JP2016156341A - Fluid machine and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance corrosion resistance at a connection portion of a metal member included in a fluid machine and another member.SOLUTION: A centrifugal blower includes: a metal impeller casing 54 forming a space S1, and connected to a recirculation pipe 84; and an anticorrosion member 57a arranged between the impeller casing 54 and the recirculation pipe 84 in a state where the impeller casing 54 and the recirculation pipe 84 are connected, and connected to the impeller casing 54. In the centrifugal blower, an anticorrosion layer 58a is formed so as to cover an end part on the space S1 side of the connection part between impeller casing 54 and the anticorrosion member 57a.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fluid machine for transporting corrosive gas and a method for manufacturing the fluid machine.

In general, exhaust gas discharged from an internal combustion engine such as a marine diesel engine is a corrosive gas containing NOx, SOx and the like. By reacting NOx and SOx contained in the corrosive gas with water, an acidic substance that corrodes a metal member such as nitric acid or sulfuric acid is generated.
Therefore, in a fluid machine such as a blower that conveys a corrosive gas, a technique for coating a member constituting the fluid machine with a corrosion-resistant material is known in order to increase the corrosion resistance against an acidic substance (for example, Patent Documents). (See 1)
In Patent Document 1, a metal rotor blade surface of an axial fan for a flue gas desulfurization apparatus is coated with a resin layer.

Japanese Patent No. 3426863

  The technique described in Patent Document 1 is to coat an independent metal member incorporated in a fluid machine with a corrosion-resistant material. Therefore, each of the metal parts exposed to corrosive gas is coated with a corrosion-resistant material before the fluid machine is assembled, and then the coated metal parts are incorporated into the fluid machine, thereby preventing corrosion. It is possible to manufacture a fluid machine with improved performance.

  However, the connecting portion of the metal member connected to other members inside the fluid machine and the connecting portion of the metal member connected to other devices are subject to excessive load due to the tightening work when connecting. There is such a possibility. Therefore, even if a metal member to be connected is coated with a corrosion-resistant material in advance, the corrosion-resistant material may be peeled off from the metal member due to a tightening operation or the like when being connected.

On the other hand, the corrosion resistance of the metal member can be improved by coating the connecting portion between the metal member and another member with a corrosion-resistant material after the fluid machine is assembled.
However, when a relatively small fluid machine or the like has a connection portion that is difficult to be coated after assembly, the corrosion resistance of the metal member at the connection portion cannot be increased.

  This invention is made in view of such a situation, and provides the fluid machine which improved the corrosion resistance in the connection part of the metal member with which a fluid machine is equipped, and another member, and its manufacturing method. Objective.

In order to achieve the above object, the present invention employs the following means.
In the fluid machine according to one aspect of the present invention, a metal first member that forms a space in which a corrosive gas is conveyed and is connected to a second member, and the first member and the second member are connected. A corrosion-resistant member disposed between the first member and the second member and bonded to the first member in a state where the first member and the corrosion-resistant member are joined. A corrosion-resistant layer is formed so as to cover the end portion on the space side.

In the fluid machine according to one aspect of the present invention, a corrosion-resistant member is bonded to a metal first member that forms a space in which a corrosive gas is conveyed and is connected to the second member. Moreover, a corrosion-resistant member is arrange | positioned among these in the state which the 1st member and the 2nd member were connected.
Therefore, even when an excessive load is applied due to a tightening operation or the like when the first member is connected to the second member, the corrosion resistance of the joint portion of the first member joined to the corrosion-resistant member is ensured. The

Moreover, the corrosion-resistant layer is formed so that the edge part by the side of the space of the junction part of a 1st member and a corrosion-resistant member may be covered.
Therefore, the corrosive substance is prevented from entering the joint portion from the space side end of the joint portion between the first member and the corrosion-resistant member.
Thus, according to the fluid machine which concerns on 1 aspect of this invention, the corrosion resistance in the connection part of the 1st member with which a fluid machine is equipped, and a 2nd member can be improved.

  A fluid machine according to an aspect of the present invention includes an impeller that rotates around an axis and blows the corrosive gas flowing from the outside, and the first member accommodates the impeller inside and follows the axis. And the second member is formed with a second flange portion connected to the first flange portion formed in the suction port. The corrosive gas may be a member that guides the corrosive gas to the suction port, and the corrosion-resistant member may be joined to the first flange portion.

  According to the fluid machine of this configuration, the corrosion-resistant member is joined to the first flange portion formed at the suction port of the metal impeller casing. Further, the corrosion-resistant member is disposed between the first flange portion formed at the inlet of the impeller casing and the second flange portion formed at the second member connected to the impeller casing. Is done.

Therefore, even if an excessive load is applied due to a tightening operation or the like when the first flange portion of the impeller casing is connected to the second flange portion of the second member, the first flange portion joined to the corrosion-resistant member. Corrosion resistance of the joint is ensured.
Moreover, the corrosion-resistant layer is formed so that the edge part by the side of the space of the junction part of an impeller casing and a corrosion-resistant member may be covered. Therefore, the corrosive substance is prevented from entering the joint from the space-side end of the joint between the impeller casing and the corrosion-resistant member.

  A fluid machine according to an aspect of the present invention includes an impeller that rotates around an axis and blows the corrosive gas flowing from the outside, and a rotating shaft that is connected to the impeller and rotates around the axis. The first member is an impeller casing that houses the impeller therein and includes a first flange portion formed on the rotating shaft side, and the second member is a second connected to the first flange portion. A seal box that is disposed on the outer peripheral surface of the rotary shaft and that suppresses the outflow of the corrosive gas in the impeller casing; and the corrosion-resistant member is attached to the first flange portion. The structure joined may be sufficient.

  According to the fluid machine of this configuration, the corrosion-resistant member is joined to the first flange portion formed on the rotating shaft side of the metal impeller casing. Further, the corrosion-resistant member is disposed between the first flange portion formed on the rotating shaft side of the impeller casing and the second flange portion formed on the seal box connected to the impeller casing. Is done.

Therefore, even if an excessive load is applied due to a tightening operation or the like when the first flange portion of the impeller casing is connected to the second flange portion of the seal box, the first flange portion joined to the corrosion-resistant member Corrosion resistance of the joint is ensured.
Moreover, the corrosion-resistant layer is formed so that the edge part by the side of the space of the junction part of an impeller casing and a corrosion-resistant member may be covered. Therefore, the corrosive substance is prevented from entering the joint from the space-side end of the joint between the impeller casing and the corrosion-resistant member.

  A fluid machine according to an aspect of the present invention includes an impeller that rotates around an axis and blows the corrosive gas flowing from the outside, and a rotating shaft that is connected to the impeller and rotates around the axis. The second member is an impeller casing that houses the impeller therein and includes a second flange portion that is formed on the rotating shaft side, and the first member is connected to the second flange portion. A seal box that is disposed on the outer peripheral surface of the flange portion and the rotary shaft and includes a seal portion that suppresses the outflow of the corrosive gas in the impeller casing, and the corrosion-resistant member is joined to the first flange portion It may be configured.

  According to the fluid machine of this configuration, the corrosion-resistant member is joined to the first flange portion formed in the metal seal box. Further, the corrosion-resistant member is disposed between the first flange portion formed in the seal box and the second flange portion formed on the rotating shaft side of the impeller casing in a connected state.

Therefore, even if an excessive load is applied due to a tightening operation or the like when the first flange portion of the seal box is connected to the second flange portion of the impeller casing, the first flange portion joined to the corrosion-resistant member Corrosion resistance of the joint is ensured.
Moreover, the anticorrosion layer is formed so that the edge part by the side of the space of the junction part of a seal box and a corrosion-resistant member may be covered. For this reason, the corrosive substance is prevented from entering the joint from the space-side end of the joint between the seal box and the corrosion-resistant member.

  A fluid machine according to an aspect of the present invention includes an impeller that rotates around an axis and blows the corrosive gas flowing from the outside, and the first member accommodates the impeller inside and follows the axis. An impeller casing having a suction port for introducing the corrosive gas flowing in and an exhaust port for discharging the corrosive gas blown by the impeller, wherein the second member is formed in the discharge port. A second flange portion connected to the first flange portion, and a member that forms a discharge flow path through which the corrosive gas discharged from the discharge port flows, wherein the corrosion-resistant member is the first flange The structure joined to the part may be sufficient.

  In the fluid machine according to one aspect of the present invention, the first flange portion formed in the discharge port of the metal impeller casing that forms a space in which the corrosive gas is conveyed and is connected to the second member is provided with a resistance to the first flange portion. Corrosive members are joined. Further, the corrosion-resistant member is disposed between the first flange portion of the impeller casing and the second flange portion of the second member connected to each other.

Therefore, even if an excessive load is applied due to a tightening operation or the like when the first flange portion formed at the discharge port of the impeller casing is connected to the second flange portion of the second member, the anti-corrosion member is joined. Corrosion resistance of the joined portion of the first flange portion is ensured.
Moreover, the corrosion-resistant layer is formed so that the edge part by the side of the space of the junction part of a 1st member and a corrosion-resistant member may be covered. Therefore, the corrosive substance is prevented from entering the joint from the space-side end of the joint between the impeller casing and the corrosion-resistant member.

In the fluid machine according to one aspect of the present invention, the corrosive gas may be a gas containing nitrogen oxide or sulfur oxide.
By doing in this way, the metal first member is formed by sulfuric acid produced by the reaction of nitric acid or sulfur oxide produced by reacting water with nitrogen oxide contained in the corrosive gas and water. Corrosion can be suppressed.

In the fluid machine according to one aspect of the present invention, the corrosion-resistant member may be joined to the first member by cold welding.
By doing in this way, a 1st member and a corrosion-resistant member can be firmly joined, without producing a volume change. Moreover, it becomes possible to machine the corrosion-resistant member and the first member integrally joined by cold welding at the same time, and the workability of machining is improved.

  A manufacturing method of a fluid machine according to an aspect of the present invention includes a joining step of joining a corrosion-resistant member to a metal first member connected to the second member while forming a space in which a corrosive gas is conveyed, Forming a corrosion-resistant layer on the opposing surface of the first member; and connecting the first member to the second member so that the corrosion-resistant member is disposed between the second member and And a step of forming a corrosion-resistant layer so as to cover an end portion on the space side of the joint portion between the first member and the corrosion-resistant member.

In the fluid machine manufactured by the manufacturing method according to one aspect of the present invention, the corrosion-resistant member is bonded to the first metal member that forms a space in which the corrosive gas is conveyed and is connected to the second member. Has been. Moreover, a corrosion-resistant member is arrange | positioned among these in the state which the 1st member and the 2nd member were connected.
Therefore, even when an excessive load is applied due to a tightening operation or the like when the first member is connected to the second member, the corrosion resistance of the joint portion of the first member joined to the corrosion-resistant member is ensured. The

Moreover, the corrosion-resistant layer is formed so that the edge part by the side of the space of the junction part of a 1st member and a corrosion-resistant member may be covered. Therefore, the corrosive substance is prevented from entering the joint portion from the space side end of the joint portion between the first member and the corrosion-resistant member.
Thus, according to the manufacturing method of the fluid machine which concerns on 1 aspect of this invention, the fluid machine which improved the corrosion resistance in the connection part of the 1st member with which a fluid machine is equipped, and a 2nd member can be manufactured. .

  ADVANTAGE OF THE INVENTION According to this invention, the fluid machine which improved the corrosion resistance in the connection part of the metal member with which a fluid machine is equipped, and another member, and its manufacturing method can be provided.

It is a schematic block diagram which shows the exhaust gas recirculation system of this embodiment. It is a fragmentary longitudinal cross-section which shows the centrifugal blower shown in FIG. FIG. 3 is a partially enlarged view of a position P1 shown in FIG. FIG. 3 is a partially enlarged view of a position P2 shown in FIG. FIG. 3 is a partially enlarged view of a position P3 shown in FIG. It is AA arrow sectional drawing of the bearing part shown in FIG.

Hereinafter, the exhaust gas recirculation system of the present embodiment will be described with reference to the drawings.
The exhaust gas recirculation system of the present embodiment is a system for reducing NOx by mixing a part of exhaust gas (corrosive gas) generated by fuel combustion into combustion air and lowering the combustion temperature.
In the exhaust gas recirculation system of the present embodiment, a part of the exhaust gas is mixed into the combustion air to reduce the oxygen concentration, thereby delaying the combustion rate that is a reaction between fuel and oxygen. Thereby, the maximum temperature of a flame falls and the production | generation of NOx is suppressed.

  As shown in FIG. 1, the exhaust gas recirculation system of the present embodiment is 100, a marine internal combustion engine 10 that is a main engine for marine propulsion, a supercharger 20 that supercharges with exhaust gas discharged from the marine internal combustion engine 10, An EGR valve 30, a scrubber 40 for cleaning exhaust gas, a centrifugal blower 50 (fluid machine) for blowing exhaust gas, an air cooler 60 for cooling compressed air, and a chimney 70 for discharging the exhaust gas to the outside of the ship are provided. .

In the present embodiment, the internal combustion engine is a marine internal combustion engine 10 and further a marine diesel engine, which is a main engine for marine propulsion that rotates a propeller shaft and a propeller for propulsion (not shown).
The marine internal combustion engine 10 obtains a driving force for rotating a propeller shaft by burning diesel engine fuel such as heavy oil and light oil. Exhaust gas generated by combustion in the marine internal combustion engine 10 is discharged to the exhaust pipe 81 and supplied to the supercharger 20 through the exhaust pipe 81. The exhaust pipe 81 is a pipe that guides the exhaust gas discharged from the marine internal combustion engine 10 to the supercharger 20.

The supercharger 20 includes a turbine 21 and a compressor 22 and a rotor shaft 23 to which these are attached at both ends.
The turbine 21 is driven by the exhaust gas flowing from the exhaust pipe 81 to rotate the rotor shaft 23. The compressor 22 has a turbine impeller (not shown) that rotates with the rotation of the rotor shaft 23, compresses external air by the rotation of the turbine impeller, and guides it to the air cooler 60.
Exhaust gas used as power for rotating the turbine 21 flows into the exhaust pipe 82.

The EGR valve 30 is a device that adjusts the flow rate of the exhaust gas that flows into the exhaust pipe 82 and that is guided to the intake pipe 86 via the recirculation pipes 84 and 85. One end (upstream end) of the EGR valve 30 is connected to the downstream end of the exhaust pipe 82, and the other end (downstream end) is connected to the scrubber 40. The EGR valve 30 adjusts the flow rate of the exhaust gas led to the recirculation pipe 84 with respect to the total flow rate of the exhaust gas flowing through the exhaust pipe 82 by adjusting the opening of a valve body mechanism (not shown) provided therein.
Exhaust gas other than the exhaust gas flowing into the EGR valve 30 is guided to the exhaust pipe 83 and discharged from the chimney 70 to the outside of the ship.

The scrubber 40 is a device that collects and separates particles (NOx, SOx, dust, etc.) in exhaust gas in liquid droplets or a liquid film of exhaust gas using a liquid such as water as a cleaning liquid. The scrubber 40 collects particles in the exhaust gas flowing from the EGR valve 30 and supplies the cleaned exhaust gas to the recirculation pipe 84.
The cleaning liquid that has collected the particles in the exhaust gas in the scrubber 40 is supplied to the water treatment device 42 by the pump 41. The water treatment device 42 removes particles in the exhaust gas contained in the cleaning liquid and supplies the cleaning liquid to the scrubber 40.

  The temperature of the exhaust gas flowing into the scrubber 40 from the EGR valve 30 is, for example, 250 ° C to 300 ° C. On the other hand, the temperature of the exhaust gas flowing into the recirculation pipe 84 from the scrubber 40 is about 50 ° C. The temperature of the exhaust gas is lowered in this way because the heat of the exhaust gas is absorbed by the cleaning liquid.

The centrifugal blower 50 is a fluid machine that compresses and blows (conveys) the exhaust gas supplied from the recirculation pipe 84 and supplies the compressed exhaust gas to the recirculation pipe 85. The exhaust gas supplied to the centrifugal blower 50 is purified by the scrubber 40, but contains NOx and SOx to some extent. In addition, acidic substances such as nitric acid and sulfuric acid produced by the reaction of NOx, SOx and the like with water are included to some extent.
As will be described later, the centrifugal blower 50 of the present embodiment has a structure in which corrosion resistance against acidic substances such as nitric acid and sulfuric acid is ensured.

  The air cooler 60 is a device that cools the air compressed by the compressor 22 of the supercharger 20 and supplies the air to a cylinder (not shown) of the marine internal combustion engine 10 via the intake pipe 86. The air cooler 60 is a device that increases the gas density of the air and improves the compression ratio by cooling the air supplied from the compressor 22 and improves the output of the marine internal combustion engine 10.

  The air cooler 60 cools the air supplied from the compressor 22 and the exhaust gas supplied from the recirculation pipe 85, mixes them, and supplies the mixed gas to the intake pipe 86. The mixed gas supplied to the marine internal combustion engine 10 via the intake pipe 86 is cooled and has a low oxygen concentration. Therefore, the exhaust gas recirculation system 100 of the present embodiment can improve the output of the marine internal combustion engine 10 and suppress the generation of NOx.

Next, the centrifugal blower 50 of this embodiment is demonstrated with reference to FIGS.
As shown in FIG. 2, the centrifugal blower 50 includes an impeller 51, a rotating shaft 52, a drive motor 53, an impeller casing 54, a seal box 55, and a bearing portion 56.
Moreover, as shown in FIGS. 3-5, the centrifugal blower 50 of this embodiment is provided with the corrosion-resistant members 57a-57e and the corrosion-resistant layers 58a-58d.

  The impeller 51 rotates around the axis X by the rotational force transmitted by the drive motor 53 via the drive shaft 53a and the rotation shaft 52, and boosts the exhaust gas supplied from the recirculation pipe 84 to blow a predetermined flow rate. The impeller 51 includes a disk-shaped main plate 51a, a disk-shaped side plate 51b having the same diameter as the main plate, and a plurality of blades 51c disposed between the main plate 51a and the side plate 51b.

The rotating shaft 52 is a member that is connected to the impeller 51 and rotates about the axis X. As shown in the longitudinal sectional view of FIG. 2, the rotating shaft 52 and the impeller 51 are formed as a single member.
The rotating shaft 52 and the impeller 51 are made of a metal material having high strength and corrosion resistance. As the metal material, for example, stainless steel having corrosion resistance such as SUS317 or nickel alloy such as Inconel (registered trademark) is used.

  The drive motor 53 is a device that includes a drive shaft 53 a connected to the rotation shaft 52 and rotates the drive shaft 53 a around the axis X. Various motors such as so-called DC motors and AC motors can be used as the drive motor 53, and a gear structure capable of adjusting the rotation speed and the rotation torque may be incorporated.

  As shown in FIG. 2, the impeller casing 54 is a member in which a guide portion 54 a that guides exhaust gas supplied from the recirculation pipe 84 and a casing portion 54 b that houses the impeller 51 are integrally formed of a metal material. It is. As the metal material, for example, cast iron materials such as gray cast iron and ductile cast iron are used.

The guide portion 54a of the impeller casing 54 includes a facing surface that faces the space S1 in which the exhaust gas is conveyed and is connected to the recirculation pipe 84.
Further, the casing portion 54b of the impeller casing 54 includes a facing surface that faces the space S2 in which the exhaust gas is conveyed and is connected to the seal box 55.
The casing portion 54b of the impeller casing 54 includes a facing surface facing the space S3 in which the exhaust gas is conveyed and is connected to the recirculation pipe 85.

The impeller casing 54 includes a suction port 54c that guides the exhaust gas supplied from the recirculation pipe 84 along the axis X, and a discharge port 54d that discharges the exhaust gas blown by the impeller 51 to the recirculation pipe 85.
The exhaust gas flowing in from the suction port 54c is guided to the space S1 formed by the guide portion 54a. The exhaust gas guided to the space S1 flows into the impeller 51 along the axis X, is guided from the axis X direction to the radial direction perpendicular to the axis X direction, passes through the blades 51c, and is guided to the space S2. The exhaust gas guided to the space S2 is blown into the space S3 on the discharge port 54d side and is discharged from the discharge port 54d to the recirculation pipe 85.

The seal box 55 is a cylindrical metal member that houses a connecting portion where one end of the rotating shaft 52 and one end of the drive shaft 53a are connected.
As the metal material forming the seal box 55, for example, cast iron materials such as gray cast iron and ductile cast iron are used.

The end of the seal box 55 on the impeller 51 side in the axis X direction is connected to the impeller casing 54, and the end of the seal box 55 on the drive motor 53 side in the axis X direction is connected to the drive motor 53.
The seal box 55 includes a facing surface that faces the space S <b> 2 in which the exhaust gas is conveyed and is connected to the impeller casing 54.

A dry gas seal (seal part) 55f is attached to the end surface on the impeller 51 side inside the seal box 55 with a fastening bolt so as to surround the rotating shaft 52.
The dry gas seal 55f supplies air from the seal air supply port to the space S4 formed inside the seal box 55 and allows air to flow from the space S4 toward the space S2. By maintaining the space S4 at a higher pressure than the space S2, the exhaust gas, which is a corrosive gas, flows from the space S2 toward the space S4.

  Inside the seal box 55, a space S5 is formed separately from the space S4, and the space S5 is in a state of communicating with the outside through a plurality of communication holes 55b. Since the space S5 is maintained at atmospheric pressure, even if the air that has flowed into the space S4 from the sealing air supply port 55a flows into the space S5, the air that has flowed in is discharged from the communication hole 55b. Therefore, the pressure of the air supplied from the seal air supply port 55a is suppressed from being transmitted to the drive motor 53.

  In the space S5 inside the seal box 55, a connecting portion of the drive shaft 53a and the rotating shaft 52 is accommodated, and a temperature rise may occur due to windage loss or the like of the connecting portion. Also in this case, there is an effect of suppressing the temperature rise of the space S5 by discharging the air that has flowed into the space S5 from the communication hole 55b or allowing the inside of the space S5 and the outside air to flow.

Next, the corrosion resistance structure of the connecting portion between the impeller casing 54 and the recirculation pipe 84 will be described with reference to FIG.
As shown in FIG. 3, a flange portion 54 e is formed at the end portion of the guide portion 54 a of the impeller casing 54 on the recirculation pipe 84 side. The end surface of the flange portion 54e on the recirculation pipe 84 side has an annular shape centering on the axis X. A thin plate-like corrosion-resistant member 57a having the same shape as the flange portion 54e in plan view is joined to the annular end surface.

  The corrosion-resistant member 57a is made of a metal material having high strength and corrosion resistance. As the metal material, for example, stainless steel having corrosion resistance such as SUS317 is used. In addition, the corrosion-resistant member 57a desirably has a thickness T1 along the axis X direction of 5 mm or more and 10 mm or less (for example, 9 mm) in consideration of strength and corrosion resistance.

  Various joining methods can be used for joining the corrosion-resistant member 57a and the flange portion 54e, but it is desirable to join them by cold welding. Cold welding is a method in which members are firmly joined by mixing a base agent and an activator and applying the mixture to a joining portion and allowing it to pass for a certain period of time. In cold welding, since the volume change is small before and after welding, the sealing performance of the joint portion can be maintained. In addition, the corrosion-resistant member 57a and the flange portion 54e that are integrally joined by cold welding can be simultaneously machined, and the workability of machining is improved.

As shown in FIG. 3, a flange portion 84 a is formed at the end portion of the recirculation pipe 84 on the impeller casing 54 side. The end surface of the flange portion 84a on the impeller casing 54 side has an annular shape centered on the axis X.
As shown in FIG. 3, the flange portion 54e and the flange portion 84a are connected by a fastening bolt 91 and a fastening nut 92, and the corrosion-resistant member 57a is in a state where the flange portion 54e and the flange portion 84a are connected. They are sandwiched between these members.

  In FIG. 3, only a pair of fastening bolts 91 and fastening nuts 92 are shown, but the recirculation pipe 84 and the impeller casing 54 are a plurality of pairs of fastening bolts 91 provided at a plurality of locations around the axis X. And a fastening nut 92.

  In the present embodiment, a corrosion-resistant member 57a formed of a metal material having high strength and corrosion resistance is disposed between the flange portion 54e and the flange portion 84a. Therefore, even if an excessive load is applied due to a tightening operation or the like when the fastening bolt 91 is fastened to the fastening nut 92, the state where the flange portion 54e is protected from the exhaust gas by the corrosion-resistant member 57a can be maintained.

  The recirculation pipe 84 is a member that guides exhaust gas to the suction port 54 c of the impeller casing 54. Therefore, exhaust gas is guided to the facing surface that faces the space S1 on the inner peripheral side of the guide portion 54a of the impeller casing 54. In order to protect the facing surface facing the space S1 of the guide portion 54a from corrosion due to exhaust gas, a corrosion-resistant layer 58a is formed on the facing surface.

For the corrosion resistant layer 58a, it is preferable to use a coating agent that prevents gas permeation and is firmly bonded to the metal impeller casing 54. For example, Fuji Flakes (vinyl ester resin containing glass flakes) manufactured by Fuji Resin Co., Ltd. It is preferable to use it.
The thickness of the corrosion-resistant layer 58a can be set as appropriate, but is preferably set in the range of, for example, 1500 μm or more and 2000 μm or less.

  As described above, the corrosion resistance of the flange portion 54e is ensured by joining the corrosion-resistant member 57a to the flange portion 54e. In addition, the corrosion resistance of the guide portion 54a is ensured by forming the corrosion-resistant layer 58a on the surface facing the space S1 of the guide portion 54a of the impeller casing 54.

In the present embodiment, as shown in FIG. 3, the corrosion resistant layer 58a is formed so as to cover the space S1 side end of the joint portion between the flange portion 54e of the guide portion 54a and the corrosion resistant member 57a, The corrosive substance is prevented from entering the joint.
In this way, after connecting the flange portion 54e of the impeller casing 54 and the flange portion 84a of the recirculation pipe 84, the corrosion-resistant layer 58a is not formed so as to cover these connection positions, and the connection position can be changed. Corrosion resistance can be ensured.

Next, the corrosion resistance structure of the connecting portion between the impeller casing 54 and the seal box 55 will be described with reference to FIG. 4 (partially enlarged view of the position P2 shown in FIG. 2).
As shown in FIG. 4, a flange portion 54 f is formed at the end portion of the casing portion 54 b of the impeller casing 54 on the seal box 55 side. The end surface of the flange portion 54f on the seal box 55 side has an annular shape centering on the axis X. A thin plate-like corrosion-resistant member 57b having the same shape as that of the flange portion 54f in plan view is joined to the annular end surface.
The material and thickness of the corrosion-resistant member 57b are the same as those of the corrosion-resistant member 57a described above.
Also, the method of joining the corrosion resistant member 57b to the flange portion 54f is the same as that of the corrosion resistant member 57a described above.

As shown in FIG. 4, a flange portion 55 d is formed at the end portion of the seal box 55 on the impeller casing 54 side. An end surface of the flange portion 55d on the side of the impeller casing 54 has an annular shape centered on the axis X. A thin plate-like corrosion-resistant member 57c having the same shape as the flange portion 54f in plan view is joined to the annular end surface.
The material and thickness of the corrosion-resistant member 57c are the same as those of the corrosion-resistant member 57c described above.
Further, the method of joining the corrosion resistant member 57c to the flange portion 55d is also the same as that of the corrosion resistant member 57a described above.

  As shown in FIG. 4, the flange portion 54e and the flange portion 55d are connected by a fastening bolt 93 and a fastening nut 94, and the corrosion-resistant member 57a and the flange portion 54f and the flange portion 55d are connected in a state where the flange portion 54f and the flange portion 55d are connected. A corrosion-resistant member 57c is disposed between these members.

  4 shows only a pair of fastening bolts 93 and fastening nuts 94, the seal box 55 and the impeller casing 54 are a plurality of pairs of fastening bolts 93 provided at a plurality of locations around the axis X. They are connected by a fastening nut 94.

  In the present embodiment, corrosion resistant members 57b and 57c formed of a metal material having high strength and corrosion resistance are disposed between the flange portion 54f and the flange portion 55d. Therefore, even if an excessive load is applied due to a tightening operation or the like when the fastening bolt 93 is fastened to the fastening nut 94, the flange portion 54f can be kept protected from the exhaust gas by the corrosion resistant member 57b. Similarly, the state in which the flange portion 55d is protected from the exhaust gas by the corrosion resistant member 57c can be maintained.

  As shown in FIG. 4, the corrosion resistant member 57 d is joined to the seal box 55 by cold welding at the attachment position of the dry gas seal 55 f of the seal box 55. Therefore, the attachment position portion of the dry gas seal 55f of the seal box 55 facing the space S2 is also protected from the exhaust gas by the corrosion resistant member 57d.

  The space S2 is a space where the exhaust gas is conveyed. Therefore, exhaust gas is guided to the facing surface facing the inner circumferential space S2 of the casing portion 54b of the impeller casing 54. In order to protect the facing surface facing the space S2 of the casing portion 54b from corrosion due to exhaust gas, a corrosion-resistant layer 58b is formed on the facing surface. Similarly, in order to protect the facing surface facing the space S2 of the seal box 55 from corrosion due to exhaust gas, a corrosion-resistant layer 58c is formed on the facing surface.

For the corrosion resistant layer 58b, it is preferable to use a coating agent that prevents gas permeation and is firmly bonded to the metal impeller casing 54, such as Fuji Flakes (vinyl ester resin containing glass flakes) manufactured by Fuji Resin Co., Ltd. Is preferably used.
The thickness of the corrosion-resistant layer 58a can be set as appropriate, but is preferably set in the range of, for example, 1500 μm or more and 2000 μm or less.
The thickness of the corrosion-resistant layer 58b can be set as appropriate, but in the example shown in FIG. 4, it is set to the same thickness as the corrosion-resistant member 57c. For example, it may be set in the range of 1500 μm or more and 2000 μm or less.

  As described above, the corrosion resistance of the flange portion 54f is ensured by joining the corrosion-resistant member 57b to the flange portion 54f. Moreover, the corrosion resistance of the casing part 54b is ensured by forming the corrosion-resistant layer 58b on the opposite surface of the impeller casing 54 facing the space S2 of the casing part 54b.

In the present embodiment, as shown in FIG. 4, the corrosion resistant layer 58b is formed so as to cover the space S2 side end of the joint portion between the flange portion 54f of the casing portion 54b and the corrosion resistant member 57b. The corrosive substance is prevented from entering the joint.
In this way, after connecting the flange portion 54f of the impeller casing 54 and the flange portion 55d of the seal box 55, the corrosion resistance at the connection position is formed without forming a corrosion-resistant layer so as to cover these connection positions. Sex can be secured.

  Similarly, the corrosion resistance of the flange portion 55d is ensured by joining the corrosion-resistant member 57c to the flange portion 55d. Further, the corrosion resistance of the seal box 55 is ensured by forming the corrosion-resistant layer 58c on the surface facing the space S2 of the seal box 55.

Further, in the present embodiment, as shown in FIG. 4, the corrosion resistant layer 58 c is formed so as to cover the space S2 side end of the joint portion between the flange portion 55 d of the seal box 55 and the corrosion resistant member 57 c, The corrosive substance is prevented from entering the joint.
In this way, after connecting the flange portion 55d of the seal box 55 and the flange portion 54f of the impeller casing 54, the anticorrosion layer at the connection position is formed without forming a corrosion-resistant layer so as to cover these connection positions. Sex can be secured.

Next, the corrosion resistance structure of the connecting portion between the impeller casing 54 and the recirculation pipe 85 will be described with reference to FIG. 5 (partially enlarged view of the position P3 shown in FIG. 2).
As shown in FIG. 5, a flange portion 54g is formed at an end portion of the casing portion 54b of the impeller casing 54 on the recirculation pipe 85 side. The end surface of the flange portion 54g on the recirculation pipe 85 side has an annular shape centering on the axis Y. A thin plate-like corrosion-resistant member 57e having the same shape as the flange portion 54g in plan view is joined to the annular end surface.
The material and thickness of the corrosion-resistant member 57e are the same as those of the corrosion-resistant member 57a described above.
Further, the method of joining the corrosion resistant member 57e to the flange portion 54g is also the same as that of the corrosion resistant member 57a described above.

As shown in FIG. 5, a flange 85a is formed at the end of the recirculation pipe 85 on the impeller casing 54 side. The end surface of the flange portion 85a on the side of the impeller casing 54 has an annular shape centered on the axis Y.
As shown in FIG. 5, the flange portion 54g and the flange portion 85a are connected by a fastening bolt 95 and a fastening nut 96, and the corrosion-resistant member 57e is in a state where the flange portion 54g and the flange portion 85a are connected. They are sandwiched between these members.

  In FIG. 5, only two pairs of fastening bolts 95 and fastening nuts 96 are shown, but the recirculation pipe 85 and the impeller casing 54 are a plurality provided at a plurality of three or more around the axis X. A pair of fastening bolts 95 and a fastening nut 96 are connected.

  In the present embodiment, a corrosion resistant member 57e formed of a metal material having high strength and corrosion resistance is disposed between the flange portion 54g and the flange portion 85a. Therefore, even if an excessive load is applied due to a tightening operation or the like when the fastening bolt 95 is fastened to the fastening nut 96, the flange portion 54g can be kept protected from the exhaust gas by the corrosion-resistant member 57e.

  The recirculation pipe 85 is a member that forms a discharge passage through which the exhaust gas discharged from the discharge port 54d of the impeller casing 54 flows. Therefore, exhaust gas is guided to the facing surface facing the space S3 of the casing portion 54b of the impeller casing 54. In order to protect the facing surface facing the space S3 of the casing portion 54b from corrosion due to exhaust gas, a corrosion-resistant layer 58d is formed on the facing surface.

For the corrosion resistant layer 58d, it is preferable to use a coating agent that prevents gas permeation and is firmly bonded to the metal impeller casing 54. For example, Fuji Flakes (vinyl ester resin containing glass flakes) manufactured by Fuji Resin Co., Ltd. Is preferably used.
The thickness of the corrosion-resistant layer 58d can be set as appropriate, but is preferably set in the range of, for example, 1500 μm or more and 2000 μm or less.

  As described above, the corrosion resistance of the flange portion 54g is secured by joining the corrosion-resistant member 57e to the flange portion 54g. Moreover, the corrosion resistance of the casing part 54b is ensured by forming the corrosion-resistant layer 58d on the facing surface facing the space S3 of the casing part 55a of the impeller casing 54.

Further, in the present embodiment, as shown in FIG. 5, the corrosion resistant layer 58d is formed so as to cover the space S3 side end of the joint portion between the flange portion 54g of the casing portion 54b and the corrosion resistant member 57e, The corrosive substance is prevented from entering the joint.
In this way, after connecting the flange part 54g of the impeller casing 54 and the flange part 85a of the recirculation pipe 85, the corrosion-resistant layer 58d is not formed so as to cover these connection positions, and the connection position Corrosion resistance can be ensured.

Next, the bearing part 56 shown in FIG. 2 is demonstrated with reference to FIG. 6 (AA arrow sectional drawing of the bearing part shown in FIG. 2).
As shown in FIG. 2, the bearing portion 56 is a bearing device that rotates the drive shaft 53 while supporting the vertical load of the drive shaft 53, the rotary shaft 52 coupled to the drive shaft 53, and the impeller 51.
As shown in FIG. 6, the bearing portion 56 is held in a state sandwiched between a bearing holding member 56 b connected to the seal box 55, a bearing support member 56 c disposed above the bearing holding member 56 b, and bearing holding members 56 b and 56 c. A ball bearing 56a.

  The inner ring of the ball bearing 56a is attached to the drive shaft 53a by shrink fitting. Further, the outer ring of the ball bearing 56a is fixed to the seal box 55 by being fastened by fastening bolts 97 sandwiched between the bearing holding members 56b and 56c.

  As described above, the drive motor 53 and the seal box 55 are connected in a state where the axis X is matched. Further, the drive shaft 53 a is supported on the axis X by the bearing portion 56. Therefore, the drive shaft 53a and the rotating shaft 52 connected thereto are appropriately arranged so as to coincide with the axis X.

Next, the manufacturing method of the centrifugal blower 50 of this embodiment is demonstrated.
First, the impeller casing 54 and the seal box 55 are manufactured by a manufacturing process such as casting.
Second, the corrosion resistant member 57a is joined to the flange portion 54e of the impeller casing 54 by cold welding, the corrosion resistant member 57b is joined to the flange portion 54f of the impeller casing 54 by cold welding, and the flange portion of the impeller casing 54 is joined. The corrosion resistant member 57e is joined to 54g by cold welding.
Third, the corrosion resistant member 57c is joined to the flange portion 55d of the seal box 55 by cold welding, and the corrosion resistant member 57d is joined to the seal box 55 at the mounting position of the dry gas seal 55f by cold welding.

Fourthly, a corrosion-resistant layer 58a is formed on the surface facing the space S1 of the guide portion 54a of the impeller casing 54. At this time, the corrosion resistant layer 58a is formed so as to cover the end of the joint portion between the flange portion 54e of the guide portion 54a and the corrosion resistant member 57a on the space S1 side.
Fifth, the anti-corrosion layer 58b is formed on the surface facing the space S2 of the casing portion 54b of the impeller casing 54. At this time, the corrosion resistant layer 58b is formed so as to cover the end of the joint portion between the flange portion 54f of the casing portion 54b and the corrosion resistant member 57b on the space S2 side.
Sixth, a corrosion-resistant layer 58d is formed on the facing surface facing the space S3 of the casing portion 54b of the impeller casing 54. At this time, the corrosion-resistant layer 58d is formed so as to cover the end of the joint portion between the flange portion 54g of the casing portion 54b and the corrosion-resistant member 57e on the space S3 side.

  Seventh, a corrosion-resistant layer 58c is formed on the facing surface of the seal box 55 that faces the space S2. At this time, the space S2 side end of the joint portion between the seal box 55 and the corrosion resistant member 57c and the space S2 side end portion of the joint portion between the seal box 55 and the corrosion resistant member 57d are covered. Layer 58c is formed.

Eighth, the flange portion 54e of the impeller casing 54 and the flange portion 84a of the recirculation pipe 84 are fastened by the fastening bolt 91 and the fastening nut 92.
Ninth, after the dry gas seal 55f is attached to the seal box 55, the flange portion 54f of the impeller casing 54 and the flange portion 55d of the seal box 55 are fastened by the fastening bolt 93 and the fastening nut 94.
Tenth, the drive motor 53 is attached to the seal box 55.
The centrifugal blower 50 of this embodiment is manufactured as described above.

  The operation and effect of the centrifugal blower 50 of the present embodiment described above will be described.

According to the centrifugal blower 50 of the present embodiment, the corrosion-resistant member 57a is joined to the flange portion 54e formed in the suction port 54c of the metal impeller casing 54. Further, in a state where the flange portion 54e formed at the suction port 54c of the impeller casing 54 and the flange portion 84a formed at the recirculation pipe 84 connected to the impeller casing 54 are connected, a corrosion-resistant member is interposed therebetween. 57a is arranged.
Therefore, even when an excessive load is applied due to a tightening operation or the like when the flange portion 54e of the impeller casing 54 is connected to the flange portion 84a of the recirculation pipe 84, the flange portion 54e joined to the corrosion resistant member 57a. Corrosion resistance of the joint is ensured.

Further, a corrosion-resistant layer 58a is formed on the facing surface of the impeller casing 54 facing the space S1 in which the exhaust gas is conveyed. The corrosion-resistant layer 58a is formed so as to cover the end portion on the space S1 side of the joint portion between the impeller casing 54 and the corrosion-resistant member 57a.
Therefore, the corrosion resistance of the facing surface of the impeller casing 54 is ensured, and a corrosive substance is prevented from entering the joint from the end on the space S1 side of the joint between the impeller casing 54 and the corrosion-resistant member 57a. Is done.

Further, according to the centrifugal blower 50 of the present embodiment, the corrosion-resistant member 57b is joined to the flange portion 54f formed on the rotating shaft 52 side of the metal impeller casing 54. Further, in a state where the flange portion 54f formed on the rotating shaft 52 side of the impeller casing 54 and the flange portion 55d formed on the seal box 55 connected to the impeller casing 54 are connected, a corrosion-resistant member is interposed therebetween. 57b is arranged.
Therefore, even when an excessive load is applied due to a tightening operation or the like when the flange portion 54f of the impeller casing 54 is connected to the flange portion 55d of the seal box 55, the flange portion 54f to be joined to the corrosion-resistant member 57b. Corrosion resistance of the joint is ensured.

Further, a corrosion resistant layer 58b is formed on the facing surface of the impeller casing 54 facing the space S2 in which the exhaust gas is conveyed. The corrosion-resistant layer 58b is formed so as to cover the end portion on the space S2 side of the joint portion between the impeller casing 54 and the corrosion-resistant member 57b.
Therefore, the corrosion resistance of the facing surface of the impeller casing 54 is ensured, and the corrosive substance is prevented from entering the joint from the end of the joint between the impeller casing 54 and the corrosion-resistant member 57b on the space S2 side. Is done.

Further, according to the centrifugal blower 50 of the present embodiment, the corrosion-resistant member 57 c is joined to the flange portion 55 d formed in the metal seal box 55. Further, in a state where the flange portion 55d formed in the seal box 55 and the flange portion 54f formed on the rotating shaft 52 side of the impeller casing 54 are connected, a corrosion-resistant member 57c is disposed therebetween.
Therefore, even when an excessive load is applied due to a tightening operation or the like when the flange portion 55d of the seal box 55 is connected to the flange portion 54f of the impeller casing 54, the flange portion 55d to be joined to the corrosion-resistant member 57c. Corrosion resistance of the joint is ensured.

Further, a corrosion resistant layer 58c is formed on the facing surface of the seal box 55 facing the space S2 in which the exhaust gas is conveyed. The corrosion-resistant layer 58c is formed so as to cover the space S2 side end of the joint between the seal box 55 and the corrosion-resistant member 57c.
Therefore, the corrosion resistance of the opposing surface of the seal box 55 is ensured, and the corrosive substance is prevented from entering the joint portion from the end portion on the space S2 side of the joint portion between the seal box 55 and the corrosion-resistant member 57c. Is done.

Further, in the centrifugal blower 5 of the present embodiment, a flange portion formed in the discharge port 54d of the metal impeller casing 84 which has a facing surface facing the space S3 in which the exhaust gas is conveyed and is connected to the recirculation pipe 85. A corrosion resistant member 57e is joined to 54g. Further, the corrosion resistant member 57e is disposed between the flange portion 54g of the impeller casing 54 and the flange portion 85a of the recirculation pipe 85 in a connected state.
Therefore, even when an excessive load is applied due to a tightening operation or the like when the flange portion 54g formed at the discharge port 54d of the impeller casing 54 is connected to the flange portion 85a of the recirculation pipe 85, the corrosion-resistant member 57e. Corrosion resistance of the joint portion of the flange portion 54g to be joined is ensured.

Further, a corrosion-resistant layer 58d is formed on the facing surface of the impeller casing 54 facing the space S3 in which the exhaust gas is conveyed. The corrosion-resistant layer 58d is formed so as to cover the end portion on the space S3 side of the joint portion between the impeller casing 54 and the corrosion-resistant member 57e.
Therefore, the corrosion resistance of the facing surface of the impeller casing 54 is ensured, and the corrosive substance is prevented from entering the joint portion from the end portion on the space S3 side of the joint portion between the impeller casing 54 and the corrosion-resistant member 57e. Is done.

10 Marine Internal Combustion Engine (Internal Combustion Engine)
20 Supercharger 50 Centrifugal blower (fluid machine)
51 Impeller 52 Rotating Shaft 53 Drive Motor 53a Drive Shaft 54 Impeller Casing 54a Guide Portion 54b Casing Portion 54c Suction Port 54d Discharge Port 54e Flange Portion 54f Flange Portion 54g Flange Portion 55 Seal Box 55a Seal Air Supply Port 55b Communication Hole 55d Flange Portion 55f Dry gas seal (seal part)
56 Bearing portion 56a Ball bearing 56b, 56c Bearing holding member 57a, 57b, 57c, 57d, 57e Corrosion resistant member 58a, 58b, 58c, 58d Corrosion resistant layer 81, 82, 83 Exhaust pipe 84, 85 Recirculation pipe 84a, 85a Flange portion 86 Intake pipe 91, 93, 95, 97 Fastening bolt 92, 94, 96 Fastening nut 100 Exhaust gas recirculation system P1, P2, P3 Position S1, S2, S3, S4, S5 Space

Claims (8)

A first member that forms a space in which the corrosive gas is conveyed and is connected to the second member;
A corrosion-resistant member disposed between the first member and the second member in a state where the first member and the second member are connected, and a corrosion-resistant member joined to the first member;
A fluid machine in which a corrosion-resistant layer is formed so as to cover the space side of the joint portion between the first member and the corrosion-resistant member. An impeller that rotates around the axis and blows the corrosive gas flowing from the outside,
The first member is an impeller casing including a suction port that houses the impeller inside and guides the corrosive gas flowing along the axis to the inside.
The second member is a member that is formed with a second flange portion connected to a first flange portion formed at the suction port and guides the corrosive gas to the suction port.
The fluid machine according to claim 1, wherein the corrosion-resistant member is joined to the first flange portion. An impeller that rotates around an axis and blows the corrosive gas flowing from the outside;
A rotation shaft connected to the impeller and rotating around the axis,
The first member is an impeller casing that houses the impeller therein and includes a first flange portion formed on the rotating shaft side,
The second member includes a second flange portion connected to the first flange portion and a seal portion that is disposed on an outer peripheral surface of the rotating shaft and suppresses the corrosive gas from flowing out in the impeller casing. A seal box,
The fluid machine according to claim 1, wherein the corrosion-resistant member is joined to the first flange portion. An impeller that rotates around an axis and blows the corrosive gas flowing from the outside;
A rotation shaft connected to the impeller and rotating around the axis,
The second member is an impeller casing that includes the second flange portion that is housed in the impeller and formed on the rotating shaft side,
The first member is a seal including a first flange portion connected to the second flange portion and a seal portion which is disposed on an outer peripheral surface of the rotating shaft and suppresses the corrosive gas from flowing out in the impeller casing. Box,
The fluid machine according to claim 1, wherein the corrosion-resistant member is joined to the first flange portion. An impeller that rotates around the axis and blows the corrosive gas flowing from the outside,
The first member includes an intake port that houses the impeller therein and guides the corrosive gas flowing along the axis to the inside, and an exhaust port that discharges the corrosive gas blown by the impeller. A casing,
The second member is formed with a second flange portion connected to the first flange portion formed at the discharge port, and forms a discharge flow path for circulating the corrosive gas discharged from the discharge port. Is a member,
The fluid machine according to claim 1, wherein the corrosion-resistant member is joined to the first flange portion.   The fluid machine according to any one of claims 1 to 5, wherein the corrosive gas is a gas containing nitrogen oxides or sulfur oxides.   The fluid machine according to any one of claims 2 to 6, wherein the corrosion-resistant member is joined to the first member by cold welding. A joining step of joining the corrosion-resistant member to the metal first member connected to the second member while forming a space in which the corrosive gas is conveyed;
Connecting the first member to the second member such that the corrosion-resistant member is disposed between the second member and the second member;
Forming a corrosion resistant layer so as to cover the space side of the joint between the first member and the corrosion resistant member.

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