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

Abstract

A jacket heater (10) includes: a heater wire (14); an inner heat insulation layer (11) that is disposed outward of the heater wire (14); an outer heat insulation layer (12) that is disposed outward of the inner heat insulation layer (11); and a thermostat (21) that is disposed outward of the inner heat insulation layer (11). Thus, even if increased output from the jacket heater is required in order to increase the temperature of piping, a small thermostat having a low operating temperature (temperature for interrupting the heater wire current) can be used in the jacket heater.

Description

[Technical Field]

[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. [Background Art]

[0002] To prevent condensation and precipitation of gas inside the pipe, the pipe may be covered with a jacket heater. For example, various gases are used in film forming steps and etching steps in the manufacture of semiconductor devices. A jacket heater is sometimes used to prevent these gases from condensing and precipitating inside the pipe. Patent Document 1 discloses an example of such a jacket heater. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] International Publication No. WO 2011 / 126051 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] A thermostat is sometimes used to prevent the heater wire of the jacket heater from overheating. When increasing the temperature of the pipe, it is necessary to use a thermostat with a high operating temperature, which is the temperature at which the current to the heater wire is cut off. However, thermostats with high operating temperatures are generally larger in size. This causes problems such as difficulty in attaching the thermostat to the jacket heater, and difficulty in attaching the jacket heater to the pipe. [Means for Solving the Problem]

[0005] The jacket heater proposed in this disclosure is a jacket heater that covers the outer circumference of a pipe and comprises a heater wire, a first insulating layer disposed outside the heater wire, a second insulating layer disposed outside the first insulating layer, and a thermostat disposed outside the first insulating layer. With this jacket heater, the temperature of the thermostat is lower than that of the inner circumference of the jacket heater where the heater wire is located. As a result, even when it is necessary to increase the output of the jacket heater to raise the temperature of the pipe, a small thermostat 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.

[0006] The method for manufacturing a jacket heater proposed in this disclosure includes the steps of covering a heater wire with a first insulating layer, covering the outside of the first insulating layer with a second insulating layer, and arranging a thermostat on the outside of the first insulating layer. In a jacket heater manufactured by this method, the temperature of the thermostat will be lower than that of the inner circumference of the jacket heater where the heater wire is located. As a result, even when it is necessary to increase the output of the jacket heater to raise the temperature of the piping, a small thermostat with a low operating temperature can be used in the jacket heater.

[0007] The thermal insulation structure proposed in this disclosure is a thermal insulation structure for mounting on the outer circumference of a pipe, and comprises a heater wire, a first thermal insulation layer disposed outside the heater wire, a second thermal insulation layer disposed outside the first thermal insulation layer, and a thermostat disposed outside the first thermal insulation layer. With this thermal insulation structure, the temperature of the thermostat is lower than that of the inner circumference of the thermal insulation structure where the heater wire is located. As a result, even when it is necessary to increase the output of the jacket heater to raise the temperature of the pipe, a small thermostat with a low operating temperature can be used in the jacket heater. [Brief explanation of the drawing]

[0008] [Figure 1]This is a cross-sectional view showing the jacket heater proposed in this disclosure attached to a pipe. The cross-sectional plane is perpendicular to the pipe. [Figure 2] Figure 1 shows a cross-sectional view of the jacket heater obtained along line II-II. [Figure 3] This is a perspective view showing modified examples of the inner and outer insulation layers. [Figure 4] This is a cross-sectional view showing a modified heat transfer layer. [Figure 5] This is a cross-sectional view showing another variation of the heat transfer layer. [Figure 6] This is an exploded view of the jacket heater to illustrate the placement of the thermostat. [Modes for carrying out the invention]

[0009] The jacket heater proposed in this disclosure will be described below. In this specification, as an example, the jacket heater 10 shown in Figure 1, etc., will be described.

[0010] The jacket heater 10 covers the pipe 90. By heating the pipe 90, the jacket heater 10 prevents the gas flowing inside the pipe 90 from condensing or precipitation.

[0011] As shown in Figures 1 and 2, the jacket heater 10 has a heater wire 14 and a heater wire base material 18 to which the heater wire 14 is attached. The heater wire 14 is, for example, a nickel-chromium metal resistor. As the heater wire base material 18, for example, an inorganic fiber cloth made of inorganic fibers such as glass fiber, silica fiber, alumina fiber, or silica-alumina fiber can be used. The heater wire 14 is sewn onto the heater wire base material 18. The heater wire 14 is connected to an external power supply via a lead wire 14b (see Figure 6).

[0012] As shown in Figure 1, the jacket heater 10 has an inner insulation layer 11 (first insulation layer) and an outer insulation layer 12 (second insulation layer). The inner insulation layer 11 is located outside the heater wire 14 and the heater wire base material 18 and covers them. The outer insulation layer 12 is located further outside the inner insulation layer 11 and covers this inner insulation layer 11.

[0013] The inner insulation layer 11 and the outer insulation layer 12 are formed from, for example, an inorganic fiber insulation layer. The inorganic fiber may be, for example, glass fiber, ceramic fiber, or silica fiber. Alternatively, the inner insulation layer 11 and the outer insulation layer 12 may be inorganic or organic insulation materials containing polyimide or silica, having voids with an average void width of less than or equal to a certain value (for example, voids with an average void width smaller than the mean free path of air molecules). The materials of the inner insulation layer 11 and the outer insulation layer 12 may be the same or different.

[0014] The inner insulation layer 11 may consist of a single layer or multiple layers stacked on top of each other. Figure 3 shows a modified example of the inner insulation layer 11. In this figure, the inner insulation layer 11 has a first layer 11A and a second layer 11B. The number of layers constituting the inner insulation layer 11 may be more than two. Similarly, the outer insulation layer 12 may consist of a single layer or multiple layers stacked on top of each other. If each insulation layer 11 and 12 consists of multiple layers, they may be made of the same material or different materials.

[0015] Furthermore, the jacket heater 10 has a heat transfer layer 13 positioned between the inner insulation layer 11 and the outer insulation layer 12. The heat transfer layer 13 is made of a material with a higher thermal conductivity than the inner insulation layer 11 and the outer insulation layer 12. This heat transfer layer 13 conducts the heat emitted from the piping 90 and heater wire 14 to an area away from the thermostat 21 (described later), thereby preventing the temperature at the thermostat 21 from becoming locally high. The heat transfer layer 13 may be, for example, a metal layer. In this case, electromagnetic waves that cause heat radiation can be reflected by the heat transfer layer 13. As a result, the jacket heater 10 can efficiently heat the piping 90. Also, because 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 is improved.

[0016] The heat transfer layer 13 is preferably made of a flexible material with high thermal conductivity. Using such a material effectively suppresses localized temperature increases at the location of the thermostat 21. Furthermore, the heat transfer layer 13 is preferably made of a flexible material with high reflectivity to infrared radiation. An example of such a material for the heat transfer layer 13 is aluminum. The material of the heat transfer layer 13 may also be other metals such as copper or stainless steel. Note that the material of the heat transfer layer 13 is not limited to metal. For example, the heat transfer layer 13 may be carbon graphite. Even in this case, the heat emitted from the piping 90 and heater wire 14 can be conducted to an area away from the thermostat 21, suppressing localized temperature increases at the location of the thermostat 21.

[0017] The heat transfer layer 13 is, for example, a metal foil having a thickness of 10 μm to 700 μm. This thickness allows the heat transfer layer 13 to maintain flexibility while preventing unintended rupture. Preferably, the thickness of the heat transfer layer 13 is 10 μm to 200 μm. This thickness allows the heat transfer layer 13 to maintain flexibility while preventing unintended rupture.

[0018] As shown in Fig. 1, the heat transfer layer 13 may be formed over substantially the entire circumference of the pipe 90. That is, the heat transfer layer 13 may surround the pipe 90 over substantially 360 degrees. Further, the heat transfer layer 13 may be provided over substantially the entire jacket heater 10 in the longitudinal direction of the pipe 90. As will be described later, the heat transfer layer 13 may be provided only on a part of the jacket heater 10.

[0019] As shown in Fig. 1, the jacket heater 10 has an inner skin 16 covering the inner side of the heater wire base material 18. An insulating layer 15 for reliably insulating the heater wire 14 from the pipe may be disposed between the inner skin 16 and the heater wire base material 18. The jacket heater 10 has an outer skin 17 covering the outer side of the outer heat insulating layer 12. As the outer skin 17 and the inner skin 16, for example, heat-resistant sheets (including cloths) can be used. The material of the outer skin 17 and the material of the inner skin 16 may be the same or different. As the outer skin 17 and the inner skin 16, for example, a porous sheet, an inorganic fiber sheet, a resin sheet, or the like can be used. An example of the porous sheet is a sheet of PTFE (polytetrafluoroethylene). An example of the inorganic fiber sheet is glass cloth. The resin sheet is, for example, a fluororesin sheet. Further, the inorganic fiber sheet may be coated with silicon or fluorine.

[0020] The jacket heater 10 has flexibility. That is, each of the heat insulating layers 11 and 12, the heat transfer layer 13, the outer skin 17, the inner skin 16, the heater wire 14, and the heater wire base material 18 constituting the jacket heater 10 has flexibility. The jacket heater 10 is formed into a cylindrical shape by being wound around the outside of the pipe 90 during the installation process.

[0021] The jacket heater 10 includes 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 includes, as the fixing member, for example, a plurality of hook-and-loop fasteners 22 arranged along a first edge 10a (see FIG. 6) of the jacket heater 10. The hook-and-loop fasteners 22 may be attached to an outer surface of the jacket heater 10. The hook-and-loop fasteners 22 may be sewn onto the jacket heater 10. The hook-and-loop fasteners 22 are attached to a second edge 10b (the edge opposite to the first edge 10a, see FIG. 6) of the jacket heater 10 in a state where the jacket heater 10 is wound around the pipe 90. Note that the fixing member is not limited to the hook-and-loop fasteners 22. The fixing member may be formed of, for example, a hook, or may include a belt wound around an outer side of the jacket heater 10.

[0022] As shown in FIG. 1 and FIG. 2, the jacket heater 10 includes a thermostat 21. A lead wire 21a is connected to the thermostat 21. The thermostat 21 may be connected to a heater wire 14 via the lead wire 21a. When the temperature of the jacket heater 10 becomes higher than a predetermined operating temperature for reasons such as excessive current flowing through the heater wire 14, the thermostat 21 is turned off to stop the current supply to the heater wire 14. The thermostat 21 may also be connected via the lead wire 21a to a power supply that supplies current to the heater wire 14.

[0023] As shown in Figures 1 and 2, the thermostat 21 is positioned outside the inner insulation layer 11. Therefore, the temperature of the thermostat 21 is lower than the temperature of the inner surface of the jacket heater 10 where the heater wires 14 are located, and also lower than the temperature of the piping 90. As a result, even when it is necessary to increase the output of the jacket heater 10 to raise the temperature of the piping 90, a small thermostat 21 with a low operating temperature (temperature at which the current to the heater wires is cut off) can be used in the jacket heater 10. 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 (temperature at which the current is cut off) set to 300°C or higher is usually required. However, in the jacket heater 10 proposed in this disclosure, since the thermostat 21 is positioned outside the inner insulation layer 11, the ambient 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 piping 90 can be heated to a temperature sufficiently higher than its operating temperature (300°C in the example described here).

[0024] As shown in Figures 1 and 2, the thermostat 21 may be positioned between the inner insulation layer 11 and the outer insulation layer 12. That is, a portion of the outer insulation layer 12 may be located on the outside of the thermostat 21 (towards the outer sheath 17 of the thermostat 21). This reduces the influence of the outside air temperature on the thermostat 21. For example, it is possible to avoid a situation where the thermostat 21 does not operate even though the temperature of the heater wire 14 is higher than the pre-determined temperature when the outside air temperature is low.

[0025] As shown in Figures 1 and 2, a recessed housing chamber 12a may be formed on the inner surface of the outer insulation layer 12. The thermostat 21 may be placed inside this housing chamber 12a. This structure reduces the unevenness of the outer surface of the jacket heater 10 caused by the thermostat 21. The outer insulation layer 12 may be partially cut out at the location of the housing chamber 12a. As described above, the outer insulation layer 12 may be composed of multiple layers. In this case, holes may be formed through some of the layers, and these holes may function as housing chambers 12a. For example, the outer insulation layer 12 may consist of a first layer and a second layer placed outside the first layer. In this case, holes may be formed through the first layer, and these holes may function as housing chambers 12a. The second layer may cover the outside of the thermostat 21.

[0026] As shown in Figure 3 as a modified example of the outer insulation layer 12, the outer insulation layer 12 may have holes 12b that penetrate it in the thickness direction. These holes 12b may function as a housing chamber 12a in which the thermostat 21 is placed. In this case, the thermostat 21 may be located between the inner insulation layer 11 (and heat transfer layer 13) and the outer sheath 17. The thermostat 21 is exposed to the outside from the outer insulation layer 12, and the lead wires 21a may be arranged along the outer circumferential surface of the outer insulation layer 12.

[0027] The thickness of the inner insulation layer 11 may be set based on the difference between the operating temperature of the thermostat 21 and the temperature of the required piping 90. In other words, the larger the difference, the greater the thickness of the inner insulation layer 11 may be.

[0028] The thickness of the inner insulation layer 11 may be the same as or less than the thickness of the outer insulation layer 12. With this structure, the distance from the pipe 90 and heater wire 14 to the heat transfer layer 13 is reduced, so the space inside the heat transfer layer 13 is reduced. As a result, the heat emitted from them remains in a narrow space, and the temperature of the pipe 90 can be efficiently maintained. It is preferable that the heat transfer layer 13 is made of a material that has a high reflectivity to infrared rays.

[0029] The thickness of the inner insulation layer 11 may be, for example, 5 mm to 100 mm. The thickness of the outer insulation layer 12 may be 5 mm to 100 mm. With such thicknesses, insulation performance can be ensured while keeping the space required for installing the jacket heater 10 down. Preferably, the thickness of the inner insulation layer 11 may be 5 mm to 50 mm. With such thicknesses, the space required for installing the jacket heater 10 can be further reduced. More preferably, the thickness of the inner insulation layer 11 may be 8 mm to 30 mm. On the other hand, preferably, the thickness of the outer insulation layer 12 may also be 5 mm to 50 mm. More preferably, the thickness of the outer insulation layer 12 may be 8 mm to 30 mm.

[0030] Since the thermostat 21 is positioned outside the heater wire 14, the heater wire 14 does not need to avoid the position of the thermostat 21. As a result, it is possible to avoid the temperature of the piping 90 becoming lower at the position of the thermostat 21. In the example shown in Figure 2, the thermostat 21 is positioned in the thickness direction of the jacket heater 10 (direction D1 in Figure 2) relative to a portion 14a of the heater wire 14. That is, when the jacket heater 10 is viewed in the thickness direction, the thermostat 21 overlaps with a portion 14a of the heater wire 14. In other words, it is possible to position the heater wire 14 without avoiding the position of the thermostat 21. As a result, it is possible to avoid the temperature of the piping 90 becoming lower at the position of the thermostat 21.

[0031] As described above, a heat transfer layer 13 is positioned between the outer insulation layer 12 and the inner insulation layer 11. The thermostat 21 is located outside the heat transfer layer 13. That is, when the jacket heater 10 is viewed in its thickness direction, the thermostat 21 overlaps with the heat transfer layer 13. The thermostat 21 may be positioned between the heat transfer layer 13 and the outer insulation layer 12. With this structure, the heat transferred to the heat transfer layer 13 via the inner insulation layer 11 spreads through the heat transfer layer 13 in the circumferential and longitudinal directions of the piping 90. As a result, it is possible to suppress localized temperature increases or decreases at the location of the thermostat 21, for example. This allows for optimization of the operating timing of the thermostat 21 (the timing of interrupting the current flowing through the heater wire 14).

[0032] The inner insulation layer 11, the heat transfer layer 13, and the outer insulation layer 12 are sewn together with heat-resistant thread. It is preferable that these three layers be sewn together together. That is, it is preferable that these three layers be sewn together with a single thread. This reduces the manufacturing process of the jacket heater 10. In addition to these three layers, other layers such as the inner skin 16 and outer skin 17 may also be sewn together together. As the heat-resistant thread, for example, glass yarn, silica yarn, alumina yarn, or yarns coated with fluororesin may be used.

[0033] The position of the thermostat 21 may be fixed to the inner insulation layer 11, the heat transfer layer 13, and the outer insulation layer 12 using thread (not shown) that is used to sew the inner insulation layer 11, etc. For example, the insulation layers 11 and 12 and the heat transfer layer 13 may be sewn together with thread around the thermostat 21 so that the position of the thermostat 21 does not move between the heat transfer layer 13 and the outer insulation layer 12. This can reduce the number of parts.

[0034] As described above, the thermostat 21 is connected to the heater wire 14 via a lead wire 21a. Holes 13a and 11a may be formed in the heat transfer layer 13 and the inner insulation layer 11, as shown in Figure 1. Holes 13a and 11a are, for example, holes that penetrate the heat transfer layer 13 and the inner insulation layer 11. The lead wire 21a may pass through these holes 13a and 11a and be connected to the heater wire 14.

[0035] Note that holes 13a and 11a do not necessarily have to be formed. In this case, the lead wire 21a extending from the thermostat 21 may be connected to the heater wire 14 by passing outside the outer edge of the heat transfer layer 13 and the outer edge of the inner insulation layer 11.

[0036] Furthermore, the thermostat 21 does not necessarily have to be connected to the heater wire 14. As shown in Figure 3, the lead wire 21a extending from the thermostat 21 may be connected, for example, to a control device that supplies current to the heater wire 14. The thermostat 21 turns off when it detects overheating of the heater wire 14, and stops the supply of current from the control device to the heater wire 14. In this case, the holes 13a and 11a that penetrate the heat transfer layer 13 and the inner insulation layer 11 do not need to be formed.

[0037] The arrangement of the heat transfer layer 13 is not limited to the examples shown in Figures 1 and 2. For example, the jacket 110 shown in Figure 4 has a heat transfer layer 113. The heat transfer layer 113 may be provided only in a portion of the jacket heater 110 in the circumferential direction of the pipe 90. That is, the heat transfer layer 113 may cover only a portion of the pipe 90 in the circumferential direction. For example, the heat transfer layer 113 may be provided only in a range smaller than 180 degrees in the circumferential direction of the pipe 90. The width of the heat transfer layer 113 in the circumferential direction of the pipe 90 may be less than 90 degrees, or greater than 90 degrees and less than 180 degrees. In other parts (areas where the heat transfer layer 113 is not provided), the inner insulation layer 11 and the outer insulation layer 12 may be in direct contact. The thermostat 21 is located outside the heat transfer layer 113. In other words, when the jacket heater 10 is viewed in the thickness direction, the thermostat 21 should overlap with the heat transfer layer 13. This arrangement of the heat transfer layer 113 reduces the amount of material (e.g., aluminum) used for the heat transfer layer 113. It also reduces the curvature of the heat transfer layer 113, making it easier to install the jacket heater 110 onto the piping 90.

[0038] The width of the heat transfer layer 113 in the circumferential direction may be greater than that of the thermostat 21. The width of the heat transfer layer 113 in the circumferential direction may be greater than twice the width of the thermostat 21. The width of the heat transfer layer 113 in the circumferential direction may be less than half the width of the jacket heater 110.

[0039] In the structure shown in Figure 4, the heat transfer layer 113 does not need to have a hole (hole 13a through which the lead wire 21a shown in Figure 1 passes) for connecting the heater wire 14 to the thermostat 21. The lead wire 21a extending from the thermostat 21 may be connected to the heater wire 14 while avoiding the location of the heat transfer layer 113. That is, the lead wire 21a may pass outside the outer edge of the heat transfer layer 113 and through a hole 11b that penetrates the inner insulation layer 11 to connect to the heater wire 14.

[0040] As yet another example, the jacket heater 210 shown in Figure 5 has a heat transfer layer 213. The heat transfer layer 213 may be located only on a portion of the jacket heater 210 in the longitudinal direction of the piping 90. The thermostat 21 is located 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. Also, compared to, for example, the case where the heat transfer layer is provided over the entire jacket heater 10, the installation work of the jacket heater 10 to the piping 90 can be made easier. The length of the heat transfer layer 213 (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 be less than half the length of the jacket heater 210.

[0041] In the structure shown in Figure 5, the heat transfer layer 213 does not need to have a hole (hole 13a through which the lead wire 21a shown in Figure 1 passes) for connecting the heater wire 14 to the thermostat 21. The lead wire 21a extending from the thermostat 21 may be connected to the heater wire 14 by passing outside the outer edge of the heat transfer layer 213, avoiding the location of the heat transfer layer 213. The lead wire 21a may be connected to the heater wire 14 by passing through a hole 11b that penetrates the inner insulation layer 11.

[0042] In one example, the heat transfer layer 213 shown in Figure 5 may cover substantially the entire circumference of the pipe 90, as shown in Figure 1. Alternatively, the heat transfer layer 213 shown in Figure 5 may cover only a portion of the pipe 90 in the circumferential direction, as shown in Figure 4. Furthermore, in one example, the heat transfer layer 113 shown in Figure 4 may have substantially the same size as the jacket heater 10 in the longitudinal direction of the pipe 90. Alternatively, the heat transfer layer 113 shown in Figure 4 may be provided only in a portion of the pipe 90 in the longitudinal direction, as shown in Figure 5.

[0043] [Position of the thermocouple] A thermocouple 19 (see Figure 2) may be attached to the inner surface of the jacket heater 10. When the jacket heater 10 is mounted on the outside of the piping 90, the thermocouple 19 is in contact with the outer surface of the piping 90. The thermocouple 19 is connected to a control device (not shown). The control device controls the current supplied to the heater wire 14 based on the output signal of the thermocouple 19.

[0044] [Manufacturing method for jacket heaters] An example of a method for manufacturing a jacket heater 10 will be described. The worker prepares an inner insulation layer 11, an outer insulation layer 12, and a heat transfer layer 13. The worker then forms a housing chamber 12a for the thermostat 21 in the outer insulation layer 12.

[0045] The worker sews the inner insulation layer 11, the heat transfer layer 13, and the outer insulation layer 12 together with heat-resistant thread 31a. At this time, the worker may sew the inner insulation layer 11 and the heat transfer layer 13 together, and then sew the outer insulation layer 12 to the inner insulation layer 11 and the heat transfer layer 13. As another example, the worker may sew the inner insulation layer 11, the heat transfer layer 13, and the outer insulation layer 12 together. The worker also sews the heater wire 14 to the heater wire base material 18. At this time, the worker may also sew the insulating layer 15 to the heater wire 14 and the heater wire base material 18.

[0046] Next, the worker places the thermostat 21 on the outside of the inner insulation layer 11. More specifically, the worker places the thermostat 21 inside the housing chamber 12a formed in the outer insulation layer 12. Then, the worker covers the inside of the heater wire 14, the insulating layer 15, and the heater wire base material 18 with the inner sheath 16. The worker covers the outer insulation layer 12 and the thermostat 21 with the outer sheath 17, and then sews the inner sheath 16 and the outer sheath 17 together.

[0047] [summary] (1) The jacket heaters 10, 110, and 210 each include a heater wire 14, an inner insulation layer 11 positioned outside the heater wire 14, an outer insulation layer 12 positioned outside the inner insulation layer 11, and a thermostat 21 positioned outside the inner insulation layer 11. With this structure, even when it is necessary to increase the output of the jacket heaters 10, 110, and 210 to raise the temperature of the piping 90, a small thermostat with a low operating temperature (the temperature at which the current to the heater wire 14 is cut off) can be used as the thermostat 21 to prevent overheating of the jacket heaters 10, 110, and 210.

[0048] (2) In the structure of (1), the thermostat 21 may be placed between the inner insulation layer 11 and the outer insulation layer 12. This structure reduces the influence of the outside air temperature on the thermostat 21.

[0049] (3) In the structure of (1) or (2), a housing chamber 12a, which is a hole or recess penetrating the outer insulation layer 12, may be formed in the outer insulation layer 12, and a thermostat 21 may be placed inside the housing chamber 12a. This reduces the unevenness of the outer surface of the jacket heater 10 caused by the thermostat 21.

[0050] (4) In any of the structures of (1) to (3), the heat transfer layers 13, 113, and 213 may be arranged outside the inner insulation layer 11. With this structure, the heat transferred to the heat transfer layer 13 via the inner insulation layer 11 spreads through the heat transfer layer 13 in the circumferential and / or longitudinal direction of the piping 90. As a result, localized temperature increases or decreases at the location of the thermostat 21 are suppressed.

[0051] In the structure of (5)(4), the heat transfer layer 13 may be a metal layer placed between the inner insulation layer 11 and the outer insulation layer 12. This allows the heat transfer layer 13 to reflect electromagnetic waves that cause heat radiation. As a result, the piping 90 can be heated efficiently. In addition, because the outer insulation layer 12 is located outside the heat transfer 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.

[0052] In the structure of (6)(4), the heat transfer layers 113 and 213 may be arranged only in a portion of the jacket heater 10 in at least one direction of the circumferential direction of the pipe 90 and the longitudinal direction of the pipe 90. This reduces the amount of material used for the heat transfer layers 113 and 213. It also simplifies the installation of the jacket heater 10 to the pipe 90.

[0053] (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 piping 90 from becoming low at the location of the thermostat 21.

[0054] (8) A method for manufacturing a jacket heater 10 to be attached to the outer circumference of a pipe 90 includes the steps of covering the heater wire 14 with an inner insulation layer 11, covering the outside of the inner insulation layer 11 with an outer insulation layer 12, and arranging a thermostat 21 on the outside of the inner insulation layer 11.

[0055] (9) The insulation structure for attachment to the outer circumference of the piping 90 comprises a heater wire 14, an inner insulation layer 11 positioned outside the heater wire 14, an outer insulation layer 12 positioned outside the inner insulation layer 11, and a thermostat 21 positioned outside the inner insulation layer 11.

[0056] The jacket heater proposed in this disclosure is not limited to the jacket heater 10 exemplified in Figure 1, etc. For example, the jacket heater proposed in this disclosure does not necessarily have to have a heat transfer layer 13.

Claims

1. A jacket heater that covers the outer circumference of a pipe, Heater wire and, A first insulating layer is placed on the outside of the heater wire, A second insulating layer is positioned outside the first insulating layer and covers the outside of the first insulating layer, A thermostat and A jacket heater that has this feature.

2. The thermostat is positioned between the first insulation layer and the second insulation layer. A jacket heater as described in claim 1.

3. The second insulation layer has a housing chamber formed therein, which is a hole or recess penetrating the second insulation layer, and the thermostat is positioned inside the housing chamber. A jacket heater as described in claim 1.

4. The device further comprises a heat transfer layer, which is disposed on the outside of the first insulation layer and is made of a material with a higher thermal conductivity than the first insulation layer and the second insulation layer. The thermostat is located outside the heat transfer layer. A jacket heater as described in claim 1.

5. The heat transfer layer is a metal layer disposed between the first insulating layer and the second insulating layer. A jacket heater as described in claim 4.

6. The heat transfer layer is positioned only on a portion of the jacket heater in at least one direction: the circumferential direction of the piping or the longitudinal direction of the piping. A jacket heater as described in claim 4.

7. The thermostat overlaps with a portion of the heater wire in the thickness direction of the jacket heater. The jacket heater according to claim 1.

8. A method for manufacturing a jacket heater to be attached to the outer circumference of a pipe, The process of covering the heater wire with the first insulation layer, The steps of placing a second insulation layer on the outside of the first insulation layer and covering the outside of the first insulation layer with the second insulation layer, Steps to place a thermostat on the outside of the first insulation layer. including A method for manufacturing a jacket heater.

9. An insulating structure for attachment to the outer circumference of a pipe, Heater wire and, A first insulating layer is placed on the outside of the heater wire, A second insulating layer is positioned outside the first insulating layer and covers the outside of the first insulating layer, A thermostat and An insulating structure that has this feature.

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