Jacket heater, jacket heater manufacturing method, and heat insulation structure

Abstract

A jacket heater (10) includes: a first heat insulation layer (11); a reflection layer (13) that is disposed outward of the first heat insulation layer (11); a second heat insulation layer (12) that is disposed outward of the reflection layer (13); and a heater wire (14) that is disposed inward of the first heat insulation layer (11). Thus, piping can be sufficiently heated while suppressing power consumption.

Description

Jacket heater, jacket heater manufacturing method, and heat insulation structure

[0001] The present invention relates to a jacket heater for covering a pipe, a method for manufacturing the jacket heater, and a heat insulating structure.

[0002] In order to prevent condensation and deposition of gases inside the piping, the piping may be covered with a jacket heater. For example, various gases are used in film formation processes and etching processes in the manufacture of semiconductor devices. In order to prevent these gases from condensing and depositing inside the piping, a jacket heater may be used. Patent Document 1 discloses an example of such a jacket heater.

[0003] International Publication No. 2011 / 126051

[0004] Reducing power consumption in manufacturing equipment is important for reducing manufacturing costs and environmental impact. Therefore, reducing power consumption in jacket heaters is also required. Power consumption can be reduced by increasing the thickness of the insulation layer of the jacket heater. However, increasing the thickness of the insulation layer requires a large space around the piping to install the jacket heater. Therefore, increasing the thickness of the insulation layer to reduce power consumption may not be desirable.

[0005] The jacket heater proposed in this disclosure is a jacket heater for attachment to the outer periphery of a pipe, and includes a first insulating layer, a reflective layer disposed outside the first insulating layer, a second insulating layer disposed outside the reflective layer, and a heater wire disposed inside the first insulating layer. Because this jacket heater includes a reflective layer, power consumption in the jacket heater is reduced and the pipe is sufficiently heated. Furthermore, because the second insulating layer is disposed outside the reflective layer, the outer surface of the jacket heater can be cooled to an appropriate temperature. As a result, workability around the jacket heater is improved.

[0006] The manufacturing method of a jacket heater proposed in the present disclosure includes a step of sewing together a first insulating layer covering a heater wire, a reflective layer covering the outside of the first insulating layer, and a second insulating layer covering the outside of the reflective layer, and a step of sewing the heater wire to the first insulating layer. A jacket heater manufactured by this manufacturing method reduces power consumption in the jacket heater and sufficiently heats the pipe. Furthermore, because the second insulating layer is located outside the reflective layer, the outer surface of the jacket heater can be cooled to an appropriate temperature. As a result, workability around the jacket heater can be improved.

[0007] The thermal insulation structure proposed in this disclosure is an insulation structure for attachment to the outer periphery of a pipe, and includes a first insulation layer, a reflective layer disposed outside the first insulation layer, a second insulation layer disposed outside the reflective layer, and a heater wire disposed inside the first insulation layer. This thermal insulation structure reduces power consumption in the heater wire and ensures sufficient heating of the pipe. Furthermore, because the second insulation layer is disposed outside the reflective layer, the outer surface of the thermal insulation structure can be cooled to an appropriate temperature. As a result, workability around the jacket heater can be improved.

[0008] Fig. 2 is a cross-sectional view showing a state in which the jacket heater proposed in the present disclosure is attached to a pipe. Fig. 3 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 4 is a diagram for explaining an example of stitching around a third sensor passing hole formed in a reflective layer, and is a schematic diagram showing a state viewed from the reflective layer side to the first insulating layer side in the thickness direction of the jacket heater. Fig. 5 is a diagram for explaining another example of stitching around a third sensor passing hole formed in a reflective layer, and is a schematic diagram showing a state viewed from the reflective layer side to the first insulating layer side in the thickness direction of the jacket heater. Fig. 6 is a perspective view showing another example of a passing hole formed in a reflective layer.

[0009] The jacket heater proposed in the present disclosure will be described below, taking the jacket heater 10 shown in FIG. 1 as an example.

[0010] 1, a jacket heater 10 covers a pipe 90. The jacket heater 10 heats the pipe 90 to prevent the gas flowing inside the pipe 90 from condensing or separating out.

[0011] As shown in Figure 2, the jacket heater 10 has a heater wire 14 and a heater wire substrate 18 to which the heater wire 14 is attached. The heater wire 14 is, for example, a nickel-chromium metal resistor. The heater wire substrate 18 can be, for example, an inorganic fiber cloth made of inorganic fibers such as glass fiber, silica fiber, alumina fiber, or silica-alumina fiber. The heater wire 14 is sewn to the heater wire substrate 18. The heater wire 14 is connected to an external power supply via lead wires 14b.

[0012] 2 , the jacket heater 10 has a first insulating layer 11 and a second insulating layer 12. The first insulating layer 11 is disposed outside the heater wire 14 and the heater wire substrate 18 and covers them. The second insulating layer 12 is disposed further outside the first insulating layer 11 and covers the first insulating layer 11.

[0013] The first insulating layer 11 and the second insulating layer 12 are formed of, for example, an inorganic fiber insulating material. The inorganic fiber may be, for example, glass fiber, ceramic fiber, silica fiber, etc. Alternatively, the first insulating layer 11 and the second insulating layer 12 may be an inorganic or organic insulating material containing polyimide or silica and having voids with an average void width of a certain amount or less (for example, voids with an average void width smaller than the mean free path of air molecules). The materials of the first insulating layer 11 and the second insulating layer 12 may be the same or different.

[0014] The first insulating layer 11 may be composed of a single layer or multiple layers stacked together. Similarly, the second insulating layer 12 may be composed of a single layer or multiple layers stacked together. When each of the insulating layers 11 and 12 is composed of multiple layers, the layers may be made of the same material or different materials.

[0015] The thickness of the first insulating layer 11 may be, for example, 5 mm to 100 mm. The thickness of the second insulating layer 12 may also be 5 mm to 100 mm. Such thicknesses ensure thermal insulation performance while minimizing the space required for installing the jacket heater 10. The thickness of the first insulating layer 11 may preferably be 5 mm to 50 mm. The thickness of the first insulating layer 11 may more preferably be 8 mm to 30 mm. The thickness of the second insulating layer 12 may also preferably be 5 mm to 50 mm. The thickness of the second insulating layer 12 may more preferably be 8 mm to 30 mm.

[0016] As shown in Figure 2, the jacket heater 10 has a reflective layer 13 disposed between the first insulating layer 11 and the second insulating layer 12. This allows heat (electromagnetic waves) emitted from the piping 90 and the heater wire 14 to be reflected by the reflective layer 13. As a result, the piping 90 is heated efficiently. In addition, since the second insulating layer 12 is located outside the reflective layer 13, the outer surface of the jacket heater 10 can be cooled to an appropriate temperature. As a result, workability around the jacket heater 10 can be improved.

[0017] The reflective layer 13 is preferably made of a material that has high reflectivity for infrared rays. The material of the reflective layer 13 is, for example, a metal. Aluminum is a suitable material for the reflective layer 13, but other metals such as copper and stainless steel may also be used. The reflective layer 13 may also be made of materials other than metals, such as ceramic, silicon carbide, or zirconia.

[0018] The reflective layer 13 is, for example, a metal foil having a thickness of 10 μm to 700 μm. This thickness can prevent the reflective layer 13 from unintentionally breaking while maintaining the flexibility of the reflective layer 13. The thickness of the reflective layer 13 is preferably 10 μm to 200 μm.

[0019] 1 , the reflective layer 13 may be formed over substantially the entire circumference of the pipe 90. That is, the reflective layer 13 may surround the pipe 90 over substantially 360 degrees. Furthermore, the reflective layer 13 may be provided over substantially the entire jacket heater 10 in the length direction of the pipe 90.

[0020] 2 , the jacket heater 10 has an inner skin 16 provided on the inside of a heater wire substrate 18. An insulating layer 15 may be disposed between the inner skin 16 and the heater wire substrate 18 to reliably insulate the heater wire 14 from the piping 90. The jacket heater 10 also has an outer skin 17 that covers the outside of the second insulating layer 12.

[0021] The outer skin 17 and the inner skin 16 may be made of, for example, a heat-resistant sheet (including cloth). The outer skin 17 and the inner skin 16 may be made of the same material or different materials. The outer skin 17 and the inner skin 16 may be made of, for example, a porous sheet, an inorganic fiber sheet, or a resin sheet. An example of a porous sheet is a PTFE (polytetrafluoroethylene) sheet. An example of an inorganic fiber sheet is a glass cloth. An example of a resin sheet is a fluororesin sheet. The inorganic fiber sheet may also be coated with silicone or fluorine.

[0022] The jacket heater 10 is flexible. That is, each of the insulating layers 11 and 12, the reflective layer 13, the outer cover 17, the inner cover 16, the heater wire 14, and the heater wire substrate 18 that constitute the jacket heater 10 is flexible. In the installation process, the jacket heater 10 is wrapped around the outside of the pipe 90, thereby forming a cylindrical shape.

[0023] The jacket heater 10 has a fixing member that fixes the jacket heater 10 in a state where it is wrapped around the piping 90. The jacket heater 10 has, as the fixing member, for example, a plurality of hook-and-loop fasteners 22 (see FIG. 1 ) lined up along one edge of the jacket heater 10. The hook-and-loop fasteners 22 may be attached to the outer surface of the jacket heater 10. When the jacket heater 10 is wrapped around the piping 90, the hook-and-loop fasteners 22 are attached to the opposite edge of the jacket heater 10. Note that the fixing member is not limited to the hook-and-loop fasteners 22. The fixing member may be, for example, a hook, or may include a belt that is wrapped around the outside of the jacket heater 10.

[0024] [Lead Wire Passing Holes] As shown in FIG. 2 , a first lead wire passing hole 11b is formed in the first insulating layer 11. A second lead wire passing hole 12b is formed in the second insulating layer 12. A third lead wire passing hole 13b is formed in the reflective layer 13. The lead wire passing holes 11b, 12b, and 13b penetrate the insulating layers 11 and 12 and the reflective layer 13 in their thickness directions. The positions of the first, second, and third lead wire passing holes 11b, 12b, and 13b in the longitudinal and circumferential directions of the piping 90 may be substantially the same. That is, when the jacket heater 10 is viewed in the thickness direction, the first lead wire passing hole 11b may overlap a portion of the second lead wire passing hole 12b and a portion of the third lead wire passing hole 13b. The first, second, and third lead wire passing holes 11b, 12b, and 13b may form a single passing hole extending in the thickness direction of the jacket heater 10.

[0025] 2, a lead wire 14b is connected to the heater wire 14. The lead wire 14b extends from the heater wire 14 to the outside of the second insulating layer 12, passing through the first lead wire passing hole 11b, the third lead wire passing hole 13b, and the second lead wire passing hole 12b.

[0026] The lead wire 14b may pass through an opening 17a formed in the outer cover 17 and extend to the outside of the jacket heater 10. The heater wire 14 may be connected to an external power source (a control device that controls the current supplied to the heater wire 14) via the lead wire 14b. In the example shown in Fig. 2, the lead wire 14b passes through the opening 17a that penetrates the outer cover 17 in the thickness direction of the outer cover 17 (the radial direction of the piping 90) and extends to the outside of the jacket heater 10. Alternatively, the lead wire 14b may extend to the outside of the jacket heater 10 from a gap formed at the edge of the outer cover 17.

[0027] Two lead wires 14b may be connected to the heater wire 14. The two lead wires 14b may pass through common lead wire passing holes 11b, 12b, and 13b in this order and extend to the outside of the second insulating layer 12. Alternatively, lead wire passing holes 11b, 12b, and 13b may be formed for each of the two lead wires 14b. That is, the lead wire passing holes 11b, 12b, and 13b through which the first lead wire 14b passes may be formed in the first insulating layer 11, the second insulating layer 12, and the reflective layer 13, and the lead wire passing holes 11b, 12b, and 13b through which the second lead wire 14b passes may be formed in the first insulating layer 11, the second insulating layer 12, and the reflective layer 13.

[0028] The third lead wire passing hole 13b may be formed inside the outer peripheral edge of the reflective layer 13. That is, the inner edge of the third lead wire passing hole 13b may be annular and surround the lead wire 14b. Similarly, the first and second lead wire passing holes 11b and 12b may be formed inside the outer peripheral edges of the heat insulating layers 11 and 12. That is, the inner edges of the first and second lead wire passing holes 11b and 12b may be annular and surround the lead wire 14b.

[0029] Alternatively, the third lead wire passing hole 13b may be a recess formed on the outer periphery of the reflective layer 13. Similarly, the first and second lead wire passing holes 11b and 12b may be recesses formed on the outer periphery of the heat insulating layers 11 and 12. The positions of these recesses in the longitudinal direction and circumferential direction of the pipe 90 may be substantially the same.

[0030] The size of the third lead wire passing hole 13b is larger than the sizes of the first and second lead wire passing holes 11b and 12b. Specifically, the diameter Rb (see FIG. 2) of the third lead wire passing hole 13b is larger than the diameters of the first and second lead wire passing holes 11b and 12b. This limits the positional change of the lead wire 14b inside the third lead wire passing hole 13b by the lead wire passing holes 11b and 12b. As a result, contact between the lead wire 14b and the reflective layer 13 is suppressed. By doing so, for example, even if the outer covering of the lead wire 14b is torn, charging of the reflective layer 13 due to current flowing from the lead wire 14b to the reflective layer 13 can be prevented.

[0031] The size of each lead wire passing hole 11b, 12b, 13b may be the diameter of the passing hole if it is circular. Furthermore, the size of each lead wire passing hole 11b, 12b, 13b may be the width of one side of the inner edge of the passing hole if it is rectangular. The first and second lead wire passing holes 11b, 12b may be located at the center of the third lead wire passing hole 13b.

[0032] Unlike the example shown in Fig. 2, the diameter Rb of the third lead wire passing hole 13b may be larger than the diameter of one of the two lead wire passing holes 11b, 12b but may be the same as or smaller than the diameter of the other lead wire passing hole 11b, 12b. For example, the diameter Rb of the third lead wire passing hole 13b may be larger than the diameter of the first lead wire passing hole 11b but may be the same as or smaller than the diameter of the second lead wire passing hole 12b. Even in this case, the positional change of the lead wire 14b inside the third lead wire passing hole 13b is limited by the first lead wire passing hole 11b.

[0033] The third lead wire passing hole 13b may have a rectangular shape, for example. In this case, the width of one side of the inner edge of the third lead wire passing hole 13b may be larger than the width of one side of the inner edge of the lead wire passing holes 11b and 12b.

[0034] The diameter of the lead wire passing holes 11b and 12b formed in the thermal insulating layers 11 and 12 may correspond to the thickness of the lead wire 14b. In other words, the thermal insulating layers 11 and 12 may be in contact with the lead wire 14b at the inner surfaces of the lead wire passing holes 11b and 12b. This more effectively prevents the position of the lead wire 14b from changing inside the third lead wire passing hole 13b.

[0035] The diameter of the first lead wire passing hole 11b and the diameter of the second lead wire passing hole 12b may be different from each other. For example, the diameter of the first lead wire passing hole 11b may correspond to the thickness of the lead wire 14b, and the inner surface of the first lead wire passing hole 11b may be in contact with the lead wire 14b, while the diameter of the second lead wire passing hole 12b may be larger than the thickness of the lead wire 14b (in this case, the diameter of the first lead wire passing hole 11b). This facilitates the task of passing the lead wire 14b through the second lead wire passing hole 12b. The size relationship between the lead wire passing holes 11b and 12b may be reversed from that described here.

[0036] The distance from the inner edge of the lead wire passing holes 11b and 12b to the inner edge of the third lead wire passing hole 13b is preferably 3 mm or more. This distance is more preferably 5 mm or more. This effectively prevents contact between the lead wire 14b and the reflective layer 13.

[0037] [Sensor Passage Hole] As shown in FIG. 2, the jacket heater 10 has a sensor 19. The sensor 19 has a temperature-sensing part 19A. Specifically, the sensor 19 is a thermocouple. In this case, the temperature-sensing part 19A has two wires (not shown) made of different materials inside it. The temperature-sensing part 19A holds the two wires in an insulated state. The temperature-sensing part 19A has a sheath made of metal on its surface, and the wires may be arranged inside the sheath. The number of wires that the temperature-sensing part 19A has may be more than two.

[0038] The tip 19e of the temperature sensing part 19A is located inside the first insulating layer 11. The tip 19e of the temperature sensing part 19A may be exposed inside the inner skin 16 and in direct contact with the outer surface of the pipe 90. The sensor 19 has a lead wire 19b, and may be connected to an external device (e.g., a control device that controls the current supplied to the heater wire 14) via the lead wire 19b.

[0039] As shown in FIG. 2 , a first sensor passing hole 11a is formed in the first insulating layer 11. A second sensor passing hole 12a is formed in the second insulating layer 12. A third sensor passing hole 13a is formed in the reflective layer 13. The sensor passing holes 11a, 12a, and 13a penetrate the insulating layers 11 and 12 and the reflective layer 13 in their thickness directions. The positions of the first, second, and third sensor passing holes 11a, 12a, and 13a in the longitudinal and circumferential directions of the piping 90 may be substantially the same. That is, when the jacket heater 10 is viewed in the thickness direction, the first sensor passing hole 11a may overlap a portion of the second sensor passing hole 12a and a portion of the third sensor passing hole 13a. As a result, the first, second, and third sensor passing holes 11a, 12a, and 13a may form a single passing hole extending in the thickness direction of the jacket heater 10.

[0040] 2, the sensor 19 extends from the tip 19e of the temperature sensing part 19A located inside the first insulating layer 11, passing through the first sensor passing hole 11a, the third sensor passing hole 13a, and the second sensor passing hole 12a in this order, to the outside of the second insulating layer 12. Note that a passing hole for the sensor 19 to pass through may also be formed in a member located inside the first insulating layer 11, such as the inner skin 16.

[0041] 2, the temperature sensing portion 19A may have a first portion 19g located inside the inner skin 16, a second portion 19h located inside the sensor passing holes 11a, 12a, and 13a, and a third portion 19i located outside the second insulating layer 12. The second portion 19h may be bent relative to the first portion 19g, and the third portion 19i may be bent relative to the second portion 19h. The third portion 19i may extend in the longitudinal direction or circumferential direction of the pipe 90 between the second insulating layer 12 and the outer skin 17. The temperature sensing portion 19A may be flexible to allow such bending.

[0042] As shown in Fig. 2, the temperature sensing portion 19A and the lead wire 19b may be connected to each other at a position outside the second insulating layer 12. The lead wire 19b may extend to the outside of the jacket heater 10 from an opening 17a formed in the outer skin 17. In the example shown in Fig. 2, the lead wire 19b and the lead wire 14b extending from the heater wire 14 extend to the outside of the jacket heater 10 from a common opening 17a. However, the lead wire 19b and the lead wire 14b may also extend to the outside of the jacket heater 10 from separate openings.

[0043] 2, the entire temperature sensing portion 19A may be disposed inside the first insulating layer 11. In this case, lead wires 19b may be passed through the sensor passing holes 11a, 12a, and 13a.

[0044] The size of the third sensor passing hole 13a is larger than the sizes of the first and second sensor passing holes 11a and 12a. Specifically, as shown in FIG. 2, the diameter Ra of the third sensor passing hole 13a is larger than the diameters of the first and second sensor passing holes 11a and 12a. This limits the positional change of the sensor 19 inside the third sensor passing hole 13a by the sensor passing holes 11a and 12a. As a result, contact between the sensor 19 and the reflective layer 13 is suppressed. In this way, even if the reflective layer 13 becomes charged, the electricity can be prevented from flowing into the piping 90 via the sensor 19.

[0045] Here, the size of the sensor passing holes 11a, 12a, and 13a may be the diameter of the passing hole if they are circular, or the width of one side of the inner edge of the passing hole if they are rectangular.

[0046] The distance from the inner edge of the passage holes 11 a and 12 a to the inner edge of the third sensor passage hole 13 a is preferably 3 mm or more. It is even more preferable to ensure this distance is 5 mm or more. This effectively prevents contact between the sensor 19 and the reflective layer 13.

[0047] 2, the diameter Ra of the third sensor passing hole 13a may be larger than the diameter of one of the first and second sensor passing holes 11a and 12a but may be the same as or smaller than the diameter of the other of the first and second sensor passing holes 11a and 12a. For example, the diameter Ra of the third sensor passing hole 13a may be larger than the diameter of the first sensor passing hole 11a but may be the same as or smaller than the diameter of the second sensor passing hole 12a. Even in this case, the positional change of the sensor 19 inside the third sensor passing hole 13a can be limited by the first sensor passing hole 11a.

[0048] Third sensor passing hole 13a may have a rectangular shape, for example. In this case, the width of one side of the inner edge of third sensor passing hole 13a may be larger than the width of one side of the inner edge of sensor passing holes 11a and 12a.

[0049] The diameter of the sensor passing holes 11a and 12a formed in the insulating layers 11 and 12 may correspond to the thickness of the sensor 19. That is, the insulating layers 11 and 12 may be in contact with the sensor 19 (e.g., the temperature sensing portion 19A) at the inner surfaces of the sensor passing holes 11a and 12a. This more effectively suppresses the positional change of the sensor 19 inside the third sensor passing hole 13a.

[0050] The diameter of the first sensor passing hole 11a and the diameter of the second sensor passing hole 12a may be different from each other. For example, the diameter of the first sensor passing hole 11a may correspond to the thickness of the sensor 19 (e.g., the temperature sensing portion 19A), and the inner surface of the first sensor passing hole 11a may be in contact with the sensor 19, while the diameter of the second sensor passing hole 12a may be larger than the thickness of the sensor 19 (in this case, the diameter of the first sensor passing hole 11a). This facilitates the task of passing the sensor 19 through the second sensor passing hole 12a. The size relationship between the sensor passing holes 11a and 12a may be reversed from that described here.

[0051] 2 , the third sensor passing hole 13a may be formed inside the outer peripheral edge of the reflective layer 13. That is, the inner edge of the third sensor passing hole 13a may be annular and surround the periphery of the sensor 19. Similarly, the first and second sensor passing holes 11a and 12a may be formed inside the outer peripheral edges of the heat insulating layers 11 and 12.

[0052] 2, the third sensor passing hole 13a may be a recess formed in the outer peripheral edge of the reflective layer 13. Similarly, the first and second sensor passing holes 11a and 12a may be recesses formed in the outer peripheral edges of the thermal insulating layers 11 and 12. The positions of these recesses in the longitudinal and circumferential directions of the pipe 90 may be substantially the same.

[0053] [Stitching of Reflective Layer and Heat Insulating Layer] The heat insulating layers 11 and 12 and the reflective layer 13 may be sewn together with heat resistant thread. Examples of heat resistant threads that may be used include glass yarn, silica yarn, alumina yarn, and those coated with fluororesin.

[0054] 3A and 3B, the third sensor passing hole 13a may be surrounded by a thread 31a. That is, the reflective layer 13 and the first insulating layer 11 may be sewn together by the thread 31a surrounding the third sensor passing hole 13a. This effectively prevents misalignment between the third sensor passing hole 13a and the first sensor passing hole 11a. As a result, contact between the sensor 19 and the reflective layer 13 is more effectively prevented.

[0055] As shown in Fig. 3A, the thread 31a may include a portion located inside the inner edge of the third sensor passing hole 13a and a portion located outside the inner edge of the third sensor passing hole 13a. Alternatively, as shown in Fig. 3B, the entire thread 31a surrounding the third sensor passing hole 13a may be located only outside the inner edge of the third sensor passing hole 13a.

[0056] 3A and 3B , the periphery of the third lead wire passing hole 13 b, through which the lead wire 14 b of the heater wire 14 passes, may also be sewn together with thread 31 a. That is, the reflective layer 13 and the first heat insulating layer 11 may be sewn together with the thread 31 a surrounding the third lead wire passing hole 13 b.

[0057] The reflective layer 13 may also be sewn to the first insulating layer 11 with heat-resistant thread at other positions. The stitching may be provided along the outer periphery of the reflective layer 13 so as to surround the entire reflective layer 13, or may be provided only at a plurality of positions inside the outer periphery of the reflective layer 13. The second insulating layer 12 may also be sewn to the first insulating layer 11 and the reflective layer 13 with thread. Furthermore, to increase the strength of the stitching, the first insulating layer 11 and the reflective layer 13 may also be sewn to the heater wire substrate 18 to which the heater wire 14 is sewn, or to the inner skin 16 with thread.

[0058] [Common Passage Hole] The structures of the lead wire passing holes 11b to 13b and the sensor passing holes 11a to 13a are not limited to the examples shown in FIG. 2 and the like.

[0059] FIG. 4 shows a modified example of the passing hole. In the example shown in this figure, a lead wire passing hole 13c is formed in the reflective layer 13. When the jacket heater 10 is viewed from above (when the passing hole 13c is viewed in the radial direction of the piping 90), the sensor passing holes 11a and 12a and the lead wire passing holes 11b and 12b are located inside the lead wire passing hole 13c. Therefore, the lead wire 14b of the heater wire 14 passes through the lead wire passing holes 11b and 12b and the lead wire passing hole 13c and extends to the outside of the insulating layer 12. Furthermore, the sensor 19 passes through the sensor passing holes 11a and 12a and the lead wire passing hole 13c and extends to the outside of the insulating layer 12. This structure allows for a reduction in the number of passing holes formed in the reflective layer 13. As a result, the number of manufacturing steps for the reflective layer 13 can be reduced.

[0060] The size of the lead wire passing hole 13c is larger than the sizes of the sensor passing holes 11a and 12a and the lead wire passing holes 11b and 12b. For example, it is desirable to ensure a distance of 3 mm or more from the inner edge of the lead wire passing hole 13c to the inner edges of the passing holes 11a, 12a, 11b, and 12b. This distance may preferably be 5 mm or more. This reduces contact between the lead wire 14b and the reflective layer 13. Even if the outer covering of the lead wire 14b is torn, for example, electricity can flow from the lead wire 14b to the reflective layer 13, preventing the reflective layer 13 from becoming charged. Furthermore, contact between the sensor 19 and the reflective layer 13 is reduced. This prevents the electricity from flowing to the piping 90 via the sensor 19, even if the reflective layer 13 becomes charged.

[0061] 2, the jacket heater 10 may have a thermostat 21. The thermostat 21 may be connected to the heater wire 14 via lead wires (not shown), or may be connected to an external power source (a control device that supplies current to the heater wire 14). The thermostat 21 turns off when it detects an excessive temperature rise in the heater wire 14, and stops the current to the heater wire 14.

[0062] As shown in FIG. 2 , a housing chamber 12d for housing a thermostat 21 may be formed in the second insulating layer 12. The thermostat 21 may be disposed outside the reflective layer 13. With this arrangement of the thermostat 21, the temperature of the thermostat 21 is lower than the temperature of the inner surface of the jacket heater 10 where the heater wire 14 is disposed and the temperature of the piping 90. As a result, even if the output of the jacket heater 10 needs to be increased to raise the temperature of the piping 90, a small thermostat with a low operating temperature (temperature at which current is cut off) can be used as the thermostat 21 to prevent the jacket heater 10 from overheating. For example, if the temperature of the piping rises to 300°C due to heating by the jacket heater, a large thermostat with an operating temperature set to 300°C or higher is usually required. However, in the jacket heater 10 proposed in the present disclosure, the thermostat 21 is disposed outside the reflective layer 13, and therefore the temperature around the thermostat 21 does not reach 300° C. Therefore, a thermostat with an operating temperature lower than 300° C. (for example, a small thermostat with an operating temperature of about 200° C.) can be used as the thermostat 21, and the pipe 90 can be heated to a temperature sufficiently higher than the operating temperature (300° C. in the example described here).

[0063] Unlike the example shown in FIG. 2, the thermostat 21 may be disposed inside the reflective layer 13 .

[0064] [Method of Manufacturing Jacket Heater] An example of a method of manufacturing the jacket heater 10 will be described. An operator prepares a first insulating layer 11 and a second insulating layer 12. The operator forms a first lead wire passing hole 11b and a first sensor passing hole 11a in the first insulating layer 11, and forms a second lead wire passing hole 12b and a second sensor passing hole 12a in the second insulating layer 12. The operator also prepares a reflective layer 13 and forms a third lead wire passing hole 13b and a third sensor passing hole 13a in it. At this time, a lead wire passing hole 13c may be formed in the reflective layer 13, as shown in FIG. 4 .

[0065] The worker sews the first insulating layer 11, the reflective layer 13, and the second insulating layer 12 together with heat-resistant thread 31a. At this time, the worker may sew the first insulating layer 11 and the reflective layer 13 together, and then sew the second insulating layer 12 to the first insulating layer 11 and the reflective layer 13. As another example, the worker may sew the first insulating layer 11, the reflective layer 13, and the second insulating layer 12 together. The worker also sews the heater wire 14 to the heater wire substrate 18. At this time, the worker may sew the insulating layer 15 to the heater wire 14 and the heater wire substrate 18.

[0066] Next, the worker passes the lead wire 14b of the heater wire 14 through the lead wire passing holes 11b, 12b, and 13b and pulls it out to the outside of the second insulating layer 12. Next, the worker covers the inside of the heater wire 14, the insulating layer 15, and the heater wire substrate 18 with the inner cover 16. Then, the worker passes the sensor 19 through holes formed in the inner cover 16, the insulating layer 15, and the heater wire substrate 18, and further through the sensor passing holes 11a, 13a, and 12a, pulling it out to the outside of the second insulating layer 12. Next, the worker covers the outside of the second insulating layer 12 with the outer cover 17 and pulls the lead wires 14b and 19b out to the outside of the jacket heater 10 through the opening 17a formed in the outer cover 17. Then, the worker sews the inner cover 16 and the outer cover 17 together, and houses the heater wire 14, the first insulating layer 11, and the like inside them.

[0067] [Summary] (1) The jacket heater 10 has a first insulating layer 11, a reflective layer 13 disposed outside the first insulating layer 11, a second insulating layer 12 disposed outside the reflective layer 13, and a heater wire 14 disposed inside the first insulating layer 11. Because the jacket heater 10 has the reflective layer 13, it can sufficiently heat the piping 90 while reducing power consumption. In addition, because the second insulating layer 12 is disposed outside the reflective layer 13, the outer surface of the jacket heater 10 can be cooled to an appropriate temperature. As a result, workability around the jacket heater 10 can be improved.

[0068] (2) In the structure of (1), a lead wire 14b may be connected to the heater wire 14. A first lead wire passing hole 11b may be formed in the first insulating layer 11, a second lead wire passing hole 12b may be formed in the second insulating layer 12, and a third lead wire passing hole 13b (or passing hole 13c, FIG. 4) may be formed in the reflective layer 13. The lead wire 14b may pass through the first lead wire passing hole 11b, the third lead wire passing hole 13b (or passing hole 13c), and the second lead wire passing hole 12b and extend to the outside of the second insulating layer 12. The size of the third lead wire passing hole 13b (or passing hole 13c) may be larger than the size of at least one of the first lead wire passing hole 11b and the second lead wire passing hole 12b. This structure prevents the lead wire 14b connected to the heater wire 14 from coming into contact with the conductive reflective layer 13. As a result, charging of the reflective layer 13 can be prevented.

[0069] (3) In the structure of (1) or (2), the jacket heater 10 may have a sensor 19 having a temperature-sensing portion 19A with at least a tip portion 19e located inside the first insulating layer 11. A fourth sensor passing hole may be formed in the first insulating layer 11, a second sensor passing hole 12a may be formed in the second insulating layer 12, and a third sensor passing hole 13a (or passing hole 13c, FIG. 4) may be formed in the reflective layer 13. The sensor 19 may extend from the tip portion 19e through the first sensor passing hole 11a, the third sensor passing hole 13a (or passing hole 13c), and the second sensor passing hole 12a to the outside of the second insulating layer 12. The size of the third sensor passing hole 13a (or passing hole 13c) may be larger than the size of at least one of the first sensor passing hole 11a and the second sensor passing hole 12a. This structure prevents the sensor 19 from coming into contact with the conductive reflective layer 13. As a result, even if the reflective layer 13 becomes charged, the electricity is prevented from flowing through the sensor 19 to the piping.

[0070] (4) In the structure of (2), the jacket heater 10 may have a sensor 19 having a temperature-sensing part 19A with at least a tip portion 19e located inside the first insulating layer 11. A first sensor passing hole 11a may be formed in the first insulating layer 11, and a second sensor passing hole 12a may be formed in the second insulating layer 12. The sensor 19 may extend from the tip portion 19e through the first sensor passing hole 11a, the lead wire passing hole 13c (see FIG. 4), and the second sensor passing hole 12a to the outside of the second insulating layer 12. With this structure, the sensor 19 and the lead wire 14b pass through the same passing hole 13c, thereby reducing the number of passing holes formed in the reflective layer 13. As a result, the number of manufacturing steps for the reflective layer 13 can be reduced.

[0071] (5) In the structure of (2), the size of at least one of the first lead wire passing hole 11 b and the second lead wire passing hole 12 b may correspond to the thickness of the lead wire 14 b. This structure more effectively prevents the positional change of the lead wire 14 b inside the third lead wire passing hole 13 b. As a result, contact between the reflective layer 13 and the lead wire 14 b is more effectively prevented.

[0072] (6) In the structure of (3), the size of at least one of the first sensor passing hole 11 a and the second sensor passing hole 12 a may correspond to the thickness of the sensor 19. This structure more effectively prevents the position of the sensor 19 from changing inside the third sensor passing hole 13 a. As a result, contact between the reflective layer 13 and the sensor 19 is more effectively prevented.

[0073] (7) In the structure of (2) or (5), the first insulating layer 11 and the reflective layer 13 may be sewn together with a heat-resistant thread 31a (FIGS. 3A and 3B). The thread 31a may surround the periphery of the third lead wire passing hole 13b. This structure reduces misalignment between the third lead wire passing hole 13b and the lead wire passing holes 11b and 12b. As a result, contact between the reflective layer 13 and the lead wire 14b is more effectively reduced.

[0074] (8) In the structure of (3) or (6), the first insulating layer 11 and the reflective layer 13 may be sewn together with heat-resistant thread 31a (FIGS. 3A and 3B). The thread 31a surrounds the periphery of the third sensor passing hole 13a. This structure reduces misalignment of the third sensor passing hole 13a relative to the sensor passing holes 11a and 12a. As a result, contact between the reflective layer 13 and the lead wire 14b is more effectively reduced.

[0075] (9) A manufacturing method of a jacket heater 10 for attachment to the outer periphery of a pipe 90 includes a step of sewing together a first insulating layer 11 for covering the heater wire 14, a reflective layer 13 covering the outside of the first insulating layer 11, and a second insulating layer 12 covering the outside of the reflective layer 13, and a step of sewing the heater wire 14 to the first insulating layer 11.

[0076] (10) The thermal insulation structure to be attached to the outer periphery of the pipe 90 includes a first thermal insulation layer 11, a reflective layer 13 disposed outside the first thermal insulation layer 11, a second thermal insulation layer 12 disposed outside the reflective layer 13, and a heater wire 14 disposed inside the first thermal insulation layer 11.

[0077] The jacket heater proposed in the present disclosure is not limited to the above-described example, and various modifications may be made. For example, the jacket heater may have multiple thermal insulation structures, each of which may include a first thermal insulation layer 11, a reflective layer 13, and a second thermal insulation layer 12.

Claims

1. A jacket heater for mounting on the outer periphery of a pipe, A first insulation layer; A reflective layer disposed on the outer side of the first thermal insulation layer; A second heat insulating layer disposed on the outer side of the reflective layer; A heater wire disposed inside the first insulating layer; Possesses Jacket heater.

2. A lead wire is connected to the heater wire, A first lead wire passage hole is formed in the first heat insulating layer, A second lead wire passage hole is formed in the second heat insulating layer, a third lead wire passage hole is formed in the reflective layer; The reflective layer is electrically conductive, the lead wire passes through the first lead wire passing hole, the third lead wire passing hole, and the second lead wire passing hole, and extends to the outside of the second insulating layer, The size of the third lead wire passing hole is larger than the size of at least one of the first lead wire passing hole and the second lead wire passing hole.

2. The jacket heater according to claim 1.

3. a sensor having a temperature sensing part whose tip is located inside the first insulating layer; a first sensor passage hole is formed in the first heat insulating layer; a second sensor passage hole is formed in the second heat insulating layer; a third sensor passing hole is formed in the reflective layer; The reflective layer is electrically conductive, the sensor extends from the tip portion through the first sensor passing hole, the third sensor passing hole, and the second sensor passing hole to an outside of the second insulating layer; The third sensor passing hole has a size larger than at least one of the first sensor passing hole and the second sensor passing hole.

3. A jacket heater according to claim 1 or 2.

4. a sensor having a temperature sensing part whose tip is located inside the first insulating layer; a first sensor passage hole is formed in the first heat insulating layer; a second sensor passage hole is formed in the second heat insulating layer; The sensor extends from the tip portion through the first sensor passing hole, the third lead wire passing hole, and the second sensor passing hole to the outside of the second insulating layer.

3. The jacket heater according to claim 2.

5. The size of at least one of the first lead wire passing hole and the second lead wire passing hole corresponds to the thickness of the lead wire.

3. The jacket heater according to claim 2.

6. The size of at least one of the first sensor passing hole and the second sensor passing hole corresponds to the thickness of the sensor.

4. The jacket heater according to claim 3.

7. The first heat insulating layer and the reflective layer are sewn together with a heat resistant thread; The thread surrounds the third lead wire passing hole.

6. A jacket heater according to claim 2 or 5.

8. The first heat insulating layer and the reflective layer are sewn together with a heat resistant thread; The thread surrounds the third sensor passage hole.

4. The jacket heater according to claim 3.

9. A method for manufacturing a jacket heater for mounting on an outer periphery of a pipe, comprising the steps of: A step of sewing together a first insulating layer for covering the heater wire, a reflective layer covering the outside of the first insulating layer, and a second insulating layer covering the outside of the reflective layer; Stitching the heater wire to the first insulating layer Includes A manufacturing method for a jacket heater.

10. A thermal insulation structure for mounting on an outer periphery of a pipe, A first insulation layer; A reflective layer disposed on the outer side of the first thermal insulation layer; A second heat insulating layer disposed on the outer side of the reflective layer; A heater wire disposed inside the first insulating layer; An insulating structure having the above structure.