Method of Cleaning Turbine Blades

Patent metadata

Field	Value
Publication number	US-2016101446-A1
Application number	US-201414511749-A
Country	US
Kind code	A1
Filing date	Oct 10, 2014
Priority date	Oct 10, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

In a process for cleaning contaminating silicon dioxide SiO 2 off of turbine blades, silicon dioxide that is on the turbine blades is reduced selectively in a vacuum process that takes place in dry conditions and at elevated temperature inside a high vacuum furnace, by feeding gas having a reducing action, consisting of hydrogen gas or carbon monoxide, is introduced into the high vacuum furnace. The temperature inside the high vacuum furnace is at least about 1000 degrees Celsius, and the residence time of the turbine blades in the high vacuum furnace is determined with reference to the diminishment of the SiO concentration, as analysed with a mass spectrometer. The electrically heatable high vacuum furnace is evacuable by means of a vacuum system that consists of a backing pump and a turbomolecular pump with an adjustable throttle valve and a water-cooled baffle. Further, the gas with reducing action is fed into the furnace via a precision high vacuum regulating valve, and it is equipped with a mass spectrometer.

First claim

1 . Process for cleaning contaminating silicon dioxide, SiO 2 , off of turbine blades, said process being carried out in a dry vacuum process that takes place at elevated temperature inside a high vacuum furnace, and in which at least some of the silicon dioxide on the turbine blades that are to be cleaned is removed by means of a gas with reducing action, characterised in that the silicon dioxide, SiO 2 , to be removed is reduced selectively to the silicon monoxide stage SiO by the gas with reductive action consisting of hydrogen gas H 2 or carbon monoxide CO, which contains a minimum quantity of H 2 O or CO 2 respectively, is then vaporised in a vacuum and pumped out in gas form, wherein the residence time of the turbine blades ( 2 ) in the high vacuum furnace ( 1 ) is selected until the time when the SiO concentration falls significantly.

2 . Process according to claim 1 , characterised in that the gas with reductive action consists of hydrogen gas, H 2 , which contains a minimum quantity of H 2 O with oxidising effect and is monitored for the maximum permitted concentration value of these reaction products by checking the gas flow rate by means of mass spectrometer analysis.

3 . Process according to claim 1 , characterised in that the gas with reductive action consists of carbon monoxide, CO, which contains a minimum quantity of CO 2 with oxidising effect and is monitored for the maximum permitted concentration value of these reaction products by checking the gas flow rate by means of mass spectrometer analysis.

4 . Process according to claim 1 , characterised in that the temperature in the high vacuum furnace ( 1 ) is at least 1000 degrees Celsius.

5 . Process according to claim 1 , characterised in that the residence time of the turbine blades ( 2 ) in the high vacuum furnace ( 1 ) is selected at least until the time when the SiO concentration ( 44 ) falls significantly (mass spectrometer).

6 . Device for performing the process according to claim 1 , characterised by a high vacuum furnace ( 1 ), in which the turbine blades ( 2 ) to be cleaned may be placed, and which is evacuable via a vacuum system ( 3 - 6 ), and into which the gas with reducing action can be introduced via a gas inlet system ( 7 ).

7 . Device according to claim 6 , characterised in that the vacuum system consists of a backing pump ( 3 ) and a turbomolecular pump ( 4 ) with an adjustable throttle valve ( 5 ) and a water-cooled baffle ( 6 ).

8 . Device according to claim 6 , characterised in that the gas inlet system consists of a precision high vacuum regulating valve ( 7 ).

9 . Device according to claim 6 , characterised in that the high vacuum furnace ( 1 ) is equipped with a mass spectrometer ( 8 ).

10 . Device according to claim 6 , characterised in that the high vacuum furnace ( 1 ) can be heated electrically.

Assignees

• Airbus Ds Gmbh

Inventors

• Schwarting Walter

Classifications

• B23P6/002

  Repairing turbine components, e.g. moving or stationary blades, rotors, (B23P6/045 takes precedence) · CPC title

• C23G5/00 Primary

  Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents · CPC title

• F01D5/005

  Repairing methods or devices · CPC title

• B08B7/04 Primary

  by a combination of operations · CPC title

• B08B7/0071

  by heating (B08B7/0035 takes precedence) · CPC title