Claims:We claim:
1. A method for bending of mini panels of burner panel in a pressing machine for tower type boiler, the method comprising:
positioning (402) a straight mini panel (6) which is to bent on a bending device (10);
applying (404) hydrostatic pressure on the straight mini panel (6) position over the bending device (10) by a die (7) to bend the straight mini panel (06).

2. The method as claimed in claim 1, wherein angle of bending achieved by the bending device.

3. The method as claimed in claim 1, wherein the hydrostatic pressure of the die (07) depends on angle of bend and spring back force of the straight mini panel (06).

4. The method as claimed in claim 1, wherein the pressing machine is 2000 ton press.

5. The method as claimed in claim 1, wherein the bending device comprises a bottom plate (03), four lifting plates (04) are welded to the bottom plate (03) to lift the bending device (100), and two pipes (05) are welded on the bottom plate (03) to receive the straight mini panels (06) for bending.

6. A bending device (10) to be used for bending straight mini panels (06) in pressing machine, the bending device (10) comprising:

a bottom plate (03); and
four lifting plates (04) are welded to the bottom plate (03) to lift the bending device (100);
two pipes (05) are welded on the bottom plate (03) to receive the straight mini panels (06) for bending.

7. The bending device (10) as claimed in claim 6, wherein length of the two pipes (05) is atleast 3500mm.

8. The bending device (10) as claimed in claim 6, wherein the two pipes (05) are welded on the bottom plate (03) at a distance at least 282mm from each other.

9. The bending device (10) as claimed in claim 6, wherein dimensions of the bottom plate (03), the four lifting plates (04), and the two pipes (05) depends on angle of bend and dimensions of the straight mini panels (06).

10. The bending device (10) as claimed in claim 6, wherein angle of bend is achieved by placement of two pipes (05).
, Description:PRESSING OF MINI PANELS IN BURNER PANEL OF A TOWER TYPE BOILER IN 2000 T PRESS
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a method of pressing/bending of straight mini panels in burner panels of a tower type boiler in a 2000 ton press machine. More particularly the present invention relates to improvements over an existing process, by developing bending device with novel features.
BACKGROUND AND PRIOR ART:
[002] Conventionally bent panels are formed by using bend tubes and fins/plates/shaped plates that are also bent suiting the tubes. They are set in place and are welded manually. These conventional procedure takes more time because following reasons:
[003] (1) Each tube has to be bended separately in bending machine. Owing to the large quantum of tubes, time consumption is high. Individual bending is also difficult due to handling, storage and inventory management.
[004] Fins/plates/shaped plates have to be manufactured separately according to the type of bend profile. Top and bottom side manual welding process of these plates to the bents tube is time consuming. Figure 1 shows the typical panel assembly comprising of tubes (1) and fins/plates/shaped plates(2) are welded by welding process, such as Submerged Arc Welding (SAW).
[005] Hence there is need to find out a suitable fabrication method to get bent panels in a 2000 ton press. Usually 2000 ton press is using for pressing of reducer, dish ends of boiler drums, various elbows and tees which having a very high thickness. Following materials are used for the fabrication of mini panels:
[006] SA213T11 tubes of diameter 38.1 mm and having thickness of 6 mm
[007] SA387GR12CL12 fin flat of thickness 6 mm and having width of 22mm.
[008] So direct pressing of straight panels in 2000 ton press may leads to failure of straight panel because of low tube thickness and high hydraulic pressure. So a suitable bending device with inventive dimensions has to be designed for bending of the straight panels.
OBJECTS OF THE INVENTION:
[009] The principal objective of the present invention is to provide a method for pressing of straight mini panels in burner panels of a tower type boiler in 2000 ton press.
[0010] Another object of the present subject matter is to provide a bending device for pressing of straight mini panels of tower type boiler in 2000 ton press.
[0011] Another object of the present subject matter is to make easy and fast bending of the straight min panels for burner panels of a tower type boiler in 2000 ton press.
SUMMARY OF THE INVENTION:
[0012] The subject matter disclosed herein relates to a method for bending of mini panels of burner panel in a pressing machine for tower type boiler. In the present method, straight mini panels are positioned over a bending device. Once the straight mini panel is placed, a hydrostatic pressure is applied on the straight mini panel by a die to bend the straight mini panel as per angle of bend.
[0013] In another embodiment of the present subject, a bending device used for bending straight mini panels in pressing machine. The bending device has a bottom plate of dimension 190 mm X 1100 mm X 3000mm and four lifting plates of 300 mm X 200 mm X 25 mm dimension are welded to bottom plate. The four lifting plates are used for lifting of entire fixture. Two full length pipes of length 3500 mm, diameter 368 mm and thickness of 48 mm thickness are kept at a distance of 282 mm. The two pipes are welded with 250 mm over hang on either side of the plate. The two pipes to be welded to the plates on both sides with 40 mm fillet for full length of 3000 mm.
[0014] In order 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 scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] 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, the left-most digit(s) of 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 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:
[0016] Fig. 1 illustrates bent mini panel after pressing as known in the arts;
[0017] Fig. 2 illustrates structure of bending device bottom for pressing of mini panels to form the bent panels terminal tubes of panels, in accordance with an embodiment of the present subject;
[0018] Fig 3 illustrates side view of the bending device, in accordance with an embodiment of the present subject; and
[0019] Fig. 4 illustrates method for bending of mini panels in the bending device with press, in accordance with the present subject matter.
[0020] 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.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0021] The subject matter disclosed herein relates to a method for bending of mini panels of burner panel in a pressing machine for tower type boiler. In the present method, straight mini panels are positioned over a bending device. Once the straight mini panel is placed, a hydrostatic pressure is applied on the straight mini panel by a die to bend the straight mini panel as per angle of bend.
[0022] In another embodiment of the present subject, a bending device used for bending straight mini panels in pressing machine. The bending device has a bottom plate of dimension 190 mm X 1100 mm X 3000mm and four lifting plates of 300 mm X 200 mm X 25 mm dimension are welded to bottom plate. The four lifting plates are used for lifting of entire fixture. Two full length pipes of length 3500 mm, diameter 368 mm and thickness of 48 mm thickness are kept at a distance of 282 mm. The two pipes are welded with 250 mm over hang on either side of the plate. The two pipes to be welded to the plates on both sides with 40 mm fillet for full length of 3000 mm.
[0023] 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.
[0024] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0025] The Burner panel is the most complicated piece of item in tower type pressure parts. The burner panels are made in spiral wall area. In a tower type burner panel total 18 mini panels are there. Out of which two are bend panels. It is very difficult to fabricate these bend panels conventionally because individual bending of each tubes, welding of each plates/shaped plates/fins to tubes is time consuming. A new fabrication process is established to avoid these difficulties. The present invention relates to a new method pressing of mini panels in burner panels of a tower type boiler with the help of a specially designed bending device suitable for placing in 2000 ton press so that required bend panel can be obtained from the straight panel assembly.
[0026] In present method of fabrication, instead of bending of each tubes separately, a straight panel is being formed with all process allowances in 20 torch panel formation machine. This straight panel is pressed to desired shape in 2000 ton press by using a specially designed fixture. This fixture is specially designed to distribute stress in the bent regions to avoid sharp bends. This drastically reduces the cycle time involved in manufacturing of the bent panels.
[0027] Referring to fig. 2, bending device or fixture used for pressing of panels in 2000 ton pressing is illustrated. The bending device 10 includes a bottom plate (03) and four lifting plates (4) which are welded to the bottom plate (3). The four lifting plates (4) are used for lifting of entire bending device fixture. The bottom plate (03) has dimensions of dimension 190 mm X 1100 mm X 3000mm. Further, dimensions of the bottom plate depend on the size of the mini panel. Therefore, the bottom plate (03) can be any dimensions as per subject matter of the present invention. The four lifting plates (04) have dimensions of dimension 300 mm X 200 mm X 25 mm. Further, dimensions of the four lifting plates depend on the size of the bottom plate (03). Therefore, the four lifting plates (04) can be any dimensions as per subject matter of the present invention.
[0028] Further, the bending device (10) has two full length pipes (5). The dimension of the two pipes (05) is length atleast 3500 mm, diameter 368 mm, and thickness of 48 mm thickness is kept at a distance of 282 mm. The present dimensions are given for the better results, i.e., bending of straight panel in the burner panel of the tower type boiler with standard dimensions. If there is any change in the dimensions of the tower type boiler, the dimension of the bending device varies. The two pipes (05) are fitted with 250 mm over hang on either side of the bottom plate (3). The two pipes (5) are welded to the bottom plate (3) on both sides with 40 mm fillet for full length of at least 3000 mm. Complete dimensions of the bending device (10) can vary according to requirements. All dimensions with present structure falls under the scope of the present subject matter. Further, the dimensions of the bending device depend on the angle of bend of the straight mini panels and dimension of the straight mini panels which are to be bent.
[0029] A straight mini panel (6) which is to be pressed is kept on the two pipes (5). A hydrostatic pressure is applied on placed straight mini panel (06) by upward and downward movement of die (7) of the 2000 ton press. The hydrostatic pressure can be controlled by the upward and downward movements of the die (7) of the press. Further, the required Hydrostatic pressure which is to be applied on the straight mini panel (6) can be found out by considering following things:
[0030] angle of bend
[0031] Spring back of panels
[0032] Figure 4 illustrate the method for bending of straight mini panels of burner panel in a pressing machine of 2000 tone for tower type boiler. At step 402, straight mini panel (6) which is positioned over the bending device (10). At step 404, a hydrostatic pressure is applied on the positioned straight mini panel (6) by a die (7) of the 2000 ton press. The die (07) bends the straight mini panel (06) as per decided angle of bend. The angle of bending is achieved by the bending device (10).
[0033] Although embodiments for the present subject matter have been described in language specific to structural 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/component 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.