly introduced. According to the theory of porous media, the resistance coefficient and the pressure drop calculation equations, and the processing method in the numerical simulation of turbulent flow were established.Secondly, the dry resistance characteristic experiment of rubber material was tested. With different air flow and different drying stages, the quality, the temperature and the pressure drop data was got. Through the velocity-pressure drop data, the viscous resistance coefficient and the inertia resistance coefficient of fluid were calculated and fitting. The old and the new drying system with different air flow obtained the curves of moisture content comparison to the experiment results, the resistance distribution of the old and the new drying system with different air flow were calculated, and the corresponding air volume of the low and high temperature drying period of fan power consumption level were determined.Thirdly, a dry physical model was made, by using fluent software, numerical simulation the airflow distribution of rubber drying process with different circulation air and different dry stages, different thicknesses of rubber layer and different channel conditions. The simulation analysis found that the airflow distribution through the rubber layer is non-uniform, and the problem of fluid distribution uniformity was basically solved by changing the structure of passage. Characterization of fluid distribution unevenness of the standard deviation from the original0.120was reduced to0.011.Finally, according to the basic principles of heat transfer in porous media, the equations for calculating the cooling section of rubber heat transfer were established, the effective thermal conductivity, fluid convection heat transfer coefficient and the total heat transfer coefficient were calculated, by the approximate model, the rubber material heat transfer area was determined, and finally calculate the outlet temperature of the rubber after cooling. Compare with the cooling effect of the old and the new drying system with different airflow, and combined with the corresponding air motor power consumption and exhaust emissions, a comprehensive energy consumption analysis on rubber dry was made.