Cleaning of internal passages of airfoils
AssigneeHowmet Research Corporation
InventorsJohn E. Schilbe, Rebecca J. Boczkaja, Bruce M. Warnes
Life of this patent
Estimating the term…
Abstract
A chemical cleaning method for cleaning an internal passage of an engine-run gas turbine engine airfoil wherein the airfoil is immersed in an inorganic hydroxide medium at superambient temperature and atmospheric pressure for a short time to remove accumulated oxides and dirt from the internal passage. The hydroxide medium can comprise molten KOH and immersion times of the engine-run airfoil not exceeding 10 minutes are involved.
Claims13
A method of cleaning an internal passage of a gas turbine engine-run airfoil, comprising the steps of:
- a) providing a gas turbine engine-run airfoil that has been used in a gas turbine engine such that foreign material is present in an internal passage of said airfoil,
- b) providing a vessel open to ambient atmospheric pressure and containing a liquid, said liquid comprising at least 50%. by weight of a hydroxide selected from the group consisting of an alkali hydroxide and an alkaline earth hydroxide and the balance water, and
- c) cleaning said airfoil in said vessel open to said ambient atmospheric pressure by immersing said airfoil in said liquid for a period of time to remove foreign material from the internal passage of said airfoil, wherein said liquid is at said ambient atmospheric pressure and at a temperature of about 275 degrees F. and above during said cleaning step.
A method of cleaning an internal passage of a gas turbine engine-run airfoil, comprising the steps of:
- a) providing a gas turbine engine-run airfoil that has been used in a gas turbine engine such that foreign material is present in an internal passage of said airfoil,
- b) providing a vessel open to ambient atmospheric pressure and containing a molten hydroxide, said molten hydroxide comprising 80 weight % or greater of a hydroxide selected from the group consisting of an alkali hydroxide and an alkaline earth hydroxide and the balance water, and
- c) cleaning said airfoil in said vessel open to said ambient atmospheric pressure by immersing said airfoil in said molten hydroxide for a period of time to remove foreign material from the internal passage of said airfoil, wherein said molten hydroxide is at said ambient atmospheric pressure and at a temperature of about 400 degrees F. and above during said cleaning step.
Dependencies are inferred from the claim text.