JP2023137365A - Sealing device for heat transfer tube of heat exchanger - Google Patents

Abstract

To provide a sealing device for a heat transfer tube which can easily seal a defective heat transfer tube when a defect occurs in a part of heat transfer tubes in a heat exchanger including the multiple heat transfer tubes.SOLUTION: A sealing device 1 for a heat transfer tube includes: a rod-like part 2 inserted into a heat transfer tube 101; a bush 10 and a nut 18 attached to both ends 6 of the rod-like part 2; and a first seal material 20 and a second seal material 21 for sealing an inlet 103 and an outlet 104 of the heat transfer tube 101. The bush 10 is attached to a male screw part 6 provided at an end of the rod-like part 2 and closes the inlet 103 and the outlet 104 of the heat transfer tube 101 from the outer side of a pipe plate 120 supporting the heat transfer tube 101. The nut 18 is threadedly engaged with the male screw part 6 to be fastened thereto. The first seal material 20 is provided so as to be sandwiched between the bush 10 and the pipe plate 120 and enclose a hole 122a of the pipe plate 120. The second seal material 21 is provided between an inner peripheral surface of the heat transfer tube 101 and the rod-like part 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat exchanger equipped with a plurality of heat transfer tubes.

BACKGROUND ART Shell-and-tube heat exchangers have been known that are provided with a plurality of heat transfer tubes for flowing a fluid whose temperature is to be adjusted and transferring heat to the fluid (for example, see Patent Document 1). Tube sheets are provided at both ends of the heat transfer tubes, and the ends of the heat transfer tubes are supported so as to be inserted into holes for each heat transfer tube formed in the tube sheet. Furthermore, Patent Document 1 discloses that a heat exchanger that adjusts the temperature of the pickling solution in the pickling process line is made of a high melting point active material (such as titanium, zirconium, niobium, tantalum, etc.) that comes into contact with the pickling solution. It is described that it is composed of metals or alloys thereof.

Utility Model Publication No. 4-129695

In this type of heat exchanger, heat transfer tubes or Damage such as surface defects and through holes may occur at the welded portion between the heat transfer tube and the tube sheet. Furthermore, if an object hits the heat transfer tube during maintenance, the heat transfer tube may become deformed.

In such cases, measures are required to prevent fluid from leaking from the defective heat transfer tube. However, the heat transfer tube is welded to the tube plate and cannot be easily removed. In addition, if the heat transfer tube and tube sheet are made of a high melting point active material (tantalum, tantalum alloy, niobium, niobium alloy, zirconium, zirconium alloy, titanium, titanium alloy, etc.), the gas Shielding with inert gas when performing shielded arc welding is difficult on site. Therefore, in the past, the heat exchanger was removed from the installation site and brought to a repair shop, and the defective heat transfer tube was replaced with a new heat transfer tube at the repair shop, or the defective heat transfer tube was repaired by welding. Measures were taken such as:

The present invention has been made in view of the above circumstances, and provides a method to prevent fluid from leaking from the defective heat transfer tube without having to take the defective heat transfer tube to a repair shop when a defect occurs in some of the heat transfer tubes. The objective is to provide an invention that can be easily carried out in the field.

In order to solve the above problems, the sealing device for heat transfer tubes of a heat exchanger of the present invention has the following features:
a plurality of heat transfer tubes for flowing a fluid whose temperature is to be adjusted and transferring heat to the fluid;
applied to a heat exchanger comprising a tube sheet having an outer surface formed with a hole for each heat transfer tube into which an end of each heat transfer tube is inserted;
a rod-shaped part inserted into the heat transfer tube;
a closing part that is provided at each end of the rod-shaped part and closes the entrance and exit of the heat transfer tube from outside the outer surface;
a sealing part that seals the heat transfer tube between the closing part,
At least one of the closing parts is removable from the rod-shaped part.

According to the sealing device for heat transfer tubes of a heat exchanger of the present invention, since the heat transfer tube can be sealed by the closing part and the sealing part, it is possible to suppress fluid from entering the heat transfer tube, and as a result, heat transfer Fluid can be prevented from leaking from the tube. Furthermore, since at least one of the closing portions provided at each of both ends of the rod-shaped portion is removable from the rod-shaped portion, the rod-shaped portion can be inserted into the target heat transfer tube with the closing portion removed from the rod-shaped portion. Thereafter, by attaching a closing part to the rod-shaped part inserted into the heat transfer tube, the closing part can block the entrance and exit of the heat transfer tube from outside the outer surface of the tube sheet, and the position of the sealing part can be changed. It can be kept in a retained state. Further, by providing the closing portion on the outside of the tube sheet, it is possible to suppress the heat transfer tube sealing device from coming off from the heat transfer tube. Based on the above, when a defect occurs in some heat transfer tubes, measures can be taken to prevent fluid leakage from the defective heat transfer tubes (specifically, measures to seal the heat transfer tubes) without having to take the tubes to a repair shop. ) can be easily performed at the installation site. Note that the term "rod-shaped" in the "rod-shaped part" of the present invention includes both hollow rods (ie, tubes, tubes) and solid rods.

It is a sectional view of a state where a heat transfer tube sealing device is attached to a heat transfer tube. It is a sectional view of the rod-like part which constitutes a part of sealing device for heat exchanger tubes. It is a sectional view of the bush which constitutes a part of sealing instrument for heat exchanger tubes. They are a sectional view ((a) in the same figure) and a plan view ((b) in the same figure) of a nut that constitutes a part of the sealing device for a heat transfer tube. It is a sectional view of the 1st sealing material which constitutes a part of sealing device for heat transfer tubes. It is a sectional view of the 2nd sealing material which constitutes a part of sealing device for heat transfer tubes. It is a sectional view of a heat exchanger. FIG. 3 is a perspective view of a tube sheet of a heat exchanger. FIG. 2 is a cross-sectional view of the heat transfer tube of the heat exchanger and the tube plate supporting the end portion thereof, showing a state in which a heat transfer tube sealing device is not attached. FIG. 3 is a cross-sectional view of a heat transfer tube of a heat exchanger and a tube sheet that supports the end portion thereof, showing a modification of the outer surface of the tube sheet.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which a heat transfer tube sealing device of this embodiment is attached to a heat transfer tube of a heat exchanger. Further, FIGS. 2 to 6 show each component constituting the heat transfer tube sealing device. Further, FIGS. 7 to 9 show a heat exchanger to which a heat transfer tube sealing device is attached. First, the heat exchanger will be explained with reference to FIGS. 7 to 9.

The heat exchanger 100 in FIG. 7 is configured as a shell-and-tube heat exchanger including a plurality of heat transfer tubes 101. The heat exchanger 100 is used in a pickling process line that uses a pickling solution such as high temperature and high concentration hydrochloric acid or sulfuric acid for descaling hot rolled steel strips, cold rolled steel sheets, stainless steel strips, etc. It is used to adjust the temperature of the washing liquid (for example, to about 70 to 120°C).

The heat exchanger 100 includes a plurality of heat transfer tubes 101, a housing 110, and a tube plate 120. Each heat transfer tube 101 is a tube through which a fluid whose temperature is to be adjusted flows to conduct heat between the outside (heating medium or refrigerant) and the fluid. Note that the fluid whose temperature is to be adjusted is, for example, the above-mentioned pickling liquid (hydrochloric acid, sulfuric acid, etc.). Each heat transfer tube 101 is formed into a straight tube shape (in other words, a cylindrical shape). Further, each heat transfer tube 101 has the same shape (same length and same diameter) and is made of the same material. Furthermore, in order to reduce the cost of the heat exchanger 100, the thickness of the heat transfer tube 101 may be, for example, 1 mm or less.

Further, the plurality of heat transfer tubes 101 are provided in the housing 110 in parallel to each other at intervals in a direction perpendicular to the axis L2 of the heat transfer tubes 101. Both ends 102 of each heat transfer tube 101 are supported by a tube plate 120. Specifically, each end portion 102 is supported by the tube sheet 120 by being inserted into through holes 121a and 122a (see FIGS. 8 and 9) formed in the tube sheet 120. The outer peripheral surface of the end portion 102 is in contact with the inner peripheral surface of the through holes 121a and 122a. Further, the outer periphery of the openings 103 and 104 located at the tip of the end portion 102 and the outer periphery of the hole 122a formed in the sheet surface 122, which is the outer surface of the tube sheet 120, are fixed by welding 123 (Fig. 9).

One opening 103 formed at the tip of the heat transfer tube 101 in the direction of the axis L2 (the opening on the left side in the paper plane of FIGS. 7 and 9) is defined as the inlet of the fluid (the fluid before temperature adjustment) to the heat transfer tube 101. It will be done. The position of the inlet 103 in the direction of the axis L2 of the heat transfer tubes 101 is set at the same position among the plurality of heat transfer tubes 101. Further, the inlet 103 is located on the sheet surface 122, which is the outer surface of the tube sheet 120 (see FIGS. 7 and 9). The other opening 104 of the heat transfer tube 101 is defined as an outlet of the fluid (temperature-adjusted fluid) from the heat transfer tube 101 . The position of the outlet 104 in the direction of the axis L2 of the heat transfer tubes 101 is set at the same position among the plurality of heat transfer tubes 101. Further, the outlet 104 is located on the sheet surface 122 of the tube sheet 120 opposite to the tube sheet 120 that supports the inlet 103 (see FIGS. 7 and 9).

The heat transfer tube 101 is made of a material (specifically, for example, metal) that allows heat to be transferred between the heat medium or coolant supplied into the housing 110 and the fluid flowing inside the heat transfer tube 101. Note that the heat medium or the coolant may be, for example, gas (high temperature steam or cold air) or liquid. Further, the heat transfer tube 101 is made of, for example, a material that is resistant to high temperature and high concentration acid (acid-resistant and heat-resistant material), and specifically, made of, for example, a high melting point active material. High melting point active materials are, for example, tantalum (Ta), tantalum alloys, zirconium (Zr), zirconium alloys, niobium (Nb), niobium alloys, titanium (Ti), titanium alloys. Among tantalum, zirconium, niobium, and titanium, tantalum has the most acid resistance and heat resistance. Further, among tantalum, zirconium, niobium, and titanium, titanium is the cheapest, but it is inferior in acid resistance or heat resistance compared to tantalum, zirconium, and niobium. In addition to the above materials such as tantalum, examples of high melting point active materials include molybdenum, molybdenum alloys, tungsten, and tungsten alloys.

The housing 110 is formed into a shape that accommodates each heat transfer tube 101 inside and has a space 111 into which a heat medium or a coolant is supplied. In this embodiment, the housing 110 is formed into a tubular shape with a central axis L1 (see FIG. 7) parallel to the axis L2 of the heat transfer tube 101. The housing 110 includes an introduction part 112 that introduces a heat medium or a coolant into an inner space 111, and a discharge part 113 that discharges a heat medium or a coolant from the inner space 111. The introduction part 112 and the discharge part 113 are provided so as to introduce or discharge the heat medium or the coolant from a direction (radial direction) perpendicular to the central axis L1 of the housing 110. Furthermore, the introduction section 112 and the discharge section 113 are located on opposite sides of each other in the direction of the central axis L1. That is, the introduction part 112 is provided at a position closer to one of the two tube sheets 120 (the right tube sheet 120 in the paper of FIG. 7). On the other hand, the discharge section 113 is provided at a position closer to the other tube sheet 120 (the tube sheet 120 on the left side in the paper of FIG. 7). The outlet 104 of the heat transfer tube 101 is provided at a position closer to the introduction part 112 than the discharge part 113. The inlet 103 of the heat transfer tube 101 is provided at a position closer to the discharge part 113 than the inlet 112. That is, the flow direction of the heat medium or the coolant in the inner space 111 is set to be opposite to the flow direction of the fluid to be temperature adjusted flowing in the heat transfer tube 101.

Moreover, the introduction part 112 and the discharge part 113 are located on opposite sides to each other in the direction perpendicular to the central axis L1. The introduction part 112 is located on the upper side in the paper of FIG. 7, whereas the discharge part 113 is located on the lower side.

The housing 110 is made of a heat-resistant material, for example, a metal such as stainless steel or copper. Note that since it is not assumed that the housing 110 will come into contact with a pickling solution such as high temperature and high concentration hydrochloric acid or sulfuric acid, the housing 101 may be formed of a material that is less acid resistant than the heat transfer tube 101.

The tube plate 120 is provided at each of both ends of the housing 110 in the direction of the central axis L1 so as to close the ends. Each tubesheet 120 supports the end 102 of each heat transfer tube 101, as described above. The tube sheet 120 includes a tube sheet main body 121 and an outer surface portion 122, as shown in FIGS. 8 and 9. The tubesheet body 121 closes the end of the housing 110 and supports the outer surface 122. Specifically, the tube plate main body 121 is formed into a disk shape with a diameter larger than the outer diameter of the housing 110. The radial center of the tube plate body 121 is located on the central axis L1 of the housing 110. The thickness of the tube plate main body 121 (the plate thickness in the direction parallel to the central axis L1 of the housing 110) is larger than the outer surface portion 122. Further, the tube plate main body 121 has a projecting portion projecting outward in the radial direction with respect to the housing 110.

The tube plate body 121 is formed with through holes 121a into which each heat transfer tube 101 is inserted. Since it is not assumed that the fluid (pickling liquid) whose temperature is to be adjusted comes into contact with the tube sheet body 121, the tube sheet body 121 is formed of a material with lower acid resistance than the outer surface portion 122 and the heat transfer tubes 101. It's fine. Specifically, for example, the tube plate body 121 is formed of metal such as stainless steel or copper.

The outer surface portion 122 is a member that forms the outer surface (sheet surface) of the tube sheet 120. The outer surface portion 122 is formed into a disk shape with a thickness smaller than that of the tube plate body 121 and a diameter smaller than that of the tube plate body 121. The outer surface portion 122 is fixed to the surface of the tube sheet body 121. At this time, the center of the outer surface portion 122 and the center of the tube plate body 121 are aligned.

A through hole 122 a for each heat transfer tube 101 is formed in the outer surface portion 122 . As shown in FIG. 9, this hole 122a is provided so as to protrude outward in a direction parallel to the axis L2 of the heat transfer tube 101 or the central axis L1 of the housing 110. Note that, like the tube sheet outer surface section 130 of the modified example of FIG. 10, the tube sheet outer surface section 130 may be configured to be flat without the through holes 131 of each heat transfer tube 101 protruding outward. Although the tubesheet outer surface section 122 of FIG. 9 will be described below, the following description also applies to the outer surface section 130 of FIG. 10. The center axis of the hole 122a in the outer surface portion 122 and the center axis of the through hole 121a in the tube plate body 121 are aligned. Further, the diameter of the hole 122a is the same as the diameter of the through hole 121a of the tube plate body 121. The end portion 102 of the heat transfer tube 101 is inserted into each hole 122a. As described above, the welding part 23 for fixing the outer periphery of the inlet/outlet ports 103 and 104 of the heat transfer tube 101 is provided at the outer periphery of the tip of the hole 122a.

A fluid whose temperature is to be adjusted (pickling liquid) comes into contact with the outer surface portion 122 . Therefore, like the heat transfer tube 101, the outer surface portion 122 is made of an acid-resistant and heat-resistant material. Specifically, it is formed of the above-mentioned high melting point active material (tantalum (Ta), tantalum alloy, zirconium (Zr), zirconium alloy, niobium (Nb), niobium alloy, titanium (Ti), titanium alloy, etc.). More specifically, the outer surface portion 122 is formed of the same material as the heat transfer tube 101, which is a high melting point active material. Further, the outer surface portion 122 may be formed of a material having higher acid resistance than the tube sheet main body 121.

The heat exchanger 100 having the above-described configuration may be provided so that the center axis L1 of the housing 110 is oriented in the vertical direction, or may be provided so that the center axis L1 is oriented in the horizontal direction. In the heat exchanger 100, a fluid is introduced into each heat transfer tube 101 from the left side in FIG. 7, and a heat medium and a refrigerant are introduced into the housing 110. The fluid introduced into each heat transfer tube 101 is heated by the heat medium or cooled by the coolant, and then flows out to the right side in FIG.

Next, a heat transfer tube sealing device 1 (hereinafter sometimes simply referred to as a sealing device) will be described with reference to FIGS. 1 to 6. The sealing device 1 includes a rod-shaped portion 2 shown in FIG. 2, a bush 10 shown in FIG. 3, a nut 18 shown in FIG. 4, a first sealing material 20 shown in FIG. 5, and a second sealing material 21 shown in FIG. There is.

The rod-shaped portion 2 in FIG. 2 includes a cylindrical portion 3 and a bolt portion 4. The cylindrical portion 3 is formed into a straight cylindrical shape (in other words, a tubular shape). The outer diameter of the cylindrical portion 3 is set to be smaller than the inner diameter of the heat transfer tube 101. That is, when the cylinder part 3 is inserted into the heat transfer tube 101, there is a gap between the outer peripheral surface of the cylinder part 3 and the inner peripheral surface of the heat transfer tube 101.

Further, the length of the cylindrical portion 3 is shorter than the heat transfer tube 101, but is determined to be close to the length of the heat transfer tube 101. Specifically, the length of the cylindrical portion 3 is such that, for example, when the cylindrical portion 3 is inserted into the heat transfer tube 101, the end portion of the cylindrical portion 3 (joint portion with the bolt portion 4) is connected to the tube plate main body. 121 so as to be located within the through hole 121a. Further, the length of the cylindrical portion 3 is determined so as to cover, for example, a defective portion 105 (see FIG. 1) such as a hole or scratch formed in the heat transfer tube 100 from the inside.

The cylindrical portion 3 is made of a high melting point active material (tantalum (Ta), tantalum alloy, zirconium (Zr), zirconium alloy, niobium (Nb), niobium alloy, titanium (Ti), titanium alloy, etc.). Note that the cylindrical portion 3 is less likely to come into contact with the fluid (pickling liquid) whose temperature is to be adjusted than the bolt portion 4, the bush 10, and the nut 18. Therefore, the cylindrical portion 3 may be formed of a material (a cheap material) having lower acid resistance than the bolt portion 4, the bush 10, and the nut 18. However, if the bolt part 4 is made of a high melting point active material and the cylindrical part 3 is made of a material other than the high melting point active material, it becomes difficult to fix the cylindrical part 3 and the bolt part 4 by welding. Therefore, in order to facilitate the fixation of the cylindrical part 3 and the bolt part 4 by welding, the cylindrical part 3 is made of a material (for example, titanium) that is cheaper in cost than the bolt part 4 among the above-mentioned high melting point active materials. It's fine. According to this, the cost of the sealing device 1 can be suppressed. Note that the present invention is not limited to this, and the cylindrical portion 3 may be formed of the same material as the bolt portion 4. Note that the cylindrical portion 3 corresponds to the rod-shaped main body of the present invention.

The bolt portion 4 is a connection portion that can be connected to the nut 18 in FIG. 4 by threading. The bolt portions 4 are provided at both ends of the cylindrical portion 3, respectively. Each bolt part 4 is fixed to the cylinder part 3 by welding and is integrated with the cylinder part 3. That is, the joint 9 between the bolt part 4 and the cylinder part 3 includes a welded part. Specifically, each bolt part 4 has a base part 5 fixed to the end of the cylindrical part 3 by welding, and a male screw part 6 protruding from the base part 5. A protrusion 7 is formed on the side surface of the base 5 and protrudes in a direction perpendicular to the axis L4 of the male threaded portion 6. The convex portion 7 is formed continuously over the entire circumference around the axis L4. In other words, the convex portion 7 is formed so as to draw a circle centered on the axis L4 when viewed in a cross section perpendicular to the axis L4. The convex portion 7 functions as a seating portion on which the second sealing material 21 of FIG. 6 is seated. In other words, the convex portion 7 moves the second sealing material 21 toward the cylindrical portion 3 in the direction of the axis L4 when the second sealing material 21 is attached to the rod-shaped portion 2 (that is, the state shown in FIG. 1). This is the regulatory department that regulates. The convex portion 7 may be formed so as to be in contact with the inner circumferential surface of the heat transfer tube 101 when the rod-shaped portion 2 is inserted into the heat transfer tube 101 (the state shown in FIG. 1), or may be formed to contact the inner circumferential surface of the heat transfer tube 101. It may be formed with a slight gap between the two.

The outer circumferential side surface 8 of the base portion 5 on the side closer to the male screw portion 6 than the convex portion 7 is formed to draw a circle centered on the axis L4 when viewed in a cross section perpendicular to the axis L4. In the state shown in FIG. 1, an annular second sealing material 21 is attached to the outside of the outer peripheral side surface 8. As shown in FIG. In other words, the outer peripheral side surface 8 is inserted inside the second sealing material 21 . In the state shown in FIG. 1, the outer circumferential side surface 8 and the inner circumferential surface of the second sealing material 21 are in contact with each other. In this way, the outer circumferential side surface 8 functions as a support portion that supports the inner circumferential surface of the second sealing material 21.

The male threaded portion 6 is integrally formed with the base portion 5 from the same material. Further, the male threaded portion 6 is formed in the shape of a round bar that defines the axis L4 of the bolt portion 4. The male threaded portion 6 is formed to have a smaller diameter than the base portion 5. A thread groove is formed on the outer peripheral surface of the male threaded portion 6 to be screwed into the nut 18 shown in FIG. The male threaded portion 6 is provided so that its axis L4 coincides with the axis L3 of the cylindrical portion 3 and protrudes from the base portion 5 in the direction away from the cylindrical portion 3. The two bolt parts 4 provided at both ends of the cylindrical part 3 are formed in the same shape except that the male threads 6 protrude from the base part 5 in opposite directions.

The length of the bolt part 4 (male thread part 6) is the length from the outer surface 122 (sheet surface) of the tube sheet 120 to the outside when the sealing device 1 is attached to the heat transfer tube 101 (the state shown in FIG. 1). It is determined to protrude and also protrude from the bush 10.

The bolt portion 4 is made of a high melting point active material (tantalum (Ta), tantalum alloy, zirconium (Zr), zirconium alloy, niobium (Nb), niobium alloy, titanium (Ti), titanium alloy, etc.). Note that the bolt part 4 is more likely to come into contact with the fluid (pickling liquid) whose temperature is to be adjusted than the cylinder part 3. Therefore, the bolt part 4 may be formed of a material (for example, tantalum) that has higher acid resistance than the cylindrical part 3 among high melting point active materials. Moreover, the bolt part 4 may be formed of the same material as the bush 10 or the nut 18 among high melting point active materials, or may be formed of a different material. Note that the bolt portion 4 corresponds to the male screw portion and attachment portion of the present invention.

The bush 10 in FIG. 3 is provided at each of both ends 6 (external threaded portion) of the rod-shaped portion 2 in a state where the sealing device 1 is attached to the heat transfer tube 101 (the state shown in FIG. 1). The two bushes 10 have the same shape and are made of the same material. The bush 10 is a member that can be attached to and detached from the bolt portion 4 (male thread portion 6) and closes the entrances and exits 103 and 104 of the heat transfer tube 101 from the outside of the outer surface 122 of the tube sheet 120. Further, the bush 10 is a member for sandwiching the first seal 20 material shown in FIG. 5 between the bush 10 and the outer surface 122 of the tube sheet 120. Further, the bush 10 is a member for sandwiching the second sealing material 21 shown in FIG. 6 between the bush 10 and the convex part 7 of the bolt part 4. The bush 10 also indirectly or directly contacts the outer surface 122 of the tube sheet 120 via the first sealing material 20 to prevent the sealing device 1 from coming off the heat transfer tube 101. It is a member. That is, the bush 10 is provided outside the outer surface 122 and is formed to have a larger diameter than the hole 122a of the tube sheet 120.

The bush 10 is formed into a cylindrical shape with a through hole 11. The through hole 11 is a hole into which the male screw portion 6 is inserted. Note that no thread groove is formed on the inner circumferential surface of the through hole 11. The diameter of the through hole 11 may be determined so that the outer circumferential surface of the male threaded portion 6 and the inner circumferential surface of the through hole 11 come into contact with each other when the male threaded portion 6 is inserted, or the diameter of the outer circumferential surface and the inner circumferential surface of the It may be determined to have a slight gap between it and the surrounding surface. One end surface 17 of the bush 10 in the direction of the axis L5 (center axis of the through hole 11) is formed into a flat surface. This end surface 17 is a surface facing toward the nut 18 in the state shown in FIG. 1, and is set as a seating surface on which the nut 18 is seated. That is, the end surface 17 is a surface that defines the amount of engagement between the male threaded portion 6 and the nut 18 .

An end 18 of the bush 10 opposite to the end surface 17 in the direction of the axis L5 faces toward the outer surface 122 of the tube sheet 120 in the state shown in FIG. The end portion 18 is formed with a protrusion 12 that protrudes in a direction parallel to the axis L5. The protruding portion 12 is formed continuously over the entire circumference around the axis L5. In other words, the protrusion 12 is formed so as to draw a circle centered on the axis L5 when viewed in a cross section perpendicular to the axis L5. In the state shown in FIG. This is a portion for sandwiching the second sealing material 21 between the sealing material 7 and the sealing material 7. In the state shown in FIG. 1, a portion of the protrusion 12 on the tip 13 side surrounds the outside of the side surface of the base 5 of the bolt portion 4, and the tip 13 of the protrusion 12 is in contact with the second sealing material 21. In the state shown in FIG. 1, the protrusion 12 may be in contact with the inner circumferential surface of the hole 122a of the tube sheet 120, or there may be a slight gap between the inner circumferential surface and the protrusion 12. In this way, the protruding part 12 functions as a regulating part that regulates the movement of the second sealing material 21 toward the through hole 11 in the direction of the axis L5, in other words, it maintains the position of the second sealing material 21. Functions as a seal holder.

Further, a recess 14 is formed in the end portion 18 at a position radially outward of the protrusion 12 and adjacent to the protrusion 12 . This recess 14 is a portion into which an annular portion 122a (a portion forming a hole 122a) formed to protrude from the outer surface 122 of the tube sheet 120 is inserted. The recess 14 is formed continuously over the entire circumference around the axis L5. In other words, the recess 14 is formed so as to draw a circle centered on the axis L5 when viewed in a cross section perpendicular to the axis L5.

Further, the end portion 18 has an outer portion 15 at a position radially outer than the recess 14 and adjacent to the recess 14 . The outer portion 15 is formed continuously over the entire circumference around the axis L5. In other words, the outer portion 15 is formed to draw a circle centered on the axis L5 when viewed in a cross section perpendicular to the axis L5. The outer portion 15 is located radially outward from the hole 122a formed in the outer surface 122 of the tube sheet 120 in the state shown in FIG. That is, the outer part 15 is provided so as to surround the entire circumference of the hole 122a of the outer surface 122 in the state shown in FIG.

The outer portion 15 is a portion for sandwiching the first sealing material 20 between the outer surface 122 and the outer surface 122 . Specifically, a recess 16 is formed in the end surface of the outer portion 15 in the direction of the axis L5. The recess 16 is formed continuously over the entire circumference around the axis L5. In other words, the recess 16 is formed to draw a circle centered on the axis L5 when viewed in a cross section perpendicular to the axis L5. The recessed portion 16 is a portion into which a portion of the first sealing material 20 in the axial direction is inserted to maintain the position of the first sealing material 20. That is, the recessed portion 16 functions as a seal holding portion that holds the position of the first sealing material 20.

The bush 10 is made of a high melting point active material (tantalum (Ta), tantalum alloy, zirconium (Zr), zirconium alloy, niobium (Nb), niobium alloy, titanium (Ti), titanium alloy, etc.). Note that the bush 10 is more likely to come into contact with the fluid (pickling liquid) whose temperature is to be adjusted than the cylindrical portion 3. Therefore, the bush 10 may be formed of a material having higher acid resistance than the cylindrical portion 3 (for example, tantalum) among high melting point active materials. Further, the bush 10 may be made of the same material as the bolt portion 4 or the nut 18 among high melting point active materials, or may be made of a different material.

Nuts 18 in FIG. 4 are provided at both ends 6 (externally threaded portions) of rod-shaped portion 2 in a state in which sealing device 1 is attached to heat transfer tube 101 (state in FIG. 1). The two nuts 18 have the same shape and are made of the same material. The nut 18 is attachable to and detachable from the bolt portion 4 (male threaded portion 6). Specifically, the nut 18 is formed into a cylindrical shape with a through hole 19. A threaded groove is formed on the inner circumferential surface of this through hole 19. Note that the nut 18 may be a hexagonal nut, for example (see FIG. 4(b)). As shown in FIG. 1, the nut 18 is screwed onto a portion of the male threaded portion 6 to which the bush 10 is attached, which protrudes from the bush 10, so that the nut 18 is secured to the outer surface 122 of the tube plate 120. It is a member for sandwiching.

The nut 18 is made of a high melting point active material (tantalum (Ta), tantalum alloy, zirconium (Zr), zirconium alloy, niobium (Nb), niobium alloy, titanium (Ti), titanium alloy, etc.). Note that the nut 18 is more likely to come into contact with the fluid (pickling liquid) whose temperature is to be adjusted than the cylindrical portion 3. Therefore, the nut 18 may be formed of a material having higher acid resistance than the cylindrical portion 3 (for example, tantalum) among high melting point active materials. Further, the nut 18 may be made of the same material as the bolt portion 4 or the bush 10 among high melting point active materials, or may be made of a different material. Note that the nut 18 corresponds to the female threaded portion of the present invention. Moreover, the bush 10 and the nut 18 correspond to the closing part of the present invention. The bush 10 corresponds to the main body of the closing part.

The first sealing material 20 in FIG. 5 is a member for sealing the entrances and exits 103 and 104 of the heat transfer tube 101 so that the fluid whose temperature is to be adjusted does not enter the defective heat transfer tube 101. Specifically, as shown in FIG. 1, a portion of the first sealing material 20 is fitted into a recess 14 formed in the bushing 10, so that the outer portion 15 of the bushing 10 and the pipe are connected to each other. It is provided so as to be sandwiched between the outer surface 122 of the plate 120 and the outer surface 122 of the plate 120 . In this way, the first sealing material 20 is a sealing part for sealing between the bush 10 and the outer surface 122, in other words, it seals so as to surround the hole 122a in the outer surface 122. This is the seal part.

One first sealing material 20 is provided on each of the inlet 103 side and the outlet 104 side of the heat transfer tube 101 when the sealing device 1 is attached to the heat transfer tube 101 (the state shown in FIG. 1). The two first sealing materials 20 have the same shape and are made of the same material.

The first sealing material 20 is formed into an annular shape having a larger diameter than the second sealing material 21 in FIG. Although FIG. 5 shows an example in which the first sealing material 20 has a square cross section (that is, the first sealing material 20 is a square ring), it may be an O-ring with a circular cross section.

Further, the first sealing material 20 is made of, for example, an elastomer (elastic body, rubber). Specifically, the first sealing material 20 is made of a material with high heat resistance and corrosion resistance (chemical resistance, acid resistance), such as Kalrez, which is a polymeric material classified as perfluoroelastomer. (registered trademark). Kalrez (registered trademark) (perfluoroelastomer) is a fluoropolymer consisting of a main chain part (TFE: tetrafluoroethylene), a branched part (PMVE: perfluoromethyl vinyl ether), and a crosslinked part. Note that common sealing materials include EPDM (ethylene propylene rubber), silicone rubber, nitrile rubber, fluororubber, and fluororesin (polytetrafluoroethylene, etc.). The first sealing material 20 may be formed of a material other than perfluoroelastomer as long as it can withstand the environment in which the heat exchanger 100 is used. Note that the first sealing material 20 corresponds to the seal portion and the outer seal portion of the present invention.

The second sealing material 21 in FIG. 6 is a member for sealing the entrances and exits 103 and 104 of the heat transfer tube 101 so that the fluid whose temperature is to be adjusted does not enter the defective heat transfer tube 101. Specifically, as shown in FIG. 1, the second sealing material 21 is fitted on the outside of the base 5 of the bolt part 4, and the second sealing material 21 is fitted on the outside of the base 5 of the bolt part 4, and the second sealing material 21 is inserted between the convex part 7 of the base 5 and the bushing inside the heat transfer tube 101. It is provided in a state where it is sandwiched between the protrusion part 12 of 10. Further, the second sealing material 21 is provided between the inner circumferential surface of the heat transfer tube 101 and the side surface of the rod-shaped portion 2 (the side surface of the base portion 5 of the bolt portion 4) in the state shown in FIG. At this time, the second sealing material 21 is in contact with the inner circumferential surface of the heat transfer tube 101 and the side surface of the rod-shaped portion 2, respectively. In this way, the second sealing material 21 is provided between the bush 10 (protrusion 12) and the base 5 (convex part 7) of the bolt part 4, and between the inner circumferential surface of the heat transfer tube 101 and the side surface of the rod-shaped part 2. (the side surface of the base 5).

Two second sealants 21 are provided on each of the inlet 103 side and the outlet 104 side of the heat transfer tube 101 when the sealing device 1 is attached to the heat transfer tube 101 (the state shown in FIG. 1). A total of four second sealing materials 21 have the same shape and are made of the same material. Note that in this embodiment, an example is shown in which two second sealants 21 are provided on one side, but if the desired sealing performance can be ensured, one second sealant 21 may be provided on one side. It's okay. Furthermore, three or more second sealants 21 may be provided on one side.

The second sealing material 21 is formed into an annular shape having a smaller diameter than the first sealing material 20 of FIG. Although FIG. 6 shows an example in which the second sealing material 21 has a circular cross section (that is, the second sealing material 21 is an O-ring), it may be a square ring with a quadrangular cross-section.

Further, like the first sealing material 20, the second sealing material 21 is made of, for example, an elastomer (elastic body, rubber). Specifically, the second sealing material 21 is made of a material with high heat resistance and corrosion resistance (chemical resistance, acid resistance), for example, the above-mentioned Kalrez (registered trademark). Note that the second sealing material 21 may be formed of the same material as the first sealing material 20, or may be formed of a different material. Further, the second sealing material 21 may be formed of a material other than perfluoroelastomer as long as it can withstand the environment in which the heat exchanger 100 is used. Note that the second seal material 21 corresponds to the seal portion and the inner seal portion of the present invention.

The sealing device 1 having the above-described configuration is used so as to be attached to the defective heat transfer tube 101. For example, if a foreign object such as a stone gets mixed into the fluid whose temperature is to be adjusted, this foreign object may cause defects 105 (see FIGS. 1 and 9) such as holes or scratches in the heat transfer tube 101. There is. Further, the heat exchanger 100 becomes high temperature when in operation, but becomes low temperature when stopped. Thermal stress is generated in each part of the heat exchanger 100 (such as the heat transfer tubes 101 and the tube sheets 120 that support them) due to temperature changes due to repeated operation and stop of the heat exchanger 100. This thermal stress may cause the welded portion 123 (see FIG. 9) between the heat transfer tube 101 and the tube sheet 120 to be cut, or cause a defective portion 105 (see FIG. 9) to occur on the side surface of the heat transfer tube 101. be. In particular, when the heat transfer tube 101 is formed of the above-mentioned high melting point active material and the tube sheet 120 is formed of a material other than the high melting point active material (such as stainless steel), the material of the heat transfer tube 101 and the tube sheet 120 are A large stress may be applied to the heat transfer tube 101 due to the difference in linear expansion coefficient from that of the material. Furthermore, if an object or contents collide with the heat transfer tube 101 during maintenance or operation of the heat exchanger 100, the heat transfer tube 101 may be deformed.

The heat transfer tube 101 is welded to the tube sheet 120, and due to the difference in linear expansion coefficient between the material of the heat transfer tube 101 and the material of the tube sheet 120, the heat transfer tube 101 is welded to the hole 121a of the tube sheet 120, Since it is strongly fixed to the inner peripheral surface of the heat transfer tube 122a, it cannot be easily removed even if a defect occurs in the heat transfer tube 101.

In such a case, the sealing device 1 is attached to the defective heat transfer tube 101 as shown in FIG. 1. Note that the sealing device 1 is not attached to the heat transfer tube 101 that does not have any defects.

An example of a procedure for attaching the sealing device 1 to the heat transfer tube 101 will be described below. Note that before attaching the sealing device 1 to the heat transfer tube 101, the outer surface 122 of each tube sheet 120 that supports both ends of the heat transfer tube 101 is exposed in advance. First, the second sealing material 21 shown in FIG. 6 is attached to each of both ends 4 (bolt parts) of the rod-shaped part 2 shown in FIG. In this embodiment, two second sealing materials 21 are attached to each bolt portion 4, respectively. At this time, the second sealing material 21 is attached to the outside of the base portion 5 of the bolt portion 4. The second sealing material 21 is supported by the convex portion 7 and the outer circumferential side surface 8 of the base portion 5 .

Next, the rod-shaped portion 2 equipped with the second sealing material 21 is inserted into the inside of the heat transfer tube 101 to be sealed. At this time, the rod-shaped portion 2 may be inserted from the inlet 103 side of the heat transfer tube 101 or may be inserted from the outlet 104 side. Then, the male threaded portions 6 on both sides of the rod-shaped portion 2 are made to protrude outward from the holes 122a in the outer surface 122 of the tube sheet 120 (in other words, the entrances and exits 103 and 104 of the heat transfer tube 101).

Note that in the above, the second sealing material 21 was attached to the rod-shaped portion 2 in advance before the rod-shaped portion 2 was inserted into the heat transfer tube 101. Alternatively, after the rod-shaped portion 2 is inserted into the heat transfer tube 101, the second sealing material 21 may be attached to the outside of the base portion 5 of the rod-shaped portion 2.

Next, the first sealing material 20 shown in FIG. 5 is fitted into the recess 16 of the bush 10 shown in FIG. 3 (installed). Then, the bush 10 with the first sealing material 20 attached thereto is inserted into each male threaded portion 6 of the rod-shaped portion 2 inserted into the heat transfer tube 101 . Thereafter, the nut 18 shown in FIG. 4 is fastened to the male screw portion 6 protruding from the through hole 11 of the bush 10. Thereby, as shown in FIG. 1, the hole 122a on the outside of the tube sheet 120 and the inlet/outlet ports 103 and 104 of the heat transfer tube 101 are closed with bushes from the outside of the outer surface 122 of the tube sheet 120. In addition, the first sealant 20 is sandwiched between the bushing 10 and the outer surface 122 of the tubesheet 120. Further, the second sealing material 21 is sandwiched between the protrusion 7 of the base 5 and the protrusion 12 of the bush 10. Through the above steps, the sealing device 1 is attached to the heat transfer tube 101 (the state shown in FIG. 1).

Note that, in the above example, after inserting the rod-shaped portion 2 into the heat transfer tube 101, the first sealing material 20, the bush 10, and the nut 18 are attached to each of both ends 6 of the rod-shaped portion 2. Instead, before inserting the rod-like part 2 into the heat transfer tube 101, the first sealing material 20, the bush 10, and the nut 18 are attached to only one end 6 (male threaded part) of the rod-like part 2. I'll let you. Thereafter, this rod-shaped portion 2 is inserted into the heat transfer tube 101 from the side where the first sealing material 20, bushing 10, and nut 18 are not attached, and the first sealing material 20, bushing 10, and nut 18 are attached. The male threaded portion 6 that is not open is made to protrude from the hole 122a of the tube plate 120. Thereafter, the first sealing material 20, the bush 10, and the nut 18 may be attached to the male threaded portion 6.

The effects of this embodiment will be explained below. According to this embodiment, when a defect occurs in the heat transfer tube 101, the heat transfer tube 101 can be sealed with the sealing device 1 without removing the heat transfer tube 101 from the heat exchanger 100. Thereby, the operation of the heat exchanger 100 can be continued without having to bring the heat exchanger 100 to a repair shop. Furthermore, it is possible to prevent the fluid whose temperature is to be adjusted from entering the defective heat transfer tube 101 while the heat exchanger 100 is in operation, and by extension, to prevent the fluid from leaking to the outside from the defective heat transfer tube 101. can be suppressed. Since the sealing device 1 is attached to the heat transfer tube 101 by screwing the male threaded portion 6 and the nut 18, the sealing device 1 can be easily attached (defects can be removed) at the site where the heat exchanger 100 is installed. A procedure for sealing the heat transfer tube can be performed.

Further, since the second sealing material 21 is provided between the inner circumferential surface of the heat transfer tube 101 and the rod-shaped portion 2, it is assumed that the male threaded portion 6 and the through hole 19 of the nut 18 or the through hole 11 of the bush 10 are connected to each other. Even if fluid passes through the gap, the second sealing material 21 can prevent this fluid from entering the cylindrical portion 3 side.

Further, since the first sealing material 20 is provided between the bush 10 and the outer surface 122 of the tube plate 120, it is possible to suppress fluid from entering from between the bush 10 and the outer surface 122. Further, since the welded portion 123 between the heat transfer tube 101 and the tube sheet 120 is located in the path between the first sealing material 20 and the second sealing material 21, even if the welded portion 123 is damaged, , it is possible to suppress fluid from entering into the housing 110 from this welded portion 123.

Furthermore, since the rod portion 2 (cylindrical portion 3, bolt portion 4), bush 10, and nut 18 are made of a high melting point active material, even if the heat exchanger 100 is operated with the sealing device 1 attached, Also, deterioration of the rod-shaped portion 2, bush 10, and nut 18 due to high temperature and high concentration acid (fluid) can be suppressed. Moreover, since the first sealing material 20 and the second sealing material 21 are formed of Kalrez (registered trademark), for example, even if the heat exchanger 100 is operated with the sealing device 1 attached, the first sealing material It is possible to suppress deterioration of the material 20 and the second seal material 21 due to high temperature and high concentration acid (fluid).

Moreover, since the rod-shaped portion 2 has a cylindrical portion 3 other than the bolt portion 4, the weight and cost of the sealing device 1 can be reduced.

Moreover, since the bush 10 is provided outside the tube sheet 120 and is formed to have a larger diameter than the hole 122a of the tube sheet 120, it is possible to suppress the sealing device 1 from coming off from the heat transfer tube 101.

Note that the present invention is not limited to the above embodiments, and various modifications are possible. For example, in the above embodiment, an example is shown in which the two closing parts (bush, nut) provided at each end of the rod-shaped portion are both attachable to and detachable from the rod-shaped portion. Alternatively, one of the closing parts may be provided in a detachable manner on the rod-shaped part, and the other closing part may be provided in a non-removable manner (that is, integrated with the rod-shaped part). According to this, first, the rod-shaped part is inserted into the heat transfer tube with the removable closing part removed from the rod-shaped part. Thereafter, by attaching this closing portion to the rod-shaped portion from outside the outer surface of the tube sheet, both the entrance and exit of the heat transfer tube can be closed with the closing portion from outside the outer surface of the tube sheet.

Further, in the above embodiment, an example was shown in which the rod-shaped main body (portion of the rod-shaped portion other than the bolt portion) of the rod-shaped portion was formed in a hollow rod shape (cylindrical shape). Alternatively, the rod-shaped main body may be formed in the shape of a solid rod. In this case, the solid rod-shaped main body and the male threaded portion at the end thereof may be integrally formed of the same material. According to this, it is possible to eliminate the joint portion (welded portion) between the rod-shaped main body and the male threaded portion.

Further, in the above embodiment, an example was shown in which the end portion of the rod-shaped portion was configured with a male screw portion, and the closing portion was configured with a female screw portion. Alternatively, the end of the rod-like portion may be a female thread, and the closing portion may be a male thread.

1 Heat transfer tube sealing device 2 Rod-shaped portion 3 Cylindrical portion (rod-shaped main body)
4 Bolt part (mounting part)
5 Base of bolt part 6 Male thread part 10 Bush (main body part of closing part)
18 Nut (female thread)
20 First seal material (outer seal part)
21 Second seal material (inner seal part)
100 Heat exchanger 101 Heat transfer tube 110 Housing 120 Tube sheet 122 Outer surface of tube sheet 122a Hole on outer surface of tube sheet

Claims (6)

a plurality of heat transfer tubes for flowing a fluid whose temperature is to be adjusted and transferring heat to the fluid;
applied to a heat exchanger comprising a tube sheet having an outer surface formed with a hole for each heat transfer tube into which an end of each heat transfer tube is inserted;
a rod-shaped part inserted into the heat transfer tube;
a closing part that is provided at each end of the rod-shaped part and closes the entrance and exit of the heat transfer tube from outside the outer surface;
a sealing part that seals the heat transfer tube between the closing part,
at least one of the closing parts is removable from the rod-shaped part;
Sealing device for heat transfer tubes of heat exchangers. The sealing device for a heat transfer tube of a heat exchanger according to claim 1, wherein the rod-shaped portion and the closing portion are connected by screwing. The end of the rod-shaped portion is a male screw portion that protrudes outward from the hole on the outer surface when inserted into the heat transfer tube, and has a thread formed on the outer periphery;
The closure part is
a main body portion having a seal holding portion that is formed with a through hole into which the male screw portion is inserted and holds the position of the seal portion;
The sealing device for a heat transfer tube of a heat exchanger according to claim 1 or 2, further comprising a female screw portion fastened to the male screw portion protruding from the through hole of the main body portion. The rod-shaped part includes a rod-shaped main body and an attachment part connected to an end of the rod-shaped main body and to which the closing part is attached,
The sealing device for a heat transfer tube of a heat exchanger according to any one of claims 1 to 3, wherein the attachment portion is made of a material with higher acid resistance than the rod-shaped main body. The sealing device for a heat transfer tube of a heat exchanger according to any one of claims 1 to 4, wherein the seal portion includes an outer seal portion provided between the closing portion and the outer surface. The heat exchanger according to any one of claims 1 to 5, wherein the seal part includes an inner seal part provided between the closing part and the rod-shaped part so as to be in contact with the inner circumferential surface of the heat transfer tube. Sealing device for heat transfer tubes of exchangers.

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