JP2017009235A - Heat exchanger and heat exchanger corrosion prevention method, and hand tool for winding tape used for heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent low-temperature corrosion at low cost, be capable of installing in a low-temperature corrosion atmosphere to recover unused low-temperature heat energy and readily and easily prevent low-temperature corrosion for a heat transfer pipe.SOLUTION: A bare tube-type heat exchanger exchanges heat by indirectly bringing fluid flowing through the metal heat transfer pipe 4 into contact with an exhaust gas G flowing outside of the heat transfer pipe 4, where a surface of the heat transfer pipe 4 coming into contact with the exhaust gas G is covered by a corrosion-proof tape 9.SELECTED DRAWING: Figure 1

Description

  The present invention mainly relates to a waste treatment facility that incinerates municipal waste (general waste) and industrial waste, a melt treatment facility that melts incineration residues and fly ash, and a binary that generates heat using the heat of exhaust gas. TECHNICAL FIELD The present invention relates to a bare tube type heat exchanger used in power generation facilities and the like, used in a low-temperature corrosive atmosphere and recovering heat from exhaust gas containing acid gas, a corrosion prevention method for the heat exchanger, and a tape winding tool used for the heat exchanger. Is.

  In general, heat exchangers used in waste incineration processing equipment, melting processing equipment, binary power generation equipment, etc., are boilers that recover heat from exhaust gas, economizers that preheat feed water using residual heat of exhaust gas There are an air preheater that preheats combustion air to be sent to a combustion device, a hot water heat exchanger that heats hot water supplied to a binary power generation facility of a low temperature exhaust gas heat source, and these are exhaust gas and water or exhaust gas and air or exhaust gas and hot water It is a heat exchanger by heat exchange.

  By the way, in the said heat exchanger, since acidic gas, such as sulfur oxide (SOx) and hydrogen chloride (HCl), is contained in the exhaust gas discharged | emitted from a waste incinerator, a melting furnace, etc., the said acidic gas When the temperature falls below the dew point temperature, it condenses on the surface of the metal heat transfer tube, causing sulfuric acid and hydrochloric acid to cause low temperature corrosion that erodes the heat transfer tube.

In particular, exhaust gas containing acid gas is greatly affected by SO ₃ (sulfuric anhydride). As the proportion of acid gas increases, the dew point temperature rises, and metals (heat transfer tubes) below the dew point temperature undergo severe low temperature corrosion. It will be. For example, when the moisture in the exhaust gas is 30%, SO ₃ is 1 ppm and the dew point is 130 ° C., and the dew point is about 150 ° C. at 10 ppm.

Therefore, in various facilities using heat exchangers, the following countermeasures (a) to (e) have been taken in order to avoid low temperature corrosion due to acidic gas in the exhaust gas.
(A) Take measures to reduce the sulfur content in the waste to be incinerated or melted, use high-quality fuel to reduce the concentration of acid gas, or spray chemicals such as slaked lime and caustic soda into the exhaust gas Then, the acid dew point temperature in the exhaust gas is lowered by lowering the concentration of the acid gas (see, for example, Patent Document 1).
(B) The equipment is remodeled so that the heat exchanger tube of the heat exchanger in contact with the exhaust gas containing the acidic gas is in a temperature range higher than the dew point temperature, or the operation method of the equipment is changed (for example, Patent Documents 1 to 3). reference).
(C) When low-temperature corrosion occurs in the heat exchanger tube of the heat exchanger, the heat exchanger is replaced as a consumable item.
(D) The surface of the heat exchanger tube of the heat exchanger is coated with a corrosion resistant material such as a fluororesin (for example, see Patent Document 4).
(E) Abandon the installation of heat exchangers.

However, the problems shown in the following (a ′) to (e ′) occur even if the measures shown in (a) to (e) are taken.
(A ′) In order to reduce the concentration of acid gas in the exhaust gas, the amount of the exhaust gas treatment chemicals such as slaked lime and caustic soda to be sprayed into the exhaust gas, or the fuel used in the combustion apparatus is changed to high quality waste or fuel Increasing the cost increases the cost.
(B ') If the equipment is remodeled so that the heat exchanger tubes of the heat exchanger are in the temperature range above the dew point temperature, it will be costly to remodel, and if the entire equipment is viewed, the operation will be inefficient. There is a possibility of being forced.
(C ′) If the heat exchanger itself is periodically replaced as a consumable item, it will be expensive.
(D ′) When the surface of the heat exchanger tube of the heat exchanger is coated with a corrosion-resistant material such as fluororesin, the cost is very high.
(E ′) If there is a problem such as cost effectiveness (cost performance), a heat exchanger cannot be installed.

  As described above, the heat exchanger under the low temperature corrosion atmosphere has a problem that it is expensive to prevent the low temperature corrosion.

JP 2011-237137 A Japanese Patent Laid-Open No. 2002-357397 JP 2011-237048 A JP 2013-78742 A

  The present invention has been made in view of such problems, and its purpose is to prevent low-temperature corrosion at low cost and to be installed in a low-temperature corrosive atmosphere to recover unused low-temperature thermal energy. Another object of the present invention is to provide a heat exchanger, a corrosion prevention method for the heat exchanger, and a tape winding tool used for the heat exchanger, which can be performed easily and easily against the low temperature corrosion of the heat transfer tube.

  In order to achieve the above object, a first invention of the present invention is a bare tube type that performs heat exchange by indirectly contacting a fluid flowing in a metal heat transfer tube and an exhaust gas flowing outside the heat transfer tube. The heat exchanger is characterized in that the surface of the heat transfer tube that contacts the exhaust gas is covered with an anticorrosion tape.

  The second aspect of the present invention is a method for preventing corrosion of a bare tube heat exchanger that performs heat exchange by indirectly contacting a fluid flowing in a metal heat transfer tube and an exhaust gas flowing outside the heat transfer tube. The surface of the heat transfer tube is prevented from being corroded by wrapping the surface of the heat transfer tube by wrapping the surface of the heat transfer tube around the surface of the heat transfer tube that contacts the exhaust gas.

  The third invention of the present invention is characterized in that, in the second invention, a strip-shaped anticorrosion tape is spirally wound around the surface of the heat transfer tube without a gap.

  A fourth invention of the present invention is a tape winding tool for spirally winding an anticorrosion tape around the surface of the heat transfer tube of the heat exchanger, the tape winding tool being arranged on the surface of the heat transfer tube. A base plate supported so as to be freely rotatable in the longitudinal direction and movable in the longitudinal direction of the heat transfer tube, a tape holder provided on the base plate, and an anticorrosive tape that is supported by the tape holder so as to be freely rotatable and drawn out and wound in a roll shape. It is characterized by having.

  According to a fifth aspect of the present invention, in the fourth aspect, the base plate is composed of two semicircular plates obtained by dividing a circular plate having a through hole having a diameter larger than the outer diameter of the heat transfer tube at the center, It is characterized in that one end of two semi-circular plates are connected to each other in a freely rotatable manner, and the other end of the two semi-circular plates can be opened and closed by an opening / closing means, and is detachable from a heat transfer tube. .

  According to a sixth aspect of the present invention, in the fourth or fifth aspect of the present invention, a plurality of roller mounting brackets in which the base plate is annularly disposed on both surfaces or one surface of the base plate and positioned around the heat transfer tube And a plurality of guide rollers that are rotatably supported by the respective roller mounting brackets and that can contact the surface of the heat transfer tube in the same circumferential direction and at the same inclination angle with respect to the axis of the heat transfer tube, As the heat transfer tube of the base plate rotates in the circumferential direction, the heat transfer tube is guided by an inclined guide roller and moved in the longitudinal direction of the heat transfer tube.

  According to a seventh aspect of the present invention, in the sixth aspect, at least a part of the plurality of guide rollers is movable and adjustable toward the center side of the base plate, and the guide roller is made of a cushion material or an elastic body. It is characterized in that it is pressed against the surface of the heat transfer tube by elastic force.

  The eighth invention of the present invention is characterized in that, in the fourth invention, the axis of the tape holder is inclined with respect to the axis of the heat transfer tube.

  Since the heat exchanger of the present invention coats the surface of the heat transfer tube in contact with the exhaust gas containing acid gas with an anticorrosion tape, it can be installed in a place of a low-temperature corrosive atmosphere that has been difficult to install until now, Unused low-temperature thermal energy can be recovered.

  Since the heat exchanger of the present invention can prevent low-temperature corrosion simply by coating the surface of the heat transfer tube with an anticorrosion tape, the heat exchanger or heat transfer tube in which the surface of the heat transfer tube is coated with a corrosion resistant material such as fluororesin. Compared to heat exchangers with improved grades using stainless steel, sulfuric acid corrosion resistant steel, etc. with excellent corrosion resistance, the low temperature corrosion can be prevented at a lower cost.

The heat exchanger of the present invention covers the surface of the heat transfer tube with anticorrosion tape, so there is no need to use expensive stainless steel or sulfuric acid corrosion resistant steel as the material of the heat transfer tube, and the heat transfer tube is relatively inexpensive. It is also possible to use carbon steel, and since it is not necessary to consider the corrosion allowance, the thickness of the heat transfer tube can be reduced, the weight can be reduced, and the material cost can be reduced.
In particular, in the heat exchanger of the present invention, when a fluororesin adhesive tape is used for the anticorrosion tape, the surface to which the adhesive of the anticorrosion tape is not applied has non-adhesiveness and peelability. Dust in exhaust gas is difficult to adhere to the surface. Moreover, since the fluororesin adhesive tape has elasticity, the anticorrosion tape follows even if the heat transfer tube is thermally expanded, and there is no fear of the coating being cracked or peeled off like the coated heat transfer tube.

  In the heat exchanger of the present invention, the surface of the heat transfer tube is covered with an anticorrosion tape to prevent the heat transfer tube from corroding. Therefore, the heat exchanger has better thermal conductivity than the rusted heat transfer tube (metal bare tube), and the overall transfer The thermal coefficient is about 1.7 times that of a bare metal tube.

The anticorrosion method for a heat exchanger according to the present invention prevents corrosion of the surface of the heat transfer tube by wrapping the surface of the heat transfer tube by wrapping an anticorrosion tape around the surface of the heat transfer tube in contact with the exhaust gas containing acid gas. Therefore, the same operational effects as the heat exchanger of the present invention described above can be obtained.
In particular, the anticorrosion method of the heat exchanger of the present invention is such that a strip-shaped anticorrosion tape is spirally wound around the surface of the heat transfer tube without any gaps, so that the anticorrosion tape can be wound around the heat transfer tube easily and in a short time. .

  A tape winding tool of the present invention comprises a base plate supported on the surface of a heat transfer tube of a heat exchanger so as to be rotatable in the circumferential direction of the heat transfer tube and movable in the longitudinal direction of the heat transfer tube, a tape holder provided on the base plate, The anticorrosion tape that is supported by the tape holder so as to be rotatable and drawable and wound in a roll shape can be easily and easily wound around the surface of the heat transfer tube, and the anticorrosion tape can be wound in a short time. Can be installed.

  In the tape winding tool of the present invention, the base plate is formed into a disk shape for compactness, and is configured to be detachable from the heat transfer tube, so that the heat transfer tube is welded in a meandering manner, Even in a state where the gap between the heat transfer tubes is narrow, it can be attached to the heat transfer tube and the anticorrosion tape can be wound around the surface of the heat transfer tube.

  The tape winding tool of the present invention has a plurality of guide rollers that can abut on the surface of the heat transfer tube at the same circumferential direction and at the same inclination angle with respect to the axis of the heat transfer tube on both surfaces or one surface of the base plate. Since the base plate is configured to move in the longitudinal direction of the heat transfer tube, guided by the inclined guide roller in accordance with the rotation of the heat transfer tube in the circumferential direction of the base plate, an anticorrosion tape is applied to the surface of the heat transfer tube of the heat exchanger. It can be wound with high accuracy and at an equal pitch.

  The tape winding tool of the present invention can freely change the spiral winding pitch (anticorrosion tape overlap) of the anticorrosion tape by changing the angle between the axis of the tape holder and the axis of the guide roller.

  In the tape winding tool of the present invention, at least a part of the guide roller is movable and adjustable toward the center side of the base plate, and the guide roller is pressed against the surface of the heat transfer tube by the elastic force of the cushion material or the elastic body. For this reason, the heat exchanger tube is mounted without rattling, and even if the outer diameter of the heat transfer tube changes slightly, it can be mounted to the heat transfer tube well and reliably.

It is a front view of the heat exchanger which concerns on one Embodiment of this invention. It is a top view of the heat exchanger shown in FIG. It is a front view of the state which shows the tape winding tool which concerns on one Embodiment of this invention, and is mounted | worn with the heat exchanger tube of the heat exchanger, and is winding the anticorrosion tape. It is an AA line expanded sectional view of FIG. FIG. 4 is an enlarged sectional view taken along line B-B in FIG. 3. It is a side view of the state which opens the base plate of a tape winding tool, and is mounted | worn with a heat exchanger tube.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
1 and 2 show an example of a bare tube type heat exchanger subjected to the anticorrosion method of the present invention, and the heat exchanger is installed in an exhaust gas path of a waste incineration treatment facility, and heat exchange with exhaust gas is performed. It is configured as a hot water heat exchanger that heats the hot water supplied to the binary power generation facility.

  That is, the heat exchanger includes a heat exchange section 5 in which a plurality of meandering heat transfer tubes 4 are arranged in a casing 3 having an inlet 1 and an outlet 2 for the exhaust gas G. The low-temperature hot water W from the evaporation section of the binary power generation facility flowing in the heat pipe 4 and the exhaust gas G flowing in the casing 3 are heat-exchanged via the heat transfer pipe 4, and the thermal energy held by the exhaust gas G is converted into the low-temperature hot water W. It is something to give.

  In FIGS. 1 and 2, 6 is a header, 7 is a hot water inlet, and 8 is a hot water outlet.

  Then, as shown in FIG. 2, this heat exchanger has a strip-shaped anticorrosive tape 9 wound spirally around the surface of the straight tube portion or the bent portion of the heat transfer tube 4 with which the exhaust gas G containing acid gas comes into contact. By covering the surface of the heat tube 4, corrosion of the surface of the heat transfer tube 4 is prevented.

  As the anticorrosion tape 9, a fluororesin adhesive tape is used in which a strip-like fluororesin film is used as a base material, and a silicone adhesive material is applied to one side of the base material. This fluororesin adhesive tape has flexibility, stretchability, followability to the shape of the object, non-adhesiveness and releasability on the tape surface, and the maximum use temperature is 200 ° C. . Further, the width of the fluororesin adhesive tape is appropriately selected according to the diameter of the heat transfer tube 4 and the like.

  Since the surface of the heat transfer tube 4 that contacts the exhaust gas G containing acid gas is covered with the anticorrosion tape 9, the heat exchanger can be installed in a place of a low-temperature corrosive atmosphere that has been difficult to install until now. It is possible to recover unused low-temperature thermal energy.

  Moreover, since this heat exchanger can prevent low-temperature corrosion only by coat | covering the anticorrosion tape 9 on the surface of the heat exchanger tube 4, the heat exchanger which coat | covered corrosion resistant materials, such as a fluororesin, on the surface of the heat exchanger tube 4 Compared with a heat exchanger whose grade is improved by using stainless steel or sulfuric acid corrosion resistant steel having excellent corrosion resistance as the material of the heat transfer tube 4, low temperature corrosion can be prevented at a lower cost.

Further, in this heat exchanger, since the surface of the heat transfer tube 4 is covered with the anticorrosion tape 9, it is not necessary to use expensive stainless steel or sulfuric acid corrosion resistant steel as the material of the heat transfer tube 4, and the heat transfer tube 4 It is also possible to use relatively inexpensive carbon steel, and since it is not necessary to consider the corrosion allowance, the thickness of the heat transfer tube 4 can be reduced, and the weight can be reduced and the material cost can be reduced. Can be reduced.
In particular, since this heat exchanger uses a fluororesin adhesive tape for the anticorrosion tape 9, the surface of the anticorrosion tape 9 on which the adhesive is not applied has non-adhesiveness and peelability. The dust in the exhaust gas G hardly adheres to the surface of 9. Moreover, since the fluororesin adhesive tape is stretchable, the anticorrosion tape 9 follows even if the heat transfer tube 4 is thermally expanded, and there is no fear of the coating being cracked or peeled off like the coated heat transfer tube.

  Furthermore, since this heat exchanger prevents the corrosion of the heat transfer tube 4 by covering the surface of the heat transfer tube 4 with the anticorrosion tape 9, the heat conductivity is higher than that of the rusted heat transfer tube 4 (metal bare tube). Well, the overall heat transfer coefficient is about 1.7 times that of a bare metal tube.

In the above embodiment, the hot water heat exchanger has been subjected to the anticorrosion method. However, as the heat exchanger to which the anticorrosion method of the present invention is applied, the exhaust gas G containing acid gas (corrosive gas) and water or air or Any heat exchanger may be used as long as it is a gas heat exchanger.
For example, the heat exchanger that performs the anticorrosion method of the present invention includes a boiler that recovers heat from the exhaust gas G, an economizer that preheats feed water using the residual heat of the exhaust gas G, and combustion air that is sent to the combustion device It may be an air preheater or the like that preheats.

Moreover, in said embodiment, although the fluororesin adhesive tape was used as the anticorrosion tape 9, the anticorrosion tape 9 is not limited to the thing based on said embodiment, It is helically formed in the heat exchanger tube 4. Any material can be used as long as it can be wound to prevent low temperature corrosion of the heat transfer tube 4.
For example, the anticorrosion tape 9 is a long article such as an adhesive tape, a non-adhesive tape, a belt-like film, a rope, a thread, etc., and any anticorrosive tape 9 may be used as long as it has corrosion resistance and heat resistance. In the case of the non-adhesive anticorrosion tape 9, it is necessary to stop the start and end portions of the anticorrosion tape 9 on the surface of the heat transfer tube 4 with the adhesive tape.

  3 to 6 show an example of a tape winding tool 10 for winding the anticorrosion tape 9 around the surface of the heat transfer tube 4 of the heat exchanger, and the tape winding tool 10 is formed on the surface of the heat transfer tube 4 with a circle of the heat transfer tube 4. A base plate 11 supported so as to be rotatable in the circumferential direction and movable in the longitudinal direction of the heat transfer tube 4, a plurality of roller mounting brackets 12 arranged on both surfaces of the base plate 11, and rotatably supported by the roller mounting bracket 12. A plurality of guide rollers 13 that can come into contact with the surface of the heat transfer tube 4, a tape holder 14 provided on the base plate 11, and an anticorrosion tape 9 that is supported by the tape holder 14 so as to be rotatable and freely drawable and wound in a roll shape. I have.

  Specifically, the base plate 11 has two semicircles formed by dividing a synthetic resin, metal, or wooden disc having a through hole 11b having a diameter larger than the outer diameter of the heat transfer tube 4 at the center. It consists of a plate 11a, and one end portions of the two semicircular plates 11a are rotatably connected by a hinge fitting 15, and the other end portions of the two semicircular plates 11a can be opened and closed by an opening / closing means 16, and a heat transfer tube 4 is configured to be detachable with respect to 4.

  The hinge metal fitting 15 includes a pair of hinge plates 15a arranged across both end surfaces of the two semicircular plates 11a, and a stopper 15b for fixing the hinge plates 15a to one of the semicircular plates. Both hinge plates 15a and a support shaft 15c inserted and supported by the other semi-disc 11a are provided. For the opening / closing means 16, a conventionally known patch-on lock is used.

  Each of the roller mounting brackets 12 is formed of a metal plate in an L-shaped cross section, and is annularly disposed on both surfaces of the base plate 11 so as to be positioned around the heat transfer tube 4. It is fixed on both sides. The roller mounting brackets 12 are annularly disposed on both surfaces of the base plate 11 at equal angles. In this embodiment, four roller mounting brackets 12 are disposed on one surface of the base plate 11, and the other surface of the base plate 11. Three are arranged.

  Each of the guide rollers 13 is formed in a disk shape and is rotatably supported by each roller mounting bracket 12 via a roller support frame 18. Each guide roller 13 is rotatably supported on each roller support frame 18 via a roller shaft 19 so that its axis is in the same circumferential direction and the same inclination angle with respect to the axis φ of the heat transfer tube 4. In other words, it can come into contact with the surface of the heat transfer tube 4 in an inclined posture. The guide roller 13 may be formed of any material as long as the rotation direction (movement direction) is determined, and the guide roller 13 does not slide on the surface of the heat transfer tube 4. For example, the guide roller 13 is preferably formed of a soft rubber material or a synthetic resin material.

  Each roller support frame 18 is formed of a metal plate in a U-shaped cross section, and is attached to each roller mounting bracket 12 by a fastening tool 20 (for example, a bolt and a nut). A part of the roller support frame 18 is attached to the roller mounting bracket 12 so as to be movable toward the center of the base plate 11 with a slightly longer fastening tool 20, and the remaining roller support frame 18 is attached to the roller mounting bracket 12. It is fixed by a fastener 20.

  In addition, at least some of the plurality of guide rollers 13 are movable toward the center side of the base plate 11, and are pressed against the surface of the heat transfer tube 4 by the elastic force of the cushion material 21. It has become. That is, some of the guide rollers 13 have a cushion material 21 (for example, a sponge cushion) interposed between the roller mounting bracket 12 and a roller support frame 18 movably attached to the center side of the base plate 11, The base plate 11 can be moved toward the center of the base plate 11 via the roller support frame 18 and the fastening tool 20.

  Further, the distance between the guide rollers 13 facing each other is set to be slightly smaller than the outer diameter of the heat transfer tube 4 in a state where the cushion material 21 is not contracted, and each guide roller 13 contacts the surface of the heat transfer tube 4. The cushion material 21 is shrunk when in contact. As a result, the guide roller 13 is pressed against the surface of the heat transfer tube 3 by the elastic force of the cushion material 21.

  The tape holder 14 is provided on one surface of the base plate 11, is attached to one surface of the base plate 11 in a posture inclined with respect to the axis φ of the heat transfer tube 4, and the anticorrosion tape 9 wound in a roll shape. A cylindrical or solid tape insertion rod 14a into which the tape is rotatably inserted, and a corrosion-resistant tape 9 which is detachably fitted to the tip of the tape insertion rod 14a and is inserted into the tape insertion rod 14a. And a cap 14b for preventing the anticorrosion tape 9 from shaking in the axial direction. Further, the tape insertion rod 14 a has the same direction as the inclination of the guide roller 13 and the same angle as the inclination of the guide roller 13.

  The anticorrosion tape 9 is composed of a fluororesin adhesive tape in which a strip-like fluororesin film is used as a base material, and a silicone adhesive material is applied to one side of the base material, and is wound in a roll shape so that the adhesive surface faces inward. It is. This fluororesin adhesive tape has flexibility, stretchability, followability to the shape of the object, non-adhesiveness and releasability on the tape surface, and the maximum use temperature is 200 ° C. . Further, the width of the fluororesin adhesive tape is appropriately selected according to the diameter of the heat transfer tube 4 and the like.

  Next, the case where the anticorrosion tape 9 is wound around the heat transfer tube 4 using the tape winding tool 10 described above will be described.

  First, the opening / closing means 16 (Patchon lock) of the tape winding tool 10 is removed, and the two semicircular plates 11a of the base plate 11 are rotated around the support shaft 15c of the hinge metal fitting 15 to open the base plate 11. (See FIG. 6).

  Next, the opened base plate 11 is fitted into the heat transfer tube 4 around which the anticorrosion tape 9 of the heat exchanger is wound, and the two semicircular plates 11a of the base plate 11 are rotated in the closing direction around the support shaft 15c of the hinge fitting 15. After that, the opening / closing means 16 (Patchon lock) is closed and the base plate 11 is closed. Thereby, the tape winding tool 10 is attached to the heat transfer tube 4 (see FIGS. 4 and 5).

  At this time, the interval between the guide rollers 13 facing the tape winding tool 10 is set slightly narrower than the outer diameter of the heat transfer tube 4 when the cushion material 21 is not contracted. When contacting the surface of the heat pipe 4, the cushion material 21 contracts and is brought into pressure contact with the surface of the heat transfer pipe 4 by the elastic force of the cushion material 21. As a result, the tape winding tool 10 is mounted on the heat transfer tube 4 without rattling, and a frictional force is generated between each guide roller 13 and the surface of the heat transfer tube 4.

When the tape winding tool 10 is attached to the heat transfer tube 4, the anticorrosion tape 9 wound in a roll shape is attached to the tape insertion rod 14a of the tape holder 14, and the cap 14b is fitted to the tip of the tape insertion rod 14a. Thereby, the roll-shaped anticorrosion tape 9 is prevented from coming off from the tape insertion bar 14a, and the axial movement of the tape insertion bar 14a is prevented.
The roll-shaped anticorrosion tape 9 may be previously attached to the tape holder 14 before the tape winding tool 10 is attached to the heat transfer tube 4.

  Thereafter, the tip portion of the anticorrosion tape 9 is pulled out and attached to the surface of the heat transfer tube 4. In this state, the outer peripheral edge of the base plate 11 is held by hand and rotated in the circumferential direction of the heat transfer tube 4. Is advanced along the longitudinal direction of the heat transfer tube 4 at a uniform speed by a plurality of guide rollers 13 arranged in an inclined posture, and the anticorrosion tape 9 is sequentially pulled out as the base plate 11 rotates, and the anticorrosion tape 9 is spirally wound around the surface of the heat transfer tube 4 at an equal pitch without a gap.

  Then, after the anticorrosion tape 9 is wound around the surface of the heat transfer tube 4, the anticorrosion tape 9 is cut with scissors or the like, and the end portion of the anticorrosion tape 9 is attached to the surface of the heat transfer tube 4, and the opening / closing means 16 (Patchon lock) is attached. The base plate 11 is removed and the tape winding tool 10 is removed from the heat transfer tube 4.

  If the tape winding tool 10 is used, the anticorrosion tape 9 can be easily and easily wound around the surface of the heat transfer tube 4 of the heat exchanger, and the anticorrosion tape 9 can be spirally wound in a short time.

  Moreover, since the tape winding tool 10 is formed compactly and is detachably attached to the heat transfer tube 4, the heat transfer tube 4 is welded and joined in a meandering manner so that a gap between the heat transfer tubes 4 is provided. Even in a narrow state, it can be attached to the heat transfer tube 4 and the anticorrosion tape 9 can be wound around the surface of the heat transfer tube 4.

  Further, the tape winding tool 10 is provided with a plurality of guide rollers 13 in an inclined posture on both surfaces of the base plate 11 so as to move at a uniform speed in the longitudinal direction of the heat transfer tube 4, so that the heat transfer tube of the heat exchanger The anticorrosion tape 9 can be wound around the surface 4 with high accuracy and at an equal pitch.

  Further, the tape winding tool 10 is configured such that at least a part of the guide roller 13 can be moved and adjusted to the center side of the base plate 11, and the guide roller 13 is pressed against the surface of the heat transfer tube 4 by the elastic force of the cushion material 21. Therefore, the heat exchanger tube 4 can be attached to the heat exchanger tube 4 without shaking, and even if the outer diameter of the heat exchanger tube 4 is slightly changed, it can be attached to the heat exchanger tube 4 in a good and reliable manner.

  In the above embodiment, the guide rollers 13 are provided on both sides of the base plate 11. However, in other embodiments, the guide rollers 13 may be provided only on one side of the base plate 11. In this case, the tape winding tool 10 can be further downsized. Further, the number of guide rollers provided on the base plate 11 is not limited to that according to the above embodiment, and two or more guide rollers may be provided on both surfaces or one surface of the base plate 11.

  In the above-described embodiment, at least a part of the plurality of guide rollers 13 can be moved and adjusted toward the center of the base plate 11. However, in other embodiments, all the guide rollers 13 13 may be adjustable to move toward the center of the base plate 11.

  Furthermore, in the above embodiment, the cushion material 21 is interposed between the roller mounting bracket 12 and the roller support frame 18, and the guide roller 13 is pressed against the surface of the heat transfer tube 4 by the elastic force of the cushion material 21. However, in another embodiment, an elastic body (compression coil spring or leaf spring) is interposed between the roller mounting bracket 12 and the roller support frame 18, and the guide roller 13 is caused by the elastic force of the elastic body. May be brought into pressure contact with the surface of the heat transfer tube 4.

  Furthermore, in the above embodiment, the angle between the axis of the guide roller 13 and the axis of the tape holder 14 is constant, but in other embodiments, the roller support frame 18 can be swung on the roller mounting bracket 12. At the same time, the tape insertion rod 14a of the tape holder 14 may be attached to the base plate 11 so that the angle can be adjusted, and the angle of the axis of the guide roller 13 and the axis of the tape holder 14 can be adjusted. In this case, the pitch of the spiral winding of the anticorrosion tape 9 (overlap margin of the anticorrosion tape 9) can be freely changed.

  Furthermore, in the above embodiment, a patchon lock is used as the opening / closing means 16 of the base plate 11. However, the opening / closing means 16 is not limited to the patchon lock, and any structure can be used as long as the base plate 11 can be opened and closed. It may be.

  The present invention can be applied not only to bare tube heat exchangers that are intended for heat exchange, but also to corrosion prevention of pipes that are not intended for heat exchange.

  1 is an exhaust gas inlet, 2 is a casing, 3 is an exhaust gas outlet, 4 is a heat transfer tube, 5 is a heat exchange section, 6 is a header, 7 is a hot water inlet, 8 is a hot water outlet, 9 is an anticorrosion tape, 10 is a tape winding Hand tool, 11 is a base plate, 11a is a semicircular plate, 11b is a through hole, 12 is a roller mounting bracket, 13 is a guide roller, 14 is a tape holder, 14a is a tape insertion rod, 14b is a cap, 15 is a hinge bracket, 15a Is a hinge plate, 15b is a stopper, 15c is a support shaft, 16 is an opening / closing means, 17 is a screw, 18 is a roller support frame, 19 is a roller shaft, 20 is a fastener, 21 is a cushioning material, G is exhaust gas, W is Hot water, φ is the axis of the heat transfer tube.

Claims (8)

  A bare tube heat exchanger that performs heat exchange by indirectly contacting a fluid flowing inside a metal heat transfer tube and an exhaust gas flowing outside the heat transfer tube, the surface of the heat transfer tube contacting the exhaust gas A heat exchanger characterized by being coated with anticorrosion tape.   An anticorrosion method for a bare tube heat exchanger that performs heat exchange by indirectly contacting a fluid flowing inside a metal heat transfer tube and an exhaust gas flowing outside the heat transfer tube, and contacting the exhaust gas of the heat transfer tube An anticorrosion method for a heat exchanger, wherein the surface of the heat transfer tube is prevented from being corroded by wrapping the surface of the heat transfer tube by winding an anticorrosion tape around the surface of the heat exchanger.   The anticorrosion method for a heat exchanger according to claim 2, wherein a belt-like anticorrosive tape is spirally wound around the surface of the heat transfer tube without any gap.   A tape winding tool for spirally winding an anticorrosion tape around the surface of a heat transfer tube of a heat exchanger, the tape winding tool being rotatable on the surface of the heat transfer tube in the circumferential direction of the heat transfer tube and the length of the heat transfer tube A tape comprising: a base plate movably supported in a direction; a tape holder provided on the base plate; and an anticorrosion tape that is supported by the tape holder so as to be rotatable and freely drawable and wound in a roll shape. Winding tool.   The base plate is composed of two semi-discs obtained by dividing a disc having a through-hole having a diameter larger than the outer diameter of the heat transfer tube at the center thereof, and one end portions of the two semi-discs are rotatably connected to each other. In addition, the tape winding tool according to claim 4, wherein the other end portions of the two semicircular plates can be opened and closed by an opening and closing means, and can be freely attached to and detached from the heat transfer tube.   The base plate is annularly arranged on both sides or one side of the base plate and is mounted on a plurality of roller mounting brackets located around the heat transfer tube, and is rotatably supported by each roller mounting bracket, and is the same with respect to the axis of the heat transfer tube A plurality of guide rollers that can contact the surface of the heat transfer tube in the circumferential direction and at the same inclination angle, and are guided to the guide roller in an inclined posture as the heat transfer tube of the base plate rotates in the circumferential direction. The tape winding tool according to claim 4 or 5, wherein the tape winding tool is configured to move in a longitudinal direction of the heat transfer tube.   Among the plurality of guide rollers, at least a part of the guide rollers can be moved and adjusted to the center side of the base plate, and the guide rollers are brought into pressure contact with the surface of the heat transfer tube by the elastic force of the cushion material or the elastic body. The tape winding hand tool according to claim 6.   The tape winding tool according to claim 4, wherein the axis of the tape holder is inclined with respect to the axis of the heat transfer tube.

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