The formation of Soot particles during pyrolytic carbon deposition in a tumbling bed and its effects on the mechanical properties of the pyrolytic carbon have been investigated under various deposition conditions.
The results are as follows. The soot particles formed during the deposition were mainly distributed as a form of clusters. The fraction of soot particles decreased with decreasing the bed temperature and the propane concentration, and increasing the total flow rate and the amount of bed particles. The effect of RPM on the fraction of soot particles, however, was somewhat complicate.
The deposition mechanism for nucleation, growth and agglomeration of the soot particles was discussed with respect to the variation of the size and the shape of the soot particles.
Mechanical properties, fracture strength, Young's modulus and strain energy to fracture, were measured by three-point bending test and all of these properties increased as the fraction of soot particles decreased.
1. 열분해 카본 증착층에 함유된 soot particle 은 gas phase 에서 탄화수소 분자가 polymerization 및 nucleation 을 하여 particle 을 형성하고 이것이 growth 및 aggromeration 으로 크기가 자라게 되어 열분해 카본과 함께 증착된다고 유추 된다.
2. Soot fraction 은 증착온도가 낮을수록, 반응기체중의 프로판 농도가 낮을수록, 총유속이 높을수록, bed particle 이 많을 수록, 그리고 증착속도가 낮아지는 RPM 일수록 감소하였다.
3. 열분해 카본의 fracture strength, Young's modulus 및 strain energy to fracture 는 soot particle 의 fraction 에 주로 의존하며, 이들 기계적 성질들은 soot fraction 이 감소 할 수록 증가하였다.
