Pyrolytic carbon was deposited in a tumbling bed varying process variables such as RPM, total flow rate, bed surface area, temperature and the concentration of propane gas; RPM in the range of 1 to 70, total flow rate, 0.1 ℓ/min to 4.0 ℓ/min, bed particle weight, 0 g to 14 g, bed temperature, 930℃ to 1150℃ and the propane concentration, 1% to 11.5%.
Laminar structure is obtained when propane concentration and temperature are low, large amount of bed particle is mixed and RPM is high.
It is suggested that laminar structure is formed as a result of periodic deposition of droplets by eddy current and surface growth at droplet seeds. The deposition mechanisms of columnar and isotropic pyrolytic carbon can also be explained in view of the mechanism of the laminar structure. The deposition kinetics of pyrolytic carbon at low propane concentration were coincided well with the deposition mechanism suggested in the present work.
