JP2001259940A - Method for drawing capillary tube of heat exchanger and drawing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently draw a capillary tube of a heat exchanger. SOLUTION: When the capillary tube 20 secured to a securing part 21 of the heat exchanger is drawn, capillary tube drawing arrows 4 are respectively inserted into multiple capillary tubes 20 to be drawn while guide pins 3 are inserted into other capillary tubes 20, and multiple capillary tube drawing arrows 4 and guide pins 3 are inserted into an insertion hole 2a provided in a base plate 2. The base plate 2 is driven to a direction to draw the capillary tube 20 by a jack device 5 with leaving each capillary tube drawing arrow 4 licked to the base plate 2. Multiple capillary tubes 20 selected are thereby drawn together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extracting a thin tube of a heat exchanger and an apparatus therefor.

[0002]

2. Description of the Related Art A condenser in a power plant and various heat exchangers generally used in the industrial field have a plurality of thin tubes arranged in parallel in a cylindrical casing. It is configured to be fixed in a liquid-tight manner to a fixing part such as the above. If such a heat exchanger is used for a long period of time, the thin tube will be corroded, so that it is necessary to replace the thin tube at an appropriate time. Conventionally, in order to replace the thin tubes of the heat exchanger, each thin tube was first cut slightly inside a tube plate as a fixing portion thereof, and finally the thin tubes remaining in the fixing portion were pulled out one by one. For the drawing, a method is generally employed in which a thin tube drawing arrow is driven in and then the thin tube drawing arrow is pulled using a drawing jig or the like.

[0003]

However, in such a method of pulling out the thin tubes one by one, the working efficiency is low,
In particular, in the case of a large-sized heat exchanger having thousands to tens of thousands of thin tubes, the improvement of the thin tube exchange work has been strongly demanded because it requires a lot of days and labor to replace the thin tubes. Therefore, an object of the present invention is to solve such a problem, and an object of the present invention is to provide a new thin tube drawing method and a new drawing device therefor, and a thin tube drawing arrow which can be suitably used for the drawing.

[0004]

That is, according to the present invention, there is provided a method for extracting a thin tube arranged and fixed on a fixing portion of a heat exchanger, wherein a thin tube extracting arrow is inserted into a plurality of thin tubes to be extracted. The guide pin 3 is inserted into the thin tube, and a plurality of thin tube drawing arrows and the guide pins are inserted into the insertion holes provided in the base plate. With the thin tube drawing arrows hooked on the base plate, the base plate is drawn out by the jack device. A method for drawing a thin tube of a heat exchanger, characterized in that the tube is driven in a direction. According to the above-described drawing method, a plurality of thin tubes can be stably and collectively drawn by the guide pin and the base plate.
It has high drawing efficiency and can pull out many thin tubes in a short time.

In the above-mentioned drawing method, when a plurality of thin tube drawing arrows are hooked on the base plate, at least a part of the thin tube drawing arrows are made to have different axial locking positions, whereby the jack is drawn. It is possible to cause a difference in the drawing start position of the thin tube drawing arrow by the device. In this way, by providing a difference between the drawing start positions of the plurality of thin tube drawing arrows, the capacity of the jack device and the strength of the base plate can be reduced.

A thin tube pulling device according to the present invention is a device for pulling out thin tubes arranged and fixed on a fixing portion of a heat exchanger, wherein a base plate provided with a plurality of insertion holes arranged so as to match the arrangement position of the thin tubes. And a plurality of thin tube drawing arrows having a fitting portion, a shaft portion, and a movement restricting member having a higher hardness than the thin tube, and a jack device for driving the base plate,
In a state where the fitting portions of the thin tube drawing arrows are respectively fitted into a plurality of thin tubes to be drawn, the plurality of thin tube drawing arrows are inserted into the insertion holes provided in the base plate, and each thin tube drawing arrow is hooked on the base plate by the movement restricting member. A thin tube drawing device for a heat exchanger, wherein a base plate can be driven in a thin tube drawing direction by a jack device.
The drawing device configured as described above can suitably implement the above-described drawing method.

[0007] In the above-mentioned drawing device, a suspending fitting can be provided on the base plate. By providing such a hanger 15, the base plate can be hung on a moving means such as a crane device and moved using the hanger 15, so that many thin tubes can be sequentially and efficiently pulled out. It can be carried out. Further, the thin tube drawing arrow of the drawing device of the present invention is suitably used when pulling out the thin tubes arranged and fixed to the fixing portion of the heat exchanger, and is a detachable movement restricting member that is detachable from the fitting portion and the shaft portion. Has,
The fitting portion has a hardness higher than that of the thin tube and an outer diameter slightly larger than the inner diameter of the thin tube, and a spiral thread groove is formed on an outer peripheral portion of the fitting portion. By using the thin tube drawing arrow configured as described above, the thin tube drawing method of the present invention can be efficiently performed. Further, in the thin tube drawing arrow, the detachable movement restricting member may be constituted by a nut screwed on a screw portion provided on the shaft portion, and an engaging portion for engaging the rotating tool with the nut may be provided. The thin tube drawing arrow configured as described above can be easily fitted into the thin tube with a rotating tool.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view showing an example of an apparatus for carrying out the method for extracting a thin tube of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is an enlarged front view of a thin tube drawing arrow in FIG. In these figures, both ends of a plurality of thin tubes 20 arranged in parallel in a casing (not shown) of a heat exchanger are connected to a liquid through a through hole provided in a fixing portion 21 such as a tube sheet. It is tightly fixed. The thin tube drawing device 1 includes an elliptical base plate 2 having a plurality of insertion holes 2a arranged at the same interval as the thin tube 20, a plurality of guide pins 3, a plurality of thin tube drawing arrows 4, and a plurality of jack devices 5 for driving the base plate 2.
It has. As shown in FIG. 2, in this example, two guide pins 3 and five thin tube drawing arrows 4 are mounted in seven through holes 2a provided in the base plate 2.

The inner diameter of the insertion hole 2 a of the base plate 2 is formed to be equal to or slightly larger than the outer diameter of the shaft portion 9. The guide pin 3 has a shaft portion 6 that can be inserted into the thin tube 20 and an enlarged head portion 7 having an enlarged diameter provided at a rear end thereof. The thin tube pull-out arrow 4 is attached to and detached from a rear end portion of the shaft portion 9 having a cylindrical fitting portion 8 having a hardness higher than that of the thin tube 20 by quenching or the like, a tip portion inserted and fixed to the fitting portion 8. It has a movement restricting member 10 freely provided. As shown in FIG. 3, the fitting portion 8 of the thin tube drawing arrow 4 has a conical tip, and a spiral threaded groove 11 is formed on the outer peripheral portion. Further, the movement restricting member 10 is constituted by a cap nut having a hook portion 12 such as a hexagonal groove for hooking a rotary tool such as an impact drill on the head, and is formed on the shaft 9 on an inner screw of the cap nut. The two are joined by screwing the screw portion 9a.

In FIG. 2, three narrow tube drawing arrows 4 which are distinguished by blacking out the movement restricting member 10 have a shorter shaft portion 9 than the remaining two thin tube drawing arrows 4.
The two long shaft portions 9 in this example are set to a length obtained by adding a value slightly larger than the thickness dimension C (see FIG. 1) of the tube sheet 21 to the length value of the three short shaft portions 9. ing. The guide pin 3 has a shaft portion 6 longer than the long thin tube drawing arrow 4 of the shaft portion 9, thereby preventing the base plate 2 from falling off even after the thin tube 20 is drawn. As the jack device 5, a commercially available hydraulic jack can be used, and for example, it is preferable that the jack device 5 is remotely operated by an operation unit (not shown). In this example, two jack devices 5 are provided, and the bottom of each jack device 5 is
3, the bolts are fixed to both opposing edges of the base plate 2 so that the output shaft 14 presses the outer surface of the fixing portion 21 which is the tube plate of the heat exchanger via the protective curing material 22. . In addition, a suspending bracket 15 for suspending the base plate 2 is attached to one of the fixing brackets 13 by a crane device or the like (not shown).

Next, a method for extracting a thin tube using the above-described extraction device will be described. First, each thin tube 20 is cut slightly inside a tube plate as a fixed portion thereof, and then the thin tube drawing arrows 4 are fitted into the thin tubes 20 to be drawn by one operation. That is, a rotating tool such as an impact drill is engaged with the engaging portion 12 of the movement restricting member 10 screwed to the thin tube drawing arrow 4, and the rotating tool is activated and pressed in the axial direction. The thin tube 20 is inserted into the thin tube 20 while forming an internal screw by the spiral screw groove 11 formed in the above. FIG. 1 shows a state in which a plurality of thin tube drawing arrows 4 are fitted into each of the selected thin tubes 20 in this manner.
Next, the movement restricting member 10 is removed from each of the thin tube drawing arrows 4 and inserted into the insertion hole 2 a of the base plate 2. That is, the base plate 2 to which the jack device 5 is attached in advance is
It is suspended by a moving means such as a crane device (not shown) using the hanging fitting 15 and moved to the position of the thin tube drawing arrow 4, and each thin tube drawing arrow 4 is inserted into the insertion hole 2a. At the same time, a predetermined number of guide pins 3 are inserted into the insertion holes 2 a of the base plate 2, and the distal ends thereof are pulled out and inserted into other thin tubes 20 located near the selected thin tube 20, thereby positioning the base plate 2.

Next, after the movement restricting member 10 is screwed to the end of the shaft portion 9 of each thin tube drawing arrow 4, each jack device 5 is simultaneously driven to extend the output shaft 14 in the direction of the arrow in FIG. Then, the base plate 2 moves in parallel in the pulling direction of the thin tube 20. The thin tubes 20 selected by this moving operation are pulled out collectively. In this example, five thin tube pullout arrows 4 are used for one operation. As described above, three of the thin tube drawing arrows 4 (see FIG. 2), which are painted out in black, are different from the others in that the shaft 9
Is short. Therefore, when the base plate 2 is moved, the movement restricting members 10 of the three thin tube drawing arrows 4 having short lengths are hooked on the base plate 2, and the three thin tubes 20 into which the thin tube drawing arrows 4 are fitted are drawn first. It is. When the base plate 2 is further moved by the jack device 5, the movement restricting members 10 of the remaining two thin tube drawing arrows 4 are hooked on the base plate 2, and similarly, the two thin tubes 20 into which the thin tube drawing arrows 4 are fitted. Is pulled out.

By changing the length of the shaft portion 9 of the thin tube drawing arrow 4 in this way, the axial movement limit position changes, thereby causing a difference in the drawing start position of the thin tube drawing arrow 4 by the jack device 5. be able to. Therefore, since the stress applied to the jack device 5 and the base plate 2 is not instantaneously concentrated but dispersed and averaged over time, their design capacity and design strength can be reduced. After the plurality of selected thin tubes 20 are pulled out by the above operation at once, the base plate 2 is slightly moved to a position of the undrawn thin tubes 20 by a moving means such as a crane device, and the same operation is repeated to thereby obtain another thin tube. The thin tube group can be sequentially pulled out. In the last withdrawal operation, the thin tube 20 into which the guide pin 3 is to be inserted no longer exists. In this case, the guide pin 3 is inserted into the through hole of the fixing portion 21 after the thin tube 20 is pulled out to stabilize. Then, a similar pull-out operation can be performed.

In the above drawing operation, a plurality of thin tube drawing arrows 4
The base plate 2 is attached to the thin tube pullout arrows 4 after fitting the small tube into the thin tube 20. Alternatively, the fitting operation to the thin tube 20 can be performed after a plurality of thin tube pullout arrows 4 are mounted to the base plate 2. In that case, first, a plurality of thin tube drawing arrows 4 are inserted into the insertion holes 2a of the base plate 2, and then the movement restricting members 10 are screwed to the respective thin tube drawing arrows 4,
A predetermined number of guide pins 3 are inserted into insertion holes 2 a of base plate 2.
Through. In this state, the base plate 2 is moved to the withdrawn position, and the guide pins 3 are inserted into the thin tubes 20 to position the base plate 2. Next, after a plurality of thin tube drawing arrows 4 are sequentially fitted into the thin tube 20 with a rotary tool such as an impact drill, the thin tube 20 may be pulled out by the jack device 5 as described above.

[0015]

As described above, according to the method for extracting thin tubes of a heat exchanger of the present invention, a plurality of thin tubes can be extracted stably and collectively by a guide pin and a base plate. Can pull out many thin tubes. In the above-described drawing method, when the plurality of thin tube drawing arrows are hung on the base plate, at least a part of the thin tube drawing arrows are axially hooked at different positions, whereby the thin tube by the jack device is formed. It is possible to cause a difference in the drawing start position of the drawing arrow, so that the capacity of the jack device and the strength of the base plate can be designed to be small.

Next, by using the thin tube drawing device of the present invention, the above drawing method can be suitably carried out. Further, by using the thin tube drawing arrow of the drawing device of the present invention, the thin tube drawing method of the present invention can be efficiently performed. Further, in the thin tube drawing arrow, the detachable movement restricting member is constituted by a nut screwed to a screw portion provided on the shaft portion, and a hook portion for hooking the rotating tool to the nut can be provided. The thin tube pullout arrow can be easily fitted into the thin tube with a rotating tool.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an example of an apparatus for carrying out a method for extracting a thin tube according to the present invention.

FIG. 2 is a front view of FIG. 1;

FIG. 3 is an enlarged front view of a thin tube drawing arrow in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 thin tube drawing device 2 base plate 2a insertion hole 3 guide pin 4 thin tube drawing arrow 5 jack device 6 shaft portion 7 enlarged head 8 insertion portion 9 shaft portion 9a screw portion 10 movement restricting member 11 screw cutting groove 12 hooking portion 13 fixing bracket 14 Output shaft 15 Suspension fitting 20 Thin tube 21 Fixed part 22 Curing material

Claims (6)

[Claims] 1. A method for pulling out thin tubes 20 arranged and fixed to a fixing portion 21 of a heat exchanger, wherein a thin tube pulling arrow 4 is fitted into each of a plurality of thin tubes 20 to be drawn, and a guide pin 3 is inserted into another thin tube 20. At the same time, the plurality of thin tube drawing arrows 4 and the guide pins 3 are inserted into the insertion holes 2 a provided in the base plate 2, and the base plate 2 is pulled out by the jack device 5 while each thin tube drawing arrow 4 is hooked on the base plate 2. A method for drawing a thin tube of a heat exchanger, characterized in that the tube is driven in a direction. 2. A method according to claim 1, wherein the plurality of thin tube drawing arrows are connected to the base plate.
When at least a part of the thin tube drawing arrow 4 is hooked, the hooking positions of the thin tube drawing arrow 4 are made different from each other, thereby causing a difference in the drawing start position of the thin tube drawing arrow 4 by the jack device 5. The method for drawing a thin tube of a heat exchanger according to claim 2, wherein 3. A base plate 2 provided with a plurality of insertion holes 2a arranged so as to be aligned with the arrangement position of the thin tubes 20, wherein the base plate 2 is provided in a device for pulling out the thin tubes 20 arranged and fixed on the fixing portion 21 of the heat exchanger. A plurality of thin tube drawing arrows 4 having a fitting portion 8, a shaft portion 9, and a movement restricting member 10 having a hardness higher than 20, and a jack device 5 for driving the base plate 2 are provided. The fitting portion 8 of the thin tube drawing arrow 4 should be drawn out. Multiple thin tubes 20
Are inserted into the insertion holes 2a provided in the base plate 2, and each of the thin tube pull-out arrows 4 is hooked to the base plate 2 by the movement restricting member 10. Characterized in that it can be driven in the direction of pulling out a thin tube. 4. The movement limiting device according to claim 3, comprising: a guide pin 3 having a shaft portion 6 and an enlarged head 7 that can be inserted into the thin tube 20; and a fixing bracket 13 provided on the jack device 5. A member 10 is detachably screwed to an end of the thin tube drawing arrow 4, holds the base plate 2 with a suspending fitting 15, inserts the shaft portion 6 of the guide pin 3 into the thin tube 20, and
A plurality of thin tube drawing arrows 4 and guide pins 3 are attached to a base plate 2
The jack device 5 is positioned between the fixed portion 21 which is a tube sheet and the base plate 2, and the movable portion thereof is extended to extend the base plate 2.
Characterized in that it can be driven in the direction of pulling out a thin tube. 5. The thin tube drawing arrow 4 used for pulling out the thin tubes 20 arranged and fixed to the fixing portion 21 of the heat exchanger according to claim 3 or 4, wherein the thin tube drawing arrow 4 is fitted with the fitting portion 8 and the shaft portion 9.
The fitting portion 8 has a higher hardness than the thin tube 20 and an outer diameter slightly larger than the inner diameter of the thin tube 20, and further has a helical thread cut on the outer peripheral portion of the fitting portion 8. A thin tube drawing device for a heat exchanger, wherein a groove 11 is formed. 6. The screw portion 9 according to claim 5, wherein the detachable movement limiting member 10 is provided on the shaft portion 9.
A thin tube drawing device for a heat exchanger, comprising a nut screwed to a, and a hook portion 12 for hooking a rotating tool to the nut.