UNIVERSAL FIXTURE FOR MANUFACTURING COIL ASSEMBLY OF CIRCUIT TUBES WITH DIFFERENT PITCH DISTANCE OF STRAIGHT CONNECTORS AND A METHOD THEREOF
FIELD OF INVENTION
The field of invention relates to manufacturing of coil assembly components for steam generators. More particularly, the present invention relates to a fixture used for fixing different components on the coil assembly and particularly relating to assembly of components of various pitch distance in the coil assembly.
BACKGROUND OF THE INVENTION
In the manufacturing of high pressure high temperature steam generators, water wall panel is one of the major and critical assembly in the steam generators. Referring to the Figure-1 Item no.1 shows the coil assembly used in the steam generators. This assembly consist of varying dimension of individual circuits (2) with 14 to 16 nos per coil assembly. This individual circuit may have bends as per the requirements. This coil assembly is to be fitted with straight connectors (4), tangent connectors (3) and roof seal binder (6) as shown in the Figure-1. Figure-5 shows the existing fixture used to make the coil assembly. This fixture consists of longitudinal beam named as I-beam (7) which is welded with channels depending upon the distance between the straight connectors (4). Bracket plates (9) are used to support between beam (7) and channel (8). The length of the I-beam is depending on the length of the coil assembly. The length of the channel is depending on width of the coil assembly. The individual circuits (2) are placed over the channel (8) and the roof seal binder (6), tangent connectors (3) and straight connectors (4) are welded as shown in the Figure-4, Figure-2 and Figure-3 respectively. Figure-9, Straight connectors (4) is of two types. Item (11) Male Straight connectors and Item (12) Female Straight connectors. The Female straight connectors are welded with the one of the circuit (2) and Male straight connectors are welded with the pairing circuit (2). Hence Female straight connectors slide on the male connectors during the operation to accommodate thermal expansion. This ensures the circuit (2) to stay in single plane. Similarly, In Figure 2, Item (3) is welded with circuit (2) and slides with another Item (3) which is welded with the pairing Circuit (2). All the Welding dimensions are prefixed by the Channels (8) placed above the I-beam. Now the job is completed.

In order to make the similar another coils assembly but varying the distance between the straight connectors (4), the bracket plate (9) and channels (8) are to be removed by gouging and gas cutting. To make the smooth surface again grinding is to be carried out. For this work 4 person per shift and three shifts are required. More over this I-beam (7) and channels (8) and bracket plate (9) cannot be used third time to make another coil assembly. The gas cutting also creates bow which is again to be corrected. Hence on alternate method was to be found out to eliminate the above manpower and material loss.
Prior Art
Patent search made no similar patent has been found in the search.
OBJECT OF THE INVENTION
It is therefore an object of the present invention to develop a fixture for fixing the different components on the coil assembly with varying pitch distance of straight connectors.
Another object of the invention is to propose a method of coil manufacturing assembly that saves material and manpower loss.
SUMMARY OF THE INVENTION
Accordingly, to the invention referring to the Figure-7 intermediate plate (10) of size 1000 mm length, 140 mm width having 6 mm thickness is inserted between I-beam (7) and channel (8). The number of intermediate plates (10) is increased depending upon the length of the I-beam (7).
The intermediate plates (10) are tack welded with I-beam (7) on the four corners of each intermediate plate (10). Now the bracket plates (9) are welded with intermediate plates (10). By this method new fixture as shown in Figure-7 is ready for making a coil assembly as shown in the Figure-1. In the above method channels (8) are fixed depending on the distance between the straight connectors (4).
In order to make another type of coil assembly if the distance between the straight connectors (4) are different, then the particular intermediate plates (10) which is required

to be replaced by just removing the tack weld at four corners and a fresh intermediate plate (10) can be welded, thereby the damages to the I-beam (7) and channel (8) are totally avoided and within a single shift the whole fixture of new coil assembly can be completed and hence productivity increased. By this above method, any type of coil assembly can be manufactured with the developed fixture shown in Figure-7.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure-1 Shows the coil assembly manufactured using the fixture.
Figure-2 Shows the welding of the circuits tubes (2) with tangent connectors (3).
Figure-3 Shows welding details of circuit tubes (2) and straight connectors (4).
Figure-4 Shows the welding detailed of circuits tubes (2) with roof seal binder (6).
Figure-5 Shows the prior art fixture used for making coil assembly.
Figure-6 Shows the view A and view B of the Figure-5.
Figure-7 Shows the developed fixture with intermediate plate (10).
Figure-8 Shows the Two views of Figure-7.
Figure-9 Shows the detailed view of item (4).
DETAILED DESCRIPTION OF THE INVENTION
The figure-5 shows the fixture assembly in which a pair of I-beam (7) of required length are placed parallel. The sizes of I-beam depending on the length of tubes (2) in coil assembly. Initially the channels (8) were placed directly on the I-beam (7) and connected on both sides with a pair of bracket plates (9). The plates (9) were then welded on one end with channel (8) and on other end with the I-beam (7).
According to the present invention as per Figure-7, an intermediate plate (10) of size approximately 1000 mm in length, 140 mm in width and 6mm in thickness is inserted between I-beam (7) and channel (8) instead of placing the channel (8) directly over the I-beam (7) as per earlier figure-5.

The intermediate plates (10) are tack welded with I-beam (7) on the four corners of each intermediate plate (10). Now the bracket plates (9) are welded with intermediate plates (10). By this method new fixture is ready for making a coil assembly as shown in the Figure-1. In the above method, channels (8) are fixed depending on the distance between the straight connectors (4).
In order to make another type of coil assembly if the distance between the straight connectors (4) are different then the particular intermediate plates (10) which is required to be replaced by just removing the tack weld at four corners and a fresh intermediate plate (10) can be welded thereby the damages to the I-beam (7) and channel (8) are totally avoided and within a single shift the whole new fixture for coil assembly can be completed and hence productivity increased. By this above method any type of coil assembly can be manufactured with the developed fixture shown in Figure-8.
During assembly, the individual circuits (2) are placed over the channel of figure-7 and connected with roof seal binder as per figure-4. The tubes (2) are welded with tangent connectors (3) as per figure-2 and with straight connectors (4) as per figure-3.
The location of the channels (8) are such that they are below the location of roof seal binder (6) and corresponding row of connectors (4) progressively onward during welding of the tubes (2) with the tangent connectors (3), straight connectors (4) and roof seal binder (6). Location of channels (8) is considered as the location for welding of tangent connectors (3) with circuit (2), straight connectors (4) with circuit (2), roof seal binder (6) with circuit (2). There is no welding of circuit (2), tangent connectors (3), straight connectors (4) with channels (8).

We Claim

1. A universal fixture for manufacturing coil assembly of circuits tubes with different
pitch distance of straight connectors and a method thereof comprising:
a plurality of C channel (8) in a parallel arrangement placed over a couple of I-beam (7) ;
the intermediate space between the I-beam (7) and channel (8) being filled with plurality of intermediate plates (10) ;
the said channel (8) being fixed with I-beam (7) by plurality of bracket plates (9) wherein one end of said bracket plate (9) is welded on to the channel (8) side and the other end welded with the intermediate plate (10) ;
the lateral movement of the intermediate plate (10) over the I-beam (7) being restricted by tacking the intermediate plate (10) with the I-beam (7) at four points ;
the top surfaces of channel (8) thus forming a stable planar surface over which the tubes are placed for assembly and welding operation of tubes (2) with roof seal binder (6), tangent connectors (3) and straight connectors (4).
2. A method of assembly of coil assembly components of steam generator of various
pitch distance comprising:
placing the tubes (2) side by side over the top surface of channel (8) ;
inserting the roof seal binder (6) from the bottom into the circuit (2) and welding with the tubes (2) as per figure-4 ;
simultaneously welding the tubes with tangent connectors (3) as per figure-2 and with straight connectors (4) as per figure-3 ;

repeating the operation for further coil assembly components until the setup of universal assembly is altered in case of pitch variation of straight connectors (4) where the tack welding between the intermediate plate (10) and I-beam (7) removed first followed by replacing the intermediate plate of a different dimension according to pitch, shifting the channel (8) at required distance and the again tack welding the intermediate plate (10) with I-beam (7) in the new setting.