1. A method comprising:
removing a gas turbine hot gas path component from service;
removing a damaged portion of the component to reveal a repair surface;
covering the repair surface with a powder comprising a superalloy material and a flux material;
applying an energy beam to the powder to melt selected portions of the powder to form a patterned first layer of superalloy material joined to the repair surface and covered by a layer of slag;
removing the layer of slag from the first layer of superalloy material;
covering at least the first layer of superalloy material with an additional amount of the powder;
applying the energy beam to the additional amount of the powder to form a second layer of superalloy material joined to the first layer and covered by a further layer of slag,
removing the further layer of slag;
repeating the covering, applying and removing steps until the layers of superalloy material form a new portion of the component to replace the damaged portion; and
returning the component to service
2. The method of claim 1, wherein the component is a gas turbine vane and the damaged portion is a honeycomb seal.
3. The method of claim 1, wherein the component is a gas turbine blade and the damaged portion is a blade tip seal.
4. The method of claim 1, wherein the step of removing a damaged portion of the component comprises removing a portion of a superalloy seal member and an underlying braze layer to reveal the repair surface as a superalloy substrate of the component; and
forming the new portion as a new superalloy seal member deposited directly onto the superalloy substrate without an intervening braze layer.
5. A gas turbine engine component formed by the method of claim 4
6. A method comprising:
premoving a damaged portion of a seal of a gas turbine engine component;
forming a new portion of the seal in place of the damaged portion by:
selectively heating respective regions of successive layers of powder comprising superalloy material and flux material to form respective layers of deposited superalloy material covered by slag; and
removing the slag from each layer before heating the next successive layer.
7. The method of claim 6, wherein the powder comprises mixed superalloy particles and flux particles
8. The method of claim 7, wherein a mesh size range of the alloy particles and a mesh size range of the flux particles overlap
9. The method of claim 6, wherein the powder comprises composite particles of the superalloy material and the flux material
10. The method of claim 6, wherein the damaged portion of the seal is joined to the component by a braze prior to being removed, and the new portion of the seal is joined to the component without any intervening braze material
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An internal combustion engine, comprising:
a carburetor having an intake air passage, and a fuel chamber in fluid communication with said passage, said chamber containing a volume of liquid fuel and an air space;
a fuel tank in fluid communication with said fuel chamber, said fuel tank containing a volume of liquid fuel and an air space; and
a fuel vapor control device including a housing containing fuel vapor absorbent media and having a substantially elongate profile along an axis, said housing defining first and second ends and a central portion therebetween, said carburetor passage in fluid communication with one of said first and second ends and the other of said first and second ends in fluid communication with the atmosphere, at least one of said carburetor air space and said fuel tank air space in fluid communication with said central portion of said housing at a location on said housing disposed axially in between said first and second ends;
whereby fuel vapors collect within said fuel vapor absorbent media initially within said central portion of said housing and thereafter outwardly toward said first and second ends, and passage of air through said carburetor passage induces a flow of air from the atmosphere axially through said housing to said carburetor passage to purge fuel vapors from said housing.
2. The internal combustion engine of claim 1, wherein said fuel vapor absorbent media is charcoal media.
3. The internal combustion engine of claim 1, wherein said housing includes a length between said first and second ends and a width, said length at least twice said width.
4. The internal combustion engine of claim 1, wherein said housing is in fluid communication with said carburetor air space and with said fuel tank air space.
5. The internal combustion engine of claim 1, further comprising an air cleaner in airflow communication with said carburetor passage, said housing integrally formed with said air cleaner.
6. The internal combustion engine of claim 1, wherein said fuel tank includes a body, said housing integrally formed with said fuel tank body.
7. An internal combustion engine operable at low and high speeds, comprising:
a carburetor, comprising:
a passage through which engine intake air is drawn, said passage having an inlet and an outlet;
a throttle valve disposed within said passage, said throttle valve movable between a substantially closed position corresponding to low engine speeds and a substantially open position corresponding to high engine speeds; and
a fuel chamber in fluid communication with said passage, said fuel chamber containing a volume of liquid fuel and an air space;
a fuel tank in fluid communication with said fuel chamber, said fuel tank containing a volume of liquid fuel and an air space; and
a fuel vapor control device including a housing containing fuel vapor absorbent media, said housing in fluid communication with at least one of said carburetor air space and said fuel tank air space, and in fluid communication with said carburetor passage at a first location proximate said throttle valve and at a second location proximate said inlet;
whereby fuel vapors collect within said fuel vapor absorbent media of said housing, and at low engine speeds, airflow through said carburetor passage with substantial closure of said throttle valve induces purging of fuel vapors from said housing in a direction from said second location to said first location, and at high engine speeds, airflow through said carburetor passage with substantial opening of said throttle valve induces purging of fuel vapors from said housing in a direction from said first location to said second location.
8. The internal combustion engine of claim 7, wherein said fuel vapor absorbent media is charcoal media.
9. The internal combustion engine of claim 7, wherein said housing is in fluid communication with said carburetor air space and with said fuel tank air space.
10. The internal combustion engine of claim 7, further comprising an air cleaner in airflow communication with said carburetor passage, said housing integrally formed with said air cleaner.
11. The internal combustion engine of claim 7, wherein said fuel tank includes a body, said housing integrally formed with said fuel tank body.
12. The internal combustion engine of claim 7, wherein said housing is elongate and includes first and second ends, said first end in fluid communication with said carburetor at said first location and said second end in fluid communication with said carburetor at said second location.
13. The internal combustion engine of claim 12, wherein said housing includes a length between said first and second ends and a width, said length at least twice said width.
14. The internal combustion engine of claim 12, wherein said housing includes a central portion between said first and second ends, said central portion in fluid communication with at least one of said carburetor air space and said fuel tank air space.
15. An internal combustion engine, comprising:
a carburetor having an intake air passage, and a fuel chamber in fluid communication with said passage, said chamber containing a volume of liquid fuel and an air space;
a fuel tank in fluid communication with said fuel chamber, said fuel tank containing a volume of liquid fuel and an air space; and
a fuel tank cap attached to said fuel tank and containing fuel vapor absorbent media, said fuel tank cap in fluid communication with said carburetor passage, the atmosphere, and with said fuel tank air space and said carburetor air space;
whereby fuel vapors collect within said fuel vapor absorbent media, and passage of air through said carburetor passage induces a flow of air from the atmosphere through said fuel tank cap to said carburetor passage to purge fuel vapors from said fuel tank cap.
16. The internal combustion engine of claim 15, wherein said fuel vapor absorbent media is charcoal media.
17. The internal combustion engine of claim 15, wherein said fuel tank cap includes a check valve therein to allow one-way flow of air from the atmosphere into said fuel tank cap.
18. An internal combustion engine, comprising:
a carburetor having an intake air passage, and a fuel chamber in fluid communication with said passage, said chamber containing a volume of liquid fuel and an air space;
a fuel tank in fluid communication with said fuel chamber, said fuel tank containing a volume of liquid fuel and an air space; and
a fuel vapor control device including a housing containing fuel vapor absorbent media, said carburetor air space and said fuel tank air space in fluid communication with said housing, said carburetor passage in fluid communication with said housing and said housing further in fluid communication with the atmosphere; and
a gravity-responsive valve disposed between said fuel tank air space and said fuel vapor control device;
whereby fuel vapors collect within said fuel vapor absorbent media, and passage of air through said carburetor passage induces a flow of air from the atmosphere through said housing to said carburetor passage to purge fuel vapors from said housing.
19. The internal combustion engine of claim 18, wherein said gravity-responsive valve includes a valve body, said valve normally open when said valve body is disposed in a substantially vertical position, said valve closing when said valve body is rotated toward a substantially horizontal position.
20. An internal combustion engine, comprising:
a fuel tank including a filler neck, said fuel tank containing a volume of liquid fuel and an air space; and
a fuel tank cap attached to said filler neck of said fuel tank and containing fuel vapor absorbent media, said fuel tank cap in fluid communication with said fuel tank and with the atmosphere, a portion of said fuel tank cap projecting into said filler neck and including liquid fuel blocking structure;
whereby fuel vapors collect within said fuel vapor absorbent media and liquid fuel from said fuel tank is blocked from contacting said fuel vapor absorbent media by said liquid fuel blocking structure.
21. The internal combustion engine of claim 20, wherein said liquid fuel blocking structure of said fuel tank cap portion includes an anti-rollover valve.