Claims:WE CLAIM:
1. A shipping fixture assembly (200) for supporting and transporting an inner casing of a steam turbine, the shipping fixture assembly (200) comprising:
a base frame (302) having a substantially rectangular shape, the frame including:
a plurality of transverse beams (304), and
a plurality of longitudinal beams (306) configured to be coupled to the plurality of transverse beams, wherein the transverse beams and the longitudinal beams defines a box channel structure obtained by joining a plurality of first channels (1) through a plurality of first plates (2), the plurality of first plates (2) facing opposite to each other; and
a plurality of vertical columns (402) configured to be disposed at corners of the base frame (302), the plurality of vertical columns (402) including:
a plurality of second channels (4) placed opposite to each other,
at least one first I-beam (5) placed between the plurality of second channels (4), and
a plurality of second plates (6) for joining the plurality of second channels (4) and the at least one first I-beam (5) to form a rectangular cross section.
2. The shipping fixture assembly (200) as claimed in claim 1, wherein a plurality of third plates (7) are placed over the plurality vertical columns (402) for resting palms (403) of the inner casing of the steam turbine.
3. The shipping fixture assembly (200) as claimed in claim 2, wherein a plurality of third channels (12) are provided on top of each of the plurality of vertical columns (402) for guiding the palms (403) of the inner casing, and restricting a sideways movement of the palms of the inner casing.
4. The shipping fixture assembly (200) as claimed in claim 3, wherein a plurality of fourth channels (11) are used for locking the inner casing with each of the plurality of vertical columns (402), the locking being achieved by fasteners.
5. The shipping fixture assembly (200) as claimed in claim 1, wherein a plurality of fifth channels (19) are secured to the base frame (302) to form a cross structure.
6. The shipping fixture assembly (200) as claimed in claim 2, wherein a plurality of sixth channels (18) are secured to the plurality of vertical columns (402) at a height below the palms of the inner casing.
7. The shipping fixture assembly (200) as claimed in claim 6, wherein at least one second I-beam (9) and a plurality of seventh channels (10) are provided in a zig-zag orientation between the base frame (302) and the plurality of sixth channels (18).
8. The shipping fixture assembly (200) as claimed in claim 7, wherein a plurality of eighth channels (8) are diagonally provided with the at least one second I-beam (9).
9. The shipping fixture assembly (200) as claimed in claim 1, wherein a plurality of stiffening plates (21) are provided at joints of the plurality of vertical columns (402) with the base frame (302).
10. The shipping fixture assembly (200) as claimed in claim 1, wherein a plurality of wooden beam frames (17) and a plurality of metallic covers (22) are used to protect the inner casing from external media.
11. The shipping fixture assembly (200) as claimed in the preceding claims, wherein the plurality of first channels (1), the plurality of second channels (4), the plurality of third channels (12), the plurality of fourth channels (11), the plurality of fifth channels (19), plurality of sixth channels (18), plurality of seventh channels (10), the plurality of eighth channels (8) are made of steel.
, Description:A shipping fixture assembly for a steam turbine
FIELD OF INVENTION
[001] This invention relates generally to turbine technology and, more specifically, to the means through which an inner casing of a low-pressure steam turbine can be shipped to and/or lifted into or out of position at its ultimate site of operation.

BACKGROUND OF THE INVENTION

[002] It is a general practice to transport the small to medium size turbine in assembled state from manufacturing unit. Whereas with the increase in power rating of steam turbines the size and weight of the steam turbines has increased. Unlike small size turbines that can be transported in an assembled condition, in order to transport a large steam turbine, the steam turbine must be disassembled because the rotor is not rigidly connected to the casing so that a relational movement between the casing and rotor is caused when the assembled steam turbine is lifted for transportation.
[003] Transport problems are greatly increased as the size of turbine units rises and therefore established means and methods of transportation, as in prior art, are not possible for large size steam turbines. Hence, owing to its large size, it was made necessary to send turbines to site in disassembled state. It generates the requirement of transporting the various components of turbine separately. The huge steam flow in high rating steam turbines has resulted into increased size of Low pressure turbines. The huge size of low pressure steam turbine inner casing has made it a critical component of the turbine from transportation point of view.
[004] When a Low-pressure Turbine Inner casing is dispatched from works facility, it consists of stationary blades. Low Pressure Turbine have multiple blade stages. One blade stage includes one moving blade ring which is mounted on Turbine Rotor and one stationary ring which is assembled with turbine casing. Initial stages of LP turbine are drum type and their stationary blades are mounted on Guide Blade Carrier (GBC). Further, GBCs are assembled with LP inner casing. Last stages of LP turbines relative much bigger in size, their stationary blades are directly welded with GBCs and further assembled with LP inner casing. This LP inner casing assembled with GBCs needs to transport safely without any damage in casing or stationary blades.
[005] Partially disassembled units, however, also pose shipping problems. For example, if the turbine outer casing and rotor are removed, it may well be possible to ship the turbine inner casing with various components remaining therein, but if not properly supported, the inner casing may deflect excessively and violate stress limits imposed by design practices. As a result, even if no permanent damage has been sustained, realignment, resetting of all clearances and increased testing may be required before the turbine can enter service.

OBJECTS OF THE INVENTION

[006] The objective of the present invention is to develop a means for safe transporting of an inner casing of a low-pressure steam turbine.

[007] Another object of invention is to design a shipping fixture assembly with proper dimensions to fit the low-pressure steam turbine inner casing into it for transportation or shipping purpose.

SUMMARY OF THE INVENTION

[008] The present disclosure relates to a shipping fixture assembly (200) for supporting and transporting an inner casing of a steam turbine. The shipping fixture assembly (200) includes a base frame (302) having a substantially rectangular shape. The base frame includes a plurality of transverse beams (304), and a plurality of longitudinal beams (306) configured to be coupled to the plurality of transverse beams (304). The transverse beams (304) and the longitudinal beams (306) defines a box channel structure obtained by joining a plurality of first channels (1) through a plurality of first plates (2), the plurality of first plates (2) facing opposite to each other. The shipping fixture assembly (200) further includes a plurality of vertical columns (402) configured to be disposed at corners of the base frame (302). The plurality of vertical columns (402) includes a plurality of second channels (4) placed opposite to each other, at least one first I-beam (5) placed between the plurality of second channels (4), and a plurality of second plates (6) for joining the plurality of second channels (4) and the at least one first I-beam (5) to form a rectangular cross section.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[009] Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings of the exemplary embodiments and wherein:
Figure 1 shows: A cross sectional view of a steam turbine.
Figure 2 shows: A perspective view of a shipping fixture assembly (200) in accordance with an embodiment of the present disclosure.
Figure 3a shows: A front view of the shipping fixture assembly (200).
Figure 3b shows: A zoomed view M of a box channel structure associated with the shipping fixture assembly (200).
Figure 4a shows: A side view of the shipping fixture assembly (200).
Figure 4b shows: A zoomed view N showing rectangular cross section of vertical columns (402).
Figure 5 shows: The shipping fixture assembly (200) being placed over a transporting medium (500).

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

[0010] The present invention, now be described more specifically with reference to the following specification.

[0011] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.

[0012] Steam turbine extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft to drive an electrical generator for generating electricity.

[0013] In larger power stations, the steam turbines are split into three separate stages, shown as a cross sectional view in Fig. 1, the first stage being the High Pressure (HP), the second stage the intermediate Pressure (IP) and the third the Low Pressure (LP) stage where high, intermediate and low describe the pressure of the steam. The High Pressure (HP) turbine module (102) is the first turbine to receive steam from the main steam system, while Low Pressure (LP) turbine module (104) is the last. The turbine in between the HP and LP is an intermediate Pressure (IP) Turbine module (103). These turbines are designed to efficiently extract work out of high pressure of the steam as steam passes through all the modules and converts thermal energy (high pressure and high temperature) of working fluid in to mechanical energy.

[0014] In general, a steam turbine includes a rotor and a casing for enclosing the rotor. A pair of bearing boxes, which enclose bearings for rotationally supporting the opposite ends of the rotor, are provided on the opposite end portions of the rotor. The casing includes a steam inlet through which steam is directed to turbine portions which are symmetrically provided on either side of the rotor. Each of the turbine portions includes multistage stationary and moving blades provided around and along the rotor.

[0015] Fig. 2, illustrates a perspective view of a shipping fixture assembly (200) in accordance with an embodiment of the present disclosure. In an embodiment, the shipping fixture assembly (200) is configured to receive an inner casing (not shown) of a steam turbine. The inner casing being placed in the shipping fixture assembly (200) is configured to be transported to the site of operation.
[0016] Fig. 3a illustrates a front view of the shipping fixture assembly 200, wherein the inner casing is placed on the shipping fixture assembly. A base frame (302) of the shipping fixture assembly (200) is manufactured from plurality of first mild steel channels (1), which are welded together by using a plurality of first plates (2) facing opposite to each other. The plurality of first mild steel channels (1) and the plurality of first plates (2) are combined to form a box channel structure as shown in zoomed view M in Fig. 3b. The box channel structure is used to make transverse beams (304) of length (L’) and longitudinal beams (306) of length (L), and are joined in a way to accommodate the LP inner casing in the shipping fixture assembly (200).

[0017] Fig. 4a illustrates a side view of the shipping fixture assembly (200), wherein the inner casing is placed on the shipping fixture assembly (200). As shown, a plurality of vertical columns (402) of the shipping fixture assembly (200) are manufactured using a plurality of second mild steel channels (4) having suitable web length, and placed facing opposite to each other, with at least one first I-beam (5) in between. A plurality of second plates (6) are used to weld the plurality of second mild steel channels (4) with the at least one first I-beam (5) to form a rectangular cross section as shown in zoomed view N in Fig. 4b to form a rectangular cross section. The plurality of vertical columns (402) are connected to the base frame (302) at four corners of the base frame (302) with help of welding.

[0018] With continued reference to Figs. 2, 3a, 3b, 4a, and 4b, structural and functional characteristics of various components of the shipping fixture assembly (200) will now be described in the following specification. A plurality of third plates (7) are placed over the plurality of vertical columns (402) where palms (403) of the LP inner casing are rested. The load of the LP inner casing is being transferred to all the four vertical columns (402), and is further transferred to the base frame (302) of the shipping fixture assembly (200). A plurality of third mild steel channels (12) are used at the top of each of the plurality of vertical columns (402) to guide the LP inner casing palms (403) and restrict its sideways movements. A plurality of fourth mild steel channels (11) are used to lock the LP inner casing with corresponding vertical column (402) of the plurality of vertical columns (402) with help of fasteners.

[0019] A plurality of fifth mild steel channels (19) are used to strengthen the base frame (302), and are welded at the level of the base frame (302) to form cross structure. A plurality of sixth channels (18) are used to connect with all of the plurality of vertical columns (402) at a certain height below the LP inner casing’s support palm level. This will enhance load capacity of the plurality of vertical columns (402) and don’t let them move in sideways direction. Further, at least one second I-beam (9) and a plurality of seventh mild steel channels (10) are used in zig-zag orientation to strengthen the shipping fixture assembly (200) as shown on the front view between the base frame (302) and the plurality of sixth mild steel channels (18). A plurality of eighth mild steel channels (8) are used to support the at least one second I-beam (9) diagonally to further strengthen the shipping fixture assembly 200. All these aforementioned and described structural members are used to transfer and distribute load of the LP inner casing from the plurality of vertical columns (402) to the base frame (302) uniformly. In accordance with an embodiment of the present disclosure, the shipping fixture assembly (200) is analyzed for various loading conditions using a Finite Element simulation program (FE software), prior to the industrial use of the shipping fixture assembly (200).

[0020] After placement of the LP inner casing in the shipping fixture assembly (200), the inner casing is locked with the plurality of vertical columns (402) with help of the plurality of fourth mild steel channels (11). A joint plain of the LP inner casing is secured safe with the help of wooden beams (13) at both ends. The wooden beams (13) are locked with the LP inner casing with the help of Bolt (14) and Nuts (15). A top wooden plank (16) is used to cover the LP inner casing carrying stationary blades inside. Further, a plurality of frames (17) formed by wooden beams are used to cover the LP inner casing diffuser area in a way, so as to restrict an entrance of external particles into the LP inner casing. Further, a plurality of metallic covers (22) are used to protect multiple extraction openings present below the LP inner casing from external media. A plurality of stiffening plates (21) are used to reduce stresses at the joints of the plurality of vertical columns (402) and the base frame 302. A metallic sheet (20) is used to cover the entire package from the top, i.e. over a wooden plank (15).

[0021] Fig. 5 depicts transporting of the inner casing, wherein the inner casing is being received by the shipping fixture assembly 200, and the shipping fixture assembly (200) is placed over a transporting medium 500 for transporting the inner casing to the ultimate site of operation, and further assembling with other sub parts.

[0022] It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims.