Adjustable thermal profile heated crucible method and apparatus

摘要

A heated crucible apparatus allows the adjustment of a thermal profile within a combustion chamber surrounding the crucible by introducing a sub-stoichiometric or a super-stoichiometric mixture of fuel and oxidant into the combustion chamber and varying the oxidant flow for sub-stoichiometric or fuel flow for super-stoichiometric downstream of the initial combustion to control the release of heat in defined areas within the combustion chamber. The adjustable thermal control system allows for an even thermal energy release or varying thermal energy release over the length of the crucible. The apparatus a crucible having an inlet and and outlet surrounded by the combustion chamber which chamber includes an oxidant and fuel supply at the primary injection point followed by secondary injection of the remaining oxidant supply for sub-stoichiometric (or fuel supply for super-stoichiometric) at specific intervals to achieve the desired thermal profile and heating of the crucible. The oxidant and/or fuel stream may be pre-heated to maximize thermal efficiency. The combustion system allows for the use of gaseous, liquid and solid fuels as well as oxidant streams with varying concentrations of oxygen. The crucible has a cooling heat exchanger located adjacent the outlet to control the temperature of materials leaving the crucible.