FIELD OF THE INVENTION
The invention relates to a method of connecting hopper panel with bend tubes in high pressure boilers. More particularly, the invention relates to a method of joining hopper panel and bend tubes without welding a bridge piece to form a hopper assembly for high pressure boilers.
BACKGROUND OF THE INVENTION
In the manufacturing process of hopper assembly for high pressure boilers, the hopper panels are disposed at the bottom side of the furnace. The width of the panel is varying from 1836 mm to 2322 mm consisting of about 23 tubes to 44 tubes respectively. The pitch between the center of the tubes is 54 mm and according to the pitch, a fin plate is welded along the length of the panel to connect 38.1 mm to 41.3 mm and the pitch distance remaining constant, wherein the pin width varies during connecting the hopper panel and bend tubes by conventional Tungsten inert gas welding in the root and sub sequence manual metal welding process.
A bridge piece having a size of 100 x 20 x 8 mm thick is required to place on top and bottom of the tubes and tack welding is carried out. Thereafter, the root welding is carried out by conventional Tungsten inert gas welding process.
The process of bridge piece tack welding is carried out following the steps of:
1. Bend level checking.
2. Bend center line checking.
3. Bend center offset checking.
4. Bend face level checking.

There are about 88 number of bridge pieces per panel and 14 number of panels are required per boiler. After the root welding, the bridge pieces are to be removed by gas cutting and grinding the surface for a smooth finish. In the above process of welding, during the top and bottom welding, maintaining the root gap is quite difficult because of the bridge pieces are disposed both on the top and bottom. Figure 1 shows the fit-up of a bridge piece connecting a hopper panel and tube.
Hence there is a need to devise a method of joining a hopper panel and bend tubes without welding bridge piece to form a hopper assembly for high pressure boilers.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a method of joining hopper panel and bend tubes without welding a bridge piece to form a hopper assembly for high pressure boilers.
Another object of the invention is to propose a method of joining hopper panel and bend tubes without welding a bridge piece to form a hopper assembly for high pressure boilers, which allows elimination of the bridge piece during welding of the hopper panel and bend tubes.
A further object of the invention is to propose a method of joining hopper panel and bend tubes without welding a bridge piece to form a hopper assembly for high pressure boilers, in which a plurality of hopper panel and bend tube can be simultaneously joined.
A further object of the invention is to propose a device for holding a hopper panel and bend tubes during joining of the two components.

SUMMARY OF THE INVENTION
According to the invention, a device is formed for holding the panel and bend tubes for welding. The device consists of a base plate welded with four numbers of gusset plates welded with vertical pipe piece so that it will maintain enough rigidly. The base plate is provided with four rotating wheels and four locking screws. An internal threaded sleeve with four handles are welded at 90 degree to each other and placed concentrically over the vertical pipe. An external threaded screw is screwed on the sleeve to have full length contact of the sleeve at a height of around 85mm. The other end of the screw is welded with a bottom support plate. Two channel pieces are welded on the bottom support plate and on the top of the channels. A top flat plate is welded over the channels pieces on one side of the top flat plate and equal angles are welded. On the other end of the top flat plate, the channel and an angle are welded with the top flat plate in such a way that they are in the same plane. Forty four number of equal angles are positioned length wise in the channel. Now the whole setup can be raised or lowered simply by the rotation of handles. The straight hopper panel is moved to the top angle which act as a V block to position the panel. The length of contact of the panel in the V block angle is 75mm, which is half of the V block angle length. At least 44 numbers of the bend tubes are rested on the remaining length of the V block angle, The root gap of about 4mm is provided for better penetration. The hopper panel and bend tubes are checked with a sprit level indicator for perfect flatness and also to ensure that they are in one plane. To adjust the level, the handle is rotated manually so that the support plate and the angles are moved simultaneously to ensure the hopper panel and bend tube are in the same plane. With this setup a tack welding by conventional Tungsten Inert Gas welding process is carried out for all the numbers of the panel tubes and bend tubes. The device is lowered by means of rotation of the

screw rod through handle. Now the device is taken out. Now the tack welded components is rotated 180 degree on the 'X' axis and tack weld is carried out on the other end. Now the job is ready for full welding.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIGURE 1 shows the prior art method of fit up made for welding process.
FIGURE 2 shows elevation, plan and top view of the device used for welding the Hopper panel with bend tubes without bridge pieces according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBADIMENT OF THE INVENTION
As shown in figure-2 the device consists of the following items:
Base plate (16) with four numbers of rotating wheel (17) and four numbers of
locking screw (18)
Four numbers of gusset plate are welded on four sides of a hollow cylinder (06)
Handle wheel with cylindrical head assembly (05) is mounted with stud (07) and a bottom support plate (08) which is placed on the top of the stud (07)
Two numbers of additional support angles (09) are provided on either side of the bottom support plate (08) and two number of buildup channel (10) are welded on the bottom support plate
A top flat plate (11) is rested on the buildup channel (10) of the panel. Support channel (12) is welded on the one side of the top flat plate (11). A plurality of bend tube support angles (13) welded with a final leveling plate (15) is welded

on the other end of the top platform (11). About forty-four numbers of V block angles (14) are placed along the length of the Panel support channel (12).
Initially, the device is moved by unlocking the locking screw (18) from the wheel (17), then moved towards the hopper panel (01) and the height is adjusted by operating the hand wheel (05) show that the panel tube assembly rested on the V block angle (14) in the same plane.
The panel assembly occupies 75mm length on the V block angle having 150mm length now after positioning the locking screw is locked. Now all the 44 numbers of bend tube (02) are placed in such a way that 75mm length of the bend tube rested on the remaining length of the V block angle.
The remaining length of the bend tubes resting on a finer leveling place (15) The root gap between panel and bend tubes is maintained by checking with 4mm diameter rod (not shown).
Because of the locking of the device and the joinable components, no gap between the panel and bend tubes is left. Now conventional Tungsten Inner Gas welding for 44numbers bends (02) is carried out by means of locking the locking screw (18). After completion of the root welding on one side, the locking screw is released and by rotating the hand wheel (05) the top assembly is lowered by a downward momentum of the stub (07). The device is then taken out of the components and kept aside. The tack welded assembly of the panel and bend tubes are now reversed for tack welding on the opposite sides there by totally eliminating the requirements of bridge pieces (03) for carrying out of the above operation as per the prior art.

WE CLAIM :
1. A device to guide and support panel tubes assembly and bend tubes for welding preceded by tack welding to form a hopper assembly in high pressure boilers, comprising :-
a base plate (16) with a plurality of locking screws (18) and rotating wheels (17), including a hollow cylinder head (06) welded with at least four number of gusset plates (19), the cylinder head (06) being connected to a rotating handle (05) including a stud (07) which can be moved up and down by rotating the hand wheel (05);
a flat platform (11) Is assembled with a support channel (12) on one side and with a bend tube support angle (13) on the other side; wherein,
the stud (07) is moved up and down by means of the rotating hand wheel (05) and the inward of outward motion are locked by the locking screw (18), wherein,
the panel tube assembly (01) upon movement of the device occupies about 50% length on the V block (14); wherein
the bend tubes (02) which are to be tack welded with the panel tubes assembly (01) is placed on the remaining 50% area of the length in the V block (14), and wherein a perfect leveling is obtained by placing a finer levelling plate (15) so that defect less tack welding of the panel tubes (01) and bend tubes (02) can be carried out.