Flexible heater having improved welding joint

Abstract

Disclosed is a flexible heater having an improved welding joint. A flexible heater according to the present invention includes: a liner forming a gas channel for guiding a movement of gas; an outer bellows surrounding the outside of the liner and having a corrugated pipe shape; flange covers arranged at both ends of the outer bellows, respectively; outer bellows sleeves inserted into the outer sides of ends of the outer bellows; and outer flange sleeves which are arranged between the flange covers and the outer bellows sleeves and have ends coupled to the flange covers, wherein the outer bellows is welded together with the outer bellows sleeves and the outer flange sleeves.

Description

Flexible heater with improved weld joints

[0001] The present invention relates to a flexible heater used as a piping facility that guides the movement of a reaction gas or process gas in a manufacturing process of semiconductors, etc.

[0002] Typically, in manufacturing processes such as semiconductors, reaction gases or process gases are used in a process chamber, and when a specific process is completed, residual gases or reaction byproducts are discharged through a pipeline.

[0003] Figure 1 is a schematic diagram illustrating the exhaust process of gas exhausted in a typical semiconductor manufacturing process.

[0004] Referring to Fig. 1, after performing a chemical vapor deposition process in a conventional chemical vapor deposition facility, the exhaust gas from the process chamber (not shown) is discharged to a scrubber (Scrubber, 20) along a pipe line (10) by a vacuum pump (30) connected to the outlet side of the process chamber. At this time, the vacuum pump (10) sucks in the exhaust gas from the process chamber and then sends it along the pipe line (10) to the scrubber (20), and the scrubber (20) processes the exhaust gas flowing in along the pipe line (10).

[0005] However, there was a problem that fine powder in the form of dust was generated inside the pipe line (10) during the process in which the exhaust gas passed through the pipe line (10). If this powder condenses on the inner wall of the pipe line (10), an equipment error occurs due to a decrease in exhaust pressure, and if the pipe line (10) is blocked by the powder, the exhaust gas flows back, causing a process defect, and also causing a problem in which the performance of the vacuum pump (30) is deteriorated. It was confirmed that the generation of the powder as described above occurs significantly when the temperature of the exhaust gas moving along the pipe line (10) drops below the set temperature range, and it was confirmed that it decreases when the temperature of the exhaust gas moving along the pipe line (10) is maintained within the set temperature range.

[0006] In addition, the piping line (10) should be formed in a curved shape rather than a straight shape depending on the installation location of the process chamber and the scrubber (20). However, if the piping line (10) is bent sharply at a specific location, the generation of powder increases at the bent portion of the piping line (10), so it is necessary to bend the piping line (10) in a smooth curved shape.

[0007] Accordingly, recently, a flexible heater that is easy to bend and can heat exhaust gas has been used as a pipe line (10). The flexible heater can be smoothly bent into a corrugated pipe shape and is equipped with a heating wire, so that the temperature of the exhaust gas can be controlled using the heat of the heating wire.

[0008] Here, the flexible heater (11) includes a bellows (11b) and a flange (11a) in the shape of a corrugated pipe as shown in Fig. 1. At this time, the flange (11a) is a piping component for connecting both ends of the bellows (11b) to a vacuum pump (30) or a scrubber (20), and is connected to the bellows (11b) by direct welding.

[0009] However, despite the efforts to apply the flexible heater (11) to the pipe line (10), due to issues such as narrow space, the flexible heater (11) has no choice but to be bent at almost 90 degrees as in areas 'A' and 'B' of Fig. 1 to be connected to the vacuum pump (30) or scrubber (20). In this process, if the flexible heater (11) is bent forcibly, cracks or tears (bursts) occur at the welded joint between the flange (11a) and bellows (11b) of the flexible heater (11), resulting in a problem of exhaust gas leaking from the welded joint.

[0010] Accordingly, there is an urgent need for research and development of an improved weld joint structure for a flexible heater that prevents cracks or tears from occurring at the weld joint between the bellows and the flange even when the bellows of the flexible heater is forcibly bent.

[0011] Related prior art documents include Korean Patent Publication No. 10-1891731 (Title: Flexible heater, Publication date: August 27, 2018), Korean Patent Publication No. 10-1530612 (Title: Temperature control system for heating pipe, Publication date: June 22, 2015), and Korean Patent Publication No. 10-1899336 (Title: Flexible heater and gas leak detection system for flexible heater, Publication date: September 17, 2018).

[0012] The purpose of the present invention is to provide a flexible heater that can prevent gas leakage from a welded joint by improving the welded joint structure so that cracks or tears do not occur at the welded joint between a bellows and a flange while reducing the number of welding points even when the flexible heater is bent forcibly or at a sharp angle during the process of connecting the flexible heater to a vacuum pump or scrubber, etc.

[0013] In addition, another object of the present invention is to provide a flexible heater that allows a worker to easily perform the clamping operation despite a narrow working space during the process of fastening a clamp to a flange of the flexible heater in order to connect the flange of the flexible heater to a vacuum pump or scrubber, etc.

[0014] The above object is achieved by a flexible heater with an improved weld joint, according to one embodiment of the present invention, comprising: a liner forming a gas path for guiding the movement of gas; an outer bellows in the shape of a corrugated pipe surrounding the outside of the liner; a flange cover disposed at each end of the outer bellows; an outer bellows sleeve fitted to the outside of an end of the outer bellows; and an outer flange sleeve disposed between the flange cover and the outer bellows sleeve and having one end joined to the flange cover, wherein the outer bellows is welded together with the outer bellows sleeve and the outer flange sleeve.

[0015] Preferably, the end of the outer bellows may be provided with a joint flange portion that extends radially outward and is welded together while being interposed between the outer bellows sleeve and the outer flange sleeve.

[0016] Preferably, the joint flange portion of the outer bellows can protrude radially outwardly with respect to the outer bellows sleeve and the outer flange sleeve while being interposed between the outer bellows sleeve and the outer flange sleeve.

[0017] Preferably, the flexible heater further includes an inner bellows in the shape of a corrugated pipe disposed between the outer bellows and the liner, a flange pipe penetrating the flange cover and connected to both ends of the liner so as to communicate with both ends of the gas path of the liner so that the gas can be introduced or discharged, an inner bellows sleeve fitted to the outside of an end of the inner bellows, and an inner flange sleeve disposed between the flange pipe and the inner bellows sleeve and having one end joined to the flange pipe, wherein the inner bellows can be welded together with the inner bellows sleeve and the inner flange sleeve.

[0018] Preferably, a joint flange portion may be provided at the end of the inner bellows, which extends radially outward and is welded together while interposed between the inner bellows sleeve and the inner flange sleeve.

[0019] Preferably, the joint flange portion of the inner bellows can protrude radially outwardly with respect to the inner bellows sleeve and the inner flange sleeve while being interposed between the inner bellows sleeve and the inner flange sleeve.

[0020] Preferably, the flexible heater may further include a liner sleeve inserted and positioned inside the liner and welded together with the inner bellows sleeve and the inner flange sleeve.

[0021] Preferably, the end of the liner sleeve may be provided with a joint flange portion that extends radially outward and is welded together while being interposed between the inner bellows sleeve and the inner flange sleeve.

[0022] Preferably, the joint flange portion of the liner sleeve may protrude radially outwardly with respect to the inner bellows sleeve and the inner flange sleeve while being interposed between the inner bellows sleeve and the inner flange sleeve.

[0023] Preferably, each of the welded end of the outer bellows sleeve and the welded end of the outer flange sleeve may be provided with a joint flange portion that extends radially outward and is welded together with the outer bellows. In addition, each of the outer circumferential surface of the outer bellows sleeve and the outer circumferential surface of the outer flange sleeve may have a diameter that gradually increases toward the welded end along the longitudinal direction of the flexible heater.

[0024] Preferably, each of the welded end of the inner bellows sleeve and the welded end of the inner flange sleeve may be provided with a joint flange portion that extends radially outward and is welded together with the inner bellows. In addition, each of the outer circumference of the inner bellows sleeve and the outer circumference of the inner flange sleeve may have a diameter that gradually increases toward the welded end along the longitudinal direction of the flexible heater.

[0025] Preferably, one end of the inner flange sleeve may be welded to the flange pipe, and one end of the outer flange sleeve may be welded to the flange cover.

[0026] Preferably, the flange pipe is provided with a clamp fastening flange portion protruding outward from the flange cover along the longitudinal direction of the flexible heater to which a clamp is fastened, and the flange cover is provided with a clamp fastening space portion to facilitate fastening of the clamp to the clamp fastening flange portion, and the clamp fastening space portion may be provided by having an outer circumferential surface of the flange cover gradually decrease in diameter toward the clamp fastening flange portion along the longitudinal direction of the flexible heater.

[0027] According to a flexible heater according to one embodiment of the present invention, by applying an outer bellows sleeve and an outer flange sleeve in the welded joint structure of the outer bellows and the flange cover, or applying an inner bellows sleeve and an inner flange sleeve in the welded joint structure of the inner bellows and the flange pipe, the welded joint structure is improved so that cracks or tears do not occur at the welded joint portion between the bellows and the flange even when the flexible heater is bent forcibly or at a sharp angle in the process of connecting the flexible heater to a vacuum pump or a scrubber, etc., while reducing the number of welding points, thereby preventing gas leakage at the welded joint portion.

[0028] In addition, according to the flexible heater according to one embodiment of the present invention, the outer circumferential surface of the flange cover provides a clamp fastening space portion whose diameter gradually decreases along the longitudinal direction of the flexible heater toward the clamp fastening flange portion of the flange pipe, so that, in the process of fastening a clamp to the flange pipe of the flexible heater to connect the flange pipe of the flexible heater to a vacuum pump or scrubber, etc., a worker can easily perform the clamp fastening work despite a narrow working space.

[0029] Figure 1 is a schematic diagram illustrating the exhaust process of gas exhausted in a typical semiconductor manufacturing process.

[0030] FIG. 2 is a drawing showing the appearance of a flexible heater according to one embodiment of the present invention.

[0031] Fig. 3 is a drawing showing the internal structure of the flexible heater illustrated in Fig. 2.

[0032] Fig. 4 is an exploded perspective view of the welded joint structure between the outer bellows and the flange cover in the flexible heater illustrated in Fig. 2.

[0033] Fig. 5 is an exploded perspective view of the welded joint structure between the inner bellows and the flange pipe illustrated in Fig. 2.

[0034] Fig. 6 is a drawing showing a clamp fastened to a flange pipe in the flexible heater illustrated in Fig. 2.

[0035] In order to fully understand the present invention, its operational advantages, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

[0036] Hereinafter, the present invention will be described in detail by describing preferred embodiments thereof with reference to the attached drawings. However, in explaining the present invention, descriptions of previously known functions or configurations will be omitted to clarify the gist of the present invention.

[0037] FIG. 2 is a drawing showing the exterior of a flexible heater according to one embodiment of the present invention, and FIG. 3 is a drawing showing the internal structure of the flexible heater shown in FIG. 2. In addition, FIG. 4 is an exploded perspective view of the welded joint structure between the outer bellows and the flange cover in the flexible heater shown in FIG. 2, and FIG. 5 is an exploded perspective view of the welded joint structure between the inner bellows and the flange pipe shown in FIG. 2.

[0038] Referring to FIGS. 2 to 5, a flexible heater (100) according to one embodiment of the present invention includes a liner (110), bellows (120, 130), a heating wire (140), a flange cover (150), and a flange pipe (160). For reference, unless otherwise stated in this specification, 'longitudinal direction' means the longitudinal direction of the flexible heater (100), and 'radial direction' means the radial direction of the flexible heater (100).

[0039] A liner (110) is a tubular member that forms a gas path to guide the movement of various gases generated during the manufacturing process of semiconductors, etc. This liner (110) is formed with an interlock structure so that it can be freely bent.

[0040] The bellows (120, 130) include an outer bellows (120) surrounding the outside of the liner (110), and an inner bellows (130) arranged between the outer bellows (120) and the liner (110). That is, the liner (110), the inner bellows (130), and the outer bellows (120) provide a multi-pipe structure in which they are sequentially overlapped. Accordingly, gas leaking from the liner (110) can be doubly blocked from leaking by the inner bellows (130) and the outer bellows (120). That is, since the bellows (120, 130) have a double-corrugated pipe structure of the outer bellows (120) and the inner bellows (130), even if either one is damaged, the leakage of exhaust gas can be stably blocked by the other one. However, in the present invention, the bellows is not limited to the double corrugated pipe structure of the outer bellows (120) and the inner bellows (130), and may be provided as a single corrugated pipe structure of only the outer bellows (120).

[0041] The outer bellows (120) is a member in the shape of a corrugated tube that surrounds the outer side of the inner bellows (130). The outer bellows (120) is made of a metal material with excellent corrosion resistance, and has grooves and ridges formed so that it can be bent smoothly.

[0042] The inner bellows (130) is a corrugated pipe-shaped member that surrounds the outside of the liner (110). Like the outer bellows (120), the inner bellows (130) is made of a metal material with excellent corrosion resistance, and has grooves and ridges to enable smooth bending. Meanwhile, the inner bellows (130) may be formed in two layers to enhance the safety of the flexible heater (100).

[0043] The heating wire (140) is a sheath heater that generates heat when electricity is supplied, and is a means for heating the gas moving through the liner (110) so that the temperature of the gas is maintained at a predetermined temperature. As shown in FIG. 3, the heating wire (140) is arranged to wrap around the outer side of the inner bellows (130) and the flange pipe (160) in a spiral shape along the length direction. Accordingly, the inner bellows (130) and the flange pipe (160) are directly heated by the heat generated from the heating wire (140), and the gas moving along the liner (110) and the flange pipe (160) can also be heated together.

[0044] The flange cover (150) is a member that is connected to both ends of the outer bellows (120) and surrounds the outside of the flange pipe (160). These flange covers (150) may be formed with the same shape at both ends of the flexible heater (100) or may be formed with different shapes. For example, the flange cover (150) located on the right side in FIG. 2 may be formed longer than the flange cover (150) located on the left side in FIG. 2 to secure a space for mounting a power supply device (300), a gas leak detection device (310), etc.

[0045] One end face of the flange cover (150) has an open structure so as to be in communication with the outer bellows (120), and is joined to the outer bellows (120) by a welding joint structure described later. In addition, the other end face of the flange cover (150) is formed with a flange penetration hole (150a) so that the flange pipe (160) protrudes to the outside of the flange cover (150).

[0046] The flange pipe (160) is a tubular member that is connected to both ends of the gas path of the liner (110) so that gas is introduced into the liner (110) through a vacuum pump (30, see FIG. 1) or gas is discharged from the liner (110) to a scrubber (20, see FIG. 1). This flange pipe (160) is connected to both ends of the liner (110) by penetrating the flange cover (150) through the flange penetration hole (150a) of the flange cover (150). At this time, the flange pipe (160) is joined to the flange cover (150) by welding along the perimeter of the flange penetration hole (150a) of the flange cover (150) so that the space between the flange pipe (160) and the flange cover (150) surrounding the outside thereof is blocked or sealed from the outside.

[0047] Hereinafter, the welding joint structure of the outer bellows (120) and the flange cover (150) in the flexible heater (100) according to one embodiment of the present invention will be described in detail.

[0048] Referring to FIGS. 2, 3, and 4, a flexible heater (100) according to one embodiment of the present invention further includes an outer bellows sleeve (200) and an outer flange sleeve (210). Here, the outer bellows (120) is welded together with the outer bellows sleeve (200) and the outer flange sleeve (210). Preferably, a joint flange portion (121) is provided at the end of the outer bellows (120) so as to extend radially outward and be welded together while being interposed between the outer bellows sleeve (210) and the outer flange sleeve (210), as shown in the 'C' area of ​​FIG. 3.

[0049] The outer bellows sleeve (200) is a sleeve-shaped member that is fitted to the outside of the end of the outer bellows (120) as illustrated in FIG. 3, and is arranged such that its inner surface contacts the horizontal end (122) of the outer bellows (120) without wrinkles. At this time, the inner surface (202) of the outer bellows sleeve (200) is formed with a constant inner diameter for the most part (202a), but includes an expansion portion (202b) in which the inner diameter gradually increases, thereby preventing the outer bellows (120), which has a very thin thickness compared to the outer bellows sleeve (200), from being damaged by the edge of the outer bellows sleeve (200) when the outer bellows (120) is bent. In addition, the outer bellows sleeve (200) is formed with a certain width between the inner diameter and the outer diameter of the outer bellows sleeve (200) in the radial direction so as to ensure sufficient contact area with the joint flange portion (121) of the outer bellows (120).

[0050] Meanwhile, the outer circumference (203) of the outer bellows sleeve (200) is preferably formed as a sloped surface with a diameter that gradually increases toward the end to be welded along the longitudinal direction, that is, the outer diameter of the outer bellows sleeve (200) is preferably gradually increased toward the end to be welded along the longitudinal direction, in order to improve the convenience of welding work by protruding the welded joint portion (W1) as far outward as possible in the radial direction.

[0051] In addition, it is preferable that a joint flange portion (201) be provided at the end of the outer bellows sleeve (200) that comes into contact with the joint flange portion (121) of the outer bellows (120), i.e., at the welded joint end of the outer bellows sleeve (200). The joint flange portion (201) of the outer bellows sleeve (200) extends radially outward and has an outer circumferential surface formed as a horizontal plane rather than an inclined plane. The joint flange portion (201) of the outer bellows sleeve (200) is welded to the joint flange portion (121) of the outer bellows (120) while supporting the end of the joint flange portion (121) of the outer bellows (120) together with the joint flange portion (211) of the outer flange sleeve (210) to be described later, thereby improving the convenience of the welding work and also contributing to improving the strength and rigidity of the welded joint portion (W1).

[0052] The outer flange sleeve (210) is a sleeve-shaped member that is arranged between the flange cover (150) and the outer bellows sleeve (200) as shown in FIG. 3 and has one end joined to the flange cover (150). It has an external shape almost identical to that of the outer bellows sleeve (200) described above and is arranged symmetrically left and right with respect to the outer bellows sleeve (200).

[0053] Here, the outer flange sleeve (210) is welded at one end to the flange cover (150), and specifically, the outer flange sleeve (210) can be integrally joined by a welding joint (W2) between the outer bellows sleeve (200) and the flange cover (150) in a state where the flange cover (150) side end surface (212) of the outer flange sleeve (210) is in contact with the end surface of the flange cover (150). In addition, it is preferable that the inner circumferential surface (213) of the outer flange sleeve (210) be uniformly formed with a diameter substantially the same size as the inner diameter of the flange cover (150) in order to secure an integral structure with the flange cover (150).

[0054] This outer flange sleeve (210) includes substantially the same detailed configuration as the above-described outer bellows sleeve (200), and the operational effects due to these detailed configurations are also the same.

[0055] Specifically, the outer flange sleeve (210) is formed with a constant width between the inner diameter and the outer diameter of the outer flange sleeve (210) in the radial direction so as to secure a sufficient contact area with the joint flange portion (121) of the outer bellows (120). In addition, the outer peripheral surface (214) of the outer flange sleeve (210) gradually increases in diameter toward the end where the welding is performed along the longitudinal direction to form a slope, that is, the outer diameter of the outer flange sleeve (210) gradually increases toward the end where the welding is performed along the longitudinal direction.

[0056] In addition, at the end of the outer flange sleeve (210) that comes into contact with the joint flange portion (121) of the outer bellows (120), i.e., at the welded joint end of the outer flange sleeve (210), a joint flange portion (211) that extends radially outward and has an outer circumference formed as a horizontal plane rather than an inclined plane is provided, and the joint flange portion (211) of the outer flange sleeve (210) is welded to the joint flange portion (121) of the outer bellows (120) while supporting the end of the joint flange portion (121) of the outer bellows (120) together with the joint flange portion (201) of the outer bellows sleeve (200) described above.

[0057] Meanwhile, the joint flange portion (121) of the outer bellows (120) is interposed between the outer bellows sleeve (200) and the outer flange sleeve (210) as illustrated in FIG. 3 and comes into surface contact with the outer bellows sleeve (200) and the outer flange sleeve (210). At this time, the joint flange portion (121) of the outer bellows (120) may be formed as a vertical end portion that extends radially outward at a 90-degree bend from the horizontal end portion (122) of the outer bellows (120) that does not have wrinkles. Accordingly, the outer bellows (120) can be welded integrally with the outer bellows sleeve (200) and the outer flange sleeve (210) with one welding line (point) while the joint flange portion (121) is interposed between the outer bellows sleeve (200) and the outer flange sleeve (210).

[0058] Here, the joint flange portion (121) of the outer bellows (120) is preferably formed so that its end protrudes radially outwardly with respect to the outer bellows sleeve (200) and the outer flange sleeve (210) while being interposed between the outer bellows sleeve (200) and the outer flange sleeve (210), that is, the outer diameter of the joint flange portion (121) of the outer bellows (120) is formed larger than the outer diameters of the outer bellows sleeve (200) and the outer flange sleeve (210). This means that even if the joint flange portion (121) of the relatively thin outer bellows (120) having a relatively thin thickness compared to the outer bellows sleeve (200) and the outer flange sleeve (210) is welded while being interposed between the outer bellows sleeve (200) and the outer flange sleeve (210), the outer bellows (120) This is to improve the strength and rigidity of the welded joint portion (W1) by exposing the end of the joint flange portion (121) to the outside. At this time, the end of the joint flange portion (121) of the outer bellows (120) is supported in contact by the joint flange portion (201) of the outer bellows sleeve (200) and the joint flange portion (211) of the outer flange sleeve (210), as described above.

[0059] By the above configuration, the outer bellows (120) and the flange cover (150) can be joined to each other by performing a single welding operation along the outer circumference while the joint flange portion (121) of the outer bellows (120) is interposed between the outer bellows sleeve (200) and the outer flange sleeve (210), and sufficient joining strength or rigidity of the outer bellows (120) and the flange cover (150) can be stably secured by the structural characteristics of the outer bellows sleeve (200) and the outer flange sleeve (210).

[0060] Hereinafter, the welding joint structure of the inner bellows (130) and the flange pipe (160) in the flexible heater (100) according to one embodiment of the present invention will be described in detail.

[0061] Referring to FIGS. 2, 3, and 5, a flexible heater (100) according to one embodiment of the present invention further includes an inner bellows sleeve (220) and an inner flange sleeve (230). Here, the inner bellows (130) is welded together with the inner bellows sleeve (220) and the inner flange sleeve (230). Preferably, a joint flange portion (131) is provided at the end of the inner bellows (130) so as to extend radially outward and be welded together while being interposed between the inner bellows sleeve (220) and the inner flange sleeve (230), as shown in the 'D' region of FIG. 3.

[0062] The inner bellows sleeve (220) is a sleeve-shaped member that is fitted to the outer end of the inner bellows (130) as shown in FIG. 3, and is arranged so that its inner circumferential surface is in contact with the horizontal end (132) without wrinkles of the inner bellows (130).

[0063] The inner flange sleeve (230) is a sleeve-shaped member that is arranged between the flange pipe (160) and the inner bellows sleeve (220) as shown in FIG. 3 and has one end joined to the flange pipe (160). It has an external shape almost identical to that of the inner bellows sleeve (220) and is arranged symmetrically left and right with respect to the inner bellows sleeve (220).

[0064] And, as illustrated in Fig. 3, the joint flange portion (131) of the inner bellows (130) is interposed between the inner bellows sleeve (220) and the inner flange sleeve (230) and is in surface contact with the inner bellows sleeve (220) and the inner flange sleeve (230). At this time, the joint flange portion (131) of the inner bellows (130) may be formed as a vertical end portion that extends radially outward at a 90-degree bend from the horizontal end portion (132) of the inner bellows (130) that does not have wrinkles. Accordingly, the inner bellows (130) can be welded integrally with the inner bellows sleeve (220) and the inner flange sleeve (230) with one welding line (point) while the joint flange portion (131) is interposed between the inner bellows sleeve (220) and the inner flange sleeve (230).

[0065] By the above configuration, the inner bellows (130) and the flange pipe (150) can be joined to each other by performing a single welding operation along the outer circumference while the joint flange portion (131) of the inner bellows (130) is interposed between the inner bellows sleeve (220) and the inner flange sleeve (230), and sufficient joining strength or rigidity of the inner bellows (130) and the flange pipe (160) can be stably secured by the structural characteristics of the inner bellows sleeve (220) and the inner flange sleeve (230).

[0066] Meanwhile, in the welded joint structure of the inner bellows (130) and the flange pipe (160), the inner bellows sleeve (220), the inner flange sleeve (230) and the joint flange portion (131) of the inner bellows correspond to the outer bellows sleeve (200), the outer flange sleeve (210) and the joint flange portion (121) of the outer bellows in the welded joint structure of the outer bellows (120) and the flange cover (150), respectively, and since the detailed configuration is substantially the same, the detailed description of the same detailed configuration will be applied to the description of the outer bellows sleeve (200), the outer flange sleeve (210) and the joint flange portion (121) of the outer bellows above.

[0067] Referring to FIGS. 2, 3 and 5, a flexible heater (100) according to one embodiment of the present invention further includes a liner sleeve (240).

[0068] The liner sleeve (240) is inserted and positioned inside the liner (110) and welded together with the inner bellows sleeve (220) and the inner flange sleeve, and includes a sleeve body portion (242) inserted into the gas path of the liner (110), and a joint flange portion (241) interposed between the inner bellows sleeve (220) and the inner flange sleeve (230).

[0069] Here, the joint flange portion (241) of the liner sleeve (240) is provided to extend radially outwardly to the end of the liner sleeve (240), and is welded together while being interposed between the inner bellows sleeve (220) and the inner flange sleeve (230). Specifically, the joint flange portion (241) of the liner sleeve (240) is interposed between the inner bellows sleeve (220) and the inner flange sleeve (230), as illustrated in the 'D' region of FIG. 3, and is in surface contact with the joint flange portion (131) of the inner bellows (130) and the inner flange sleeve (230). At this time, the joint flange portion (241) of the liner sleeve (240) may be formed in a structure in which it is bent 90 degrees radially outwardly from the sleeve body portion (242).

[0070] Accordingly, since the joint flange portion (241) of the liner sleeve (240) is interposed between the inner bellows sleeve (220) and the inner flange sleeve (230) together with the joint flange portion (131) of the inner bellows (130) described above, the liner sleeve (240), the inner bellows (130), the inner bellows sleeve (220), and the inner flange sleeve (230) can be welded together as one piece with a single welding line (point).

[0071] Meanwhile, the joint flange portion (241) of the liner sleeve (240) is preferably formed so that its end protrudes radially outward with respect to the inner bellows sleeve (220) and the inner flange sleeve (230) while being interposed between the inner bellows sleeve (220) and the inner flange sleeve (230), similar to the joint flange portion (131) of the inner bellows (130), that is, the outer diameter of the joint flange portion (241) of the liner sleeve (240) is formed larger than the outer diameters of the inner bellows sleeve (220) and the inner flange sleeve (230). This means that even if the joint flange portion (241) of the liner sleeve (240) is welded while being interposed between the inner bellows sleeve (220) and the inner flange sleeve (230), the end of the joint flange portion (241) of the liner sleeve (240) is exposed to the outside during welding. This is to improve the strength and rigidity of the joint area (W1).

[0072] By the configuration of the liner sleeve (240) as above, the liner (110) can be supported more firmly and can be stably connected to the flange pipe (160) through the welding joint of the liner sleeve (240) to the inner bellows sleeve (220) and the inner flange sleeve (230).

[0073] Fig. 6 is a drawing showing a clamp fastened to a flange pipe in the flexible heater illustrated in Fig. 2.

[0074] Referring to FIGS. 2, 3, and 6, in a flexible heater (100) according to one embodiment of the present invention, a flange pipe (160) is provided with a clamp fastening flange portion (161) that protrudes outward from a flange cover (150) along the longitudinal direction and to which a clamp (170) is fastened, and the flange cover (150) is provided with a clamp fastening space portion that facilitates fastening of the clamp (170) to the clamp fastening flange portion (161).

[0075] The clamp fastening flange portion (161) of the flange pipe (160) is a portion that is fastened to the pipe line (31) of the vacuum pump (30) by a clamp (170) or to the pipe line (21) of the scrubber (20) by a clamp (not shown) in order to connect the flange pipe (160) to a vacuum pump (30, see FIG. 1) or a scrubber (20, see FIG. 1).

[0076] The clamp fastening space of the flange cover (150) is intended to solve the problem of difficulty in fastening the clamp (170) due to a narrow working space during the process of fastening the clamp (170) to connect the flange pipe (160) to the vacuum pump (30) or scrubber (20), and it is preferable that the outer circumferential surface (151) of the flange cover (150) be provided with a diameter that gradually decreases along the longitudinal direction toward the clamp fastening flange portion (161).

[0077] By configuring the clamp fastening space of the flange cover (150), sufficient surrounding space is secured during the fastening operation of the clamp (170) compared to a conventional flange cover formed with a constant outer diameter, so that the worker can easily perform the fastening operation of the clamp (170) to the clamp fastening flange portion (161).

[0078] While the present invention has been described in detail through preferred embodiments thereof, it will be apparent to those skilled in the art that the present invention is not limited to the aforementioned preferred embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, such modifications and variations should fall within the scope of the claims of the present invention.

[0079] The present invention can be widely used in the field of piping equipment that guides the movement of reaction gases or process gases in the manufacturing process of semiconductors, etc.

Claims

1. A liner forming a gas path to guide the movement of gas; An outer bellows in the shape of a corrugated tube surrounding the outer side of the above liner; Flange covers arranged at each end of the outer bellows; An outer bellows sleeve fitted to the outer end of the outer bellows; and An outer flange sleeve disposed between the flange cover and the outer bellows sleeve, one end of which is joined to the flange cover. Including, The above outer bellows A flexible heater with improved welding joint characterized by being welded together with the outer bellows sleeve and the outer flange sleeve.

2. In paragraph 1, A flexible heater with improved welding joint, characterized in that a joint flange portion is provided at the end of the outer bellows, which extends radially outward and is welded together while interposed between the outer bellows sleeve and the outer flange sleeve.

3. In paragraph 2, The joint flange portion of the above outer bellows A flexible heater with improved welding joint, characterized in that the weld joint protrudes radially outwardly with respect to the outer bellows sleeve and the outer flange sleeve while being interposed between the outer bellows sleeve and the outer flange sleeve.

4. In paragraph 1, An inner bellows in the shape of a corrugated pipe arranged between the outer bellows and the liner; A flange pipe which is connected to each end of the liner by penetrating the flange cover so that the gas can be introduced or discharged by communicating with each end of the gas path of the liner; An inner bellows sleeve fitted to the outer end of the inner bellows; An inner flange sleeve arranged between the above flange pipe and the above inner bellows sleeve, one end of which is joined to the above flange pipe. Including more, The inner bellows above A flexible heater with improved welding joint characterized by being welded together with the inner bellows sleeve and the inner flange sleeve.

5. In paragraph 4, A flexible heater with improved welding joint, characterized in that a joint flange portion is provided at the end of the inner bellows, which extends radially outward and is welded together while interposed between the inner bellows sleeve and the inner flange sleeve.

6. In paragraph 4, A liner sleeve inserted and placed inside the liner and welded together with the inner bellows sleeve and the inner flange sleeve. A flexible heater having an improved welded joint characterized by further including:

7. In paragraph 6, A flexible heater with improved welding joint, characterized in that a joint flange portion is provided at the end of the liner sleeve, which extends radially outward and is welded together while interposed between the inner bellows sleeve and the inner flange sleeve.

8. In paragraph 1, A flexible heater with improved welding joints, characterized in that each of the welded end of the outer bellows sleeve and the welded end of the outer flange sleeve is provided with a welding flange portion that extends radially outward and is welded together with the outer bellows.

9. In paragraph 4, A flexible heater with improved welding joints, characterized in that each of the welded end of the inner bellows sleeve and the welded end of the inner flange sleeve is provided with a welding flange portion that extends radially outward and is welded together with the inner bellows.

10. In paragraph 4, The above flange pipe is provided with a clamp fastening flange portion that protrudes outward from the flange cover along the longitudinal direction of the flexible heater and to which a clamp is fastened. The above flange cover is provided with a clamp fastening space to facilitate fastening of the clamp to the clamp fastening flange portion. A flexible heater with improved welding joints, characterized in that the clamp fastening space portion is provided by having the outer circumferential surface of the flange cover gradually decrease in diameter toward the clamp fastening flange portion along the longitudinal direction of the flexible heater.

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