EXPERIMENTAL-STUDY OF THE OUTSIDE VAPOR-DEPOSITION PROCESS

Outside vapor deposition has been studied experimentally, and the deposition process parameters have been examined. The system consisted of an industrial-type burner and a cylindrical bait rod. The following aspects of this process were studied: 1) the temperature profile of the bait rod surface, 2) the deposition efficiency measured in terms of the mass of deposited SiO2, and 3) the size distribution of the deposited particles. The maximum bait rod surface temperature was, as expected, at the stagnation point. The temperature on the surface dropped rapidly along the axis of the bait rod away from the stagnation point; this is expected to influence the thermophoretic deposition rate. The particle size distribution shows that the particle diameters are near 0.2-mu-m and above.