EP0054116A1

EP0054116A1 - Turbomachine stator assembly, and disassembling and assembling method therefor

Info

Publication number: EP0054116A1
Application number: EP19810107994
Authority: EP
Inventors: Carl H. Geary; Arthur J. Miller
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1980-10-30
Filing date: 1981-10-06
Publication date: 1982-06-23
Also published as: EP0054116B1; DE3175308D1; JPS57105504A; JPS5925092B2

Abstract

A turbomachine (10) comprising a bladed rotor (12) including axially spaced first (14) and second (16) stage rotor blade rows; an inlet duct (18) for directing a fluid past the bladed rotor (12), and including an outwardly projecting duct flange (40); and a fluid casing (20) for receiving fluid flowing past the bladed rotor (12), and including an outwardly projecting casing flange (44). The turbomachine (10) further comprises a stator blade assembly (22) including a plurality of stator blades (30) axially located between the first (14) and second (16) stage rotor blade rows, and outwardly projecting flanges (38), (42) positioned contiguous to the duct (40) and casing flanges (44); and apparatus for releasably securing the stator blade assembly (22) to the fluid casing (20) and the inlet duct (18).

Description

This invention generally relates to rotary machines, and more specifically to stator blade assemblies thereof.
Occasionally, the rotor or stator blades of a rotary machine such as a compressor or expander must be removed from the machine for cleaning, maintenance, or replacement. For example, rotary machines are often used with fluids containing a significant amount of particulates or debris. Over an extended period, these particulates and debris may accumulate on or erode the blade surfaces, necessitating periodic removal of the rotor or stator blades from the machine to clean or replace the blade surfaces. Routine inspection and maintenance, for example to repair or realign a rotor seal or blade, may also require removal of the rotor or stator blades from the machine.
Typically, in order to remove the rotor or stator blades from a rotary machine, a large portion of the machine must be disassembled; and many of the parts which must be disassembled are large, heavy, and thus difficult to maneuver. Moreover, when reassembled, usually these parts must be very accurately realigned. As a result, installing and removing the rotor and stator blades of a rotary machine requires skilled labor and may be relatively time consuming. Further, of course, the machine is inoperable and, hence, unproductive while the rotor and stator blades are being assembled and disassembled. Naturally, thus, it is desirable to simplify and assist the assembly and disassembly of the stator and rotor blades of a rotary machine.
In addition to the foregoing, attention has been recently directed toward simplifying and facilitating the assembly and disassembly of entire rotary machines. One approach of considerable interest involves axially moving the rotor through a fluid casing of the rotary machine, with the fluid casing and other parts of the machine being designed so that this may be accomplished in a manner requiring relatively little disassembly of the rotary machine as a whole.
This approach offers significant time and cost advantages. Obtaining these advantages with a multi-stage rotary machine having two or more axially spaced sets of rotor blades is complicated, though, by the fact that a stator blade assembly, generally including a plurality of stator blades and an interstage diaphragm, is usually axially located between the different rotor stages of the machine. The stator blade assembly, which is not movable with the rotor, must be removed before the rotor can be axially moved out of the machine.
The present invention relates to a turbomachine having a stator blade assembly which may be easily installed in and removed from the turbomachine. Specifically, this invention relates to a turbomachine comprising bladed rotor means including axially spaced first and second stage rotor blade rows; an inlet duct for directing a fluid past the bladed rotor means, and including an outwardly projecting duct flange; and a fluid casing for receiving fluid flowing past the bladed rotor means, and including an outwardly projecting casing flange. The turbomachine further comprises a stator blade assembly including stator blade means axially located between the first and second stage rotor blade rows, and outwardly projecting flanges positioned contiguous to the duct and casing flanges; and means for releasably securing the stator blade assembly to the fluid casing and the inlet duct.
This invention will now be described by way of example, with reference to the accompanying drawings in which:

Figure 1 is a side view, partially in cross section, illustrating portions of a rotary machine incorporating teachings of the present invention;
Figures lA, 1B, and IC are partial, side cross sectional views showing various alternate arrangements for disengagably supporting an interstage diaphragm and a plurality of interstage stator blades within the rotary machine shown in Figure 1;
Figure 1D is an enlarged, side view, partially in cross-sectional, of a pin employed in the rotary machine shown in Figures 1, 1A, 1B, and 1C to support releasably the interstage diaphragm and stator blades therein;
Figure 2 is a front view, partially in cross section, of the stator blade assembly shown in Figure 1A;
Figures 3 and 4 are front views showing lower sections of the stator blade assembly illustrated in Figure 2 of apparatus for installing these sections of the stator blade assembly in, and removing these sections of the stator blade assembly from, the rotary machine shown in Figure 1;
Figure 5 is a partial side view of the rotary machine shown in Figure-I, including the lower sections of the stator blade assembly shown in Figure 2; and of the installation and removal apparatus shown in Figures 3 and 4.

Referring to Figure 1, there is illustrated portions of turbomachine 10 such as a multi-stage turbine incorporating teachings of the present invention. Machine 10 includes an axially extending rotor 12, first and second stage rotor blades 14 and 16, inlet duct 18, fluid casing 20, and stator blade assembly 22. Assembly 22, in turn, comprises housing 24, diaphragm 26, stator blades 30, and connecting means 32, discussed in greater detail below. Fluid casing 20 annularly extends around rotor 12, and rotor blades 14 and 16 are rigidly secured to rotor 12 and radially extend outward therefrom, forward to the left as viewed in Figure 1, of the fluid casing. Although two axially-spaced sets of rotor blades 14 and 16 are shown in Figure 1, it will be apparent to those skilled in the art that the present invention may be employed with a rotary compressor or expander having more than two spaced sets of rotor blades.
Housing 24 is located between fluid casing 20 and inlet duct 18 and annularly extends around rotor blades 14 and 16, stator blades 30, and diaphragm 26. With the embodiment illustrated in Figure 1, housing 24 is comprised of separable annular rings 34 and 36, and these rings are comprised of separable upper and lower sections, which preferably are both of semi-annular form disengagably joined together, for example by bolts, along adjacent horizontal flanges. More specifically, band 34 includes top section 34a and bottom section 34b, while band 36 includes top section 36a and bottom section 36b. Rings 34 and 36 are releasably joined together, to fluid casing 20, and to inlet duct 18. More particularly, front, outwardly extending flange portion 38 of band 34 is bolted to contiguous flange portion 40 of inlet duct 18; back, outwardly extending flange portion 42 of band 36 is bolted to contiguous flange portion 44 of fluid casing 20; and bands 34 and 36 are bolted together along adjacent, intermediate flanges 46 and 48. As will be understood by those skilled in the art, seals may be disposed between contiguous surfaces of inlet duct 18, fluid casing 20, and housing 24 to inhibit or to retard fluid flow between these surfaces.
Diaphragm 26 is disposed within housing 24 and preferably is radially spaced therefrom to allow radial expansion and contraction of the diaphragm. Diaphragm 26 annularly extends around rotor blades 14 and 16 and comprises separable upper and lower diaphragm sections 50 and 52, which also preferably are both of semi-annular form disengagably joined together along a horizontal split line in any suitable manner such as by bolts. Stator blades 30 are secured to diaphragm 26 in any conventional manner and radially extend inward therefrom, between rotor blade rows 14 and 16. A horizontal split sealing member 54 is conventionally secure to stator blades 30 and radially extends inward therefrom substantially to impeller rotor 12 to inhibit fluid flow through the area between the rotor and the stator blades.
Connecting means 32 releasably connects diaphragm 26 to housing 24 and limits relative rotation therebetween. With the embodiment illustrated in Figure 1, connecting means 32 includes inside rib portion 56 of housing band 36, annular ring 58, and one or more pins 60. Ring 58, which may be integral with rib 56, axially extends from the rib, radially outside diaphragm 26, and pins 60 extend through ring 58 into engagement with diaphragm 26 to prevent substantially relative rotation between the diaphragm and ring 58.
Preferably, ring 58 defines a plurality of pin holes 62, for example 8 or 12 equally spaced about the ring; diaphragm 26 defines a like number of diaphragm sockets 64, with sockets 64 aligned with pin holes 62; and pins 60 extend through holes 62 and into sockets 64 to engage securely the diaphragm. In order to prevent inadvertent outward movement of pins 60, set screws 66 may be threaded into diaphragm 26 to engage cooperating annular recesses (not shown) of pins 60, releasably maintaining pins 60 in position, as shown in Figure 1. With reference to Figure 1D, upper portions of pins 60 may define threaded pin sockets 68 to facilitate moving the pins into and out of diaphragm sockets 64.
With the above-described arrangement, abutting contact between pins 60 and the surfaces of ring 58 defining pin holes 62 substantially prevents rotational or axial movement of diaphragm 26. Rearward axial movement of diaphragm 26 is further prevented by rib 56 or, preferably, by a seal (not shown) which may be axially located between rib 56 and outside flange 70 of the diaphragm. At the same time, rib 56 provides radial support for diaphragm 26 within housing 24. Thus, diaphragm 26 and stator blades 30 are supported .and largely held in place within housing 24, although pins 60 allow and, in fact, guide radial expansion and contraction of the diaphragm.
Turning to Figures 1A and 1B, there are shown various alternate arrangements for supporting diaphragm 26 within housing 24. With both of these embodiments, housing 24 defines one or more radially extending housing apertures 72, pins 60 radially extend through apertures 72 and into diaphragm sockets 64, and covers 72 are disengagably secured to housing 24 and extend over pins 60 to limit radially outward movement thereof. Annular rib 76 extends inward from housing 24, and abutting contact between diaphragm 26 and rib 76 limits axially rearward movement-of the diaphragm.
With the embodiment illustrated in Figure 1B, covers 72 comprise pin caps which extend into housing apertures 72, encircle and cover pins 60, and threadably engage the surfaces of housing 24 defining the housing apertures. Alternately, with the embodiment depicted in Figure 1A, covers 72 comprise flange portions which are integral with pins 60. These covers 72 are located outside housing 24, overlay housing apertures 72 and pins 60, and are releasably secured to housing 24 via bolts 78. With this latter embodiment, 0-rings may be disposed between flange covers 72 and housing 24, encircling pins 60.
Referring to Figure 1C, there is disclosed a fourth embodiment for supporting diaphragm 26 and stator blades 30 within housing 24. With this embodiment, housing 24 may form an integral portion of inlet duct 18, and preferably the housing comprises an integral band portion encircling diaphragm 26 and stator blades 30. With the embodiment shown in Figure 1C, diaphragm 26 and stator blades 30 are supported within housing 24 via inside rib portion 80 of fluid casing 20, annular ring 82, and one or more pins 60. Annular ring 82 is separable from rib portion 80, and preferably is bolted thereto. Similar to the arrangement illustrated in Figure 1, ring 82 preferably defines a plurality of pin holes 62, with pins 60 extending through these holes and into diaphragm sockets 64, and set screws 66 may be used to maintain releasably pins 60 in sockets 64.
To operate machine 10, a fluid is induced to flow through inlet duct 18 and past blades 14 and 16. If machine 10 is a compressor, then rotor blade rows 14 and 16 are rotated to compress the fluid flowing therepast. Alternately, if machine 10 is an expander, then the fluid causes rotation of blade rows 14 and 16. In either case, the fluid flows past blades 14 and 16, through fluid casing 20, and thence is discharged from machine 10.
As previously discussed, attention has been recently directed towards simplifying the assembly and disassembly of rotary machines of the general type described above, specifically of the stator blade assemblies thereof; and in accordance with the teachings of the present invention, stator blade assembly 22 described above may be both removed from and installed in machine 10 in a relatively fast and inexpensive manner.
With the embodiment depicted in Figure 1, top and bottom sections 34a and 34b of housing ring 34 are disconnected from each other. Then housing band 34 is disconnected from inlet duct 18 and housing band 36, and band 34 is removed from machine 10. Set screws 66 are loosened or removed and pins 60 are pulled out of diaphragm sockets 64, freeing housing band 36 from diaphragm 26. Top and bottom sections 36a and 36b of housing ring 36 are disconnected from each other, the whole band 36 is disconnected from casing 20, and band 36 is removed. With housing 24 thus removed, top and bottom sections 50 and 52 of diaphragm 26 are disengaged from each other and taken away from machine 10.
To disassemble the embodiments shown in Figures lA and 1B, pin covers 74 are first disconnected from housing 24 and removed, either by removing bolts 78 of Figure 1A or by unthreading the pin caps of Figure 1B from housing apertures 72. With the arrangement illustrated in Figure lA, pins 60 are pulled out of diaphragm sockets 64 when pin covers 74 are pulled away from housing 24. With the arrangement depicted in Figure 1B, in contrast, pins 60 are manually pulled out of diaphragm sockets 64, via housing apertures 72, after covers 74 are removed. With pins 60 removed, housing 24 is free of diaphragm 26 and stator blades 30; and thence the top and bottom sections of the housing are disconnected from each other, disconnected from inlet duct 18 and fluid casing 20, and then removed from machine. Lastly, top and bottom sections 50 and 52 of diaphragm 26 are disconnected from each other and taken from machine 10.
A major advantage of the embodiments illustrated in Figures 1, 1A, and 1B, it should be pointed out, is that the entire stator housing assembly 22 may be removed without removing either inlet duct 18 or fluid casing 20.
Turning now to Figure 1C, to disassemble stator blade assembly 22 shown therein, flanges 42 and 44 are first disconnected, freeing housing 24 and inlet duct 18 from fluid casing 20. Inlet duct 18, including annular housing portion 24, is then removed. Set screws 66 are loosened or removed, and then pins 60 are removed. Ring 82 is then disconnected from rib 80 and removed. Top and bottom sections 50 and 52 of diaphragm 26 are then disengaged from each other and radially moved out of machine 10.
As will be appreciated by those skilled in the art, numerous specific apparatus may be utilized to remove stator blade assembly 22 from machine 10, and one arrangement for removing and installing the stator blade assembly 22 shown in Figure 1B will be described herein in detail. With particular reference to Figures 1B, 2 and 3, to remove the stator blade assembly 22 of Figure 1B, posts 102, including support platforms 104 and top flanges 106, are positioned adjacent to the stator blade assembly, with top flanges 106 overlaying portions of flanges 108 of lower housing section 24b. Flanges 106 and 108 are then secured together by any conventional means wherein posts 102 provide additional support for stator blade assembly 22. Preferably, guide rods. 110 are lowered through aligned apertures defined by flanges 106 and 108 into abutting contact with support platforms 104, wherein the guide rods help to guide vertical movement of lower diaphragm section 52 and lower housing section 24b. With posts 102 providing support for stator blade assembly 22, inlet duct 18 is disengaged from the stator blade assembly and removed in any suitable manner, for example by an overhead crane. Pin covers 72 and pins 60 connecting upper diaphragm section with upper housing section 24a are removed, freeing this housing section from diaphragm 26. Upper housing section 24a is then disengaged from lower housing section 24b and from fluid casing 20 and removed in any conventional manner, again for example by an overhead crane. Upper diaphragm section 50 is then disengaged from lower diaphragm section 52 and also removed in any conventional manner such as by an overhead crane.
Rails 112 are positioned adjacent machine 10, extending forward thereof between posts 102. Screw jacks 114, having top plates 116, are placed on platforms 104 of posts 102, and the screw jacks are extended to bring plates 116 into abutting contact with flanges 108 of lower housing section 24b. Lower housing section 24b is disengaged from fluid casing 20, and flanges 108 are disengaged from flanges 106. Lower housing and diaphragm sections 24b and 52 are now free to move downward; and by retracting screw jacks 114, plates 116, housing section 24b, and diaphragm section 52 are lowered toward rails 112. Before housing section 24b engages rails 112, wheels 120, 122, and 124 are secured to the lower housing section in any suitable manner to support diaphragm section 52 and housing section 24b for movement along the rails.
With wheels 120, 122, and 124 secured in place, screw jacks 114 are retracted to lower these wheels onto rails 112, as shown in Figures 4 and 5. It should be pointed out that preferably machine 10 and rails 112 are positioned on baseplate 126 having a recessed or lowered central portion, allowing the bottom of housing section 24b to extend lower than the bottom of rails 112 when wheels 120, 122, and 124 are lowered thereonto. With wheels 120, 122 and 124 lowered onto rails 112, guide rods 110 are removed, and housing section 24b and diaphragm section 52 are then manually moved along the rails, away from machine 10. Housing section 24b and diaphragm section 52 may thence be transported to a remove location in any conventional manner. Once removed from machine 10, pin covers 72 and pins 60 connecting lower housing section 24b with the lower diaphragm section 52 may be removed, separating sections 24b and 52.
To install stator blade assembly 22, the above-described removal process is generally reversed. Lower diaphragm section 52, with a plurality of stator blades 30 secured thereto and radially extending inward therefrom and with the lower half of sealing member 54 secured to and radially extending inward from these stator blades, is positioned within lower housing section 24b, slightly spaced therefrom. Diaphragm and housing sections 52 and 24b are connected together by inserting pins 60 through housing apertures 72 and into diaphragm sockets 64 and securing pin covers 72 to housing 24, locking the pins in place. Wheels 120, 122, and 124 are secured to lower housing section 24b. Diaphragm and housing sections 52 and 24b and wheels 120, 122, and 124 are mounted on rails 112 and moved therealong until the lower diaphragm and housing sections are adjacent fluid casing 20 and below rotor 12, as shown in Figure 5.
Posts 102 are located outside rails 112, with flanges 108 of lower housing section 24b directly between support platforms 104 and top flanges 106. Guide rods 110 are inserted through flanges 108 and 106. Screw jacks 114 are positioned on platforms 104 and extended to bring plates 116 into abutting contact with flanges 108 and raise lower housing section 24b off rails 112. Wheels 120, 122, and 124 are removed from lower housing section 24b. Screw jacks 112 are extended to raise housing section 24b and diaphragm section 52 into their assembled positions and bring flanges 108 into abutting contact with top flanges 106. Flanges 106 and 108 are joined together, guide rods 110 are removed, and lower housing section 24b is disengagably secured to fluid casings 20. Rails 112 may be removed.
Upper diaphragm section 50, also with a plurality of stator blades 30 secured thereto and with the upper half of sealing member 54 secured to these stator blades, is positioned, for example via an overhead crane, over lower diaphragm section 52 and rotor 12, and the upper and lower diaphragm sections are disengagably secured. together, forming diaphragm 26. Upper housing section 24a is positioned over diaphragm 26, again for example by an overhead crane, and disengagably secured to both lower housing section 24b and fluid casing 20. Upper diaphragm and housing sections 50 and 24a are disengagably connected together via pins 60 and pin covers 72, inlet duct 18 is resecured to the front of housing 24, and preferably support means (not shown) is secured to inlet duct 18 to support the duct and to provide additional support for stator blade assembly 22 and the forward end of fluid casing 20. With this additional support, flanges 106 of posts 102 are disengaged from flanges 108 of housing 24, and the posts and screw jacks 114 are removed. Stator blade assembly 22 is now reassembled within machine 10 and the machine is ready for operation.
While it is apparent that the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.

Claims

1. A turbomachine including bladed rotor means having axially spaced first and second stage rotor blade rows; an inlet duct for directing a fluid past the bladed rotor means, a fluid casing for receiving fluid flowing past the bladed rotor means, and a stator blade assembly including stator blade means axially located between the first and second stage rotor blade rows characterized in that the inlet duct (18) includes an outwardly projecting duct flange (40); the fluid casing (20) includes an outwardly projecting casing flange (44); the stator blade assembly (22) includes outwardly projecting flanges (38, 42) positioned contiguous to the duct and casing flanges (40,44); and means for releasably securing the stator blade assembly (22) to the fluid casing (20) and the inlet duct (18).

2. A turbomachine as defined by claim 1 wherein the stator blade assembly further includes a generally annular housing and a generally annular diaphragm disposed within the housing, and further characterized in that the housing (24) includes separable upper (24a) and lower (24b) housing sections; the diaphragm (26) includes separable upper (50) and lower (52) diaphragm sections; and connecting means (32) disengagably connecting the housing (24) and the diaphragm (26) to limit relative rotation therebetween.

3. A turbomachine as defined by claim 2 further characterized in that the connecting means (32) includes an annular rib portion (56) radially projecting inward from the housing (24); an annular band (58) axially projecting from the annular rib portion (56); pin means (60) radially extending through the annular band (58) into engagement with the diaphragm (26); and means (66) for releasably holding the pin means (60) within the annular band (58).

4. A turbomachine as defined by claim 3 further characterized in that the housing (24) includes axially separable front (34) and back (36) sections; the diaphragm (26) includes a plurality of diaphragm sockets (64); the pin means (60) include a plurality of pins (60) radially extending in to the diaphragm sockets (64); and the means (66) for releasably holding the pin means (60) within the annular band (58) includes a plurality of set screws (60) extending into the diaphragm (26) and into engagement with the pins (60).

5. A turbomachine as defined by claim 2 further characterized in that the connecting means (32) includes at least one radially extending housing aperture (72) defined by the housing (24); pin means (60) extending through the housing aperture (72) and into engagement with the diaphragm (26); and cover means (74) disengagably secured to the housing (24) and extending over the pin means (60) to limit radially outward movement thereof.

6. A turbomachine as defined by claim 5 further characterized in that the cover means (74) includes a cap (74) extending into the housing aperture (72), encircling and covering a portion of the pin means (60) located therein, and threadably engaging the surfaces of the housing (24) defining the housing aperture (72).

7. A turbomachine as defined by claim 5 further characterized in that the cover means (74) includes a flange cover (74) located outside the housing (24) and extending over the housing aperture (72); and bolt means (78) releasably securing the flange cover (74) to the housing (24).

8. A method of installing a stator blade assembly in a rotary machine having an axially extending rotor and fluid casing annularly extending therearound, the installing method characterized by the steps of positioning a lower diaphragm section (52) and a first set of stator blades (30) within a lower housing section (24b); positioning the lower diaphragm (52) and housing sections (24b) adjacent to the fluid casing (18) and below the rotor (12); disengagably securing the lower housing section (24b) to the fluid casing (18); positioning an upper diaphragm section (50) and a second set of stator blades (30) over the rotor (12) and the lower diaphragm section (52); disengagably connecting together the upper (50) and lower (52) diaphragm sections to form a diaphragm (26) encircling the rotor (12); positioning an upper housing section (24a) over the diaphragm (26); disengagably securing together the upper (24a) and lower housing (24b) sections to form a housing (24) encircling the diaphragm (26); disengagably securing the upper housing section (24a) to the fluid casing (18); and disengagably connecting the diaphragm (26) and the housing (24) to limit relative rotation therebetween.

9. A method as defined by claim 8 further characterized in that the step of positioning the lower diaphragm section (52) within the lower housing section (24b) includes the step of spacing the lower diaphragm section (52) therefrom; the step of positioning the upper housing section (24a) over the diaphragm (26) includes the step of spacing the upper housing section (24a) therefrom; and the step of disengagably connecting the diaphragm (26) and the housing (24) includes the steps of radially inserting a plurality of pins (60) through surfaces of the housing (24) and into engagement with the diaphragm (26), and covering the pins (60) to limit radially outward movement thereof.