Methods and systems for controlling temperature in a vessel
A system for preheating a pressure vessel includes a throat including an area of excess heat and a dome having an area of deficient heat. The throat includes a conduit extending from a pressure vessel opening to the pressure vessel interior. A plenum is defined between the throat and a seal within the dome. The throat extends from the dome toward a dome floor. The floor is substantially perpendicular to the throat. A conduit is coupled to the plenum and channels a flow of purge fluid into the plenum wherein heat from the throat is transferred to the flow of purge fluid and carried by the flow of purge fluid into the area of deficient heat via a gap defined between the seal and the floor such that the flow of purge fluid reduces temperature differential stresses within the pressure vessel and purges the area of deficient heat.
1. A system for preheating a vessel comprising:
a pressure vessel comprising a throat comprising an area of excess heat and a dome adjacent to said throat comprising an area of deficient heat, said throat defining a channel extending from a pressure vessel opening to the pressure vessel interior;
a plenum enclosed within said dome and defined between said throat and a seal circumscribing said throat, said throat extending from said dome proximate to said pressure vessel opening toward a floor of said dome, said floor erected substantially perpendicular to said throat; and
a conduit coupled to said plenum for channeling a flow of purge fluid from external to said pressure vessel into said plenum, wherein heat from the area of excess heat is transferred to the flow of purge fluid in said plenum and the heat is carried by the flow of purge fluid into the area of deficient heat via a gap defined between said seal and said floor such that the flow of purge fluid facilitates reducing temperature differential stresses within said dome and said pressure vessel, and purges the area of deficient heat.
2. A system in accordance with claim 1 wherein said throat comprises a flange configured to couple to a gasifier, said throat configured to channel products of partial oxidation into said pressure vessel.
3. A system in accordance with claim 1 wherein said throat comprises a refractory based lining.
4. A system in accordance with claim 1 wherein said seal comprises a skirt that circumscribes said throat.
5. A system in accordance with claim 1 further comprising a supplemental heat exchanger comprising a first flow path coupled in flow communication with said plenum, said supplemental heat exchanger configured to add supplemental heat to the flow of purge fluid.
6. A system in accordance with claim 5 further comprising a source of supplemental heat, wherein said supplemental heat exchanger further comprises a second flow path in thermal communication with said first flow path, said second flow path coupled in flow communication with said source of supplemental heat, said supplemental heat exchanger configured to add supplemental heat to the flow of purge fluid from said source of supplemental heat.
7. A system in accordance with claim 6 wherein said source of supplemental heat comprises a steam drum.
8. A system in accordance with claim 1 further comprising a control valve configured to modulate the flow of purge fluid through said conduit.
9. A system in accordance with claim 8 wherein said dome defines a first compartment of said pressure vessel, said floor separating said first compartment from a second compartment of said pressure vessel defined within a tube wall spaced radially inward from an outer shell of said pressure vessel.
10. A system in accordance with claim 1 wherein heat from the area of excess heat is transferred to the flow of purge fluid in said plenum and the heat is carried by the flow of purge fluid into the area of deficient heat such that the flow of purge fluid simultaneously purges the area of deficient heat.