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Indian Journal of Engineering and Materials Sciences (IJEMS) >
IJEMS Vol.17 [2010] >
IJEMS Vol.17(5) [October 2010] >
| Title: | Development of pyrolytic carbon coated zirconia pebbles in a high temperature spouted bed |
| Authors: | Sathiyamoorthy, D
Rao, V Govardhana
Rao, P T
Mollick, P K |
| Keywords: | Pyrocarbon coating
Zirconia particles
Chemical vapor deposition
Spouted bed reactor |
| Issue Date: | Oct-2010 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Pyrocarbon (PyC) coating is deposited on spherical
zirconia particles (size 480 μm, density 6300 kg/m3). The coating is
carried out at 1350 ±1°C in a spouted bed reactor (height 0.3 m, dia 0.06 m)
using acetylene and argon gas mixture. The PyC coating is uniformly deposited
by chemical vapor deposition (CVD) on the surface of the pebbles where the
precursor (acetylene) undergoes chemical bond dissociation. The spouted bed
reactor is characterized for its stable solid circulation which is responsible
to enhance heat and mass transfer. Therefore, it is expected that the
properties of the coated layer should be affected by critical parameters of the
bed during its high temperature operations. It was found that both the
thickness and density of PyC coated layer change with static height of the bed
as well as with the spouting gas velocity. With the increase in spouting gas
velocity the coating thickness decreased whereas, the density of the coated
material increased. On the other hand it is found that up to a critical static
bed height the coating rate increased beyond which it started decreasing and
the coating density remains almost unchanged up to that critical static bed
height and marginally decreased beyond this height. This paper discusses the
issues that affect spouted bed performance with respect to its stability during
PyC coating by CVD. |
| Page(s): | 349-352 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-1017 (Online); 0971-4588 (Print) |
| Source: | IJEMS Vol.17(5) [October 2010]
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