3) Particle growth by condensation. When a suspended spherical particle of radius R passes through an environment where

[answerhappygod]

3 Particle Growth By Condensation When A Suspended Spherical Particle Of Radius R Passes Through An Environment Where 1 (115.16 KiB) Viewed 73 times

3) Particle growth by condensation. When a suspended spherical particle of radius R passes through an environment where a condensable vapor is present, the vapor deposits on the particle by diffusion, as depicted below. AC Vapor diffusion R 0 Particle a. Develop a shell balance in the exterior region of the particle and obtain the concentration profile for the vapor. Assume that all the vapor that reaches the particle deposits and forms a film, therefore at the particle radius, r = R, C = 0. Also assume that the amount of the vapor far away from the particle, Co, does not change much throughout the process. You should get8: R C=C₁ (1-²) r What is the second BC? b. Find the molar deposition rate to the particle. n = 4лRDC₁ c. Develop an expression for the thickness of the vapor deposit as a function of time. You will need to consider the molar volume, Vm, for molecules of the vapor species within the film: Vm = MW/p, where MW is molecular weight. 1/2 d = R₂²+ 2DC MW 2 P t – R₂ Ro is the initial particle radius. 6 The vapor is supersaturated, but not that supersaturated to cause homogeneous nucleation. 7 This means that there is a lot of vapor, and the amount that condenses on the particle is only a minor fraction of the total.