BLAZING APPARATUS FOR ALUMINUM CLAD OBLONG TUBE FOR AIR COOLING SYSTEM
CONDENSING PLANT

Pursuant to 35 U.S.C.§ 119 (a), this application claims the benefit of earlier filing date and right of priority to Korean Patent Application . No.10-2011-0042645, filed on May 4, 2011, the contents of which is hereby incorporated by reference in their entirety.

BACKGROUND OF THE DISCLOSURE

Field

The teachings in accordance with the exemplary embodiments of this present disclosure generally relate to a brazing apparatus configured to join two materials by heating the two materials at a high temperature, and more particularly to a brazing apparatus for aluminum (AL) clad oblong tube for air cooling system condensing plant configured to braze an aluminum fin to a steam condensing tube which is a core element of an air-cooling module applied to a heavy duty power generating plant.

Background

An atomic power plant or a thermoelectric power plant uses fuels such as uranium, kerosene and coal to generate heat, and uses the heat to circulate water in a system and to generate steam. The generated steam turns a turbine to generate electricity, where the turbine-passed steam is cooled by a condenser to become water again.

Particularly, a water-cooling method, in which water is used to cool a condensing process in the steam circulation power generating method, needs a large amount of cooling water, such that sea water is usually used as cooling water in the condenser. Thus, the atomic power plant or the thermoelectric power plant is usually built near seaside to smoothly get supplied with and discharge the sea water that is used as cooling water.

However, the sea water used as cooling water is discharged in a heated state by passing through a cooling system of the power plant. The sea water discharged to the sea from the power plant in the heated state amounts to hundreds of tons per hour. The sea water in the heated state increases temperature of sea water to create various environmental problems such as destructing marine ecosystem, to name a few.

Furthermore, an amount of cooling water tube supplied to steam condenser is absolutely insufficient in land-locked countries, such that there arises a problem of using a water-cooling condenser as a cooling system.

In view of the aforementioned problem, power plants using air-cooling condenser has been recently proposed, and are widely used in up-countries in China and US, for example, where sea water supply is insufficient. Although the power station using air-cooling condenser is disadvantageous in that facilities become bulky over the existing water-cooling condenser, the power station using air-cooling condenser has come into limelight as environment-friendly power generating facilities due to the fact that it canbe advantageously installed at an inland area instead of seaside area to provide a relative flexibility in selecting a location for a power plant over a power plant that must use the water-cooling condenser, and can be free from fear of creating a marine pollution caused by temperature rise in sea water resultant from input/output of cooling water.

The air-cooling condenser uses a large number of tubes, where the tube may be categorized into two types based on the shape, that is, an AL (aluminum) clad oblong tube and a MRG (Multi Row Galvanized) tube. The steam condensing tube for power plant has a structure in which an aluminum fin is brazed to, both sides of clad tube made of aluminum and steel stacks. An external surface of aluminum in the steam condensing tube for power plant is oxidized after brazing to be denaturalized into aluminite, such that no surface corrosion is generated in the air above a predetermined level.

Furthermore, a borderline between an aluminum fin and aluminum clad material on external surface of the fused clad tube is a coupled tissue of completely fused metal that has an advantageously perpetual heat transfer effect without any corrosion.

The steam condensing tube for power plant must maintain 5~ 10 times larger cross-section than that of a cylindrical small tube (1"~ 2") to have a relatively large cross-sectional area, whereby inside air of non-condensable gas can be rapidly removed to allow a rapid initial start operation and to advantageously dispense with an inner freezing of condensing water during winter operation due to larger flow of condensing water than that of a tube with a small cross-section.

Meanwhile, the conventional heat exchange type cylindrical MRG tube is externally attached with cooling pins for increasing heat transfer effect using various methods. The metal fusion method is an electric resistance welding method using same kind metals, which is the closest method for obtaining an intrinsic tube effect by the welded cooling fins. However, the electric resistance welding method is disadvantageous in that each fin is thickened and difficulty arises in arranging a large number of pins in order to allow each of the cooling fins to have an adeguate cross-section for electric resistance welding.

The disadvantage results in degradation of cooling effect caused by decreased heating surface.

In order to solve the aforementioned disadvantages, the cooling fins may be embedded into the surface of the tube, but the embedment leads to decreased performance of entire facilities due to rapid degradation of heat transfer capability of intrinsic function of the tube caused by generation of galvanic corrosion at the borderline 2~ 3 months after exposure to air upon start of operation.

The conventional MRG tube has been largely applied, for domestic and foreign consumption, for heat transfer by air-cooling heat exchange, because the steam condensing tube is poor in pressure-resistance, and high in manufacturing cost over the MRG tube. However, the steam condensing tube is relatively excellent over the MRG tube, because steam condensation is easy if degree of vacuum is high and differential vacuum pressure is applied to an interior of the steam condensing tube.

Since 1990s, the conventional steam condensing tube for power plant developed and used particularly for European countries and US has a high defect rate in brazing process of aluminum pins and clad tubes due to outdated manufacturing method to act as a factor increasing a manufacturing cost of product.

In order to braze the clad tubes and aluminum fins according to the conventional method, steel fixed frames are vertically arranged between which an aluminum fin, a clad tube and an aluminum fin are sequentially arranged, and a portion where the aluminum fin and the clad tube face each other is coated with flux, wrapped with steel wire and inputted into an electric heating furnace. Then, the aluminum fins are depressed inside the high-temperature furnace by self weight of the steel fixing frames to be fused to upper/lower surfaces of the clad tube.

However, if the aluminum fins are partially and excessively heated, and applied with an excessive power, chances are the aluminum fins are fused to the clad tube and to the frame as well. Under these circumstances, a torch is used to separate the aluminum fin from the frame, where the product maybe inevitably damaged and no longer unusable . As a result, a necessity surfaces for developing a manufacturing method capable of enhancing productivity in the manufacturing process of the steam condensing tubes in order to extensively apply the steam condensing tubes for power plants.

SUMMARY

The present disclosure has been made to solve the foregoing disadvantages of the prior art and therefore an object of certain embodiments of the present disclosure is to provide a brazing apparatus for aluminum clad oblong tube for air cooling system condensing plant configured to reduce a defect rate that may occur in the brazing process of clad tubes and aluminum pins by improving a manufacturing process of a steam condensing tube for power plants, and to enable a mass production.

Technical subjects to be solved by the present disclosure are not restricted to the above-mentioned description, and any other technical problems not mentioned so far will be clearly appreciated from the following description by the skilled in the art. That is, the present disclosure will be understood more easily and other objects, characteristics, details and advantages thereof will become more apparent in the course of the following explanatory description, which is given, without intending to imply any limitation of the disclosure, with reference to the attached drawings.

An object of the invention is to solve at least one or more of the above problems and/or disadvantages in whole or in part and to provide at least advantages described hereinafter. In order to achieve at least the above objects, in whole or in part, and in accordance with the purposes of the disclosure, as embodied and broadly described, and in one general aspect of the present invention, there is provided a brazing apparatus for aluminum (AL) clad oblong tube for air cooling system condensing plant by inputting a clad tube and a cooling fin to an electric heating furnace to braze a cooling fin to a periphery of the clad tube, the apparatus comprising: a jig frame; a first skid set supporting the jig, supporting a bottom surface of at least one . clad tube and having an accommodation groove having a shape corresponding to a bottom shape of the clad tube to prevent the steam condensing tube from being bent and twisted by thermal deformation under a high temperature inside the electric heating furnace after the plurality of clad tubes are accommodated in arrangement positions; heat fillers guiding blazing positions of a plurality of cooling fins each to face both lateral surfaces of the plurality of clad tubes accommodated in the first skid set, and interposed between respective cooling fins to prevent adjacent cooling fins from being contacted to each other; and a pressure unit mounted at both sides of the jig frame to apply a line-contact pressure from both sides on an outmost heat filler among heat fillers wrapping the clad tube inputted into the electric heat furnace and the cooling fin and to tightly contact the clad tube to the cooling fin.

Preferably, the pressure unit comprises: a pressure lever body; and a rotation shaft, wherein the pressure lever body includes a contact pressure unit having a length corresponding to a length of lengthwise direction of the heat filler and line-contacting the outmost heat filler of the first skid set, and a balance weight accommodation unit formed with a groove for accommodating a balance weight having a predetermined weight, and the rotation shaft rotatably supports the pressure lever body to a predetermined position inside the electric heat furnace depending on whether the balance weight has been accommodated.

Preferably, the balance weight is a rod member having a round cross-section and having a length corresponding to a length of the pressure lever body.

Preferably, the groove in the balance weight accommodation unit is provided in a form of a trench with an upper surface opened and having a width corresponding to a diameter of the round cross-section of the rod member, and accommodated with the rod member through the opened upper surface.

Preferably, the pressure unit and the accommodation unit are so formed as to have an angle in the range of 90°D 150° there between about the rotation shaft.

Preferably, the apparatus further comprises a second skid set provided in a same shape as that of the first skid set to fix the clad tube and a blazing position of the cooling fin on upper sides of the clad tube and the heat filler along with the first skid set.

Preferably, mutually adjacent first skid sets are spaced apart with a same distance if no pressure is applied from the pressure unit.

Preferably, the first skid set is formed with a graphite material.

Preferably, the first and second skid sets are formed with a graphite material.

Preferably, the heat filler is formed with a graphite material.

Preferably, the heat filler takes a shape of a rectangular parallelepiped having a length corresponding to a length of the clad tube.

Preferably, each of the first and second skid sets is divided to a lengthwise direction of the clad tube with a predetermined gap (L) .

Preferably, the predetermined gap (L) is in the range of 2D2 . 5 meters.

The brazing apparatus for aluminum clad oblong tube for air cooling system condensing plant according to the present disclosure has an advantageous effect in that product defects, such as fusion between an aluminum fin and a frame that frequently occurs in a conventional steam condensing tube brazing process for power plant, can be prevented, and the tube can be manufactured two to three times more than the conventional process.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiment (s) of the disclosure, and together with the description serve to explain the principle of the disclosure. In the drawings:

FIGS. 1 and 2 are schematic views illustrating a brazing apparatus for aluminum clad oblong tube for air cooling system condensing plant according to an exemplary embodiment of the present disclosure; FIG.3 is an exploded perspective view illustrating an arrangement of first and second skid sets, a heat filler, a clad tube and a cooling fin according to an exemplary embodiment of the present disclosure; FIG. 4 is a schematic view illustrating a coupled relation between the clad tube and the cooling fin of FIG.3; and

FIG.5 is a schematic view illustrating a clad tube according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Various exemplary embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which some exemplary embodiments are shown. The present inventive concept may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these exemplary embodiments are provided so that this description will be thorough and complete, and will fully convey the scope of the present inventive concept to those skilled in the art.

It will be understood that when an element or layer is referred to as being "on, " "connected to" or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on, " "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. Like numerals refer to like elements throughout.

It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present inventive concept.

As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context . of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments of the disclosure.

Hereinafter, a brazing apparatus for aluminum clad oblong tube for air cooling system condensing plant according to the present disclosure will be described in detail with reference to the accompanying drawings .

FIGS. 1 and 2 are schematic views illustrating a brazing apparatus for aluminum clad oblong tube for air cooling system condensing plant according to an exemplary embodiment of the present disclosure, FIG. 3 is an exploded perspective view illustrating an arrangement of first and second skid sets, a heat filler, a clad tube and a cooling fin according to an exemplary embodiment of the present disclosure, FIG. 4 is a schematic view illustrating a coupled relation between the clad tube and the cooling fin of FIG. 3, and FIG. 5 is a schematic view illustrating a clad tube according to an exemplary embodiment of the present disclosure.

The brazing apparatus for aluminum clad oblong tube for air cooling system condensing plant according to an exemplary embodiment of the present disclosure includes a jig frame (100) , a first skid set (200) , a heat filler (300) and a pressure unit (500).

An electric heat furnace (1) is a device for brazing a clad tube (10) and a cooling pin (20) forming a steam condensing tube for power plant at a predetermined temperature. The electric heat furnace (1) may be formed at a floor surface with a plurality of roller members to allow the clad tube (10) and the cooling fin (20) to smoothly input and output from an inlet to an outlet. The electric heat furnace (1)

is provided therein with a plurality of heat sources (110) at an upper surface and a bottom surface to allowing heating the clad tube (10) and the cooling fin (20) inputted at a temperature range of at least 250°c 260°C. The principle and configuration of the electric heat furnace (1) are irrelevant to the subject matter of the present disclosure, such that no detailed explanation to the furnace (1) will be provided herein.

The jig frame (100) is formed to input a plurality of clad tubes (10) and the cooling fins at a time into the electric heat furnace (1), and the jig frame (100) includes the first skid set (200), the heat filler (300) and the pressure unit (500) that are to be described later.

Referring to FIGS. 1 and 2, the first skid set (200) is preferably formed with a graphite material capable of supporting a bottom surface of the plurality of clad tubes (10) . The first skid set (200) prevents the clad tube (10) from being twisted to a lengthwise direction while the brazing process is being worked out inside the electric heat furnace (1) .

Referring to FIG.2, the first skid set (200) is formed with an accommodation groove (210) having a shape corresponding to a surface opposite to the clad tube (10). The accommodation groove (210) is preferably formed with a shape of a trench opened at an upper side, and as shown in the figure, is formed with a shape corresponding to that at a bottom surface of the clad tube (10).

Referring to FIG. 3, the first skid set (200) includes a clad tube (10) for each first skid. The number of clad tubes (10) inputted into the electric heat furnace (1) varies based on size of the electric heat furnace (1), such that the number of first skids constituting the first skid set (200) may increase or decrease based on the number of inputted clad tubes (10).

Meanwhile, referring to FIG.4, a plurality of first skid sets (200) is preferably divided each at a predetermined gap (L) to a lengthwise direction of the clad tube (10) to intermittently support the clad tube (10) . If only one first skid is provided with a length corresponding to that of the clad tube (10) to support a bottom surface of the clad tube (10), heat of the electric heat furnace (1) is insufficiently transmitted to the flux (21) side to disable the brazing work. .Thus, as illustrated in FIG. 4, the gap (L) is formed in an approximate range of 202 . 5 meters to allow the plurality of first skids to preferably support a bottom side of the clad tube (10).

According to an exemplary embodiment of the present disclosure, the clad tube (10) is preferably accommodated into the first skid set (200) to allow openings formed at both ends to face an inlet and an outlet of the electric heat furnace (1). Furthermore, the cooling fin (20) of aluminum material is brazed to both lateral surfaces forming a broader surface of the clad tube (10), and a narrower portion of the clad tube (10) is preferably accommodated into the accommodation groove (210) provided at the first skid set (200).

Meanwhile, materials of the clad tube (10) are preferably made by cladding aluminum with carbon steel, whereby the aluminum cooling fin (20) is completely fused to the clad tube (10) through the brazing process, and a large number of tubes can be simultaneously welded to tube sheets to thereby accomplish an excellent weldability.

Referring to FIG.5, each of an upper side and a bottom side of the clad tube (10) preferably takes a round shape while both lateral surfaces of the clad tube (10) take a convex shape.

That is, as illustrated in FIG.5, a center width of the clad tube (10) is broader than an upper side width and a bottom side width based on a cross-section of the clad tube (10), where the center width, the upper side width and the bottom side width is formed to have a first gap (g) . The reason of convexly forming the both lateral surfaces of the clad tube (10) is to allow the clad tube (10) and the cooling fin (20) to gradually broaden a contact area and to be evenly attached and fixed.

The both lateral surfaces of the clad tube (10) is arranged with a cooling fin (20) formed by folding an aluminum plate. At this time, a portion folded in a zigzag fashion in the cooling fin (20) is arranged at an upper side and a bottom side, as illustrated in FIG. 3, to allow air to circulate in a vertical direction of the clad tube (10). A surface opposite to the clad tube (10) of the cooling fin (20) is coated with flux (21), as shown in FIG. 4, where the flux (21) receives heat from the electric heat furnace (1) to fixedly and electrically connect the clad tube (10) and the cooling fin (20). Furthermore, the cooling fin (20) is formed with a length corresponding to a length of the clad tube (10) so as to cover an entire lateral surface of the clad tube (10).

The heat filler (300) serves to guide abrazingposition of the plurality of cooling fins (20) arranged opposite to the both lateral surfaces of the plurality of clad tubes (10) accommodated in the first skid set (200), and is interposed between the cooling fins (20) lest the adjacent cooling fins (20) should be mutually contacted.

The heat filler (300) takes an approximate shape of a rectangular parallelepiped preferably having a length corresponding to that of the clad tube (10) and that of the cooling fin (20) , where the pressure unit (500) is made to fuse the cooling fin (20) to the lateral surface of the clad tube (10) with an even force. Referring to FIG. 3, a bottom side of the heat filler (300) is preferably provided with a support member (310) to support a movement of the cooling fin (20) to a gravitational direction.

The brazing apparatus for aluminum (AL) clad oblong tube for air cooling system condensing plant may further include a second skid set (400) . provided in a same shape as that of the first skid set to fix the clad tube and a blazing position of the cooling fin on upper sides of the clad tube and the heat filler along with the first skid set. The shape of the second skid set (400) preferably corresponds to that of the first skid set (200) .

Although the second skid set (400) may not be necessarily neededbecause the first skid set (200) is available, the first and second skid sets can further. prevent the clad tube (10) and the cooling fin (20) from being twisted from both upper and bottom sides.

Meanwhile, it is preferred that adjacent first and second skid sets (200, 400) are distanced from each other with an identical gap if no pressure is applied from the pressure unit (500, described later) . The gap, as illustrated in FIG.l, is preferably provided with a value smaller than a twofold of the first gap (g) . Under this configuration, if the clad tube (10) and the cooling fin (20) are tightly and completely brought into contact by the pressure unit (500) , the pressure is good enough to only flatten the convex portion of the clad tube (10) to some degree, and no more pressure is given such that the cooling fin (20) and the clad tube (10) are prevented from being twisted by an excessive force.

Furthermore, the first and second skid sets, and the heat filler are preferably formed with a graphite material. The graphite is light (density: 1.75), excellent in heat-resistance and not fused with aluminum at a high temperature, such that, unlike the prior art, defects such as fusion between aluminum cooling fin and the steel frame during working process can be prevented. Although the exemplary embodiment of the present disclosure has restricted the material of the first, second skid sets (200, 400) and the heat filler (300) to graphite, the material is not limited thereto, and any alternative material capable of preventing fusion with aluminum cooling fin may be used.

The pressure unit (500) is formed at both sides of the jig frame (100) to apply a line contact pressure to outmost heat fillers (300a, 300b) in the first and second skid sets (200, 400), among the heat fillers (300) wrapping the clad tube (10) and the cooling fin (20) inputted into the electric heat furnace for tight contact between the clad tube (10) and the cooling fin (20) . The pressure unit (500) includes a pressure lever body (510) and a rotation shaft (520) .

The pressure lever body (510) has a length corresponding to a length of lengthwise direction of the heat filler (300) and includes a contact pressure unit (511) and a balance weight accommodation unit (512).The contact pressure unit (511) line-contacts the outmost heat fillers (300a, 300b) of the first and second skid sets (200, 400), and the balance weight accommodation unit (512) is formed with a groove in which a balance weight (513) having a predetermined weight is accommodated.

The balance weight (513) is preferably a rod member having a round cross-section and having a length corresponding to a length of the pressure lever body (510).

The groove formed in the balance weight accommodation unit is preferably provided in a form of a trench with an upper surface opened and having a width corresponding to a diameter of the round cross-section of the rod member, and accommodated with the rod member through the opened upper surface.

The rotation shaft (520) rotatably supports the pressure lever body (510) to a predetermined position of the jig frame inside the electric heat furnace (1) depending on whether the balance weight (513) has been accommodated.

Meanwhile, it is preferable that the pressure unit (511) and the accommodation unit (512) be so formed as to have an angle in the range of 90°n 150°therebetween about the rotation shaft (520).

Now, operation of the brazing apparatus for aluminum (AL) clad oblong tube for air cooling system condensing plant according to the present disclosure will be described with reference to the accompanying drawings.

Referring to FIGS. 1 and 2 again, the brazing apparatus for aluminum (AL) clad oblong tube for air cooling system condensing plant according to the present disclosure is such that a plurality of clad tubes (10) is erected at one time and inputted into an electric heat furnace (1), where a cooling pin (20) formed by folding aluminum plates on flat both surfaces is brazed. To this end, a bottom side and an upper side of the clad tube (10) are supported by using the first and second skid sets (200, 400) in order to allow each flat surface of respective clad tubes (10) to form both lateral surfaces in an erect state and to be inputted into the electric heat furnace (1).

Furthermore, each of the clad tubes (10) and cooling fins (20) is interposed between the heat filler (300) , and the pressure unit (500) provided at the electric heat furnace (1) applies pressure to lateral surf aces of the clad tubes (10) and the cooling fins (20) thus prepared and performs the brazing process.

That is, although the conventional method was to sequentially arrange a frame, a cooling fin, a clad tube, a cooling fin and a frame in horizontal state, and the self-weight heavy steel frame presses the clad tubes and the cooling to braze the clad tubes (10) and the cooling fins (20), the conventional method was disadvantageous in that the cooling fins and the frames are fused to generate a damaged steam condensing tube. In addition, upper and bottom surfaces of the tubes are applied with different pressure due to weight difference.

However, the configuration according to the present disclosure is advantageous in that the cooling fin (20) is coupled to both sides of the clad tube (10) in a direction perpendicular to the gravitational direction, and the pressure unit (500), using the graphite heating filler (300), can evenly apply pressure to a surface opposite to the clad tube (10) and the cooling fin (20) as much as needed through the graphite heating filler to perforin the brazing work, whereby there is no defect during the brazing operation.

Furthermore, due to the fact that brazing operation is performed with the clad tube (10) in a vertically erect state, a larger amount of clad tubes (10) can be inputted into the electric heat furnace (1) than that of the conventional lyingbrazing operation to greatly enhance the productivity.

The previous description of the present invention is provided to enable any person skilled in the art to make or use the invention. Various modifications to the invention will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the invention. Thus, the invention is not intended to limit the examples described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

As apparent from the foregoing, the brazing apparatus for aluminum (AL) clad oblong tube for air cooling system condensing plant according to the present disclosure has an industrial applicability in that product defects, such as fusion between an aluminum fin and a frame that frequently occurs in a conventional steam condensing tube brazing process for power plant, can be prevented, and the tube can be manufactured two to three times more than the conventional process.

WHAT IS CLAIMED IS:

1. A brazing apparatus for aluminum (AL) clad oblong tube for air cooling system condensing plant by inputting a clad tube and a cooling fin to an electric heating furnace to braze the cooling fin to a periphery of the clad tube, the apparatus comprising:

a jig frame;

a first skid set supporting the jig, supporting a bottom surface of at least one clad tube and having an accommodation groove having a shape corresponding to a bottom shape of the clad tube to prevent the steam condensing tube from being bent and twisted by thermal deformation under a high temperature inside the electric heating furnace after the plurality of clad tubes are accommodated in arrangement positions;

heat fillers guiding blazing positions of a plurality of cooling fins each to face both lateral surfaces of the plurality of clad tubes accommodated in the first skid set, and interposed between respective cooling fins to prevent adjacent cooling fins from being contacted to each other; and

a pressure unit mounted at both sides of the jig frame to apply a line-contact pressure from both sides on an outmost heat filler among, heat fillers wrapping the clad tube inputted into the electric heat furnace and the cooling fin and to tightly contact the clad tube to the cooling fin.

2. The apparatus of claim 1, wherein the pressure unit comprises: a pressure lever body; and a rotation shaft, wherein the pressure lever body includes a contact pressure unit having a length corresponding to a length of lengthwise direction of the heat filler and line-contacting the outmost heat filler of the first skid set, and a balance weight accommodation unit formed with a groove for accommodating a balance weight having a predetermined weight, and the rotation shaft rotatably supports the pressure lever body to a predetermined position inside the electric heat furnace depending on whether the balance weight has been accommodated.

3. The apparatus of claim 2, wherein the balance weight is a rod member having a round cross-section and having a length corresponding to a length of the pressure lever body.

4 . The apparatus of claim 3, wherein the groove in the balance weight accommodation unit is provided in a form of a trench with an upper surface opened and having a width corresponding to a diameter of the round cross-section of the rod member, and accommodated with the rod member through the opened upper surface.

5. The apparatus of claim 2, wherein the pressure unit and the accommodation unit are so formed as to have an angle in the range of 90°~ 150°therebetween about the rotation shaft.

6. The apparatus of claim 1, further comprising a second skid set provided in a same shape as that of the first skid set to fix the clad tube and a blazing position of the cooling fin on upper sides of the clad tube and the heat filler along with the first skid set.

7. The apparatus of claim 1, wherein mutually adjacent first skid sets are spaced apart with a same distance if no pressure is applied from the pressure unit.

8. The apparatus of claim 1, wherein the first skid set is formed with a graphite material.

9. The apparatus of claim 6, wherein the first and second skid sets are formed with a graphite material.

10. The apparatus of claim 1, wherein the heat filler is formed with a graphite material.

11. The apparatus of claim 1, wherein the heat filler takes a shape of a rectangular parallelepiped having a length corresponding to a length of the clad tube.-

12. 'The apparatus of claim 6, wherein each of the first and second skid sets is divided to a lengthwise direction of the clad tube with a predetermined gap (L).

13. The apparatus of claim 12, wherein the predetermined gap (L) is in the range of 202.5 meters.