US3432048A - Apparatus for inspecting and overhauling turbine diaphragms - Google Patents

Description

March 11, 1969 R Q MUSGROVE T 3,432,048

APPARATUS FOR INSPECTING AND OVERHAULING TURBINE DIAPHRAGMS Sheet Filed Jan. 4, 1966 f)? ventorns Kano/d 0. fimggr'az e W/fl/am /./7c/7///ar7 7/7e/r' Attorney March 11, 1969 R. o. MUSGROVE ETAL 0 APPARATUS FOR INSPECTING AND OVERHAULING TURBINE DIAPHRAGMS Sheet Filed Jan. 4, 1966 [rm/en tors Fona/d Q/Vuggfiroye MW/am (1/70/7/7/5)? by i/ 1 M 7he/r' fltt-orney United States Patent Office 3,432,048 Patented Mar. 11, 1969 3,432,048 APPARATUS FOR INSPECTING AND OVER- HAULING TURBINE DIAPHRAGMS Ronald Obie Musgrove, Metairie, and William Joseph Mc- Millan, New Orleans, La., assignors to General Electric Company, a corporation of New York Filed Jan. 4, 1966, Ser. No. 518,684 US. Cl. 21441 Int. Cl. B66f 19/00 Claims ABSTRACT OF THE DISCLOSURE Our invention relates to steam turbines and in particular to apparatus to facilitate the inspection, repair and maintenance of the diaphragms of such turbines.

It has long been recognized that the work of inspecting and overhauling the diaphragms of steam turbine generators is complex and requires considerable room for operation. Thus, for example, on a large steam turbine there may be as many as 54 diaphragms each of which must be handled individually at least four times under present procedures. Furthermore, in such handling, considerable floor area is required to lay down the diaphragms during the inspection and maintenance period. Again, the present methods of inspecting and overhauling such diaphragms ties up expensive crane equipment which could be utilized for other purposes during much of the period when a diaphragm is suspended from the crane according to the present practice.

It is a primary object of our invention to provide improved apparatus for inspecting and overhauling the diaphragms of steam turbines and the like which will permit the inspection and overhauling of individual diaphragms while minimizing the space required for such operations.

It is another object of our invention to reduce the number of times that individual diaphragms must be handled during inspection and overhauling.

It is a still further object of our invention to provide improved apparatus for overhauling and inspecting the diaphragms which reduces the over-all time required for such operation and also minimizes the chances of damaging the individual diaphragms.

In accordance with our invention, individual diaphragms of a steam turbine are lifted from the turbine shell by means of a lifting bar and suspended from respective hanging racks supported by a trolley movable on an I-beam, the lifting bar being shaped to permit a diaphragm to be moved to a position directly below the I-beam, the I-beam and diaphragm assembly being movable as a unit to a position where inspection and repair may be made, the movable trolleys permitting separation of adjacent diaphragms to facilitate such inspection and repair.

The novel features which we believe to be characteristic of our invention are set forth with particularity in the appended claims. Our invention, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view of a portion of the apparatus according to our invention;

FIGURE 2 is the perspective view of other elements of the apparatus according to our invention and illustrates diaphragms suspended from such apparatus; and

FIGURE 3 is a schematic vertical view of a modification of the apparatus of our invention.

FIGURE 1 illustrates a portion of the lower half of a shell 1 of a conventional steam turbine. Such a shell conventionally comprises a casting having a plurality of separating members 2 spaced longitudinally of the shell between which are placed the individual diaphragms 3 of the turbine. As used herein, the term diaphragm means a semicircular arrangement of stationary turbine buckets, two such diaphragms being combined to form a stage of stationary turbine buckets in a well known manner. In the drawing of FIGURE 1 a number of such diaphragms have already been removed from the shell and the illustrated diaphragm 3 is shown as suspended from a lifting bar 4 which may be formed of cast iron or a welded construction of suitable size pipe and flat plate iron. The lifting bar 4 includes a dog-leg or L-shaped portion 5 which extends vertically and to the lower portion of which is attached a horizontally extending bar 6. Preferably bar 6 is formed integrally with or Welded to the L-shaped portion 5 and includes a plurality of vertically extending projections or stop members 7. At its upper end, the L-shaped portion includes a lifting eye 8 through which may be passed a cable of the type conventionally used with overhead cranes.

FIGURE 2 illustrates the lifting bar 4 supporting a diaphragm 3 by means of a plurality of chains 9 and moved from its position over the turbine shell of FIG- UR-E l to a position where the diaphragms are suspended under a handling rack of our invention. Handling rack 10 comprises a longitudinally extending supporting member 11 having a vertically extending web 12 and a plurality of laterally extending flanges 13. Supporting member 11 may comprise, for example, a conventional I-beam to the upper surface of which are attached, in any conventional manner such as by Welding, a plurality of lifting lugs 14. At each end of member 11 are placed stop-members 15 between the lower flange 13 and the upper flange 16 of the member for purposes to be explained later. Fastened to each end of the supporting member 11 and extending vertically down therefrom is a hollow pipe member 17 which is adapted to be adjusted in position as by means of pins or bolts 18 relative to vertically extending supports 19. The supports 19, in turn, are supported in a base member 20 which comprises a flat plate 21 to which is attached a pipe 22 and supporting rods 23.

Carried by the lower flanges 13 of supporting member 11 are a plurality of movable members or trolleys comprising wheels 24 which carry a pair of hangers 25 and a hanger bar 26 having a pair of hooks 32 adapted to engage a rod 33 connecting hangers 25. Preferably each hanger bar is provided with a pair of spaced upright projections 0r stops 27 near each of its ends and a collar 28 at each end thereof.

In the use of the apparatus of our invention, the lifting bar 4 is suspended from a crane and lowered over a diaphragm to be removed from the shell 1. Such removal is effected by fastening a plurality of eyebolts 30 to each shell half and using chains 9 which pass through the eyebolts and loop over horizontal bar 6 between stop members 7. The attached diaphragm 3 is then lifted by a means of an overhead crane to a position adjacent supporting member 10 which preferably has been previously placed at a point adjacent shell 1. The crane supporting lifting bar 4 and its suspended diaphragm 3 is used to lower the horizontal bar 6 to a position where it is parallel with the crossbar member 26 of one of the trolleys 24. To effect this operation, lifting bar 4 has a shape which permits the center of a diaphragm to be moved to a point substantially under web 12 of supporting member 10. When it is in such position the diaphragm is lifted sufliciently high by the crane that two additional shorter lengths of chains 31 may be passed through the eyebolts attached to the diaphragm and looped over the adjacent crossbar member 26. Thereafter the diaphragm is lowered by supporting member 4 until the chains 9 which attach the diaphragm to crossbar 6 become slack and can be unhooked. Lifting bar 4 is thus detached from the diaphragm 3 which is now supported by the crossbar 26. The lifting bar may then be returned to the turbine shell for removal of the next diaphragm following the procedure previously outlined.

When all trolleys with their supported crossbar members have been filled with half diaphragms, the supporting member 10 with its trolley and crossbar assemblies, and the diaphragms supported by such assemblies may be moved as a unit from their position adjacent the shell to a desired inspection point. To effect this operation, a crane is hooked to the two lifting lugs 14 on top of member 10 and the entire unit may be carried to an inspection point where the suspended half diaphragms may be sandblasted, inspected and magnafluxed in a conventional manner. In such operation each individual diaphragm may be moved laterally, by means of its supporting trolley, relative to the other diaphragms to a position where each of its sides is easily accessible for inspection and overhauling. Stops 15 are provided to limit the lateral movement of the end trolleys.

When the inspection and overhauling procedure has been completed the unit may be returned to a position adjacent the shell and the individual diaphragms returned to their places in the shell, reversing the procedure previously outlined.

FIGURE 3 illustrates a modification of our invention in which the handling rack 40 has a length sufficient that it can be placed directly above a turbine half. In such arrangements the vertical supports 41, which may be adjusted in height relative to the hollow pipe members 42, may be placed at the ends of a turbine shell so that the handling rack is directly above the turbine shell with its associated diaphragms. Such an arrangement reduces the lifting of the individual diaphragms 3 from the turbine shell to a simple vertical movement so that they can be attached to their respective trolleys 24, 25. While in such an arrangement we still prefer to use a lifting bar 4 with its dog-leg or L-shaped portion to raise the individual diaphragms from the shell, it is obvious that now it is not necessary to completely remove each diaphragm to a distant point for engagement to its respective hanger bar and trolley member. As in connection with the modification shown in FIGURE 2, lifting lugs 14 are provided at the top of handling rack 40 so that the handling rack with its assembly of trolleys and suspended diaphragms may be moved as a unit to a desired position for inspection and maintenance of the diaphragms.

One handling rack of the type shown in FIGURE 2 which we have employed for maintenance and overhaul of steam turbines consists of an I-beam approximately 10 /2 feet long with end supports approximately 6 feet high, the bases for such supports being approximately 4 feet wide. We have found that a rack of such dimensions permits employment of 10 trolley arrangements so that 10 diaphragms may be handled as a unit.

. One of the advantages of our invention is that it reduces considerably the time spent in handling each diaphragm during disassembly and reassembly. We have also found that with such an arrangement, inspection and cleaning can be done more thoroughly, more conveniently,

and in approximately one half the time required when using conventional methods.

A still further advantage of our arrangement is that the handling racks with the use of the lifting bar requires less space for the inspection and maintenance of a steam turbine, permits convenient handling with less chance of damage to the diaphragms, and assures greater safety to the personnel working around the turbine. When using racks of the type and dimensions mentioned previously, we have found that for large turbines five such racks, each capable of holding ten diaphragms, is adequate for the inspection and maintenance operation. Such racks not only are lightweight and easy to assembly, dismantle and transport but also are relatively inexpensive to build.

One important advantage of the use of the racks of our invention in accordance with the method described above is that the storage space for the diaphragms during a maintenance and overhaul operation is reduced by at least and the man-hours required for the overhaul and inspection is reduced by approximately 25% due to better accessibility to the individual parts of the turbine.

While we have shown particular embodiments of our invention it will, of course, be understood that we do not wish to be limited thereto, since many modifications may be made in the structural arrangements shown and in the instrumentalities employed. We contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States are:

1. In apparatus for inspecting and repairing turbine diaphragms the combination comprising:

a supporting member having a vertically extending web and a flange extending from the web,

a plurality of members movable on said flange, each of said movable members supporting a crossbar member,

a lifting bar movable from a position over a turbine shell in which a diaphragm may be attached to said lifting bar to a position in which such a diaphragm may be attached to a crossbar member, said lifting bar being shaped to permit the center of an attached diaphragm to be positioned substantially under said web, and

lifting means attached to said supporting member and attached diaphragms may be moved as a unit.

2. The apparatus of claim 1 in which said supporting member is an I-beam having laterally extending flanges and said movable members are trolleys movable on the flanges of the I-beam.

3. The apparatus of claim 1 in which said lifting bar has an L-shaped portion.

4. The apparatus of claim 1 in which the supporting member includes a vertically adjustable column at each end thereof.

5. The apparatus of claim 2 which includes a pair of chains for supporting a diaphragm from its respective crossbar member, and the crossbar member includes projections to prevent slippage of the chains.

References Cited UNITED STATES PATENTS 1,612,216 12/1926 Phillips 214-624 1,951,008 3/1934 Best 5114 2,344,476 3/ 1944 Turnbull 5114 X 3,192,677 7/1965 Johnson et al 51321 LESTER M. SWINGLE, Primary Examiner.

US. Cl. X.R. 51-14

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