De-coating / coating within a housing and process

Abstract

The invention relates to a device (1) for coating / decoating a ceramic layer system (7) of a mixing housing (1) comprising an inner (5) and an outer housing (6), between which (5,6) a gap (2) is present, wherein the device (1) comprises at least: a rotary table (14) for holding the mixing housing (1), a robot (17) with robot arms that can direct a nozzle into the gap (2) of the mixing housing (1).

Description

[0001] The invention relates to a device and a method for stripping and coating at least one layer within a housing.

[0002] A gas turbine plant essentially comprises one or more combustion chambers with burners in which a fuel is burned, a turbine to which the hot and pressurised combustion exhaust gases from the combustion chambers are fed and in which the exhaust gases perform work by cooling and expanding, thus setting the turbine in rotation, and a compressor which is coupled to the turbine via a shaft surrounded by a hub and via which the air required for combustion is sucked in and compressed to a higher pressure.

[0003] Hot-gas-conducting components such as mixing casings and inner casings are used in gas turbine systems to guide the hot combustion exhaust gases. This is particularly true for gas turbine systems that use so-called silo combustion chambers, which are usually arranged on both sides of the turbine. One such combustion chamber is disclosed in EP 2 159 380 A1.

[0004] The inner housing is often provided with a coating which may need to be replaced during servicing. For this purpose the entire mixing housing is disassembled, which is very time-consuming.

[0005] It is therefore an object of the invention to solve the above-mentioned problem.

[0006] The object is achieved by a device according to claim 1 and a method according to claim 3.

[0007] The subclaims list further advantageous measures which can be combined with one another as desired to achieve further advantages.

[0008] It shows Fig. 1, Fig. 2 a mixing housing, Fig. 3 a device according to the invention.

[0009] The description and the figures represent only embodiments of the invention.

[0010] In Fig. 1 shows an exemplary mixing housing 1 with an inner housing 5, which preferably has two funnel-shaped supply lines 4 on the right and left and opposite one another.

[0011] An annular gap 2 is present between the inner housing 5 and an outer housing 6 of the mixing housing 1. The inner housing 5 is, in particular, cylindrical in shape.

[0012] The inner housing 5 is in Fig. 2 is shown in more detail in one direction through a funnel-shaped supply line 4. The inner housing 5 is provided with at least one layer, in particular a ceramic layer system 7 on the lateral surface of its outer surface, which preferably has a metallic bonding layer (MCrAlY, PtAl, etc.) and / or a ceramic layer, preferably zirconium oxide. This ceramic layer system 7 must be renewed for a renewed, longer service life. However, for this purpose, it must first be removed. This currently involves completely disassembling the mixing housing 1 into its housing parts 4, 5, 6 and components.

[0013] To avoid this, a device 11 according to the invention is provided according to Fig. 3 suggested.

[0014] The device 11 comprises at least: • a turntable 14 on which the mixing housing 1 can be arranged or fixed and can be or is rotated: Here, the advantage is exploited that the inner housing 5 is rotationally symmetrical, in particular cylindrical, since a central axis of the inner housing 5 corresponds to the axis of rotation 23 of the turntable 14, • a robot 17 or at least its robot arm is or will preferably be arranged above the mixing housing 1 so that there are no conflicts with the funnel-shaped supply lines 4 during rotation.

[0015] By means of the robot 17, which can guide a water or laser beam, the layer or the ceramic layer system 7 is removed from the outer surface of the inner housing 5. The robot 17 has corresponding arms and joints for this purpose.

[0016] This is done by the robot 17 using its robot arm to direct a water or laser beam from the outside through the gap 2 onto the inner housing 5 and the ceramic layer system 7, thereby removing the latter.

[0017] If necessary, the robot 17 also enters the gap 2. Other decoating processes, such as irradiation with abrasive particles, are also possible.

[0018] For the decoating, the robot 17 is selected accordingly in order to guide a nozzle for the water or laser beam 20, which is arranged on the robot arm, preferably parallel to the axis of rotation 23 and with simultaneous rotation of the turntable 14, the entire outer surface of the inner housing 5 is decoated.

[0019] After decoating, the inner housing 5 can also be coated again, preferably using the same robot 17 or a comparable robot. A robot arm of the robot 17 with its coating nozzle is preferably guided parallel to the rotation axis 23, and the entire outer surface of the inner housing 5 is coated while the turntable 14 rotates simultaneously.

[0020] During coating or decoating, only the rotary table 14 can rotate initially, and the position of the nozzle on the robot remains at one height until one complete rotation is completed. It is then moved up or down a certain distance to complete the coating or decoating for the next complete rotation. This allows the coating or decoating to occur in a ring-like manner.

[0021] Alternatively, the nozzle can first be moved parallel to the rotation axis along the entire length of the inner housing 5 before the rotary table then moves further in one direction at the specified angle. This allows the coating or decoating to occur linearly.

[0022] A similar process applies to the coating.

[0023] Other movement patterns are of course also possible.

[0024] The coating is preferably carried out using plasma spraying, HVOF, cold gas spraying or similar.

[0025] This enables a defined local decoating within the mixing housing 1 without having to disassemble the mixing housing 1, thus saving time and costs. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 159 380 A1

[0003]

Claims

[1] Device (1) for decoating or coating a ceramic layer system (7) of a mixing housing (1) consisting of inner (5) and outer housing (6), between which (5,6) there is a gap (2), wherein the device (1) comprises at least: a turntable (14) for holding the mixing housing (1), a robot (17) with robot arms, which can direct a nozzle on the robot (17) in the gap (2) for decoating or coating a ceramic layer system (7) of the inner housing (5). [2] Device according to claim 1, wherein the robot (17) or at least its robot arm is arranged above the mixing housing (1). [3] Procedure for decoating or coating a ceramic layer system (7) of a mixing housing (1) consisting of an inner (5) and outer housing (6), between which (5,6) there is a gap (2), in which the mixing housing (1) is arranged on a turntable (14), and a robot (17) guides a jet (20) of a nozzle through the gap (2), that the outer surface of the inner housing (5) is completely covered, wherein the turntable (14) rotates the mixing housing (1). [4] Method according to claim 3, wherein the decoating is carried out by means of a water or laser beam. [5] Method according to claim 3, wherein the coating is carried out by means of plasma spraying, HVOF, cold gas spraying. [6] Method according to claim 3, 4 or 5, wherein the nozzle for the jet (20) is moved up and down parallel to the axis of rotation (23) of the turntable with stepwise rotation of the turntable (14). [7] Method according to claim 3, 4 or 5, wherein the turntable (14) is rotated while the nozzle for the jet (20) first remains at one height and is then gradually displaced parallel to the axis of rotation (23) of the turntable (14).

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