Effect of Carbon Black/Organoclay Hybrid Filler System on Tire Tread Compound Properties

The enhanced dispersion of organophilic layered silicates improves the mechanical properties of polymer/ silicate composites. In this work, a hybrid filler system consisting of Cloisite 15A organoclay (OC) and carbon black (CB) was used to improve the properties of the tire tread compounds. The physical and mechanical properties of compounds were assessed by measurement of their cure properties, tensile, crack growth resistance and abrasion tests. The dispersion of organoclay layers was investigated by XRD analysis and transmission electron microscopy. The results have indicated that increases in tensile strength, elongation-at-break and rupture resistance were obtained by replacement of 5 phr CB with OC. However, increases in modulus and abrasion resistance were obtained by replacement of 3 phr CB with OC. Therefore replacement of 3 phr CB with OC was an optimum formulation for tread compound. The results have also indicated that with changing the mixing conditions to enhance the dispersion of clay layers, the mechanical and abrasion properties have improved. The XRD patterns and transmission electron micrographs have revealed that the distances between the layers are increased from 5.5 nm to 13.5 nm

Large Eddy Simulation of coal combustion in a large-scale laboratory furnace

Abstract A detailed Large Eddy Simulation (LES) of pulverised coal combustion in a large-scale laboratory furnace is presented. To achieve a detailed representation of the flow, mixing and particle dispersion, a massively parallel {LES} was performed. Different phenomenological network models were applied and compared to each other in order to obtain the most adequate devolatilization kinetic data for the LES. An iterative procedure allowed to optimise the devolatilization kinetic data for the studied coal and operating conditions. The particle combustion history is studied by analysing particle instantaneous properties giving a perspective on coal combustion that currently is not available by other means than LES. Predicted major species and temperature were compared with measurements and a good agreement was obtained. The finely resolved near burner region revealed that the flame is stabilised very close to the burner. Furthermore, two distinct zones of {CO2} production were found – one in the internal recirculation zone (IRZ) due to gaseous combustion, and one downstream of the vortex breakdown, due to intense char combustion. It was found that particle properties are inhomogeneous within the IRZ, whereas in the external recirculation zone (ERZ) and downstream of the vortex breakdown they were found to be homogeneous