Abstract: A cleaning method for a combustor comprises positioning a spray portion of a nozzle through an igniter plug boss and spraying an acid solution inside the combustion chamber. The acid solution impinges the inner liner and the outer liner, dissolving contaminant deposits inside the effusion holes. The nozzle can have a second spray portion outside the combustion chamber to provide acid solution to the radially outward surface of the outer liner. After cleaning, distilled water is sprayed through the nozzle to remove the acid solution residue from the combustor. The used acid solution and distilled water can be collected, filtered and pumped through the nozzle to provide a recirculating cleaning/rinsing system.

Abstract: A cleaning method for a combustor comprises positioning a spray portion of a nozzle through an igniter plug boss and spraying an acid solution inside the combustion chamber. The acid solution impinges the inner liner and the outer liner, dissolving contaminant deposits inside the effusion holes. The nozzle can have a second spray portion outside the combustion chamber to provide acid solution to the radially outward surface of the outer liner. After cleaning, distilled water is sprayed through the nozzle to remove the acid solution residue from the combustor. The used acid solution and distilled water can be collected, filtered and pumped through the nozzle to provide a recirculating cleaning/rinsing system.

Abstract: The present application relates to a method of producing a metal article having an internal passage coated with a ceramic coating. The method comprises: preparing a core for defining the internal passage; applying the ceramic coating on the core; assembling the core with the ceramic coating applied thereon into a mold; casting metal into the mold at a pour temperature lower than the melting temperature of the ceramic coating; and removing the core. The ceramic coating may be applied by plasma spraying or slurry deposition.