JP4182385B2 - Narrow tube drawing method and drawing apparatus for heat exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for pulling out a thin tube of a heat exchanger and an apparatus therefor.
[0002]
[Prior art]
In condensers in power plants and various heat exchangers generally used in the industrial field, a plurality of thin tubes are arranged in parallel in a cylindrical casing, and both ends of the thin tubes are used as fixed parts such as tube sheets. It is configured to be liquid-tight. When such a heat exchanger is used for a long period of time, the capillaries are corroded, so that the capillaries need to be replaced at an appropriate time.
Conventionally, in order to replace the thin tubes of the heat exchanger, each thin tube is first cut slightly inside the tube plate that is the fixing portion, and finally the thin tubes remaining in the fixing portion are pulled out one by one. For drawing, a method is generally employed in which a thin tube drawing arrow is driven and then the thin tube drawing arrow is pulled using a drawing jig or the like.
[0003]
[Problems to be solved by the invention]
However, the method of pulling out the thin tubes one by one in this way is low in work efficiency. Particularly, in a large heat exchanger having thousands to tens of thousands of thin tubes, it takes a lot of days and labor for the tube replacement work. Therefore, the improvement was strongly desired. Accordingly, 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 drawing apparatus for that purpose, and a thin tube drawing arrow that can be suitably used for the drawing.
[0004]
[Means for Solving the Problems]
That is, the method of pulling out the thin tubes of the present invention is a method of pulling out the thin tubes arranged and fixed to the fixing portion of the heat exchanger.
The thin tube pulling arrows are respectively inserted into a plurality of thin tubes to be pulled out, and the guide pins 3 are inserted into the other thin tubes, and the plurality of thin tube pulling arrows and guide pins are inserted into insertion holes provided in the base plate, and each thin tube pulling arrow is inserted. A heat exchanger thin tube extraction method, wherein the base plate is driven in a thin tube extraction direction by a jack device while being hooked on the base plate.
According to the above-described extraction method, a plurality of thin tubes can be stably and collectively pulled out by the guide pins and the base plate, so that the drawing efficiency is high and many thin tubes can be pulled out in a short time.
[0005]
In the above pulling method, when the plurality of thin tube pulling arrows are hooked on the base plate, at least some of the thin tube pulling arrows have different axial latching positions, thereby narrowing the thin tubes by the jack device. A difference can be made in the drawing start position of the drawing arrow.
Thus, the capacity | capacitance of a jack apparatus and the intensity | strength of a base plate can be designed small by making a difference in the extraction start position of a some thin tube extraction arrow.
[0006]
Further, the thin tube drawing device of the present invention is a device for pulling out the thin tubes 20 arranged and fixed to the fixing portion 21 of the heat exchanger.
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,
A plurality of capillary pulling arrows 4 having a fitting portion 8, a shaft portion 9, and a movement restricting member 10, which are harder than the thin tube 20;
A jack device 5 for driving the base plate 2;
A shaft 6 that can be inserted into the narrow tube 20 and a guide pin 3 having an enlarged head 7;
The shaft portion 6 of the guide pin 3 is inserted into the thin tube 20, and the guide pin 3 is inserted into the insertion hole 2a provided in the base plate 2,
The fitting portion 8 of the thin tube pulling arrow 4 is inserted into a plurality of thin tubes 20 to be pulled out, and each thin tube pulling arrow 4 is hooked on the base plate 2 by the movement restricting member 10, and the jack device 5 pulls the base plate 2 in the thin tube pulling direction. It is comprised so that it can drive to the thin tube drawing apparatus of the heat exchanger characterized by the above-mentioned.
The drawing apparatus configured as described above can preferably carry out the above-described drawing method.
[0007]
In the above drawing device, the base plate can be provided with a hanging metal fitting. By providing such a hanging bracket 15, the base plate can be suspended and moved by a moving means such as a crane device using the hanging bracket 15, so that many thin tubes can be pulled out sequentially and efficiently. It can be carried out.
Further, the pulling-out arrow of the pulling device of the present invention is preferably used when pulling out the thin tubes arranged and fixed to the fixing portion of the heat exchanger, and is a movement limiting member that is detachable from the fitting portion and the shaft portion. The fitting portion has an outer diameter that is higher in hardness than the narrow tube and slightly larger than the inner diameter of the thin tube, and further, a helical thread groove is formed on the outer peripheral portion of the fitting portion. It is. By using the thin tube drawing arrow configured as described above, the thin tube drawing method of the present invention can be efficiently carried out.
Further, in the above-mentioned pulling-out arrow for the thin tube, a detachable movement restricting member is constituted by a nut that is screwed onto a screw portion provided on the shaft portion, and a hooking portion for hooking the rotating tool on the nut can be provided. The thin tube pulling arrow configured in this way can be easily fitted into the thin tube with a rotating tool.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial sectional view showing an example of an apparatus for carrying out the thin tube drawing method 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 liquid in a state of passing through through holes provided in a fixing portion 21 such as a tube plate. It is fixed tightly.
The thin tube extracting device 1 includes an elliptical base plate 2 provided with a plurality of insertion holes 2 a arranged at the same intervals as the thin tubes 20, a plurality of guide pins 3, a plurality of thin tube extracting arrows 4, and a plurality of jack devices 5 that drive 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 attached to seven insertion holes 2 a provided in the base plate 2.
[0009]
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 portion thereof. The thin tube drawing arrow 4 is a cylindrical insertion portion 8 that is harder than the thin tube 20 by quenching or the like, a shaft portion 9 in which a tip portion is inserted and fixed to the insertion portion 8, and a rear end portion of the shaft portion 9. It has a movement limiting member 10 provided freely.
As shown in FIG. 3, the insertion portion 8 of the thin tube drawing arrow 4 has a conical tip, and a helical thread groove 11 is formed on the outer peripheral portion. Further, the movement restricting member 10 is constituted by a cap nut provided with an engaging portion 12 such as a hexagonal groove for engaging a rotary tool such as an impact drill on the head, and is formed on the shaft portion 9 on the inner screw of the cap nut. The screw portion 9a is screwed to couple them together.
[0010]
In FIG. 2, the three thin tube pull-out arrows 4 that are distinguished by painting out the movement restriction member 10 in black have a shorter shaft portion 9 than the remaining two thin tube pull-out 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 C of the tube plate 21 (see FIG. 1) to the value of the three short lengths of the shaft portion 9. ing. The guide pin 3 has a shaft portion 6 which is longer than the long tube pulling arrow 4 having a long shaft portion 9, thereby preventing the base plate 2 from dropping even after the thin tube 20 is pulled out.
As the jack device 5, a commercially available hydraulic jack can be used. 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 portion of each jack device 5 is bolted to both opposing edges of the base plate 2 by fixing brackets 13, and the output shaft 14 is connected via a protective curing material 22. Thus, the outer surface of the fixing portion 21 which is a tube plate of the heat exchanger is pressed. Note that a suspension fitting 15 for hanging the base plate 2 is attached to one fixing fitting 13 by a crane device or the like (not shown).
[0011]
Next, a method for pulling out the thin tube using the above-described pulling apparatus will be described. First, each thin tube 20 is cut slightly inside the tube plate which is a fixed portion thereof, and then the thin tube pulling arrow 4 is inserted into each thin tube 20 to be pulled out by one operation. That is, when a rotary tool such as an impact drill is engaged with the engaging portion 12 of the movement limiting member 10 screwed to the thin tube pulling arrow 4 and the rotary tool is activated and pressed in the axial direction, the insertion portion 8 has its outer peripheral portion. The inner thread is inserted into the thin tube 20 by the helical thread groove 11 formed in the above. FIG. 1 shows a state in which a plurality of capillary pulling arrows 4 are inserted into the selected thin tubes 20 in this manner.
Next, the movement restricting member 10 is removed from each thin tube pulling arrow 4 and inserted into the insertion hole 2 a of the base plate 2. That is, the base plate 2 to which the jacking device 5 is attached in advance is suspended by moving means such as a crane device (not shown) using the hanging metal fitting 15 and moved to the position of the thin tube pulling arrow 4, and each thin tube is pulled into the insertion hole 2a. Insert the arrow 4. 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 inserted into the other thin tubes 20 located near the selected thin tube 20, thereby positioning the base plate 2.
[0012]
Next, after the movement restricting member 10 is screwed onto the end of the shaft portion 9 of each thin tube pulling arrow 4, each jack device 5 is simultaneously driven to extend its output shaft 14 in the direction of the arrow in FIG. 2 moves in parallel with the drawing direction of the thin tube 20. The thin tubes 20 selected by this moving operation are pulled out together.
In this example, five thin tube pulling arrows 4 are used for one operation, but as described above, the three parts (see FIG. 2) which are distinguished by being painted in black have a longer length of the shaft part 9 than the others. short. Therefore, when the base plate 2 is moved, the movement restricting member 10 of the three thin tube pulling arrows 4 having the short length is hooked to the base plate 2, and the three thin tubes 20 into which the thin tube pulling arrows 4 are inserted are first pulled out. 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 pulling arrows 4 are hooked on the base plate 2, and similarly, the two thin tubes 20 into which the thin tube pulling arrows 4 are fitted. Is pulled out.
[0013]
Thus, by changing the length of the shaft portion 9 of the thin tube pulling arrow 4, the movement limit position in the axial direction is changed, thereby making it possible to make a difference in the drawing start position of the thin tube pulling arrow 4 by the jack device 5. . Therefore, since the stress applied to the jack device 5 and the base plate 2 is not concentrated instantaneously but is temporally dispersed and averaged, the design capacity and design strength thereof can be reduced.
After the plurality of selected thin tubes 20 are pulled out by the above operation, the base plate 2 is slightly moved to the position of the undrawn thin tubes 20 by moving means such as a crane device, and the same operation is repeated. The tubule group can be pulled out sequentially. In the final drawing operation, there is no narrow tube 20 into which the guide pin 3 is to be inserted. In that case, the guide pin 3 is inserted into the through-hole of the fixing portion 21 after the thin tube 20 is pulled out and stabilized. It is possible to perform the same pulling operation.
[0014]
In the above-described drawing operation, after the plurality of thin tube drawing arrows 4 are fitted into the thin tubes 20, the base plate 2 is attached to the thin tube drawing arrows 4, but conversely, after the plurality of thin tube drawing arrows 4 are attached to the base plate 2, the thin tubes Insertion operation into 20 can also be performed.
In that case, first, the plurality of thin tube pulling arrows 4 are inserted into the insertion holes 2 a of the base plate 2, and then the movement restricting member 10 is screwed to each thin tube pulling arrow 4, and a predetermined number of guide pins 3 are attached to the base plate 2. It passes through the insertion hole 2a. In this state, the base plate 2 is moved to the drawing 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 pulling arrows 4 are sequentially inserted 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]
【The invention's effect】
As described above, according to the thin tube drawing method of the heat exchanger of the present invention, a plurality of thin tubes can be pulled out stably and collectively by the guide pins and the base plate, so that the drawing efficiency is high and many thin tubes can be drawn in a short time. Can be pulled out.
In the above drawing method, when the plurality of thin tube pulling arrows are hooked on the base plate, at least a part of the thin tube pulling arrows are made to have different axial latching positions so that the thin tube by the jack device is used. It is possible to make a difference in the drawing start position of the drawing arrow, whereby the capacity of the jack device and the strength of the base plate can be designed to be small.
[0016]
Next, by using the thin tube drawing apparatus of the present invention, the above drawing method can be suitably carried out.
Moreover, the thin tube drawing method of the present invention can be efficiently carried out by using the thin tube drawing arrow of the drawing device of the present invention.
Furthermore, in the above-mentioned narrow tube drawing arrow, a detachable movement restricting member is constituted by a nut that is screwed to a screw portion provided on the shaft portion, and a hooking portion for hooking a rotating tool to the nut can be provided, thereby A thin tube drawing arrow can be easily fitted into a 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 thin tube drawing method of the present invention.
FIG. 2 is a front view of FIG.
FIG. 3 is an enlarged front view of the thin tube pulling arrow in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Thin tube extraction apparatus 2 Base plate 2a Insertion hole 3 Guide pin 4 Thin tube extraction arrow 5 Jack apparatus 6 Shaft part 7 Expansion head part 8 Insertion part 9 Shaft part 9a Screw part 10 Movement limiting member 11 Screw cutting groove 12 Engagement part 13 Fixing bracket 14 Output shaft 15 Suspension bracket 20 Narrow tube 21 Fixing part 22 Curing material

Claims (6)

In the method of pulling out the thin tubes 20 arranged and fixed to the fixing part 21 of the heat exchanger,
The thin tube extraction arrows 4 are respectively inserted into the plurality of thin tubes 20 to be extracted, and the guide pins 3 are inserted into the other thin tubes 20, and the plurality of thin tube extraction arrows 4 and the guide pins 3 are inserted into the insertion holes 2 a provided in the base plate 2. A method of pulling out a thin tube of a heat exchanger, wherein the base plate 2 is driven in the direction of pulling out the thin tube by the jack device 5 in a state where each thin tube pulling arrow 4 is hooked on the base plate 2. When the plurality of thin tube pulling arrows 4 are hooked on the base plate 2, at least some of the thin tube pulling arrows 4 have different latching positions, whereby the thin tube pulling arrows 4 of the jack device 5 are used. 2. The method for pulling out a thin tube of a heat exchanger according to claim 1 , wherein a difference is caused in the drawing start position. In the apparatus for pulling out the thin tubes 20 arranged and fixed to the fixing part 21 of the heat exchanger,
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,
A plurality of capillary pulling arrows 4 having a fitting portion 8, a shaft portion 9, and a movement restricting member 10, which are harder than the thin tube 20;
A jack device 5 for driving the base plate 2;
A shaft 6 that can be inserted into the narrow tube 20 and a guide pin 3 having an enlarged head 7;
The shaft portion 6 of the guide pin 3 is inserted into the thin tube 20, and the guide pin 3 is inserted into the insertion hole 2a provided in the base plate 2,
The fitting portion 8 of the thin tube pulling arrow 4 is inserted into a plurality of thin tubes 20 to be pulled out, and each thin tube pulling arrow 4 is hooked on the base plate 2 by the movement restricting member 10, and the jack device 5 pulls the base plate 2 in the thin tube pulling direction. A thin tube drawing device for a heat exchanger, characterized in that it can be driven by In claim 3,
Comprising a fixing bracket 13 provided on the jack device 5,
The movement limiting member 10 is detachably screwed to the end of the thin tube pulling arrow 4,
The base plate 2 is held by the hanging metal fitting 15, and the jack device 5 is positioned between the fixed portion 21 which is a tube plate and the base plate 2, and the movable portion is extended to drive the base plate 2 in the direction of pulling out the thin tube. A thin tube drawing device for a heat exchanger, characterized in that it can be configured. In claim 3 or claim 4,
The thin tube extraction arrow 4 used when pulling out the thin tubes 20 arrayed and fixed to the fixing portion 21 of the heat exchanger has a fitting portion 8, a shaft portion 9, and a detachable movement restricting member 10. A heat exchanger having a higher hardness than the narrow tube 20 and having an outer diameter slightly larger than the inner diameter of the narrow tube 20, and a helical thread groove 11 formed in the outer peripheral portion of the fitting portion 8. Thin tube drawing device. In claim 5,
A heat exchanger thin tube extraction device in which a detachable movement restricting member 10 is constituted by a nut that is screwed onto a screw portion 9 a provided on a shaft portion 9, and a hooking portion 12 for hooking a rotating tool on the nut is provided.

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