Sealing structure for explosion-proof junction box of electric tracing band and explosion-proof junction box

Abstract

The invention discloses a sealing structure for an explosion-proof junction box of an electric tracing band and the explosion-proof junction box, and belongs to the field of junction boxes. Comprising a box body and a support structure, and a mounting port for containing a sealing structure is formed in the support structure. The charging valve is arranged on the box body of the junction box, inert gas can be charged into the internal space of the box body, the pressure sensor and the detection sensor are respectively arranged inside and outside the box body, and whether leakage or sealing failure exists can be judged by detecting the internal pressure condition of the box body, whether target inert gas exists outside the box body and the like. And if yes, an alarm can be given out for timely processing. The gasket and the compression spring are arranged between the sealing main body and the gland of the sealing structure, so that the pressing effect of the sealing structure is effectively ensured, the elasticity of the compression spring can be compensated even if the gland is loosened due to various reasons, and the sealing effect failure caused by the loosening of the sealing structure is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of junction boxes, in particular to a sealing structure for an explosion-proof junction box for an electric heat tracing band. BACKGROUND

[0002] An electric heat tracing band is a heat tracing and insulation product used for pipes, tanks, equipment, etc. It converts electrical energy into heat to provide heat to the pipes or equipment to prevent freezing or maintain them within a certain temperature range. The electric heat tracing band is mainly composed of a heating core wire, an insulation layer, a shielding layer and a sheath. When an electric current passes through the heating core wire, the core wire generates heat, and the heat is transferred to the surface of the pipe or equipment through the insulation layer, thereby achieving the purpose of heat preservation or anti-freezing. Its working principle is similar to that of an electric blanket, but it is specially used in industrial applications.

[0003] An electric heat tracing band explosion-proof power junction box is an electrical connection device designed specifically for flammable and explosive environments, mainly used for power distribution, line connection and safety protection of electric heat tracing systems. Its core function is to ensure the safe operation of the electric heat tracing band in flammable and explosive environments, preventing internal electric arcs, sparks or high temperatures from causing explosions. In order to ensure that the explosion energy is limited within the shell when internal short circuit, electric arc or overheating occurs, a high-strength material shell (such as aluminum alloy, stainless steel, engineering plastic, etc.) is used, the internal cavity can withstand explosion pressure, and sealing elements are installed at the connection position of the box cover and the box body and the cable passing port position to ensure sealing, ensuring that the flame cannot penetrate.

[0004] The existing explosion-proof junction box mainly includes a box body and a bottom support, wherein the bottom support is used for passing cables, and a sealing element is installed in the port of the cable passing cable. The sealing element is adapted to the passing cable and is used to squeeze the cable to achieve sealing. The sealing element is installed in the port of the support body, and then fixed and pressed by an external gland to achieve the sealing element holding the cable. The gland is fixed and connected to the support body by a bolt, and is fixed once.

[0005] However, the sealing element structure installed on the support part of the existing explosion-proof junction box is relatively simple. Since the support part is generally directly connected to the related equipment, it is easily affected by the vibration generated during the operation of some equipment. The gland is fixed and connected to the support body by a bolt and is fixed once. With the influence of external factors and the passage of time, the gland part may become loose. Once it becomes loose, the sealing sleeve will also become loose, which may cause the sealing to fail. SUMMARY

[0006] The present application provides a sealing structure for an explosion-proof junction box for an electric heat tracing band and an explosion-proof junction box, which can solve the problem of easy loosening of the sealing element in the existing explosion-proof junction box, leading to sealing failure.

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] A sealing structure for an explosion-proof junction box of an electric heat tracing band, comprising:

[0009] A sealing body, a through channel being formed in the sealing body, the outer diameter of the two ends of the sealing body being consistent with the inner diameter of the port of the installation position, at least one tightening portion being arranged at the middle portion of the sealing body, the outer diameter and the inner diameter of the position of the tightening portion being smaller than the outer diameter and the inner diameter of the two ends of the sealing body;

[0010] A tightening sleeve, one end of the tightening sleeve being larger in size than the other end, and being made of elastic material, the tightening sleeve being arranged at the position of the tightening portion, and the larger end of the tightening sleeve being fixedly connected to the inner wall of the sealing body.

[0011] In one scheme of the present application: the smaller end of the tightening sleeve is directed towards the position of the junction box.

[0012] In one scheme of the present application: the tightening sleeve is a thin-walled structure in the shape of a horn.

[0013] In one scheme of the present application: a cushion layer is arranged outside the sealing body, one end of the cushion layer being fixedly connected to the end outer wall of the sealing body, and the other end of the cushion layer being arranged in a gap with the outer wall of the sealing body.

[0014] In one scheme of the present application: an expansion portion is arranged on the outer wall of the sealing body, and the expansion portion is located inside the cushion layer.

[0015] In one scheme of the present application: the expansion portion is in communication with a gas source through a gas channel.

[0016] An explosion-proof junction box for an electric heat tracing band, comprising a fixedly connected box body and a support structure, an installation port for accommodating the sealing structure as described above being formed in the support structure, a gland being fixedly connected to the end of the installation port away from the box body, and a gasket being arranged between the end of the sealing structure and the gland.

[0017] In one scheme of the present application: a compression spring is arranged between the gasket and the gland.

[0018] In one scheme of the present application: a one-way inflation valve is arranged on the box body and is in communication with the internal space of the box body, for inflating inert gas into the internal space of the junction box after the installation of the junction box is completed, and a pressure sensor is arranged in the box body.

[0019] In one scheme of the present application: a detection sensor is arranged at the end of the installation port away from the box body.

[0020] According to the sealing structure and the explosion-proof junction box for the electric heat tracing band, at least one of the following technical effects is achieved.

[0021] By arranging the inflation valve on the box body of the junction box, inert gas can be filled into the space inside the box body, on the one hand, the inert gas can reduce the oxidation aging speed of the electrical structure inside the box body and prolong the service life, on the other hand, the inert gas can inhibit the electric arc, spark and the like, and reduce the explosion probability. Meanwhile, the pressure sensor and the detection sensor are arranged inside and outside the box body respectively, the pressure condition inside the box body and whether the target inert gas exists outside the box body are detected, whether there is leakage or sealing failure is judged, if there is, an alarm can be sent to process in time. The gasket and the compression spring are arranged between the sealing main body and the gland of the sealing structure, the compression effect of the sealing structure is effectively ensured, even if the gland is loosened due to various reasons, the elastic force of the compression spring can compensate, the compression of the sealing structure is ensured, and the sealing effect caused by the loosening of the sealing structure is avoided.

[0022] The middle part of the sealing main body of the sealing structure is provided with a tightening part, so that after the threading is completed and the compression of the gland, the two ends of the sealing main body are extruded by the gland, the axial deformation and shortening of the sealing main body are promoted, at the same time, the sealing main body is inwards contracted at the position of the tightening part in the radial direction, so as to effectively compress the cable, and the sealing performance is ensured. Further, the tightening sleeve is arranged at the position of the tightening part, the elastic deformation of the tightening sleeve is arranged, when the cable passes through, the tightening sleeve can be effectively clamped on the outer insulating skin of the cable, the sealing performance at the position is ensured, and since the tightening sleeve is a thin-walled structure, the radial deformation of the sealing main body at the position of the tightening part does not hinder the extrusion of the cable, when the sealing sleeve generates a gap with the cable due to thermal expansion and contraction, the elastic tapered sleeve can also fill the gap, and the sealing effect is ensured.

[0023] The outer part of the sealing main body is provided with a gasket, and the outer wall of the sealing main body is provided with an expansion part, the expansion part is located on the inner side of the gasket, when the control system of the background judges that there is a leakage or a sealing failure, gas can be introduced into the expansion part to increase the volume of the expansion part, and then extrude the inner wall of the gasket, so as to make the gasket deform outward to tightly adhere to the inner wall of the mounting port, and temporarily enhance the sealing effect of the mounting port. When the maintenance personnel arrive at the scene, the complete repair is carried out. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 Structure diagram of an embodiment of the junction box of the present application;

[0026] Figure 2 Structure diagram of a two-way junction box of the present application;

[0027] Figure 3 Structure diagram of a three-way junction box of the present application;

[0028] Figure 4 Structure diagram of the cooperation between the sealing structure and the support structure of the present application;

[0029] Figure 5 Structure diagram of the sealing structure of the present application.

[0030] Explanation of reference signs:

[0031] 1, box body; 2, support structure; 3, gland; 4, compression spring; 5, sealing main body; 6, tightening sleeve; 7, cushion layer; 8, expansion part. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] The existing explosion-proof junction box mainly comprises a box body 1 and a bottom support, wherein the bottom support is used for threading a cable, and a sealing element is installed in the port for threading the cable. The sealing element is matched with the threaded cable and is used for squeezing the cable to play a sealing role. The sealing element itself is matched and installed inside the port of the support, and then relies on the external gland 3 to be fixed and compressed to realize that the sealing element tightly holds the cable. The gland 3 itself is fixedly connected on the support body by bolts and is fixed once.

[0034] However, the sealing structure of the existing explosion-proof junction box support part is relatively simple. Since the support part is generally directly connected to the related equipment, it is easily affected by the vibration generated during the operation of some equipment. The gland 3 is fixedly connected to the support body by bolts, and is fixed once. With the influence of external factors and the passage of time, the gland 3 part may loosen. Once loosened, the sealing sleeve position will loosen, causing the cable to pass through the position to seal failure. And when the failure occurs, it can only rely on regular maintenance inspection to find out the problem. In the loosening condition, it cannot be handled in time. In addition, the existing sealing structure may also be affected by temperature changes in the application environment, causing thermal expansion and contraction to cause a gap between the sealing ring and the shell, resulting in sealing failure. Therefore, the present application provides a sealing structure for an explosion-proof junction box for an electric heat tracing tape and an explosion-proof junction box, which can provide more stable sealing effect and can be discovered and handled in time when the sealing fails.

[0035] As Figures 1-5 shown, the explosion-proof junction box for an electric heat tracing tape provided by the embodiment of the present application comprises a box body 1 and a support structure 2 fixedly connected, an installation port for accommodating a sealing structure is formed in the support structure 2, the installation port can be provided as a cylindrical space, especially a cylindrical space. The end of the installation port away from the box body 1 is connected with a gland 3, and the gland 3 can be locked with the support structure 2 by a locking member such as a bolt structure. A gasket is arranged between the end of the sealing structure and the gland 3. Further, a compression spring 4 is arranged between the gasket and the gland 3. By arranging the gasket and the compression spring 4, the compression effect on the sealing structure is effectively guaranteed. Even if the gland 3 loosens due to various reasons, the elastic force of the compression spring 4 can compensate for it, ensuring the compression of the sealing structure and avoiding the sealing effect failure caused by the loosening of the sealing structure. The end of the compression spring can be fixedly connected with the corresponding position of the gasket or the gland 3, so as to be more convenient for installation and to be able to maintain stability after installation.

[0036] Please refer to Figures 1-5In one of the embodiments of the present application, the box body 1 can be provided with a one-way inflation valve in communication with the internal space of the box body 1, which is used to inflate inert gas into the internal space of the junction box from the outside after the installation of the junction box is completed. A pressure sensor is arranged in the box body 1, which is used to collect the pressure condition of the internal space of the junction box and transmit to the background control system. When the inert gas is inflated into the box body 1, the pressure data collected by the pressure sensor can ensure that the inert gas inflated into the box body 1 meets the set value. At the same time, the pressure condition in the box body 1 is collected by the pressure sensor, and then the feedback data of the pressure sensor is monitored in real time by the background control system. When the inflation gas cannot reach the predetermined value for a long time or after reaching the predetermined pressure value, the pressure decreases, which means that there may be a sealing failure. At this time, an alarm is sent to remind the relevant personnel to repair in time. Further, the detection sensor is arranged at the end of the installation port away from the box body 1, which is used to detect whether there is inert gas inflated into the box body 1 outside the end of the sealing structure. If the target gas is detected, it means that there is a leakage in the position of the sealing structure. At this time, an alarm is sent to remind the relevant personnel to repair in time.

[0037] Please refer to Figures 4-5 In one of the embodiments of the present application, the sealing structure includes a sealing body 5 and a tightening sleeve 6. The sealing body 5 is provided with a cable passing channel for passing the cable. The outer diameter of the two ends of the sealing body 5 is consistent with the inner diameter of the port of the installation position, which can be slightly larger than the size of the installation port, so as to be in interference fit with the inner wall of the installation port and tightly adhere to the inner wall of the installation port, thereby fully sealing between the sealing structure and the installation port. The middle part of the sealing body 5 is provided with at least one tightening part, and the outer diameter and the inner diameter of the position of the tightening part are smaller than the outer diameter and the inner diameter of the two ends of the sealing body 5. A plurality of tightening parts can be provided, and the sealing body 5 is provided in a bellows structure. As a preferred example, one tightening part is arranged in the middle part, and the radial dimension of the sealing body 5 gradually transitions and reduces from the two ends to the position of the tightening part. In this way, after the cable is passed and compressed by the gland 3, the gland 3 extrudes the two ends of the sealing body 5, which promotes the axial deformation and shortening of the sealing body 5, and at the same time, the radial dimension of the sealing body 5 is inwardly contracted at the position of the tightening part, thereby effectively compressing the passed cable and further ensuring the sealing performance. In the drawings, the cross section of the sealing body 5 is in a circular structure, and the outer wall and the inner wall are both arc profiles in the longitudinal section, which can better deform and tighten at the tightening part.

[0038] Please refer to Figure 4In one of the embodiments of the present application, the tightening sleeve 6 is located at the tightening position, and the end with larger size is fixedly connected to the inner wall of the sealing main body 5. The end of the tightening sleeve 6 with larger size is larger than the other end, and is made of elastic material. Specifically, the tightening sleeve 6 can be a thin-walled structure in the shape of a horn. By arranging the elastic tightening sleeve 6, the cable can be effectively tightly held on the outer insulation skin when the cable passes through, so as to ensure the sealing performance at the position. Since the tightening sleeve 6 is a thin-walled structure, the radial deformation of the sealing main body 5 to tightly hold the cable at the tightening position will not be hindered. When a gap is generated between the sealing sleeve and the cable due to thermal expansion and contraction, the elastic conical sleeve can also fill the gap, so as to ensure the sealing effect. Specifically, the end with smaller size of the tightening sleeve 6 is directed to the position of the junction box, so as to facilitate the cable to pass into the junction box.

[0039] Please refer to Figures 4-5 In one of the embodiments of the present application, the sealing main body 5 is externally provided with a gasket 7. One end of the gasket 7 is fixedly connected to the outer wall of the end of the sealing main body 5, and the other end of the gasket 7 is arranged in a gap with the outer wall of the sealing main body 5. The gasket 7 can be made of elastic deformation material or flexible material, so as to be more fully in contact with the inner wall of the mounting port, thereby effectively sealing. Further, the outer wall of the sealing main body 5 is provided with an expansion part 8, which is located on the inner side of the gasket 7. The expansion part 8 can be arranged in the shape of an air bag, or a cavity can be arranged in the sealing main body 5. The outer wall of the cavity position is thin, and is made of deformable elastic or flexible material. The expansion part 8 can be provided with a gas generating structure, and the expansion part 8 can be in communication with a gas source through an air channel (such as an air pipe penetrating through the support). When the control system in the background judges that there is a leakage or a sealing failure, gas can be introduced into the expansion part 8 to increase the volume of the expansion part 8, so as to press the inner wall of the gasket 7, and promote the gasket 7 to deform outwardly to tightly adhere to the inner wall of the mounting port, thereby temporarily enhancing the sealing effect of the mounting port. When the maintenance personnel arrive at the scene, the complete repair can be carried out. Similarly, the same structure of the gasket 7 and the expansion part 8 can be arranged at the passage in the sealing main body 5. When a sealing failure occurs, the expansion part 8 presses the gasket 7 to deform inwardly to tightly adhere to the cable, so as to ensure the sealing effect at the position of the cable.

[0040] Working principle of the present application:

[0041] By setting the inflation valve on the box body 1 of the terminal box, inert gas can be filled into the space inside the box body 1, on the one hand, the inert gas can reduce the oxidation aging speed of the electrical structure in the box body 1, prolong the service life. On the other hand, the inert gas can play a restraining effect on electric arc, spark and the like, and reduce the explosion probability. At the same time, the pressure sensor and the detection sensor are arranged inside and outside the box body 1 respectively, by detecting the pressure condition inside the box body 1, whether there is target inert gas outside the box body 1 and the like, it can be judged whether there is leakage or sealing failure, if there is, an alarm can be sent to timely processing. The gasket and the compression spring 4 are arranged between the sealing body 5 and the gland 3 of the sealing structure, which effectively ensures the compression effect of the sealing structure. Even if the gland 3 is loose due to various reasons, the elastic force of the compression spring 4 can also be compensated to ensure the compression of the sealing structure and avoid the sealing effect failure caused by the loosening of the sealing structure.

[0042] The middle part of the sealing body 5 of the sealing structure is provided with a tightening part, so that after the threading is completed and is compressed by the gland 3, the two ends of the sealing body 5 are extruded by the gland 3, the sealing body 5 is axially deformed and shortened, at the same time, it is radially inwards at the position of the tightening part, thereby effectively compressing the cable, and further ensuring the sealing performance. Further, the tightening sleeve 6 is arranged at the position of the tightening part, by arranging the elastic deforming tightening sleeve 6, when the cable passes through, it can effectively tightly hold on the outer insulating skin of the cable, and ensure the sealing performance at this position. Since the tightening sleeve 6 is a thin-walled structure, it will not hinder the radial deformation of the sealing body 5 at the position of the tightening part to extrude the cable, when the sealing sleeve generates a gap with the cable due to thermal expansion and contraction, the elastic conical sleeve can also fill the gap to ensure the sealing effect.

[0043] The outer part of the sealing body 5 is provided with a gasket 7, and the outer wall of the sealing body 5 is provided with an expansion part 8, which is located inside the gasket 7. When the control system of the background judges that there is a leakage or a sealing failure, gas can be introduced into the expansion part 8 to increase the volume of the expansion part 8, thereby extruding the inner wall of the gasket 7, promoting the gasket 7 to deform outwardly to tightly adhere to the inner wall of the mounting port, playing a role of temporarily enhancing the sealing effect of the mounting port. When the maintenance personnel arrive at the scene, thorough repair can be carried out.

[0044] The above describes one embodiment of the present application in detail, but the content described is only the preferred embodiment of the present application, and cannot be considered as limiting the implementation range of the present application. Any equivalent changes and improvements made according to the scope of the present application should still belong to the scope of the claims of the present application.

[0045] In the description of the application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the application is used, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance. In the description of the application, unless otherwise specified and limited, "a plurality of" means two or more.

[0046] In the description of the application, unless otherwise specified and limited, "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0047] In the description of the application, it should be noted that, unless otherwise specified and limited, the terms "provided", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

Claims

1. A sealing structure for an explosion-proof junction box for an electric heating cable, characterized in that: include: A sealing body, wherein a through passage is formed in the sealing body, wherein the outer diameters of the two ends of the sealing body are consistent with the inner diameter of the port at the installation position, and at least one tightening portion is provided in the middle portion of the sealing body, wherein the outer diameter and inner diameter of the tightening portion are smaller than the outer diameter and inner diameter of the two ends of the sealing body; The tightening sleeve has one end that is larger than the other end and is made of elastic material. The tightening sleeve is located at the tightening portion, and the larger end is fixedly connected to the inner wall of the sealing body.

2. The sealing structure for an explosion-proof junction box for an electric heating cable according to claim 1, characterized in that: The smaller end of the tightening sleeve faces the location of the junction box.

3. The sealing structure for an explosion-proof junction box for an electric heating cable according to claim 2, characterized in that: The tightening sleeve is a trumpet-shaped thin-wall structure.

4. The sealing structure for an explosion-proof junction box for an electric heating cable according to claim 1, characterized in that: A cushion layer is provided on the outside of the sealing body, one end of the cushion layer is fixedly connected to the outer wall of the end portion of the sealing body, and the other end of the cushion layer is provided with a gap from the outer wall of the sealing body.

5. The sealing structure for an explosion-proof junction box for an electric heating cable according to claim 4, characterized in that: An expansion portion is provided on the outer wall of the sealing body, and the expansion portion is located on the inner side of the cushion layer.

6. The sealing structure for an explosion-proof junction box for an electric heating cable according to claim 5, characterized in that: The expansion portion is communicated with the air source through an air passage.

7. An explosion-proof junction box for an electric heating cable, comprising a box body and a bracket structure fixedly connected, wherein the bracket structure is provided with an installation port, and a gland is installed and connected to the end of the installation port away from the box body, characterized in that: A sealing structure for an explosion-proof junction box for electric heating cables according to any one of claims 1 to 6 is provided in the installation port, and a gasket is provided between the end of the sealing structure and the gland.

8. The explosion-proof junction box for electric heating according to claim 7, characterized in that: A compression spring is provided between the gasket and the pressure cover.

9. The explosion-proof junction box for electric heating according to claim 8, characterized in that: The box body is provided with a one-way inflation valve connected to the internal space of the box body, which is used to fill the interior of the junction box with inert gas after the junction box is connected and installed. A pressure sensor is provided in the box body.

10. The explosion-proof junction box for electric heating according to claim 9, characterized in that: A detection sensor is provided at one end of the installation port away from the box body.

Images