DESC:CLAMPING FIXTURE FOR WRAPPING AND WELDING OF FABRICATION BOX IN BOILER CRITICAL STRUCTURE

TECHNICAL FIELD
[01] The present invention relates to clamping fixture for wrapping and welding of fabrication box in boiler critical structure. More particularly the present invention relates to a device and method used for wrapping FGD sheets without stiffener plates.

BACKGROUND OF THE INVENTION
[02] Background description comprises information which may be useful in understanding the present invention while 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.
[03] In various industries, boilers are used to generate the high pressure temperature of superheated steam. In the closed stationery installation for transportation or distribution of fluids like steam and water in super critical boilers named Flue gas desulfurization is the process of removing Sulphur compounds from the exhaust emissions of fossil-fueled power stations are important and this is done through the addition of absorbents, which can remove up to 95% of the Sulphur dioxide from the flue gas. In general practice these FGD sheets (Flue gas desulfurization sheet) are made up of low thickness sheets having length 3-10m with150-400mm and thickness of 2mm. These sheets are having bends in XY (all two planes) position. These sheets are to be joined by SMAW (Shielded metal arc welding) process.
[04] Moreover, the method of carrying out the wrapping of the FGD sheets (Flue gas desulfurization sheets) on the metallic box (work piece) column involves, marking the location of the sheets on the circumference of the box by dividing the circumference in to two as per requirement. Preparation of metallic box surface by grinding on the box at sheets wrapping locations. Tacking the sheets on the metallic box surface. Since the positioned & tacked sheets is to be retained at the position without any distortion in alignment/orientation or dimensions, there is a need to constraint them with the help of stiffener plates and metallic wedges. Stiffener plate is a low thickness (12-16 mm) rectangular or “L” shaped piece, which is of the same specification as the parent metal.
[05] Generally, the purpose of the stiffener plate is to retain the tacked sheets in position, without allowing for disturbance of the dimensional location and orientation/alignment. A stiffener plate once used, cannot be re-used. After arresting the sheets in position with the help of the stiffener plate the sheet is welded on one side, using SMAW (Shielded metal arc welding) process. After one side welding of the sheet is completed the stiffener plate is removed by hammering.
[06] This method has some inherent disadvantages like, it is a time consuming process, also consumption of raw material for making of stiffener plate, while removing the stiffener plates the ugly tack marks are left behind. The tack marks are to be ground flush with the sheet surface. In-case the parent metal is scooped off during the process of removing the metallic wedge then build-up of the parent metal needs to be carried out in case of C276 material. Reworking of the sheets is cost and time consuming.
[07] Therefore, in view of the above reasons there is a necessity to find out an alternate method of without using stiffener plates for sheet wrapping and welding.

OBJECTS OF THE INVENTION
[08] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.

It is an object of invention to provide a device for metallic box with sheet wrapping and welding.
It is an object of the invention to fixing of two wrapping sheets inline alignment to make at a time vertically after welding.
It is yet another object of invention to provide method of self-aligning concentricity of rectilinear metallic box for sheet wrapping and welding the arrangement was designed to handle varying sizes of metallic box.
It is yet another object of invention to reduce the adjusting time spent on the screws of leaner type fixture.
It is yet another objective of the invention to avoid the usage of stiffener plates.
A still further object of the invention to eliminate the parent metal damage caused by the wedge with hammering, tacking of stiffener plates and scooping of parent metal, weld build up, flush grinding, NDT (Liquid penetrant inspection) and unwanted movement works.
A still further object of the invention to minimize the expenses incurred on practicing actual process layout.

[09] To further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[010] 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 numerals represent like components.

SUMMARY OF THE INVENTION
[011] This summary is provided to introduce the carrying out the wrapping of the FGD sheets on the metallic box (work piece) column involves, marking the location of the sheets on the circumference of the box by dividing the circumference in to two as per requirement. Preparation of metallic box surface by grinding on the box at sheets wrapping locations.
[012] The clamping fixture (100) for wrapping and welding FGD sheets (Flue gas desulfurization sheet) in fabrication of boiler critical structures, wherein a base plate (01) for supporting work pieces; and plurality of stand pipe (02) welded vertically under the base plate (01) for seating on the ground floor. Further, plurality of semi-angular plates (03) interconnected by side guiding pieces horizontally and top guiding pieces vertically and plurality of screws, each having internal threads at each end of the semi-angular plates (03) on the top and side, and external threads on screw rod (04) in which bottom and top screw acting as guiding piece.
[013] To further understand the characteristics and technical contents of the present subject matter, a brief description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[014] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following brief description of preferred embodiments, along with the accompanying drawing figures in which numerals represent like components.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING(S)
[015] 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. 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:

Figure 1. illustrates the base plate of device.
Figure 2. illustrates stand pipe.
Figure 3. illustrates semi Angular plate with plurality of locking screws.
Figure 4 illustrates guiding support.
Figure 5. illustrates work piece.
Figure 6. shows C276 wrapping sheet.
Figure 7. shows developed device.
Figure 8. shows the elevation for the assembly of the device along with work piece.
Figure 9. shows the side view for the assembly of the device along with work piece.

[016] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily 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 THE INVENTION WITH REFERENCE TO THE ACCOMPNAYING DRAWINGS

[017] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[018] 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 described herein 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.
[019] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
[020] The present invention relates to clamping fixture for wrapping and welding of clamping fixture boiler critical structure. More particularly the present invention relates to a device used for wrapping FGD sheets without stiffener plates.
[021] The present invention described herein regarding the lap welding joint is being carried out by positioning the work pieces in the device with suitable fixture that can be used for the C276 sheet wrapping and welding.
[022] The work piece rests on the base plate wherein each rectilinear metallic box and plurality of semi angular plates which are made up of low alloy steel is fabricated so as to cover the metallic box.
[023] Further, a semi angular plate (03) is inter-connected by two side guiding piece horizontally. Alike, a semi angular plate is interconnected by another similar one top guiding piece (06) vertically in which plurality of screws are internal threaded at each end of the semi angular plate on the top and side. The bottom and top screw acting as the as guiding piece. The plurality of screw rod made with M24 nut having external thread, the above total assembly on the horizontal base plate welded with four each places. Plurality of stand pipes are welded (180 degree) under base plate for seating on ground floor. These Portable devices can be easily carried and used anywhere location.
[024] Inserting the assembly on one end by screwing the locking screw anti-clock wise to release from the lock nut but up to the guiding nut so as to insert the device on any diameter of the pipe ranges. After opening the assembly, the complete device is then inserted in to the pipes which are to be welded by conventional welding process.
[025] Further, the total length of the device is adjusted linearly so that equal distance is maintained from the end of the pipes to be welded. The top and bottom semi angular plate assembly is tightened by air gun, screws and arrested on all directions.
[026] Thereafter, the fixture become for welding by the tightness of the device with the wrapping sheet is like over lapping joints welding by conventional process. Therefore, by this method the said drawback in conventional method of welding using the stiffener plate with wedge hammering methods are completely eliminated.
[027] Figure 1 & 2 depicts the Base plate (01) with connected stand pipe (02) which is welded and made smooth. It works as strong base for the invention whereby it is very handy to move easily to required place on floor.
[028] Figure 3 depicts semi Angular plate (03) an Alloy plate of material Gr 22 is obtained which is of the dimension (50x30x25) mm out of which a plate has been cut out of the required dimension. And locking Screw (04) rod is fabricated using a rod diameter of 30mm. In this, chromium alloy material is used for the fabrication of the screw rod and the rod is further machined with external threads M24 for ease in expansion and contraction.
[029] Further, figure 5 & figure 6 illustrates the working model by using the newly developed fixture wherein the presence of stiffener plate is completely avoided.
[030] Thus the present invention ensures reduction of material cost of stiffener plate, and furthermore the removal and welding time. The possibility of damage in to the main pipeline may be completely eliminated by this proposed invention.

Advantages of the invention
[031] The proposed clamping fixture capable to hold the C276 sheets firmly without the aid of stiffener plates thereby application of stiffener plate has been eliminated.
The application of proposed clamping fixture eliminates various processes like use of stiffener plates, scooping of parent metal, Dent, weld build up and flush grinding, NDT (magnetic penetration inspection) and movement works.
The proposed invention provides financial savings and benefits over existing methods due to reduction of material and processing stages.
Also the proposed invention drastically brings down the cycle time.

Working of the invention
[032] According to the present invention the wrapping and welding of variant size is perform by placing the work piece in the semi angular plate nearer to the apparatus and carried out in following manner:
[033] First of all, fabricating a semi angular plate (03) having a vertically connected with on the base plate (01) wherein the stand pipe (02) is welded vertically with bottom of the base plate (01) to ensure vertical distance of 600 mm between the stand pipe (02) and the base plate (01). Thereafter, placing the work Piece (07); C276 sheet -I; II;(08, 09) in the horizontal position which is having 180-degree slant opening to position the semi angular plate (03). Further the position can be adjusted by adjustment locking screws (04) on the three sides. Positioning the work piece on the horizontal directions by adjustable screws and semi angular plate (03) respectively. The outside square size of the work Piece-I (07) which is 150 to 400mm with a low thickness of 15 to 25 mm is fixed perfectly in the semi angular plate (03) with support guide plate (05, 06) fitted on each side of the work piece.
[034] Thereafter, the semi angular plates (03) and (05) (06) may be varied according to the outside size of the work piece (07); (08); (09) and tightening the locking screws (04) with help of air gun (not Shown) to hold square objects due to its self-center for vertical and horizontal position. The described working method may be used for making quality wrapping and welding joints without stiffener plates and thereby it reduces the cycle time from 8 hours to 3 hours per job and ultimately substantial saving of power, money and material involved in the process.
[035] 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.
[036] It should also be appreciated by those skilled in the art that by devising various systems 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.
[037] 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.
[038] Although embodiments for the present subject matter have been described in language specific to package features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/device of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.
[039] 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
[040] 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.
[041] 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 particular 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.
[042] 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 analogous 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.”
[043] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible.
[044] In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
,CLAIMS:We Claim:
1. A clamping fixture (100) for wrapping and welding FGD sheets (Flue gas desulfurization sheet) in fabrication of boiler critical structures, comprising:
a base plate (01) for supporting work pieces; and
plurality of stand pipe (02) welded vertically under the base plate (01) for seating on the ground floor; and
plurality of semi-angular plates (03) interconnected by side guiding pieces horizontally and top guiding pieces vertically; and
plurality of screws, each having internal threads at each end of the semi-angular plates (03) on the top and side, and external threads on screw rod (04); wherein bottom and top screw acting as guiding piece.
2. The clamping fixture device (100) as claimed in claim 1, wherein the device is configured to be inserted into pipes by locking screw (04) in anti-clockwise direction to release from lock nut up to guiding nut and allowing the device to be inserted into pipes of varying diameters.
3. The clamping fixture device (100) as claimed in claims 1 to 2, wherein the device (100) is adjustable to maintain equal linear distance from the ends of the pipe to be welded.
4. The clamping fixture device (100) as claimed in claim 1, wherein the plurality of stand pipes (02) are configured to provide stability and support for the device when seated on the ground floor, allowing for easy transportation and use at various locations.
5. A method for wrapping and welding flue gas desulfurization sheets in boiler critical structures, comprising the steps of:
Fabricating semi-angular plate (03) vertically connected to a base plate (01); and
Welding stand pipe (02) vertically to the bottom of the base plate (01) to ensure a vertical optimum distance between the stand pipe (02) and the base plate (01); and
Placing the work piece (07), C276 Sheet-I, II (08), (09), in horizontal position with a vertical slant opening to position the semi-angular plate (03); and
Adjusting the position of the semi-angular plate (03) using adjustment locking screws (04) on three sides; and
Positioning the work piece horizontally using adjustable screws and the semi-angular plate (03); and
Fixing the rectilinear workpiece-I (07), in the semi-angular plate (03) with support guide plates (05), (06) fitted on each side of the work piece; and
Varying the semi-angular plates (03), (05), (06) according to the outside size of the work piece (07), (08), (09); and
Tightening the locking screws (04) with the help of an air gun to hold rectilinear objects in a self-centered vertical and horizontal position.