Claims:WE CLAIM :

1. A compressor casing (14) comprising:
a suction nozzle (1);
a variable circular volute (4);
a discharge nozzle (5);
a circular annular ring (15);
a plurality of supporting provided on periphery of the casing;
a casting rib (11);
a plurality of support ribs (12);
wherein the suction nozzle (1), volute (4) and discharge nozzles (5) are designed as a single casting based on the suction flow of the compressor, wherein a circular annular ring (15) is attached to the casing (14) casting by welding after completion of casting process;
wherein the casing which includes suction nozzle (1), variable circular type volute (4), discharge nozzle (5) and support ribs constitutes a single casting.

2. The compressor casing as claimed in claim 1, wherein multiple ribs (11, 12) are provided on periphery of the casing (14) in vertical plane and in horizontal plane for supporting the casing.

3. The compressor casing as claimed in claim 1 or 2, wherein the casing top rib (11) thickness is increased compared to other ribs (12) to enable to lift and support the casing during machining and assembly/dis-assembly.

4. The compressor casing as claimed in claims 1-3, wherein the holes (13) are provided to lift the casing (14) by the rib (11).

5. The compressor casing as claimed in claims 1-4, wherein the at least one circular annular ring (15) is welded to casted casing.
, Description:CASING CASTING WITH VARIABLE CIRCULAR VOLUTE AND NOZZLES FOR SINGLE STAGE CENTRIFUGAL COMPRESSOR

FIELD OF THE INVENTION:
[001] This invention relates generally to the design of centrifugal compressor casing. More particularly the invention relates to a compressor casing as a single piece casting that includes suction nozzle, variable volute, discharge nozzle and support ribs.

BACKGROUND/PRIOR ART 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] Single stage Centrifugal compressors are also called overhang centrifugal compressors used to compress air or any gas medium to a higher discharge pressure as per the process requirement. The Compressor consists of different type components such as Suction nozzle, Impeller, diaphragm Casing, discharge nozzle, seal and shaft.

[004] Referring to Figure 1 showing a cross sectional view of a single stage overhang compressor. In this the gas enters from suction nozzle (1) and gets compressed through impeller, a rotating element (2), and enters into vane less diffuser (3) then enters in to variable volute (4) and then leaves from discharge nozzle (5). The rotating element is mounted on pinion shaft (10) of gearbox. Suction nozzle (1), variable volute (4) and discharge nozzle (5) are combined and cast as a single piece casing (14) and this casing is fixed to the diaphragm (6) by bolts and nuts. Diaphragm (6) is fixed to gearbox flange (7) by screws. This diaphragm (6) and compressor casing (14) form vanless diffuser (3). The gas leakage between diaphragm (6) and compressor casing (14) sealed by Seal member (8). The leakage between impeller (2) and diaphragm (6) is sealed by a labyrinth seal (9) and this seal is fixed to the gearbox flange (7).

[005] Single-stage overhang compressor is low weight, easy to manufacture, assembly/dis-assembly, maintenance, and has high rigidity and reliability.

[006] In a prior art, JP5088610B2, titled “Centrifugal Compressor casing” a compressor casing40 formed by joining the scroll member 46 and the inlet member 42. In the present invention, the compressor casing (14) formed as a single component i.e. variable volute (4), suction nozzle (1) and discharge nozzle (5). This innovation is helpful for easy of assembly/dis assembly of the compressor casing. Further, the suction flange (1) is integrated to the compressor casing, the annular recess 14 as per prior art ref [1] is eliminated in present invention. Reference may be made to figure 2 cross sectional view of compressor casing casting.

[007] In another prior art, JP2006177242A, titled “Overhang type centrifugal compressor” a casing (3) is formed by joining two components and variable volute i.e. scroll member is not circular shape. In present invention, the compressor casing (14) is a single component and it includes the suction nozzle and variable volute and discharge nozzle. The shape of volute (4) is in circular shape. Pressure loss co-efficient less is in circular shape variable volute compared to non-circular shape variable volute. Reference may be made to figure 2 cross sectional view of compressor casing casting.

[008] In view of the above, there is requirement to devise an apparatus which can address the aforesaid shortcoming(s). Hence, the present invention has been introduced.

[009] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

OBJECTS OF THE INVENTION:
[0010] It is therefore an object of the present invention is to overcome the aforementioned and other drawbacks in prior arts.

[0011] Another object of the present invention is to provide a compressor casing as a single piece casting that includes suction nozzle, variable volute, discharge nozzle and support ribs.

[0012] Still another object of the present invention is to reduce the compressor cost by avoiding the casing casting pattern for similar type multiple compressor requirement application.

[0013] Yet another objective of the present invention is to reduce the assembly/dis-assembly time.

[0014] 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:
[0015] 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.
[0016] Single stage Centrifugal compressors are also called overhang centrifugal compressor used to compress air or any gas medium to a higher discharge pressure as per the process requirement. The Compressor consists of different type components such as Suction nozzle, Impeller, diaphragm Casing, discharge nozzle, seal and shaft.

[0017] In present invention, the centrifugal compressor casing is manufactured by casting. Casing casting includes suction nozzle, variable circular type volute and discharge nozzle as single casting.

[0018] Compressor casing suction nozzle, volute and discharge nozzles are designed based on the suction flow of the compressor. For high suction flow applications, the casing casting can be manufactured without any issue. However, for low suction flow applications, when the size of the casing is very small, manufacturing of casing casting may be difficult due to small gap (D). For making pattern and removal of sand from casting during manufacturing, sufficient gap (D) is required. To overcome this problem i.e. to increase the gap (D), a circular annular ring to be manufactured separately and attached to the casing casting by welding after completion of casting process.

[0019] Object of the invention is achieved by the features of principal claim. Further, particularly advantageous embodiments of the invention are disclosed in the sub-claims.

[0020] 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.

[0021] 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.

[0022] 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:
[0023] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0024] Figure 1 illustrates the Cross sectional view of compressor.
[0025] Figure 2 illustrates the Cross sectional view of Casing Casting.
[0026] Figure 3 illustrates the Cross sectional view of Casing Casting with additional annular ring.
[0027] Figure 4 illustrates the Isometric view of compressor casing casting with support ribs.
[0028] Figure 5 illustrates the End view of compressor casing casting with support ribs.
[0029] Figure 6 illustrates the Sectional view (Vertical) of compressor casing casting with support ribs.
[0030] Figure 7 illustrates the Sectional view (Horizontal) of compressor casing casting with support ribs.

[0031] 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(S) OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:

[0032] 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.

[0033] The present invention makes a disclosure regarding a design pertinent to compressor casing (14) casting.

[0034] The Present invention relates to the single stage centrifugal compressor casing which includes suction nozzle (1), variable circular type volute (4), discharge nozzle (5) and support ribs as single casting.

[0035] The casting is monolithic/Integral casing comprising suction nozzle, variable volute, discharge nozzle and support ribs as single casting.

[0036] Most of single stage centrifugal compressor casings manufactured from forgings/fabricated from plates. The number of components required are more than two to form complete casing. Further, these casings are over hang type i.e. these casings bolted to driven component casing/flanges. Hence, the compressor casing design plays a vital role in single stage overhang type centrifugal compressors with respect to weight and handling of casing.

[0037] Reference may be made to Figure 2 indicating Cross sectional view of Casing (14) Casting. In present invention, the centrifugal compressor casing manufactured by casting. Casing casting includes suction nozzle (1), variable circular type volute (4), discharge nozzle (5) and support ribs as single casting.

[0038] Compressor casing (14) with suction nozzle (1), volute (4) and discharge nozzles (5) are designed based on the suction flow of the compressor. For high suction flow applications, the casing (14) casting can be manufactured without any issue. However, for low suction flow applications, when the size of the casing (14) is very small, manufacturing of casing (14) casting may be difficult due to less gap (D). For making pattern and removal of sand from casting during manufacturing sufficient gap (D) is required. To overcome this problem i.e. to increase the gap (D), a circular annular ring (15) to be manufactured separately and attached to the casing casting by welding after completion of casting process. In this regard reference may be made to Figure 3 showing Cross sectional view of Casing (14) Casting with at least one additional annular ring (15).

[0039] To strengthen the casing multiple ribs (11, 12) are provided on periphery of the casing, a plurality of ribs (11, 12) in vertical plane and (12, 12) in horizontal plane.

[0040] Casing top rib (11) thickness is increased compared to other three ribs (12), to enable to lift the casing during machining and assembly/dis assembly, and two set of holes (13) are provided in the rib (11). Ref. Figure 3, Cross sectional view of Casing (14) Casting with additional annular ring, Figure 5, End view of compressor casing (14) casting with support ribs and Figure 7, Sectional view (Horizontal) of compressor casing (14) casting with support ribs.

[0041] The advantage of present Invention is that it reduces the assembly/dis-assembly time.

[0042] The other advantage of present Invention is that it reduces the compressor cost by avoiding the casing casting pattern for multiple compressor requirement application.

[0043] Thus, the present invention not only reduces the compressor cost, but also enables easy of assembly/dis-assembly and maintenance.

[0044] The material above has been given as an example without restricting scope of the invention to the same. Thus, other materials readily apparent to a person skilled in the art are within scope of the invention.

[0045] 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.

[0046] 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.

[0047] 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”.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.