摘要：Peirce-Smith converters (PSC) are used to obtain almost 90% of the blister
copper. PSC are long cylindrical chemical reactors where copper matte reacts
with air. Traditionally, air is injected laterally through submerged tuyeres
at different subsonic velocities. There are several works on which the fluid
flow patterns inside the PSC are analyzed by means computational fluid dynamics
(CFD) tools. Also, several papers have studied the converter using physical
water based models. Numerous authors agree that the most important factors
are bath depth and tuyere submergence. Nevertheless, air injection at the
converter bottom has not been fully characterized. The aim of bottom injection
is to maximize the copper kinetic energy meanwhile avoiding excessive reactor
splashing. In this work, a PSC with bottom air injection is studied by means
of multiphase 3D CFD numerical simulations considering multiple air
velocities. A bubbling regime is displayed at low inlet velocity simulations.
As inlet velocity is increased, a transition to a jetting regime is obtained.
However, a new transition to the bubbling regime is observed when air is
increased again. The unexpected transition is explained in terms of bubble
geometry close to the tuyere exit and metalostatic pressure, which directly
depends on the copper matte height. An almost linear relationship between
copper matte kinetic energy and inlet air velocity is observed. However, the
lowest mixing efficiency is obtained at a medium inlet air velocity.
