Claims:WE CLAIM

1. A Centrifugal Blower with shear ring comprising of casing [1], end covers [2a &2b], diaphragms [3,3a & 3b] and rotor, wherein the process air enters into said casing [1] from suction nozzle [1a] and gets compressed through a plurality of impellers [5] mounted on a rotating shaft [4] and a flow path is formed by inner casing [3] and an intermediate diaphragms [3a], and enters into discharge diaphragm [3b] and leaves from discharge nozzle [1b].

2. The Centrifugal Blower with shear ring as claimed in claim 1, wherein the suction end cover [2a] is fixed to the casing [1] by a plurality of shear and shim ring segments [8a and 9a].

3. The Centrifugal Blower with shear ring as claimed in claim 1 or 2, wherein the discharge end cover [2b] is fixed to the casing [1] by a plurality of shear and shim ring segments [ 8b and 9b].

4. Assembly of a Centrifugal Blower with shear ring comprising the following steps:
- assembling diaphragm bundle including inner casing [3], intermediate diaphragm [3b], and rotor into casing [1] from the left side with the help of assembly/disassembly fixture;
- assembling suction end cover [2a] into the casing with help of a lifting device [14], in which the end cover is butted with inner casing face (j);
- provision of an annular circumferential groove in the casing to assemble a plurality of shear rings [8a] having ‘L’ shaped cross-section segmented into multiple pieces with a horizontal offset (z) to lock the end cover to the casing;
- determination of gap (X3) between the shear ring and casing face (g);
- assembling a plurality of shim rings [9a] having rectangular cross-section segmented into multiple pieces with a vertical offset (z),
- assembling the discharge end cover [2b] along with discharge diaphragm [3b] into the casing from the right side with help of lifting device [14].

5. Assembly of a Centrifugal Blower with shear ring as claimed in claim 4, wherein the inner casing is butted with casing face (a), in which the end cover [2a] has extended a distance of (X1) + 1mm from the casing face (d), wherein an anti-rotation pin [7] disposed in the end cover is provided to align the end covers vertical center axis to the casing vertical center axis with help of groove [7a] provided in the inner casing [3], and an ‘O’ ring is provided on the end cover to prevent pressurized air leakage from the casing to the atmosphere.

6. Assembly of a Centrifugal Blower with shear ring as claimed in claim 4 or 5, wherein once the shear ring segments assembled in the casing annular groove, a gap is maintained as assembly clearance for butting of the shear ring to the end cover face (j), in which each shear ring segment is fixed to the end cover by cap screws [12], wherein the width of the shear ring is equal to X1+X2.

7. Assembly of a Centrifugal Blower with shear ring as claimed in claims 4-6, wherein an allowance is provided on the shim ring face butting to casing face (g) i.e. the shim ring thickness is equal to X3+1mm before assembly, in which the allowance is to be machined during the final assembly after measuring gap X3, an annular circumferential groove (k) is provided in the casing for assembly of shim ring in the gap (X3), and once the shim ring is assembled in the gap between the casing and shear rings, each shim ring is fixed to the shear ring by two no. of cap screws [13].

8. Assembly of a Centrifugal Blower with shear ring as claimed in claims 4-7, wherein after completion of assembly steps III & V, the end cover, shear ring segments, and shim ring segments are unitized as a single-piece structure, in which the lifting device has a spigot 14a and an annular groove is provided on the end cover, wherein the lifting device spigot is disposed in the end cover annual groove and fixed to the end cover with the help of bolts 14b.

9. Assembly of a Centrifugal Blower with shear ring as claimed in claims 4-8, wherein a bracket assembly comprising of a bracket [10], bolt [10a], stud [10c], hexagonal cap nut [10b], and hexagon nut [10d] is provided to prevent movement or misalignment due to vibrations during the operation of the centrifugal blower, in which the bracket assembly is used for the assembly and disassembly of the end cover into the casing in the axial direction.

10. Assembly of a Centrifugal Blower with shear ring as claimed in claims 4-9, wherein the steps from II to VII are followed for assembling the shear and shim ring segments [8b and 9b] respectively to complete the blower assembly.

Description:“A CENTRIFUGAL BLOWER WITH THE SHEAR RING”

FIELD OF THE INVENTION:

[001] The field of the invention relates to the centrifugal blower end cover and casing locking feature. In particular, the invention is directed to Centrifugal Blower with shear ring.

BACKGROUND OF THE INVENTION:

[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[003] Recently, most of the thermal power plants have installed FGD (Flue Gas De-sulfurization) units to remove sulfur dioxide (SO2) from the flue gas emissions. These FGD units required low-pressure compressors/blowers to supply the air to the absorber in line with the process requirement. Hence, these blowers are typically called Oxidation blowers in the FGD unit. In the FGD system, one absorber unit requires two sets of compressors/blowers i.e. one working and one standby for continuous operation. For example, typically for a 5x800MW power plant, five number of absorbers require ten number of compressors/blowers. There are different types of compressors/blowers like roots blowers, single-stage overhung compressors, and multistage centrifugal compressors available in the market.

[004] Referring to FIG.2 regarding the existing method indicating a cross-sectional view of a centrifugal compressor, in which the end cover E1 is fixed to the casing C1 using studs N and special cap nuts M. The number of holes L required to fix the end cover to casing depends upon the casing size and process gas pressure. With this fixing method, the following manufacturing operations are required:

1. Drilling the normal holes in both suction and end covers E1 & E2.
2. Drilling the threaded holes L in the casing on both the suction and discharge sides.
3. Manufacturing of studs, special guide studs, and special cap nuts.

[005] Thus, the manufacturing cost and assembly cost have increased drastically. To minimize the above manufacturing and assembly cost thereby reducing the overall blower cast, the present invention has developed.

[006] Hence, the present invention i.e. a centrifugal blower with a shear ring has been designed in order to optimize the blower manufacturing cost, thereby reducing the total cost of the blower to meet the market requirements.

[007] In the present invention, the focus is to reduce the blower manufacturing and assembly cost by changing the end cover fixing method to the casing.

[008] Some patents may be discussed related to the end cover and casing locking feature herein below:

1. US2196895:
[009] In this prior art, ref. fig.1, a cover 10 is locked in the high-pressure cylindrical casing body member 9 with the help of heavy annular rim24 attached to the outer face of the cover 10, preferably by welding at 26, whereby a tight seal is provided between the two parts. Further, an outwardly facing annular groove 27 is provided in the rim portion, and an inwardly facing annular groove in the body member 9. These two grooves form a closed annular passage. A plurality of shear pieces 29 are disposed in the annular passage and are movable radially with help of bolts 31.
[0010] Whereas in the present invention, ref fig.4, an end cover 2a is locked in the centrifugal blower casing 1 with a plurality of shear rings 9a and shim rings 9a disposed in an annular groove provided in the blower casing 1.
[0011] In this prior art ref fig.4, annular rings37 and 38, annular gasket 36 and 33, sealing plate34, bolts 31,38 and 39, heavy annular rim24, and a plurality of shear pieces are required to lock the cover 10 to the high-pressure cylindrical member9.
[0012] Whereas in this present invention ref fig.4, fig.6 and fig.8, the end cover2a is fixed the blower casing1 by using a plurality of shear rings 8a, a plurality of shim rings 9a, and fixing bolts 12 and 13 only.
[0013] In this prior art ref fig. 4 and fig. 5, a plurality of shear pieces 29 disposed in the annular passage formed by annular grooves 27 and 28 in the annular member 24 and cylindrical body member respectively. The above shear pieces moved in the annual passage radially inward and outward using bolts 31. Practically, while assembly and disassembly of cover 10, the radial movement of shear pieces is difficult in the annular passage due to the high frictional forces generated by rubbing the three-side surface of shear pieces to the annular passage surfaces.
[0014] Whereas in this present invention ref fig. 4, fig. 6 and fig. 8, a plurality of shear rings 8a and shim rings 9a are disposed in the annular groove provided in the blower casing 1 and fixed to the end cover 2a using bolts 12 and 13. Hence, there is no radial movement allowed for shear and shim in the casing groove.
[0015] In this prior art ref fig. 4 and fig. 5, to restrict high-pressure fluid leakage from the cylindrical member 9, the heavy annular member 24 is welded to the cover 10. Further, in this prior art, to remove the cover 10 from the cylindrical member 9, weldment between annular rim 24 and cover 10 to be removed every assembly and dis-assembly.
[0016] Whereas in the present invention ref fig. 4 an O-ring 11 is disposed in the annular groove, provide in the end cover 2a to restrict the air leakage from the blower casing 1 to the atmosphere.

2. US4380405A:
[0017] In this Prior art, ref. fig. 1, fig. 2, and fig. 3 a plurality of slide keyways 17a and 17b on the inner surface of the casing1 and the outer circumferential surface of the head flange 2. A slide key 18 is disposed in each pair of slide keyways to keep the center axis of the head flange in alignment with the center axis of the casing at all times. A shear key 3 is split into a plurality of circumferentially spaced pieces and held in a shear keyway 4 formed on the inner circumferential surface of casing 1, to keep the head flange 2 from being moved outwardly by the internal pressure. The numeral 5 is an annular offset portion formed in a position on the head flange 2 juxtaposed against the inner circumferential side of the shear key 3. An annular key keep member 7 disposed in the offset portion 5 and held in place by bolts 8, to avoid dislodging of the shear key 3 from the shear keyway 4.
[0018] Whereas in the present invention ref fig. 4, fig. 6 and fig. 8, a plurality of shear rings 8a and shim rings 9a are disposed in the annular groove provided in the blower casing 1 and fixed to the end cover 2a using cap screws 12 and 13. The shear ring is disposed in the annular groove formed by casing 1 and end cover 2a in such a manner that, the outer circumferential surface of the shear ring is butting with inner surface (f) of casing 1 and the inner circumferential surface of shear ring is butting with outer surface (c) of end cover 2a very close fit. Hence, with this close fit, there is no radial movement allowed for end cover 2a in the casing. However, to achieve this close fit & for easy assembly and disassembly of shear ring in the annular groove, ref. fig.6, axial gap of 1mm provided between the shear ring and casing groove surface (d) and a radial clearance provided to reduce the frictional contact between shear ring and casing groove surface (e) as shown in fig.6.
[0019] In this Prior art, ref. fig.4 and fig.5, fig.6 and fig.7, The pairs of slide keyways 17a and 17b are located in four circumferentially equidistantly spaced positions as shown in FIG. 6, and slide key 18 (18a, 18b, 18c, and 18d) is held in each pair of slide keyways 17a and 17b. A cross-bridging bolt C as shown in fig.5 and a tension bolt 21 is useful to align the head flange2 center to the casing1 center and these two bolts help to prevent vibrations due to movement or misalignment during operation of the turbomachine.
[0020] Whereas in this present invention ref fig.4, a pin7 is disposed in the end cover2a and the same pin along with the end cover is inserted in the groove 7a provided in the counter casing3 during assembly. Due to this pin arrangement, the end cover’s vertical center axis is perfectly aligned to the casing center and the same pin helps prevent the rotation of the end cover in the casing. Further, in the present invention ref fig.4, and fig.9, a bracket assembly (comprises of a bracket 10, bolt 10a, stud 10c, hexagonal cap nut 10b, and hexagon nut10d) is used for the assembly and disassembly of the end cover into the casing. One more advantage of this bracket assembly is to prevent vibrations due to movement or misalignment during the operation of the centrifugal blower.

3. US3934752A:
[0021] In this Prior art, ref. fig.1 and fig.2, an end wall 26 is locked in the compressor casing 34 with help of segmented keys including a shear key 39 and compression key 40 both are having rectangular cross-sections are disposed in the annual groove provided in the casing 34.
[0022] Whereas in this present invention ref fig. 4, fig. 6 and fig. 8, a plurality of shear rings 8a having ‘L’ shaped cross-section and shim rings 9a having rectangular cross-section are disposed in the annular groove provided in the blower casing 1.
[0023] In this Prior art, ref. fig.1 and fig.2, each key is made up of four distinct segments to facilitate their mounting within the casing groove. In the case of the compression key, as shown in FIG. 2, these segments include parts 50-53.
[0024] Whereas in this present invention ref fig. 9 and fig. 10, each shear ring and shim ring segmented horizontally and vertically with an offset (Z) which is equal to 1/3rd of the outer diameter (D) of the shear ring and shim ring respectively as shown in fig. 10.
[0025] In this prior art, ref. fig.1 and fig.2, further, a series of cap screws49 are passed through openings provided in the compression key40 segments and treaded into the corresponding shear key segments. When tightened, the cap screws pull the two keys into tight face-to-face alignment whereby a substantially unitized one-piece structure prevents movement or misalignment. However, there is a further possibility of movement or misalignment of the above one-piece structure of the shear key and compression key in the casing annular groove during the operation of the compressor. Because this structure is not locked with either end wall or casing.
[0026] Whereas in this present invention ref fig.4, fig.6 and fig.8, each segmented shear ring piece fixed to the end cover with two no. of cap screws12. Similarly, each segmented shim ring piece fixed to the shear ring with two no. of cap screws13. With this arrangement, the end cover, shear ring, and shim ring are unitized as a one-piece structure. Further, in the present invention ref fig.4, and fig.9, a bracket assembly (comprises of a bracket 10, bolt 10a, stud 10c, hexagonal cap nut 10b, and hexagon nut10d) is used for the assembly and disassembly of the end cover into the casing. One more advantage of this bracket assembly is to prevent movement or misalignment due to vibrations during the operation of the centrifugal blower.
[0027] None of the above can fulfil the requirements of the present invention for which it has been devised, hence the present invention has been introduced.

OBJECTS OF THE INVENTION:

[0028] Main object of the present invention is to provide Centrifugal Blower with shear ring.
[0029] Another object of the invention is to provide Centrifugal Blower with shear ring, which obviates short comings of the prior art(s).
[0030] Still another object of the invention is to provide Centrifugal Blower with shear ring, which reduces the material cost, the manufacturing cost, and the assembly cost of the centrifugal blower by changing the fixing method of the end cover to the casing.
[0031] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION:

[0032] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[0033] According to this invention, there is provided a Centrifugal Blower with shear ring comprising of casing [1], end covers [2a &2b], diaphragms [3,3a & 3b] and rotor, wherein the process air enters into said casing [1] from suction nozzle [1a] and gets compressed through a plurality of impellers [5] mounted on a rotating shaft [4] and a flow path is formed by inner casing [3] and an intermediate diaphragms [3a], and enters into discharge diaphragm [3b] and leaves from discharge nozzle [1b].
[0034] The suction end cover [2a] is fixed to the casing [1] by a plurality of shear and shim ring segments [8a and 9a].
[0035] The discharge end cover [2b] is fixed to the casing [1] by a plurality of shear and shim ring segments [8b and 9b], in which the end cover [2a] is pushed into the casing.
[0036] Further according to this invention, there is provided an assembly of a Centrifugal Blower with shear ring comprising the following steps:
- assembling diaphragm bundle including inner casing [3], intermediate diaphragm [3b], and rotor into casing [1] from the left side with the help of assembly/disassembly fixture;
- assembling suction end cover [2a] into the casing with help of a lifting device [14], in which the end cover is butted with inner casing face (j);
- provision of an annular circumferential groove in the casing to assemble a plurality of shear rings [8a] having ‘L’ shaped cross-section segmented into multiple pieces with a horizontal offset (z) to lock the end cover to the casing;
- determination of gap (X3) between the shear ring and casing face (g);
- assembling a plurality of shim rings [9a] having rectangular cross-section segmented into multiple pieces with a vertical offset (z),
- assembling the discharge end cover [2b] along with discharge diaphragm [3b] into the casing from the right side with help of lifting device [14].

[0037] The inner casing is butted with casing face (a), in which the end cover [2a] has extended a distance of (X1) + 1mm from the casing face (d), wherein an anti-rotation pin [7] disposed in the end cover is provided to align the end covers vertical center axis to the casing vertical center axis with help of groove [7a] provided in the inner casing [3], and an ‘O’ ring is provided on the end cover to prevent pressurized air leakage from the casing to the atmosphere.

[0038] Once the shear ring segments assembled in the casing annular groove, a gap is maintained as assembly clearance for butting of the shear ring to the end cover face (j), in which each shear ring segment is fixed to the end cover by cap screws [12], wherein the width of the shear ring is equal to X1+X2.
[0039] An allowance is provided on the shim ring face butting to casing face (g) i.e. the shim ring thickness is equal to X3+1mm before assembly, in which the allowance is to be machined during the final assembly after measuring gap X3, an annular circumferential groove (k) is provided in the casing for assembly of shim ring in the gap (X3), and once the shim ring is assembled in the gap between the casing and shear rings, each shim ring is fixed to the shear ring by two no. of cap screws [13].

[0040] After completion of assembly steps as above, the end cover, shear ring segments, and shim ring segments are unitized as a single-piece structure, in which the lifting device has a spigot 14a and an annular groove is provided on the end cover, wherein the lifting device spigot is disposed in the end cover annual groove and fixed to the end cover with the help of bolts 14b.

[0041] A bracket assembly comprising of a bracket [10], bolt [10a], stud [10c], hexagonal cap nut [10b], and hexagon nut [10d] is provided to prevent movement or misalignment due to vibrations during the operation of the centrifugal blower, in which the bracket assembly is used for the assembly and disassembly of the end cover into the casing in the axial direction.
[0042] The above steps to be followed for assembling the shear and shim ring segments [8b and 9b] respectively to complete the blower assembly.
[0043] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[0044] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0045] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
[0046] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-
FIG-1 shows: 3D Model of Centrifugal blower sectional view with shear rings in accordance with the invention.
FIG-2 shows: Cross-sectional view of a centrifugal compressor with studs and nuts according to the prior art.
FIG-3 shows: Cross-sectional view of Centrifugal blower with shear rings of the present invention.
FIG-4 shows: Detail ‘V’ as shown in Fig.3.
FIG-5 shows: Annular grove in the centrifugal blower casing.
FIG-6 shows: Assembly of shear ring segment to the end cover.
FIG-7 shows: Distance measurement between casing and shear ring to determine the shim ring thickness.
FIG-8 shows: Assembly of shim ring segment to the shear ring segment.
FIG-9 shows: End view details of a centrifugal blower with bracket assembly.
FIG-10 shows: Typical segment method of Shear ring and shim ring.
FIG-11 shows: End cover lifting device.
FIG-12 shows: Fixing details ‘U’ of end cover lifting tool as shown in Fig.11.

[0047] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:

[0048] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0049] The invention makes a disclosure regarding a technology pertaining to a Centrifugal Blower with shear ring.

[0050] The turbomachine illustrated in FIG. 1 is a “barrel” type centrifugal blower comprising of casing 1, end covers 2a &2b, diaphragms 3,3a & 3b, and rotor, which are the main components. The process air enters into said casing 1 from suction nozzle 1a, and gets compressed through a series of impellers 5 mounted on a rotating shaft 4 and a flow path formed by inner casing 3, an intermediate diaphragms 3a, and then enters into discharge diaphragm 3b, and then leaves from discharge nozzle 1b. The main object of the present invention is to reduce the material cost, the manufacturing cost, and the assembly cost of the centrifugal blower by changing the fixing method of the end cover to the casing.

[0051] Reference may be made to fig.3 indicating cross-sectional views of the centrifugal blower of the present invention, in which the suction end cover 2a is fixed to the casing 1 by using a plurality of shear and shim ring segments 8a and 9a respectively instead of studs and special cap nuts as shown in fig.2 indicating cross-sectional view of a centrifugal compressor. Similarly, the discharge end cover 2b is fixed to the casing1 by using a plurality of shear and shim ring segments 8b and 9b respectively. In this invention, the end cover 2a is pushed into the casing thereby reducing the end cover weight on both the suction and discharge side as compared to the centrifugal compressor as shown in fig.2. Further, due to the absence of end cover fixing studs and nuts, drilling of normal holes in end cover, and threaded holes in the casing, the manufacturing cost of blower i.e. man-hours, machining hours, assembly hours, and direct material cost due to smaller end cover has reduced compared to the existing method as shown in fig.2.

[0052] In the present invention, the end cover 2a is fixed to casing 1 with the help of a plurality of shear rings 8a having substantially ‘L’ shaped cross-section and shim ring 9a having rectangular cross-section as in FIG.1 & FIG.3. These shear and shim rings are segmented into four no. of pieces with a horizontal and vertical offset (z) respectively as shown in fig.10. This offset (z) is equal to 1/3rd of the outer diameter (D) of the shear ring and shim ring. These shear and shim ring segments are disposed in the annular circumferential groove provided in the casing. Further, each shear ring segment is fixed to the end cover with help of two no. of cap screws 12, and each shim ring segment is fixed to the shear ring with help of two no. of cap screws13. With this fixing, the end cover, shear ring segments, and shim ring segments are unitized as a single-piece structure. Further, a bracket assembly (comprising of a bracket 10, bolt 10a, stud 10c, hexagonal cap nut 10b, and hexagon nut10d) as shown in fig.9 is used to prevent movement or misalignment due to vibrations during the operation of the centrifugal blower. This bracket assembly can be used for the assembly and disassembly of the end cover into the casing in the axial direction. With this invention, due to the absence of end cover fixing studs and nuts, drilling of normal holes in end cover and threaded holes in the casing, the manufacturing cost of blower including direct material cost due to smaller end cover, man-hours, machining hours, and assembly hours reduced compared to the existing method as shown in fig.2.

Detailed manufacturing and assembly steps involved in the present invention are as follows:

I. Assemble the diaphragm bundle including inner casing 3, intermediate diaphragm 3b, and rotor into casing 1 from the left side as shown in fig.3 with the help of a specially designed assembly/disassembly fixture, which is not shown in fig. During this assembly, ensure that the inner casing has to be butted with casing face (a) as shown in fig.4.
II. Assemble the suction end cover 2a into the casing with help of a special lifting device 14 as part of this present invention as shown in fig.11. Ensure that the end cover has to be butted with inner casing face (j) as shown in fig.4 and also ensure that the end cover has extended a distance of (X1) + 1mm from the casing face (d) as shown in fig.6. An anti-rotation pin 7 disposed in the end cover to be used to align the end covers vertical center axis to the casing vertical center axis with help of groove 7a provided in the inner casing 3. An ‘O’ ring is provided on the end cover to prevent pressurized air leakage from the casing to the atmosphere.
III. An annular circumferential groove as shown in fig.5 as part of this present invention to be provided in the casing to assemble a plurality of shear ring 8a having ‘L’ shaped cross-section segmented into four no. of pieces with a horizontal offset (z) as shown in fig.10 to lock the end cover to the casing. Once the shear ring segments have assembled in the casing annular groove, ensure that there is a gap of 1mm to be maintained as assembly clearance for proper butting of the shear ring to the end cover face (j). Then each shear ring segment is to be fixed to the end cover by using two no. of cap screws 12 as shown in fig.6. The width of the shear ring is equal to X1+X2.
IV. Now measure the gap (X3) between the shear ring and casing face (g) as shown in fig.5.
V. Assemble a plurality of shim ring 9a having rectangular cross-section segmented into four no. of pieces with a vertical offset (z) as shown in fig.10. Ensure that an allowance of 1mm as shown in fig.7 to be provided on the shim ring face butting to casing face (g) i.e. the shim ring thickness is equal to X3+1mm before assembly. This allowance is to be machined during the final assembly after measuring gap X3. An annular circumferential groove (k) as shown in fig.7 to be provided in the casing for easy assembly of shim ring in the gap (X3). Once the shim ring segments assembled in gap between the casing and shear rings, each shim ring is fixed to the shear ring by using two no. of cap screws 13 as shown in fig.8.
VI. After completion of assembly steps III & V, the end cover, shear ring segments, and shim ring segments are unitized as a single-piece structure. However, there is a possibility of movement or misalignment of this single-piece structure with respect to the casing.
VII. A bracket assembly (comprising of a bracket 10, bolt 10a, stud 10c, hexagonal cap nut 10b, and hexagon nut10d) as shown in fig.9 is used to prevent movement or misalignment due to vibrations during the operation of the centrifugal blower. This bracket assembly can be used for the assembly and disassembly of the end cover into the casing in the axial direction.
VIII. Assemble the discharge end cover 2b along with discharge diaphragm 3b into the casing from the right side as shown in fig.3 with help of special lifting device 14 as shown in fig.11.
IX. Follow the similar steps from II to VII for assembling the shear and shim ring segments 8b and 9b respectively to complete the blower assembly as per this present invention.

FEATURES OF INVENTION:

- A plurality of shear rings and shim rings are used to lock the end cover to the casing for a centrifugal blower as shown in fig.4.
- The shear rings have a ‘L’ shaped cross-section as shown in fig.4.
- The shim rings have a rectangular cross-section as shown in fig.4.
- The shear rings are segmented into four no. of pieces with a horizontal offset (z) as shown in fig.10.
- The horizontal offset (z) is equal to 1/3 rd of the outer diameter (D) of the shear ring as shown in fig.10.
- The shim rings are segmented into four no. of pieces with a Vertical offset (z) as shown in fig.10.
- The Vertical offset (z) is equal to 1/3 rd of the outer diameter (D) of the shear ring as shown in fig.10.
- Each shear ring segment is fixed to the end cover with two no. of cap screws 12 as shown in fig.7.
- Each shim ring segment is fixed to the shim ring segment with two no. of cap screws 13 as shown in fig.8.
- An annular circumferential groove shape as shown in fig.5 is provided the in blower casing to house the plurality of shear and shim ring segments to lock the end cover to the casing.
- A bracket assembly (comprising of a bracket 10, bolt 10a, stud 10c, hexagonal cap nut 10b, and hexagon nut10d) as shown in fig.9 is used to prevent movement or misalignment due to vibrations during the operation of the centrifugal blower. This bracket assembly can be used for the assembly and disassembly of the end cover into the casing in the axial direction.
- There are four no. of bracket assemblies required with an angle ‘P’ as shown in fig.9 assembled on both the suction and discharge side of the casing.
- The angle ‘P’ is between 35 to 45 degrees as shown in fig.9.
- The no. of bracket assemblies are not limited to four, these may be more than four depending upon the blower casing size.
- The suction end cover 2a and the discharge end cover 2b along with discharge diaphragm 3b are assembled into the casing with the help of special lifting device 14 as shown in fig.11.
- The lifting device has a spigot 14a as shown in fig.12, and similarly, an annular groove is provided on the end cover. This lifting device spigot is disposed in the end cover annual groove and then fixed to the end cover with the help of four no of bolts 14b as shown in fig.12. While lifting the end cover, the spigot and groove mechanism help to prevent the failure of fixing bolts 14b.
- The no. of fixing bolts, are not limited to four, these may be more than four depending upon the weight of the lifting component.
- The lifting device is designed in such a way that, the center of gravity (C.G) of end cover and crane hook center should fall on the same vertical line as shown in fig.11 to balance the end cover weight. This will help to assemble the end cover into the casing without any damage to both the casing and end cover.

[0053] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0054] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
[0055] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0056] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0057] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0058] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0059] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.