Silica particle deposition in superheated steam in an annular flow: Computational modeling and experimental investigation

The work presents computational modeling and an experimental investigation of silica deposition occurring in geothermal systems with superheated steam flows. An advection diffusion model was implemented for predicting silica particle transport and deposition in turbulent flows. The model includes the effect of Brownian diffusion, turbulent diffusion, turbophoresis, Saffman lift force, and drag force on particle motion. Simulation results for deposition of silica particles in superheated steam flow were validated experimentally. An experimental setup consisting of a superheated steam generating system, silica injection system and test section assembly was designed and constructed. Deposition velocity was measured for silica fume particles ranging from 1 to 20 mu m in diameter. The measured data shows agreement with the implemented model simulation results showing an increase in deposition velocity with increase in particle relaxation time in diffusion impaction regime.