JP2010077831A - Formation method for fire-retardant coating in parts for oxygen compressor, and oxygen compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a formation method for fire-retardant coating in parts for oxygen compressor and oxygen compressor, capable of significantly improving the yield of fire-retardant metals, and capable of readily forming coatings even a component with a small bore or complicated shape. <P>SOLUTION: A formation method for fire-retardant coatings includes forming coatings 21, 22 made up of fire-retardant metals by electroplating on locations (inner peripheral surface of an inlet member 5 and inner peripheral surface of a shaft seal ring 17) where there is a possibility that a rotor (impellers 7 and a rotating shaft 11), and stationary parts (the inlet member 5 and the shaft seal ring 17) surrounding the rotor come into contact with each other. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for forming a flame retardant coating on a component of an oxygen compressor that compresses oxygen gas and an oxygen compressor.

  In an air separation plant and other various plants, an oxygen compressor may be used when oxygen is supplied to a required location.

  When a centrifugal compressor (turbo compressor) is used as such an oxygen compressor, there is a possibility that the rotor and the stationary part come into contact with each other in the presence of high-concentration oxygen due to the shake of the rotational axis of the rotor. For example, there is contact in the impeller and an inlet member surrounding the impeller, and contact in a shaft seal portion provided in a portion of the compressor casing through which the impeller rotational drive shaft passes.

  When wear powder is generated by the friction between the rotor and the stationary part, the wear powder burns in the presence of a high concentration of oxygen, and ignition may occur. For this reason, in conventional oxygen compressors, the rotor and stationary parts are in contact with each other in the presence of high-concentration oxygen by forming a film of silver, which is a flame-retardant metal, on the inner surface of the inlet member and the shaft seal. Thus, even if they rub against each other, the occurrence of ignition can be prevented in advance (see, for example, Patent Documents 1 and 2 below).

Japanese Patent No. 3939814 JP 2007-154750 A

  Conventionally, as a method of forming a silver film on the inner surface of the inlet member or the shaft seal portion, a method of forming a silver film by thermal spraying or a method of brazing a silver plate to a base material has been adopted. However, in the formation of a coating by thermal spraying, if the inner diameter of the portion where the coating is formed is small, the spraying angle becomes smaller, resulting in poor adhesion, and there is a large amount of silver scattered outside the portion where the coating is formed. There is a problem that the yield is very bad. Further, in the formation of a film by brazing, there is a problem that it is difficult or impossible to form a film on a portion having a complicated shape.

  The present invention has been made in view of the above problems, and in forming a flame retardant metal film on a portion where a rotor and a stationary part may come into contact, the yield of the flame retardant metal is increased. To provide a method for forming a flame-retardant coating and an oxygen compressor in an oxygen compressor component that can be significantly improved and can easily form a coating even with a small-diameter component or a component having a complicated shape. Is an issue.

In order to solve the above problems, the following technical means is adopted for the method for forming a flame-retardant coating and the oxygen compressor in the oxygen compressor component of the present invention.
(1) The present invention is a method of forming a flame retardant coating on a part of an oxygen compressor that compresses oxygen gas by rotating a rotor including an impeller in a compressor casing, the rotor, A film made of a flame-retardant metal is formed by electroplating at a location where there is a possibility of contact with a stationary part surrounding the rotor.

(2) Moreover, in said method, the location which forms the said film is a part located in the outer periphery of the said impeller in the inlet member surrounding the said impeller.

(3) Moreover, in said method, the location which forms the said film is an internal peripheral surface of the shaft seal ring provided in the part through which the rotational drive shaft of an impeller penetrates a compressor casing.

(4) Further, according to the present invention, in the oxygen compressor that compresses oxygen gas by rotating the rotor including the impeller in the compressor casing, the rotor and a stationary part surrounding the rotor may come into contact with each other. A film made of a flame-retardant metal formed by electroplating is provided at a certain location.

  According to the present invention, since the flame-retardant metal film is formed by electroplating in a place where the rotor and the stationary part may come into contact with each other, the inner diameter of the part where the film is formed is small or the shape is complicated. Even in this case, the flame retardant metal film can be easily formed at a desired location. Further, by masking a portion that does not require film formation in electroplating, a film can be formed only in a portion where the film is desired to be formed, so that the yield of flame-retardant metal can be greatly improved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a configuration diagram of an oxygen compressor 1 according to an embodiment of the present invention. In FIG. 1, the oxygen compressor 1 includes a rotor (rotary shaft 11 and impeller 7) that is rotationally driven, and a compressor casing 3 that surrounds the rotary shaft 11 and the impeller 7.

  The rotating shaft 11 is rotatably supported by a bearing 12 supported and fixed to a bearing support portion 13. An impeller 7 composed of a hub 8 and a blade 9 is integrally connected to the tip of the rotating shaft 11, and the impeller 7 is rotated when the rotating shaft 11 is rotationally driven by a driving device (not shown). The rotating shaft 11 and the impeller 7 may be integrally formed, or may be manufactured as separate parts and then connected and fixed by appropriate connecting means.

  The compressor casing 3 includes a casing member 4 and an inlet member 5. A central opening of the casing member 4 has a circular opening (not indicated) for disposing a shaft seal ring 17 to be described later, and the rotary shaft 11 passes through the circular opening. The casing member 4 is provided with an annular scroll chamber 6 formed so as to surround the impeller 7.

The inlet member 5 is a member that forms an inlet passage for introducing oxygen gas to be compressed, and is fixed to the casing member 4 by fixing means such as bolts.
In the above configuration, when the impeller 7 is rotationally driven, oxygen gas is sucked through the inlet member 5 and is depressurized and pressurized in the process of being sent radially outward by the impeller 7 and then introduced into the annular scroll chamber 6. The gas is discharged from a discharge port (not shown).

  In order to prevent the compressed gas from leaking outside through the back side of the impeller 7, a shaft seal portion 14 that suppresses the axial gas flow between the rotating shaft 11 and the stationary portion surrounding the rotary shaft 11 is provided. It has been. The shaft seal portion 14 includes a shaft seal ring 17 and a plurality of labyrinth groups 15.

  The shaft seal ring 17 has a ring shape and is supported inside the circular opening of the casing member 4. The plurality of labyrinth groups 15 are supported on the outer peripheral portion of the rotating shaft 11 facing the shaft seal ring 17 at intervals in the axial direction. Each labyrinth group 15 is an aggregate of a plurality of fins.

  In the inner peripheral portion of the shaft seal ring 17, annular seal chambers 18 are formed between the labyrinth groups 15 at intervals in the axial direction. The shaft seal ring 17 is formed with a passage 19 that communicates the outer peripheral portion of each seal chamber 18 with the outer peripheral surface of the shaft seal ring 17. A plurality of drill holes (not shown) extending in the radial direction are formed in the casing member 4 so as to communicate with the plurality of passages 19. The compressed gas is sealed by blowing a seal gas through this hole, collecting leaked gas, or purging.

  In the oxygen compressor 1 configured as described above, in the presence of high-concentration oxygen due to the shaft center of the rotor (the impeller 7 and the rotating shaft 11) or the like, the rotor may come into contact with stationary parts surrounding it. There is. That is, in the oxygen compressor 1 of FIG. 1, the outer periphery of the impeller 7 is in contact with the inner peripheral surface of the inlet member 5, or the outer peripheral surface of the rotary shaft 11 (specifically, the labyrinth group 15) is within the shaft seal ring 17. There is a possibility of touching the peripheral surface.

  In order to prevent ignition caused by the friction between the rotor and stationary parts, the flame retardant metal formed by electroplating may be used in places where the rotor and stationary parts may come into contact. Coatings 21 and 22 are provided. In the configuration example of FIG. 1, a coating 21 made of a flame-retardant metal formed by electroplating is provided on a portion of the inlet member 5 that surrounds the impeller 7 and located on the outer periphery of the impeller 7. A coating 22 made of a flame-retardant metal formed by electroplating is provided on the inner peripheral surface of the shaft seal ring 17.

  Examples of the flame retardant metal include noble metals such as silver and gold, and alloys thereof. The coatings 21 and 22 made of such a flame-retardant metal are preferably formed to have a thickness of millimeter units, and preferably to have a thickness of about 1.5 mm to 3.0 mm. That is, it is preferable to perform thick plating. In this case, if the coatings 21 and 22 are formed so as to have a thickness of 2 mm or more, the impeller 7 and the rotating shaft 11 (specifically, the labyrinth group 15) may be moved by the vibration of the shaft center. 9 and the labyrinth group 15 bite into the coatings 21 and 22, it is possible to prevent a situation in which the blade 9 of the impeller 7 and the labyrinth group 15 reach the base material of the inlet member 5 and the shaft seal ring 17. .

  FIG. 2 is a view for explaining a method of forming a coating 21 made of a flame-retardant metal on the inlet member 5. In FIG. 2, a plating solution 25 in which a metal to be plated (a flame retardant metal) is dissolved with a chemical is placed in a plating tank 24. In the plating solution 25, the inlet member 5 and the electrode 26a are immersed. The inlet member 5 and the electrode are each supported by a jig (not shown).

  The electrode 26 a has a shape that follows the shape of the portion of the inlet member 5 where the coating 21 is to be formed, and is disposed in a state of facing the inner peripheral surface of the inlet member 5. In FIG. 2, the electrode 26a has a single ring shape as a whole, but a plurality of electrode plates may be arranged in a ring shape. Alternatively, the electrode 26 a may be a single rod-shaped electrode, and this may be inserted into the central portion of the inlet member 5.

  The inlet member 5 is connected to the positive electrode of the plating power source 27, and the electrode 26 a is connected to the negative electrode of the plating power source 27. In the inlet member 5, masking is applied to a portion that does not require the formation of a film.

  In such a state, by using the inlet member 5 as a cathode and the electrode 26a as an anode and energizing between them, the flame-retardant metal in the plating solution 25 is deposited on the inner peripheral surface of the inlet member 5, thereby A coating 21 made of a flame retardant metal is formed. Thus, after a film having a required thickness is formed, post-processing such as cleaning and final polishing is performed.

  FIG. 3 is a view for explaining a method of forming the coating 22 made of a flame-retardant metal on the shaft seal ring 17. In FIG. 3, the plating tank 24, the plating solution 25, and the plating power source 27 are the same as those shown in FIG. In the plating solution 25, the shaft seal ring 17 and the electrode 26b are immersed. The shaft seal ring 17 and the electrode 26b are supported by jigs (not shown).

  The electrode 26 b is a hollow cylindrical shape following the shape of the inner peripheral surface of the shaft seal ring 17, and is disposed in a state facing the inner peripheral surface of the shaft seal ring 17. In FIG. 3, the electrode 26b has a single hollow cylindrical shape as a whole, but a plurality of electrode plates may be arranged in a cylindrical shape. Alternatively, the electrode 26 b may be a single rod-shaped electrode, and this may be inserted into the central portion of the shaft seal ring 17.

  The shaft seal ring 17 is connected to the positive electrode of the plating power source 27, and the electrode 26 b is connected to the negative electrode of the plating power source 27. In the shaft seal ring 17, masking is applied to a portion that does not require the formation of a film.

  In such a state, the shaft seal ring 17 is used as a cathode and the electrode 26b is used as an anode. By energizing the two, a flame-retardant metal in the plating solution 25 is deposited on the inner peripheral surface of the shaft seal ring 17, Thereby, the film 22 made of a flame-retardant metal is formed. Thus, after a film having a required thickness is formed, post-processing such as cleaning and final polishing is performed.

  When the coating 22 is formed on the inner peripheral surface of the shaft seal ring 17, the shaft seal ring 17 in a state in which a groove serving as the seal chamber 18 is formed is prepared, and the required portions are masked and difficult to perform by the above-described electroplating. The flammable metal coating 22 may be formed, but in this case, the corners and irregularities of the grooves may adversely affect the formation of the coating. Therefore, as shown in FIG. 3, it is preferable to form the groove to be the seal chamber 18 after the coating 22 is formed on the inner peripheral surface of the shaft seal ring 17 before the groove to be the seal chamber 18 is formed.

  According to the present invention described above, the coatings 21 and 22 made of a flame-retardant metal are formed by electroplating at locations where the rotor and the stationary component may come into contact with each other. Even when the inner diameter of the inner peripheral surface of the inlet member 5 or the shaft seal ring 17 is small or the shape is complicated, the flame-retardant metal film can be easily formed at a desired location. Further, in electroplating, by masking a portion that does not require the formation of a coating, it is possible to form a coating only on a portion where the coating is desired to be formed, so that the yield of flame retardant metal can be greatly improved.

  In the above embodiment, the coating 21 made of a flame retardant metal is formed on the inner peripheral surface of the inlet member 5 that is a stationary component. However, the flame retardant metal is formed on the outer peripheral portion of the blade 9 of the impeller 7 that is a rotor. A film made of a flame retardant metal may be formed on both the inner peripheral surface of the inlet member 5 and the outer peripheral part of the blade 9.

  Further, in the above embodiment, the coating 22 made of a flame retardant metal is formed on the inner peripheral surface of the shaft seal ring 17 which is a stationary component. However, the outer periphery of the labyrinth group 15 disposed on the rotating shaft 11 side which is a rotor. A film made of a flame retardant metal may be formed on the part, or a film made of a flame retardant metal may be formed on both the inner peripheral surface of the shaft reeling 17 and the outer peripheral part of the labyrinth group 15.

  In the above embodiment, the shaft seal ring 17 is provided on the stationary side and the labyrinth group 15 is provided on the rotating side. However, the labyrinth group is provided on the stationary portion and the shaft sealing ring is provided on the rotating side. It is good. In this case, a coating made of a flame retardant metal may be formed on one or both of the inner peripheral portion of the labyrinth group and the outer peripheral surface of the shaft seal ring.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

It is a block diagram of the oxygen compressor which concerns on embodiment of this invention. It is a figure explaining the method of forming the film which consists of a flame-retardant metal in an inlet member. It is a figure explaining the method of forming the film which consists of a flame-retardant metal in a shaft seal ring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oxygen compressor 3 Compressor casing 4 Casing member 5 Inlet member 6 Scroll chamber 7 Impeller 8 Hub 9 Blade 11 Rotating shaft 12 Bearing 13 Bearing support portion 14 Shaft seal portion 15 Labyrinth group 17 Shaft seal ring 18 Seal chamber 19 Passage 21 22 Coating 24 made of flame-retardant metal Plating tank 25 Plating solution 26a, 26b Electrode 27 Plating power source

Claims (4)

A method of forming a flame retardant coating on an oxygen compressor component that compresses oxygen gas by rotating a rotor including an impeller in a compressor casing,
A flame retardant coating for an oxygen compressor component, characterized in that a coating made of a flame retardant metal is formed by electroplating at a location where the rotor and a stationary component surrounding the rotor may come into contact with each other. Forming method.   The method for forming a flame-retardant film in an oxygen compressor component according to claim 1, wherein the part where the film is formed is a part located on an outer periphery of the impeller in an inlet member surrounding the impeller.   The flame retardant coating for an oxygen compressor component according to claim 1 or 2, wherein the coating film is formed on an inner peripheral surface of a shaft seal ring provided at a portion where the rotary drive shaft of the impeller passes through the compressor casing. Forming method. In an oxygen compressor that compresses oxygen gas by rotating a rotor including an impeller in a compressor casing,
An oxygen compressor characterized in that a coating made of a flame-retardant metal formed by electroplating is provided at a location where the rotor and a stationary part surrounding the rotor may come into contact with each other.

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