Jacketed heater, method for manufacturing jacketed heater, and heat-insulating structure

Abstract

A jacket heater (10) is provided with: a heating wire (14); an inner heat insulating layer (11) disposed on the outer side of the heater wire (14); an outer heat insulating layer (12) disposed on the outer side of the inner heat insulating layer (11); and a thermostat (21) disposed on the outer side of the inner heat insulating layer (11). Thus, even if the output of the jacketed heater must be increased in order to seek to increase the temperature of the piping, a small-sized thermostat having a low operating temperature (temperature at which the current interrupting the heating wire is present) can be used in the jacketed heater.

Description

Technical Field

[0001] The present invention relates to a jacket heater covered on a pipe, a method for manufacturing the jacket heater, and a heat insulation structure. Background Art

[0002] To prevent gas condensation and precipitation within piping, jacket heaters are sometimes used to cover the piping. For example, various gases are used in film formation and etching steps during semiconductor device manufacturing. To prevent these gases from condensing and precipitating within the piping, jacket heaters are sometimes used. Patent Document 1 discloses an example of such a jacket heater.

[0003] Prior art literature

[0004] Patent Document 1: International Publication No. 2011 / 126051 Summary of the Invention

[0005] Problems to be solved by the invention

[0006] To prevent excessive heating of the heating wires in jacket heaters, thermostats are sometimes used. To raise the temperature of the piping, a thermostat with a higher operating temperature (the temperature at which the current to the heating wires is interrupted) is required. However, thermostats with higher operating temperatures are generally larger. This can lead to difficulties in attaching the thermostat to the jacket heater or attaching the jacket heater to the piping.

[0007] Means of solving problems

[0008] The jacket heater proposed in this disclosure is a jacket heater that covers the outer circumference of a pipe. The jacket heater comprises: a heating wire; a first thermal insulation layer disposed outside the heating wire; a second thermal insulation layer disposed outside the first thermal insulation layer; and a thermostat disposed outside the first thermal insulation layer. This jacket heater allows the temperature of the thermostat to be lower than the inner circumference of the jacket heater, where the heating wire is disposed. As a result, even when the jacket heater's output needs to be increased to raise the pipe temperature, a compact thermostat with a low operating temperature (the temperature at which the current to the heating wire is interrupted) can be used in the jacket heater.

[0009] The jacket heater manufacturing method proposed in this disclosure includes the steps of covering a heating wire with a first insulating layer; covering the outer side of the first insulating layer with a second insulating layer; and placing a thermostat outside the first insulating layer. The jacket heater manufactured using this manufacturing method can maintain a thermostat temperature lower than the inner periphery of the jacket heater where the heating wire is located. As a result, even when the jacket heater's output needs to be increased to raise the temperature of the piping, a compact thermostat with a relatively low operating temperature can be used in the jacket heater.

[0010] The thermal insulation structure proposed in this disclosure is designed to be installed around the outer periphery of a pipe. The structure comprises a heater wire; a first insulation layer disposed outside the heater wire; a second insulation layer disposed outside the first insulation layer; and a thermostat disposed outside the first insulation layer. This insulation structure allows the temperature of the thermostat to be lower than the inner periphery of the insulation structure where the heater wire is disposed. As a result, even when the output of the jacket heater is increased to raise the pipe temperature, a compact thermostat with a lower operating temperature can be used within the jacket heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a cross-sectional view showing a state in which the jacket heater proposed in the present disclosure is mounted on a pipe, and the cross-sectional surface is a plane perpendicular to the pipe.

[0012] Figure 2 For the Figure 1 The cross-sectional view of the jacketed heater obtained by cutting along the line segment II-II is shown.

[0013] Figure 3 It is a perspective view showing a modified example of the inner heat-insulating layer and the outer heat-insulating layer.

[0014] Figure 4 It is a cross-sectional view showing a modified example of the heat transfer layer.

[0015] Figure 5 It is a cross-sectional view showing another modified example of the heat transfer layer.

[0016] Figure 6 This is an expanded view of a jacket heater used to illustrate the configuration of a thermostat. DETAILED DESCRIPTION

[0017] The following describes the jacket heater proposed in this disclosure. Figure 1 The jacket heater 10 shown in FIG. 1 is used as an example for explanation.

[0018] The jacket heater 10 covers the pipe 90. The jacket heater 10 heats the pipe 90 to prevent the gas flowing through the pipe 90 from condensing or precipitating.

[0019] like Figure 1 and Figure 2 As shown in FIG. 1 , the jacket heater 10 includes a heating wire 14 and a heating wire substrate 18 to which the heating wire 14 is attached. The heating wire 14 is, for example, a nickel-chromium metal resistor. As the heating wire substrate 18, for example, an inorganic fiber cloth composed of inorganic fibers such as glass fiber, silica fiber, alumina fiber, and silica-alumina fiber can be used. The heating wire 14 is sewn to the heating wire substrate 18. The heating wire 14 is connected to the heating wire substrate 18 via a conductive wire 14b (see FIG. 1 ). Figure 6 ) is connected to an external power supply.

[0020] like Figure 1 As shown, the jacket heater 10 includes an inner insulation layer 11 (first insulation layer) and an outer insulation layer 12 (second insulation layer). The inner insulation layer 11 is disposed outside of and covers the heater wires 14 and heater wire substrate 18. The outer insulation layer 12 is disposed further outside of and covers the inner insulation layer 11.

[0021] The inner and outer insulation layers 11, 12 are formed, for example, from inorganic fiber insulation layers. Examples of inorganic fibers include glass fiber, ceramic fiber, and silica fiber. Furthermore, the inner and outer insulation layers 11, 12 may be made of inorganic or organic insulation materials, such as polyimide and silica, that have voids with an average void width of a certain value or less (e.g., voids with an average void width less than the mean free path of air molecules). The material of the inner and outer insulation layers 11, 12 may be the same or different.

[0022] The inner heat-insulating layer 11 may be a single-layer structure or a stacked-layer structure. Figure 3 A modified example of the inner thermal insulation layer 11 is shown. In the figure, the inner thermal insulation layer 11 includes a first layer 11A and a second layer 11B. The number of layers constituting the inner thermal insulation layer 11 may be greater than two. Similarly, the outer thermal insulation layer 12 may be a single layer or a stacked multilayer structure. When each thermal insulation layer 11 or 12 is a multilayer structure, the materials of the multiple layers may be the same or different.

[0023] The jacket heater 10 also includes a heat transfer layer 13 disposed between the inner insulation layer 11 and the outer insulation layer 12. The heat transfer layer 13 is formed from a material having a higher thermal conductivity than the inner insulation layer 11 and the outer insulation layer 12. This heat transfer layer 13 allows heat emitted from the pipe 90 and the heater wire 14 to be conducted to an area away from the thermostat 21, described later, thereby suppressing a local temperature rise at the location of the thermostat 21. The heat transfer layer 13 may be, for example, a metal layer. In this case, the electromagnetic waves that cause heat radiation are reflected by the heat transfer layer 13. As a result, the jacket heater 10 can efficiently heat the pipe 90. Furthermore, since the outer insulation layer 12 is located outside the heat transfer layer 13 (metal layer), 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.

[0024] The heat transfer layer 13 is preferably made of a material having high thermal conductivity and flexibility. If such a material is used, the local temperature rise at the location of the thermostat 21 can be effectively suppressed. Furthermore, the heat transfer layer 13 is preferably made of a material having high reflectivity for infrared rays and being flexible. As an example of the material of the above-mentioned heat transfer layer 13, aluminum can be cited. The material of the heat transfer layer 13 can also be other metals such as copper and stainless steel. Here, the material of the heat transfer layer 13 is not limited to metal. For example, the heat transfer layer 13 can also be carbon graphite. Even in this case, the heat emitted from the piping 90 and the heating wire 14 can be conducted to an area away from the thermostat 21, thereby suppressing the local temperature rise at the location of the thermostat 21.

[0025] The heat transfer layer 13 is, for example, a metal foil having a thickness of 10 to 700 μm. This thickness maintains the flexibility of the heat transfer layer 13 and prevents accidental damage. The thickness of the heat transfer layer 13 is preferably 10 to 200 μm. This thickness maintains the flexibility of the heat transfer layer 13 and prevents accidental damage.

[0026] like Figure 1 As shown, the heat transfer layer 13 can be formed substantially around the entire circumference of the pipe 90. That is, the heat transfer layer 13 can surround the pipe 90 substantially 360 degrees. Furthermore, the heat transfer layer 13 can be provided substantially throughout the entire length of the pipe 90. As will be described later, the heat transfer layer 13 can also be provided only on a portion of the jacket heater 10.

[0027] like Figure 1 As shown, the jacket heater 10 has an inner skin layer 16, which covers the inner side of the heater wire substrate 18. An insulating layer 15 may also be arranged between the inner skin layer 16 and the heater wire substrate 18 to reliably insulate the heater wire 14 from the piping. The jacket heater 10 has an outer skin layer 17 covering the outer side of the outer insulation layer 12. For example, heat-resistant sheets (including cloth) can be used for the outer skin layer 17 and the inner skin layer 16. The material of the outer skin layer 17 and the inner skin layer 16 can be the same or different. For example, porous sheets, inorganic fiber sheets, resin sheets, etc. can be used for the outer skin layer 17 and the inner skin layer 16. Examples of porous sheets include PTFE (polytetrafluoroethylene) sheets. Examples of inorganic fiber sheets include glass fiber cloth. Examples of resin sheets include fluororesin sheets. Inorganic fiber sheets can also be coated with silicone, fluorine, etc.

[0028] The jacket heater 10 is flexible. Specifically, the thermal insulation layers 11 and 12, the heat transfer layer 13, the outer skin layer 17, the inner skin layer 16, the heater wire 14, and the heater wire base material 18 that constitute the jacket heater 10 are all flexible. During this construction step, the jacket heater 10 is wrapped around the outside of the pipe 90 to form a cylindrical shape.

[0029] The jacket heater 10 has a fixing member that fixes the jacket heater 10 in a state where the jacket heater 10 is wound around the pipe 90. The jacket heater 10 has, for example, a first edge portion 10a (see FIG. Figure 6 ) are arranged as a fixing member. The hook and loop fastener 22 can be installed on the outer surface of the jacket heater 10. The hook and loop fastener 22 can also be sewn to the jacket heater 10. The hook and loop fastener 22 is installed to the second edge 10b (the edge on the opposite side of the first edge 10a, see the reference) of the jacket heater 10 when the jacket heater 10 is wrapped around the pipe 90. Figure 6 Here, the fixing member is not limited to the hook and loop fastener 22. The fixing member may be composed of, for example, a hook, or may include a tape wrapped around the outside of the jacket heater 10.

[0030] like Figure 1 and Figure 2 As shown, the jacket heater 10 includes a thermostat 21. A lead wire 21a is connected to the thermostat 21. The thermostat 21 can be connected to the heater wire 14 via the lead wire 21a. If the temperature of the jacket heater 10 exceeds a predetermined operating temperature due to, for example, excessive current flowing through the heater wire 14, the thermostat 21 is turned off, stopping the flow of current to the heater wire 14. The thermostat 21 can also be connected to a power source that supplies current to the heater wire 14 via the lead wire 21a.

[0031] like Figure 1 and Figure 2 As shown, the thermostat 21 is arranged outside the inner heat insulating layer 11. Therefore, the temperature of the thermostat 21 is lower than the inner surface of the jacket heater 10 on which the heater wire 14 is arranged and lower than the temperature of the pipe 90. As a result, even in a case where the output of the jacket heater 10 must be increased to increase the temperature of the pipe 90, a small thermostat 21 with a low operating temperature (the temperature at which the current to the heater wire is cut off) can be used in the jacket heater 10. For example, when the temperature of the pipe is to be raised to 300°C by heating the jacket heater, a large thermostat with an operating temperature (the temperature at which the current is cut off) set to 300°C or above is generally required. However, in the jacket heater 10 proposed in the present disclosure, since the thermostat 21 is arranged outside the inner heat insulating layer 11, the peripheral temperature of the thermostat 21 does not reach 300°C. Therefore, the thermostat 21 can use a thermostat with an operating temperature lower than 300°C (for example, a small thermostat with an operating temperature of about 200°C), and the pipe 90 can be heated to a temperature much higher than its operating temperature (300°C in the example described here).

[0032] like Figure 1 and Figure 2As shown, the thermostat 21 can be positioned between the inner insulation layer 11 and the outer insulation layer 12. Specifically, a portion of the outer insulation layer 12 can be positioned outside the thermostat 21 (on the outer skin 17 side of the thermostat 21). This reduces the effect of the outside air temperature on the thermostat 21. For example, when the outside air temperature is low, this can prevent the thermostat 21 from failing to operate even when the temperature of the heater wire 14 exceeds the preset temperature.

[0033] like Figure 1 and Figure 2 As shown, a recessed portion can be formed on the inner surface of the outer heat-insulating layer 12 as a receiving chamber 12a. The thermostat 21 can be arranged on the inner side of this receiving chamber 12a. With this structure, the unevenness of the outer surface of the jacket heater 10 caused by the thermostat 21 can be reduced. The outer heat-insulating layer 12 can be partially cut away at the position of the receiving chamber 12a. As described above, the outer heat-insulating layer 12 can be composed of multiple layers. In this case, a hole penetrating the layer can be formed on a part of the layer so that the hole functions as the receiving chamber 12a. For example, the outer heat-insulating layer 12 can be composed of a first layer and a second layer arranged on the outer side of the first layer. In this case, a hole penetrating the first layer can be formed on the first layer so that the hole functions as the receiving chamber 12a. The second layer can cover the outer side of the thermostat 21.

[0034] In addition, if Figure 3 As shown in the modified example of the outer insulation layer 12 in FIG, a hole 12b can be formed in the outer insulation layer 12, penetrating the outer insulation layer 12 along its thickness. This hole 12b can also function as a housing 12a for accommodating the thermostat 21 inside. In this case, the thermostat 21 can be located between the inner insulation layer 11 (and the heat transfer layer 13) and the outer skin layer 17. The thermostat 21 can be exposed to the outside of the outer insulation layer 12, and the lead wire 21a can be arranged along the outer circumference of the outer insulation layer 12.

[0035] The thickness of the inner heat insulating layer 11 can also be set according to the temperature difference between the operating temperature of the thermostat 21 and the required temperature of the pipe 90. That is, the greater the temperature difference, the thicker the inner heat insulating layer 11 can be set.

[0036] The thickness of inner heat-insulating layer 11 can be the same as or smaller than that of outer heat-insulating layer 12. This structure reduces the distance from pipe 90 and heater wire 14 to heat-conductive layer 13, thereby reducing the space inside heat-conductive layer 13. As a result, the generated heat is retained in a narrow space, efficiently maintaining the temperature of pipe 90. Heat-conductive layer 13 is preferably made of a material with high infrared reflectivity.

[0037] The thickness of the inner insulation layer 11 can be, for example, 5 mm to 100 mm. The thickness of the outer insulation layer 12 can also be 5 mm to 100 mm. With such a thickness, the space required for installing the jacket heater 10 can be reduced while ensuring thermal insulation performance. The thickness of the inner insulation layer 11 is preferably 5 mm to 50 mm. With such a thickness, the space required for installing the jacket heater 10 can be further reduced. The thickness of the inner insulation layer 11 is more preferably 8 mm to 30 mm. On the other hand, the thickness of the outer insulation layer 12 is also preferably 5 mm to 50 mm. The thickness of the outer insulation layer 12 is more preferably 8 mm to 30 mm.

[0038] Since the thermostat 21 is arranged outside the heater wire 14, the heater wire 14 does not need to avoid the position of the thermostat 21. As a result, the temperature of the pipe 90 can be prevented from being lowered at the position of the thermostat 21. Figure 2 In the example shown, the thermostat 21 is located in the thickness direction ( Figure 2 In other words, when viewing the jacket heater 10 along its thickness, the thermostat 21 overlaps a portion 14a of the heater wire 14. This allows the heater wire 14 to be positioned without avoiding the location of the thermostat 21. Consequently, a decrease in the temperature of the pipe 90 at the location of the thermostat 21 can be avoided.

[0039] As described above, the heat transfer layer 13 is arranged between the outer heat insulation layer 12 and the inner heat insulation layer 11. The thermostat 21 is located outside the heat transfer layer 13. That is, when viewed from the thickness direction of the jacket heater 10, the thermostat 21 overlaps with the heat transfer layer 13. The thermostat 21 can be arranged between the heat transfer layer 13 and the outer heat insulation layer 12. With this structure, the heat transferred to the heat transfer layer 13 through the inner heat insulation layer 11 will diffuse along the circumferential direction and the longitudinal direction of the pipe 90 through the heat transfer layer 13. As a result, for example, the local temperature increase or decrease at the position of the thermostat 21 can be suppressed. As a result, the timing of the action of the thermostat 21 (the timing of interrupting the current flowing through the heating wire 14) can be optimized.

[0040] The inner insulation layer 11, heat transfer layer 13, and outer insulation layer 12 are sewn together with heat-resistant thread. These three layers are preferably sewn together. In other words, they are preferably sewn together with a single thread. This method reduces the number of manufacturing steps required for the jacket heater 10. In addition to these three layers, other layers such as the inner skin layer 16 and outer skin layer 17 can also be sewn together. Heat-resistant thread can include, for example, glass yarn, silica yarn, alumina yarn, or glass yarn, silica yarn, or alumina yarn coated with fluororesin.

[0041] The thermostat 21 can also be secured to the inner insulation layer 11, the heat transfer layer 13, and the outer insulation layer 12 using a thread (not shown) used to sew the inner insulation layer 11 and the like. For example, the insulation layers 11, 12, and the heat transfer layer 13 can be sewn around the thermostat 21 using a thread to prevent the thermostat 21 from shifting between the heat transfer layer 13 and the outer insulation layer 12. This can reduce the number of parts.

[0042] As mentioned above, the thermostat 21 is connected to the heating wire 14 via the wire 21a. Figure 1 As shown, holes 13a and 11a may be formed in the heat transfer layer 13 and the inner heat insulation layer 11. The holes 13a and 11a are, for example, holes that pass through the heat transfer layer 13 and the inner heat insulation layer 11. The wire 21a may pass through these holes 13a and 11a to connect to the heating wire 14.

[0043] In this case, the lead wire 21 a extending from the thermostat 21 can pass through the outer edge of the heat transfer layer 13 and the outer edge of the inner heat insulating layer 11 to connect to the heater wire 14 .

[0044] Furthermore, the thermostat 21 may not be connected to the heating wire 14. Figure 3 As shown, the lead wire 21a extending from the thermostat 21 can be connected to, for example, a control device that supplies current to the heater wire 14. Upon detecting an excessive temperature rise in the heater wire 14, the thermostat 21 enters a shutdown state, stopping the current supply from the control device to the heater wire 14. In this case, the holes 13a and 11a penetrating the heat transfer layer 13 and the inner heat insulating layer 11 do not need to be formed.

[0045] The configuration of the heat transfer layer 13 is not limited to Figure 1 and Figure 2 For example, Figure 4 The jacket heater 110 shown has a heat transfer layer 113. The heat transfer layer 113 may be disposed only on a portion of the jacket heater 110 in the circumferential direction of the pipe 90. That is, the heat transfer layer 113 may only cover a portion of the pipe 90 along the circumferential direction of the pipe 90. For example, the heat transfer layer 113 may be disposed only in an area less than 180 degrees in the circumferential direction of the pipe 90. The circumferential range of the heat transfer layer 113 in the pipe 90 may be less than 90 degrees, or may be greater than 90 degrees but less than 180 degrees. In other areas (areas where the heat transfer layer 113 is not disposed), the inner heat insulation layer 11 and the outer heat insulation layer 12 may be in direct contact. The thermostat 21 is disposed outside the heat transfer layer 113. That is, when the jacket heater 10 is viewed in the thickness direction of the jacket heater 10, the thermostat 21 may overlap with the heat transfer layer 13. The above arrangement of the heat transfer layer 113 can reduce the amount of material (eg, aluminum) used for the heat transfer layer 113. Furthermore, since the bending of the heat transfer layer 113 can be reduced, the installation of the jacket heater 110 to the pipe 90 can be facilitated.

[0046] The circumferential extent of the heat transfer layer 113 may be greater than that of the thermostat 21. The circumferential extent of the heat transfer layer 113 may be greater than twice the width of the thermostat 21. The circumferential extent of the heat transfer layer 113 may be less than half that of the jacket heater 110.

[0047] Figure 4 In the illustrated configuration, the heat transfer layer 113 may not have holes for connecting the heating wire 14 to the thermostat 21 ( Figure 1 The wire 21a shown extends through the hole 13a. The wire 21a extending from the thermostat 21 can avoid the position of the heat transfer layer 113 and connect to the heater wire 14. In other words, the wire 21a can pass through the outer edge of the heat transfer layer 113 and through the hole 11b that penetrates the inner insulation layer 11 to connect to the heater wire 14.

[0048] Furthermore, in another example, Figure 5 The jacket heater 210 shown has a heat transfer layer 213. The heat transfer layer 213 may be provided only on a portion of the jacket heater 210 in the longitudinal direction of the piping 90. The thermostat 21 is arranged radially outward from the heat transfer layer 213. Even in this case, the amount of material (e.g., aluminum) used for the heat transfer layer 213 can be reduced. Moreover, for example, compared to a case where the heat transfer layer is provided on the entire jacket heater 10, the installation work of the jacket heater 10 on the piping 90 can be facilitated. The length of the heat transfer layer 213 (the width in the longitudinal direction of the piping 90) may be greater than that of the thermostat 21. The length of the heat transfer layer 213 may also be less than half the length of the jacket heater 210.

[0049] Figure 5 In the illustrated configuration, the heat transfer layer 213 may not have holes for connecting the heating wire 14 to the thermostat 21 ( Figure 1 The wire 21a shown extends through the hole 13a. The wire 21a extending from the thermostat 21 can avoid the position of the heat transfer layer 213, pass through the outer edge of the heat transfer layer 213, and connect to the heater wire 14. The wire 21a can pass through the hole 11b that passes through the inner insulation layer 11 to connect to the heater wire 14.

[0050] Here, Figure 5 In one example of the heat transfer layer 213 shown, the Figure 1 The substantially entire circumference of the pipe 90 is covered. Figure 5 The heat transfer layer 213 shown may also be Figure 4 As shown, only a portion of the circumferential direction of the pipe 90 is covered. Figure 4 In the example of the heat transfer layer 113 shown, the size of the jacket heater 10 may be substantially the same as that of the jacket heater 10 in the longitudinal direction of the pipe 90. Figure 4 The heat transfer layer 113 shown may also be Figure 5 As shown, it is provided only on a portion of the pipe 90 in the longitudinal direction.

[0051] [Thermocouple location]

[0052] The inner circumference of the jacket heater 10 can be equipped with a thermocouple 19 (see Figure 2 When the jacket heater 10 is mounted on the outside of the pipe 90, the thermocouple 19 contacts the outer surface of the pipe 90. The thermocouple 19 is connected to a control device (not shown). The control device controls the current supplied to the heating wire 14 based on the output signal of the thermocouple 19.

[0053] [Method for manufacturing jacketed heater]

[0054] Next, an example of a method for manufacturing the jacket heater 10 will be described. The operator prepares the inner heat insulating layer 11, the outer heat insulating layer 12, and the heat transfer layer 13. The operator also forms the accommodation chamber 12a for accommodating the thermostat 21 in the outer heat insulating layer 12.

[0055] The operator sews the inner insulation layer 11, the heat conductive layer 13, and the outer insulation layer 12 together using heat-resistant thread. Alternatively, the operator can sew the inner insulation layer 11 and the heat conductive layer 13 together, and then sew the outer insulation layer 12 to the inner insulation layer 11 and the heat conductive layer 13. Alternatively, the operator can sew the inner insulation layer 11, the heat conductive layer 13, and the outer insulation layer 12 together. Furthermore, the operator sews the heater wire 14 to the heater wire base 18. At this point, the operator can also sew the insulating layer 15 to the heater wire 14 and the heater wire base 18.

[0056] Next, the operator places the thermostat 21 outside the inner insulation layer 11. More specifically, the operator places the thermostat 21 inside the housing chamber 12a formed in the outer insulation layer 12. The operator then covers the inner sides of the heater wire 14, the insulating layer 15, and the heater wire base material 18 with the inner skin layer 16, and covers the outer insulation layer 12 and the thermostat 21 with the outer skin layer 17. The inner and outer skin layers 16 and 17 are then sewn together.

[0057] [Summarize]

[0058] (1) The jacket heater 10, 110, or 210 includes a heater wire 14, an inner heat insulating layer 11 disposed outside the heater wire 14, an outer heat insulating layer 12 disposed outside the inner heat insulating layer 11, and a thermostat 21 disposed outside the inner heat insulating layer 11. With this structure, even when the output of the jacket heater 10, 110, or 210 must be increased to raise the temperature of the pipe 90, a small thermostat with a low operating temperature (the temperature at which the current to the heater wire 14 is shut off) can be used as the thermostat 21 to prevent the jacket heater 10, 110, or 210 from overheating.

[0059] (2) In the configuration of (1), the thermostat 21 may be disposed between the inner heat insulating layer 11 and the outer heat insulating layer 12. This configuration can reduce the influence of the outside air temperature on the thermostat 21.

[0060] (3) In the configuration of (1) or (2), a housing chamber 12a may be formed in the outer heat insulating layer 12. The housing chamber 12a is a hole or recessed portion that penetrates the outer heat insulating layer 12, and the thermostat 21 may be disposed inside the housing chamber 12a. This can reduce unevenness on the outer surface of the jacket heater 10 caused by the thermostat 21.

[0061] (4) In any of the structures (1) to (3), a heat transfer layer 13, 113, or 213 may be disposed outside the inner heat insulating layer 11. With this structure, heat transferred to the heat transfer layer 13 via the inner heat insulating layer 11 is diffused along the circumferential and longitudinal directions of the pipe 90 via the heat transfer layer 13. As a result, for example, a local temperature increase or decrease at the location of the thermostat 21 can be suppressed.

[0062] (5) In the structure of (4), the heat transfer layer 13 can be a metal layer disposed between the inner heat insulation layer 11 and the outer heat insulation layer 12. Thus, the heat transfer layer 13 can reflect electromagnetic waves that cause heat radiation. As a result, the pipe 90 can be heated efficiently. Furthermore, since the outer heat insulation layer 12 is provided outside the heat transfer layer 13, the outer surface of the jacket heater 10 can be lowered to an appropriate temperature. As a result, workability around the jacket heater 10 can be improved.

[0063] (6) In the structure of (4), the heat transfer layers 113 and 213 can be arranged only on a portion of at least one of the circumferential direction and the longitudinal direction of the pipe 90 of the jacket heater 10. This can reduce the amount of material used for the heat transfer layers 113 and 213. In addition, the installation work of the jacket heater 10 on the pipe 90 can be facilitated.

[0064] (7) In any of (1) to (6), the thermostat 21 may overlap with a portion 14a of the heater wire 14 in the thickness direction of the jacket heater 10. This prevents the temperature of the pipe 90 from decreasing at the position of the thermostat 21.

[0065] (8) A method for manufacturing a jacket heater 10 for installation on the outer periphery of a pipe 90 includes: a step of covering a heating wire 14 with an inner heat-insulating layer 11; a step of covering the outer side of the inner heat-insulating layer 11 with an outer heat-insulating layer 12; and a step of arranging a thermostat 21 on the outer side of the inner heat-insulating layer 11.

[0066] (9) The heat insulating structure for installation on the outer periphery of the piping 90 comprises: a heating wire 14; an inner heat insulating layer 11, which is arranged on the outside of the heating wire 14; an outer heat insulating layer 12, which is arranged on the outside of the inner heat insulating layer 11; and a thermostat 21, which is arranged on the outside of the inner heat insulating layer 11.

[0067] In addition, the jacketed heater proposed in this disclosure is not limited to Figure 1 For example, the jacket heater proposed in the present disclosure may not necessarily have the heat transfer layer 13.

Claims

1. A jacket heater for covering the outer periphery of a pipe, the jacket heater comprising: Heating wire; a first heat-insulating layer disposed on the outside of the heating wire; a second heat-insulating layer disposed outside the first heat-insulating layer; and The thermostat is arranged outside the first heat insulation layer.

2. The jacketed heater according to claim 1, wherein The thermostat is disposed between the first thermal insulation layer and the second thermal insulation layer.

3. The jacketed heater according to claim 1, wherein A receiving chamber is formed on the second heat-insulating layer. The receiving chamber is a hole or a recess that passes through the second heat-insulating layer. The thermostat is arranged inside the receiving chamber.

4. The jacketed heater according to claim 1, further comprising a heat transfer layer, the heat transfer layer being arranged outside the first heat insulating layer and being formed of a material having a higher thermal conductivity than the first heat insulating layer and the second heat insulating layer. The thermostat is arranged outside the heat transfer layer.

5. The jacketed heater according to claim 4, wherein: The heat transfer layer is a metal layer disposed between the first heat insulation layer and the second heat insulation layer.

6. The jacketed heater according to claim 4, wherein: The heat transfer layer is disposed only on a portion of the jacket heater in at least one of a circumferential direction of the pipe and a longitudinal direction of the pipe.

7. The jacketed heater according to claim 1, wherein: The thermostat overlaps a portion of the heating wire in a thickness direction of the jacket heater.

8. A method for manufacturing a jacket heater, the method comprising: The step of covering the heating wire with a first thermal insulation layer; A step of covering the outer side of the first thermal insulation layer with a second thermal insulation layer; and The step of disposing a thermostat outside the first thermal insulation layer.

9. A heat insulation structure for installation on the outer periphery of a pipe, the heat insulation structure comprising: Heating wire; a first heat-insulating layer disposed on the outside of the heating wire; a second heat-insulating layer disposed outside the first heat-insulating layer; and The thermostat is arranged outside the first heat insulation layer.

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