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US 7,686,611 B2Granted
Flame straightening in a furnace
AssigneeAir Products and Chemicals, Inc.
InventorsMahendra Ladharam Joshi, Xianming Jimmy Li, William Robert Licht, Aleksandar Georgi Slavejkov, Stephen Paul DiMartino, Sr.
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method and furnace for generating straightened flames in a steam methane reformer or ethylene cracking furnace where fuel-staged burners are used. Fuel staging may be used for reducing NOx emissions. Criteria for generating straightened flames are provided. These criteria relate to oxidant conduit geometry and furnace geometry. Techniques for modifying the furnace and/or burners to achieve these criteria are also provided.
Claims20
A method for generating straightened flames in a furnace comprising:
- introducing an oxidant into a plurality of oxidant conduits, each of the plurality of oxidant conduits formed in a burner tile or burner block and having an outlet fluidly communicating with the furnace interior proximate a first interior end of the furnace, the first interior end of the furnace having a horizontally projected area, the plurality of oxidant conduit outlets defining a combined horizontally projected turbulent free-jet area at 30% of the average distance from the first interior end of the furnace to a second interior end of the furnace, the second interior end of the furnace opposite the first interior end of the furnace;
- introducing a fuel into a plurality of fuel conduits, each of the plurality of fuel conduits having an outlet fluidly communicating with the furnace interior proximate the first interior end of the furnace, the plurality of fuel conduits in spaced relation to the plurality of oxidant conduits;
- mixing the fuel and the oxidant in the furnace interior;
- reacting the fuel and the oxidant thereby forming a plurality of flame portions;
- transferring heat from the plurality of flame portions to a plurality of reaction chambers, said plurality of reaction chambers traversing from the first interior end of the furnace to the second interior end of the furnace, said plurality of reaction chambers having an end portion in spaced relation to the plurality of oxidant conduits and in spaced relation to the plurality of fuel conduits;
- and
- reducing the combined horizontally projected turbulent free-jet area at 30% of the average distance from the first interior end of the furnace to the second interior end of the furnace to between 10% and 105% of the horizontally projected area of the first interior end.
4 more elements
A furnace comprising:
- a first interior end having a horizontally projected area;
- a second interior end opposite the first interior end;
- a plurality of oxidant conduits proximate the first interior end, each of the plurality of oxidant conduits formed in a burner tile or burner block and having an outlet fluidly communicating with the furnace interior, said plurality of oxidant conduit outlets defining a combined horizontally projected turbulent free-jet area at 30% of the average distance from the first interior end to the second interior end;
- a plurality of fuel conduits proximate the first interior end, each of the plurality of fuel conduits having an outlet fluidly communicating with the furnace interior, said plurality of fuel conduits in spaced relation to the plurality of oxidant conduits;
- and
- a plurality of elongated reaction chambers traversing from the first interior end to the second interior end, having an end portion in spaced relation to the plurality of oxidant conduits and in spaced relation to the plurality of fuel conduits;
- wherein the combined horizontally projected turbulent free-jet area at 30% of the average distance from the first interior end to the second interior end is between 10% and 105% of the horizontally projected area of the first interior end.
4 more elements
A furnace comprising:
- a first interior end having a horizontally projected area and having an aspect ratio greater than 0.8;
- a second interior end opposite the first interior end;
- a plurality of oxidant conduits proximate the first interior end, each of the plurality of oxidant conduits formed in a burner tile or burner block and having an outlet fluidly communicating with the furnace interior, said plurality of oxidant conduit outlets defining a combined horizontally projected turbulent free-jet area at 30% of the average distance from the first interior end to the second interior end;
- a plurality of fuel conduits proximate the first interior end, each of the plurality of fuel conduits having an outlet fluidly communicating with the furnace interior, said plurality of fuel conduits in spaced relation to the plurality of oxidant conduits;
- and
- a plurality of elongated reaction chambers traversing from the first interior end to the second interior end, having an end portion in spaced relation to the plurality of oxidant conduits and in spaced relation to the plurality of fuel conduits;
- wherein the combined horizontally projected turbulent free-jet area at 30% of the average distance from the first interior end to the second interior end is between 90% and 104% of the horizontally projected area of the first interior end.
4 more elements
Dependencies are inferred from the claim text.