The deposition of magnetite particles from suspension in water at nominally
90 degrees C onto Alloy-800 surfaces has been studied by chemical and radi
otracing techniques under various conditions of flow, chemistry and boiling
heat transfer. The experiments indicated that, under non-boiling condition
s, mechanisms based on diffusion and thermophoresis control deposition whil
e removal is negligible. For sub-cooled boiling at a low rate, the frapping
of particles by bubbles is important; at a high rate, deposition during mi
crolayer evaporation dominates. Removal occurs during sub-cooled boiling an
d is nicely described by a mathematical model in which it proceeds concomit
antly with deposition.