US 5,599,182 A · Adjustable thermal profile heated crucible method and apparatus

Abstract

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.

Claims24

Dependent claims

An adjustable thermal profile continuous material heating apparatus comprising:

a combustion chamber having separate primary combustible reactant component inlets including a fuel inlet and an oxidant inlet for feeding fuel and oxidant combustible reactant components to said combustion chamber with a non-stoichiometric mix of components, said combustion chamber also having a plurality of secondary component inlets located downstream from said primary combustible reactant inlets and spaced in a predetermined spaced relationship to each other for feeding a component of said combustible reactants to said combustion chamber to form a generally stoichiometric combustion in said combustion chamber and to provide a thermal profile for controlling the temperature across said combustion chamber;
a combustion chamber outlet for the exhausting of heat from said combustion chamber;
and
a crucible located in said combustion chamber and extending generally therethrough and being surrounded by said combustion chamber and having an inlet thereinto and an outlet therefrom for passing materials to be heated therethrough, whereby said crucible can have a profiled temperature along its length for providing a controlled heating of materials passing through said crucible.

1 more element

An adjustable thermal profile continuous material heating method comprising the steps:

selecting a crucible heated by a combustion chamber, said combustion chamber having a primary fuel and a primary oxidant inlet for feeding fuel and oxidant combustible reactant components to the combustion chamber, said combustion chamber also having a plurality of secondary component reactant inlets spaced from said primary fuel and oxidant inlets and in a predetermined spaced relationship to each other and said crucible having an inlet thereinto and an outlet therefrom;
injecting fuel and oxidant into said combustion chamber through said primary fuel and oxidant inlets in, a predetermined ratio of fuel and oxidant to form a non-stoichiometric combustion reaction;
igniting said injected primary fuel and oxidant combustible reactants in said combustion chamber;
and
injecting predetermined amounts of one component of said combustible reactants into each of said plurality of secondary component reactant inlets with a combined volume from all of the plurality of spaced secondary reactant component inlets to form a resultant generally stoichiometric combustion to control the temperature in the combustion chamber over an extended area, whereby a thermal combustion profile can be adjusted over a wide range to control the heating of said crucible;
feeding a material into said crucible inlet for continuous heating of said material as it passes through said crucible;
and
feeding said heated material from said crucible outlet, whereby said crucible can have a profiled temperature along its length for providing a controlled heating of materials passing through said crucible.

5 more elements

Dependencies are inferred from the claim text.

Adjustable thermal profile heated crucible method and apparatus

Life of this patent

Adjustable thermal profile heated crucible method and apparatus

Life of this patent

Abstract

Claims24