Quick detachable COT surface thermocouple

Abstract

The utility model provides a kind of COT surface thermocouple of quick disassembly, belong to thermocouple technical field, including junction box, protection conduit and thermocouple, the protection conduit includes the first straight pipe section, elbow section and second straight pipe section that are sequentially arranged, one end of the thermocouple is arranged in protection conduit, and its other end is connected with junction box, the surface of furnace tube is provided with short pipe, channel adapted to the first straight pipe section is provided on the short pipe, the side wall of the short pipe is opened with threaded hole along radial direction, the threaded hole is connected with tight bolt, the side wall of the first straight pipe section is opened with recess portion corresponding threaded hole, and the end of the tight bolt is abutted on recess portion to form fixed.The utility model is fixed by setting short pipe on the surface of furnace tube and by tight bolt to thermocouple, when needing to replace thermocouple, only need to unscrew tight bolt, and the whole thermocouple assembly can be extracted from short pipe, to realize the quick, non-destructive replacement of thermocouple.

Description

Technical Field

[0001] This utility model relates to the field of thermocouple technology, and in particular to a COT surface thermocouple that can be quickly disassembled. Background Technology

[0002] In high-temperature reaction equipment such as ethylene cracking furnaces, the furnace tube outlet temperature (COT) is a core process parameter for controlling the cracking depth and product yield. Its measurement accuracy and response speed directly affect the safe and stable operation and economic benefits of the unit. To obtain the true furnace tube outer wall temperature, surface thermocouples are commonly used in engineering to measure the temperature by directly attaching them to the outer wall of the furnace tube.

[0003] In the existing technology, because the furnace tube of the pyrolysis furnace is under harsh conditions such as high temperature, oxidation and alternating thermal stress, the thermocouple, as a vulnerable component, needs to be disassembled, maintained or replaced regularly. However, the current surface thermocouples have the temperature sensing end directly welded to the outer wall of the furnace tube, which makes disassembly and replacement difficult. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a COT surface thermocouple that can be quickly disassembled.

[0005] The technical solution adopted by this utility model is as follows: This application provides a quick-detachable COT surface thermocouple, which is installed on the surface of the furnace tube of a pyrolysis furnace. It includes a junction box, a protective conduit, and a thermocouple. The protective conduit includes a first straight pipe section, a bent pipe section, and a second straight pipe section arranged in sequence. One end of the thermocouple passes through the protective conduit, and the other end is connected to the junction box. A short pipe is provided on the surface of the furnace tube. The short pipe has a channel adapted to the first straight pipe section. The side wall of the short pipe has a threaded hole in the radial direction. The threaded hole is connected to a set bolt. The side wall of the first straight pipe section has a groove corresponding to the threaded hole. The end of the set bolt abuts against the groove to form a fixation.

[0006] In some embodiments, the first straight pipe section is installed upside down inside the short pipe, and the bending angle of the bent pipe section is 20° to 60°.

[0007] In some embodiments, the hot junction of the thermocouple is attached to the inner wall of the protective conduit on the side closest to the furnace tube surface.

[0008] In some embodiments, the short tube is welded and fixed to the surface of the furnace tube.

[0009] In some embodiments, the wall thickness of the short tube on the side closer to the furnace tube surface is less than the wall thickness on the side farther from the furnace tube surface, and the threaded hole is located on the side of the short tube farther from the furnace tube.

[0010] In some embodiments, there are at least two threaded holes and set bolts, which are spaced apart along the axial direction of the short pipe.

[0011] In some embodiments, the short tube has a contact portion that fits against the surface of the furnace tube on the side near the furnace tube surface.

[0012] In some embodiments, a groove is provided on the side of the short tube near the surface of the furnace tube, and the groove extends through the side wall of the short tube.

[0013] In some embodiments, the end of the second straight pipe section near the junction box is connected to a reinforcing pipe via a first movable ferrule threaded assembly. The reinforcing pipe is connected to the junction box via a second movable ferrule threaded assembly. Both the first and second movable ferrule threaded assemblies include a first connector, a second connector, a first ferrule, and a second ferrule. The first connector is sleeved on the reinforcing pipe, and one end of it is embedded in a protective conduit. The second connector is threaded onto the other end of the first connector. The first and second ferrules abut against each other. The reinforcing pipe passes through the first and second ferrules. A first tapered mating portion is provided between the first ferrule and the first connector. A second tapered mating portion is provided between the first ferrule and the second ferrule. A third tapered mating portion is provided between the second ferrule and the second connector. The first and second tapered mating portions gradually expand towards the junction box, and the third tapered mating portion gradually shrinks towards the junction box.

[0014] In some embodiments, the groove is an annular groove formed on the side wall of the first straight pipe section.

[0015] The beneficial effects of this utility model are as follows: This utility model sets a short tube on the surface of the furnace tube and fixes the thermocouple with a set bolt. When the thermocouple needs to be replaced, the entire thermocouple assembly can be pulled out from the short tube simply by loosening the set bolt, thus realizing the rapid and non-destructive replacement of the thermocouple. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of this utility model.

[0017] Figure 1 This is a schematic diagram of a quick-detachable COT surface thermocouple according to this utility model. Figure 1 ; Figure 2This is a schematic diagram of a quick-detachable COT surface thermocouple according to this utility model. Figure 2 ; Figure 3 This is a partial schematic diagram of a quick-detachable COT surface thermocouple according to the present invention. Figure 1 ; Figure 4 This is a schematic diagram of a short tube according to the present invention; Figure 5 This is a schematic diagram of another type of short tube in this utility model; Figure 6 This is a schematic diagram of a quick-detachable COT surface thermocouple according to this utility model. Figure 3 ; Figure 7 This is a schematic diagram of the protective catheter in this utility model; Figure 8 This is a partial schematic diagram of a quick-detachable COT surface thermocouple according to the present invention. Figure 2 ; Figure 9 for Figure 8 Enlarged view of point A in the middle; Figure 10 This is a schematic diagram of a different type of set bolt in this utility model; Figure 11 This is a schematic diagram of another different set bolt in this utility model; In the diagram: 1-furnace tube, 2-junction box, 3-protective conduit, 301-first straight pipe section, 302-bend pipe section, 303-second straight pipe section, 4-thermocouple, 5-short pipe, 501-channel, 502-threaded hole, 503-contact part, 504-grooved part, 6-set bolt, 7-groove part, 700-annular groove, 8-reinforcing pipe, 9-first movable ferrule threaded assembly, 91-first connector, 92-second connector, 93-first ferrule, 94-second ferrule, 95-first tapered mating part, 96-second tapered mating part, 97-third tapered mating part, 10-second movable ferrule threaded assembly. Detailed Implementation

[0018] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0019] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "longitudinal", "lateral", "radial", "length", "width", "thickness", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element or component to have a specific orientation, or to be constructed and operated in a specific orientation.

[0020] It should be noted that the terms "first," "second," and similar words do not indicate any order, quantity, or importance, but are only used to distinguish different components and should not be construed as limiting the embodiments of this application.

[0021] It should be noted that the terms "installation," "setup," "equipped with," "connection," and "connected" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral structures; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two devices, components, or parts.

[0022] It should be noted that the terms "in some embodiments," "exemplarily," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "in some embodiments," "exemplarily," or "for example" should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "in some embodiments," "exemplarily," and "for example" is intended to present the relevant concepts in a specific manner, meaning that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of this application.

[0023] Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] Regarding the accompanying drawings of this application, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not necessarily drawn to scale.

[0025] In the existing technology, COT surface thermocouples are usually fixed to the surface of the pyrolysis furnace tube by welding, which makes it extremely difficult to disassemble and reassemble them after damage.

[0026] Based on the above issues, such as Figures 1 to 11As shown, this utility model proposes a quick-detachable COT surface thermocouple, installed on the surface of the furnace tube 1 of a pyrolysis furnace, including a junction box 2, a protective conduit 3, and a thermocouple 4. The protective conduit 3 is a continuous hollow tube, primarily serving to protect the internal thermocouple 4 and guide its direction.

[0027] Specifically, the protective conduit 3 includes a first straight pipe section 301, a bent pipe section 302, and a second straight pipe section 303 arranged sequentially. The first straight pipe section 301 is the pipe section where the temperature measuring end is located, used for heat transfer through contact with the surface of the furnace tube 1. The bent pipe section 302 transitions the pipe body direction from parallel to the surface of the furnace tube 1 to the terminal away from the furnace tube 1. The thermocouple 4 is entirely inserted inside the protective conduit 3, with its hot end located at the end of the first straight pipe section 301 and abutting against the inner wall of the first straight pipe section 301 on the side closest to the furnace tube surface, and its cold end connected to the terminal in the junction box 2. The junction box 2 is used to realize the output of the thermocouple signal.

[0028] A short tube 5 is provided on the surface of the furnace tube 1. The short tube 5 has a channel 501 adapted to the first straight tube section 301. The channel 501 extends axially along the short tube 5, and its inner diameter is slightly larger than the outer diameter of the first straight tube section 301, allowing the first straight tube section 301 to be smoothly inserted or removed within it. A threaded hole 502 is provided on the short tube 5, and a set bolt 6 is fitted into the threaded hole 502. Correspondingly, a groove 7 is formed on the side wall of the first straight tube section 301 at the position corresponding to the threaded hole 502, and the end of the set bolt 6 abuts against the groove 7 to form a fixation.

[0029] Preferably, the short tube 5 is provided with at least one radial threaded hole 502 on the side away from the surface of the furnace tube 1, and the groove 7 can be a conical pit, a spherical pit, etc., whose shape is adapted to the end of the set bolt 6.

[0030] Preferably, the groove 7 is an annular groove 700 formed on the side wall of the first straight pipe section 301, so that the angle of the thermocouple in the circumference of the furnace tube can also be adjusted.

[0031] When the set bolt 6 is tightened, its end is inserted into the groove 7, pressing the first straight pipe section 301 against the inner wall of the channel 501, so that its sensing surface is close to the surface of the furnace tube 1. At the same time, the axial displacement and circumferential rotation of the first straight pipe section 301 are prevented by the limiting of the set bolt 6 and the groove 7. When the thermocouple needs to be replaced, simply loosen the set bolt 6 to pull the first straight pipe section 301 out of the channel 501 of the short pipe 5, and complete the quick disassembly.

[0032] Preferably, the thermocouple 4 is an armored thermocouple: the armor material can be selected from Inconel series such as Inconel600, Incoloy series such as Incoloy800, Incoloy800H, Incoloy800HT, or GH series such as GH3030, GH3039.

[0033] Optionally, the outer diameter of the protection catheter ranges from ∅13.7mm to 21.5mm, preferably from ∅17mm to 17.2mm. In some embodiments, the first straight pipe section 301 is inverted inside the short pipe 5 from bottom to top. Traditional thermocouples are installed from top to bottom, and when removing them, the high temperature rises in the furnace tube, making it impossible to work from above. Now, it is installed from bottom to top to avoid the high temperature rise zone and facilitate on-site work.

[0034] Optionally, the bending angle of the bend in the pipe section 302 is 20°-60°, preferably 30° or 45°. Figure 2 As shown, the bending angle of the bend in the pipe section 302 is the angle between the central axis of the first straight pipe section 301 and the central axis of the second straight pipe section 303.

[0035] Preferably, the short tube 5 is directly welded and fixed to the surface of the furnace tube 1, which is simple and reliable.

[0036] In some embodiments, the wall thickness of the short tube 5 on the side closer to the surface of the furnace tube 1 is less than the wall thickness on the side farther from the surface of the furnace tube 1. The thinner bottom wall thickness reduces the thermal resistance of heat conduction, allowing heat from the surface of the furnace tube 1 to be conducted more quickly to the first straight tube section 301 within the channel 501, which is beneficial for improving the temperature measurement response speed. The thicker wall thickness provides sufficient thread engagement length for the threaded hole 502, ensuring the connection strength of the set bolt 6.

[0037] Preferably, there are at least two threaded holes 502 and at least two set bolts 6, which are spaced apart along the axial direction of the short pipe 5. Multi-point axial locking can more evenly tighten the first straight pipe section 301 and prevent temperature drift caused by single-point loosening.

[0038] In some embodiments, the short tube 5 is provided with a contact portion 503 that fits against the surface of the furnace tube 1 on the side near the surface of the furnace tube 1. The inner surface of the contact portion 503 has the same radius of curvature as the outer diameter of the furnace tube 1 to achieve surface contact, which ensures good heat conduction and increases friction to prevent slippage.

[0039] In some embodiments, a groove 504 is provided on the side of the short tube 5 near the surface of the furnace tube 1. The groove 504 penetrates the side wall of the short tube 5, which is beneficial for the transfer of the temperature of the furnace tube 1 to the thermocouple and improves the temperature measurement accuracy of the thermocouple.

[0040] In some embodiments, such as Figure 6 As shown, the end of the second straight pipe section 303 near the junction box 2 is connected to a reinforcing pipe 8 through a first movable ferrule threaded assembly 9. The reinforcing pipe 8 is connected to the junction box 2 through a second movable ferrule threaded assembly 10. The cold end of the thermocouple passes through the reinforcing pipe 8 and is connected to the anti-loosening terminal in the junction box 2.

[0041] Two movable ferrule threaded assemblies allow for individual disassembly of corresponding components. Each movable ferrule threaded assembly includes a first connector 91, a second connector 92, a first ferrule 93, and a second ferrule 94. The first connector 91 is fitted over the reinforcing tube 8, with one end embedded in the protective conduit 3. The second connector 92 is threaded onto the other end of the first connector 91, allowing for adjustment of the insertion depth. The first ferrule 93 and the second ferrule 94 abut against the first connector 91 and the second connector 92. The reinforcing tube 8 passes through... The first ferrule 93 and the second ferrule 94 are connected. A first tapered mating part 95 is provided between the first ferrule 93 and the first connector 91. A second tapered mating part 96 is provided between the first ferrule 93 and the second ferrule 94. A third tapered mating part 97 is provided between the second ferrule 94 and the second connector 92. The first tapered mating part 95 and the second tapered mating part 96 gradually expand towards the junction box, while the third tapered mating part 97 gradually shrinks towards the junction box. This increases the clamping force on the reinforcing tube 8.

[0042] The gap between the inner hole of the reinforcing tube 8 and the outer diameter of the thermocouple is 0.1mm. It can be fixed by laser welding and insulating epoxy glue, so that this extended reinforcing tube 8 can withstand connection fatigue.

[0043] Optionally, such as Figure 10 and Figure 11 As shown, the set bolt 6 is a stud bolt or a bolt with a lifting eye, etc., and the bolt length of the set bolt 6 is redundantly designed.

[0044] In summary, after reading this detailed disclosure, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that the requirements of this application encompass various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this application and are within the spirit and scope of the exemplary embodiments of this application.

[0045] Furthermore, it should be understood that in the foregoing description of the embodiments of this application, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the understanding of a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may readily identify some of the devices as separate embodiments when reading this application. That is, the embodiments in this application can also be understood as an integration of multiple sub-embodiments. It is also valid when each sub-embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

[0046] Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of the embodiments of this application. Other modified embodiments are also within the scope of this application. Therefore, the embodiments disclosed herein are merely examples and not limitations. Those skilled in the art can adopt alternative configurations to implement the applications in this application based on the embodiments in this application. Therefore, the embodiments of this application are not limited to the embodiments precisely described in the application.

Claims

1. A quick-detachable COT surface thermocouple, installed on the surface of the furnace tube of a pyrolysis furnace, characterized in that, The device includes a junction box, a protective conduit, and a thermocouple. The protective conduit comprises a first straight pipe section, a bent pipe section, and a second straight pipe section arranged sequentially. One end of the thermocouple passes through the protective conduit, and the other end is connected to the junction box. A short pipe is provided on the surface of the furnace tube, and a channel adapted to the first straight pipe section is provided on the short pipe. A threaded hole is radially opened on the side wall of the short pipe, and a set bolt is connected to the threaded hole. A groove is opened on the side wall of the first straight pipe section corresponding to the threaded hole, and the end of the set bolt abuts against the groove to form a fixation.

2. The quick-detachable COT surface thermocouple according to claim 1, characterized in that, The first straight pipe section is installed upside down inside the short pipe, and the bending angle of the bent pipe section is 20° to 60°.

3. The quick-detachable COT surface thermocouple according to claim 1, characterized in that, The hot junction of the thermocouple is attached to the inner wall of the protective conduit on the side closest to the furnace tube surface.

4. The quick-detachable COT surface thermocouple according to claim 1, characterized in that, The short tube is welded and fixed to the surface of the furnace tube.

5. A quick-detachable COT surface thermocouple according to claim 1, characterized in that, The wall thickness of the short tube on the side closer to the furnace tube surface is less than the wall thickness on the side farther from the furnace tube surface, and the threaded hole is located on the side of the short tube farther from the furnace tube surface.

6. A quick-detachable COT surface thermocouple according to claim 1, characterized in that, Both the threaded holes and the set bolts are at least two in number and are spaced apart along the axial direction of the short pipe.

7. A quick-detachable COT surface thermocouple according to claim 1, characterized in that, The short tube has a contact portion that fits against the surface of the furnace tube on the side closest to the furnace tube surface.

8. A quick-detachable COT surface thermocouple according to claim 1, characterized in that, The short tube has a groove on the side near the furnace tube surface, and the groove extends through the side wall of the short tube.

9. A quick-detachable COT surface thermocouple according to claim 1, characterized in that, The end of the second straight pipe section near the junction box is connected to a reinforcing pipe via a first movable ferrule threaded assembly. The reinforcing pipe is connected to the junction box via a second movable ferrule threaded assembly. Both the first and second movable ferrule threaded assemblies include a first connector, a second connector, a first ferrule, and a second ferrule. The first connector is sleeved on the reinforcing pipe, and one end of it is embedded in a protective conduit. The second connector is threaded onto the other end of the first connector. The first and second ferrules abut against each other. The reinforcing pipe passes through the first and second ferrules. A first tapered mating portion is provided between the first ferrule and the first connector. A second tapered mating portion is provided between the first ferrule and the second ferrule. A third tapered mating portion is provided between the second ferrule and the second connector. The first and second tapered mating portions gradually expand towards the junction box, while the third tapered mating portion gradually narrows towards the junction box.

10. A quick-detachable COT surface thermocouple according to claim 1, characterized in that, The groove is an annular groove formed on the side wall of the first straight pipe section.

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