The tumbling bed has been developed in our experiment to obtain the dense pyrolytic carbon from pyrolysis of propane by rotating the reaction tube and the resulted tumbling and rubbing actions. We have introduced graphite disks as substrates and sand particles ranging from 15 to 20 meshes in diameter in the specifically designed reaction tube.
The main object of our experiment is to obtain the isotropic pyrolytic carbon in tumbling bed developed as described above by controlling the process variables such as the concentration of propane, the bed particle weight and total flow rate at the fixed reaction bed temperature of 1,200℃ and 20 RPM (Rotation Per Minute) of the reaction tube: it was studied in propane concentration range of 10 to 100% and the bed particle weight range of 2.5 to 7.5g at the total flow rates of l l/min and 2 l/min respectively.
The results show that the isotropic pyrolytic carbon is obtainable in tumbling bed at all conditions investigated except at one condition of low concentration of hydrocarbon (about 10% of propane), high bed surface area(7.5g bed particle weight) and total flow rate (l l/min). The density and apparent crystallite size ($L_c$) of the isotropic pyrolytic carbon are respectively 2.0 g/cc and 30Å;.
