One of the main problems that affects Ruhrstahl-Heraeus (RH) degasser circulation rate is the
obstruction of the gas-injection nozzles. This study aims to elucidate the effects of obstructions
in quantity and location using a physical model that depicts 16 injection nozzles on the up-leg
distributed symmetrically in 2 rings (8 nozzles/ring). We simulated six, symmetric and
nonsymmetric, obstruction conditions to gas flow. The gas-flow rate was varied from 30 to 130
NL/min. The results for symmetric obstructions when the gas-flow rate is kept constant,
indicates that the circulation rate in the equipment does not significantly change. However,
when these obstructions are non-symmetric, the circulation rate varies drastically, even when the
gas-flow rate is kept constant. The analysis of the experimental data generated from this study
allowed to determine an equation for the circulation rate that takes into consideration the
number and distribution of blocked nozzles