Thermocouple temperature measuring device for hot-blast stove and installation method of thermocouple temperature measuring device

Abstract

The invention discloses a thermocouple temperature measuring device for a hot-blast stove and an installation method thereof, and belongs to the technical field of hot-blast stoves. The thermocouple temperature measuring device comprises an outer protective sleeve, an inner protective sleeve, a thermocouple and two sealing rings, the inner protective sleeve is nested outside the thermocouple, the outer protective sleeve is nested outside the inner protective sleeve, and the two sealing rings are arranged between the outer protective sleeve and the inner protective sleeve to form a grouting cavity; a pouring hole is formed in one end of the outer protective sleeve; a plurality of slurry overflow holes distributed at intervals in the axial direction are formed in the other end of the base; and the grout overflow hole is used for introducing grout in the grouting cavity into the thermocouple mounting channel. According to the scheme, the grout overflow hole is formed in the outer protection sleeve, grout is injected into the thermocouple installation channel through the grout overflow hole, the gap between the thermocouple installation channel and the outer protection sleeve is filled, and therefore the requirement for hole expansion of the thermocouple installation channel is lowered.

Description

Technical Field

[0001] The present invention relates to the technical field of hot blast stoves, and more particularly to a thermocouple temperature measuring device for a hot blast stove and an installation method thereof. Background Art

[0002] As a critical temperature measurement component, thermocouples play an indispensable role in the operation of hot blast stoves. Their primary function is to accurately measure the temperature inside the hot blast stove and provide operators with real-time, reliable temperature data. This precise temperature information enables operators to promptly adjust the hot blast stove's operating parameters, ensuring optimal operation and maintaining stable heat output, thereby meeting the stringent hot blast temperature requirements of the blast furnace smelting process. Furthermore, the temperature data provided by thermocouples is an important basis for monitoring the normal operation of the hot blast stove. Any abnormal temperature fluctuations can promptly alert operators, allowing them to take appropriate measures to avoid a series of safety issues and production accidents caused by uncontrolled temperature.

[0003] Hot blast furnace masonry work is carried out in a cold environment. During the construction of the thermocouple installation channel, a certain gap is reserved based on the expansion of the refractory material at operating temperature to reduce damage to the thermocouple caused by deformation of the refractory material. However, in reality, the working environment of the large wall bricks of the hot blast furnace is extremely complex and changeable, resulting in a deviation between the actual expansion of the refractory material and the theoretically calculated value, and a complete match. Furthermore, although the thermocouples used in the hot blast furnace are protected by a stainless steel or silicon carbide protective tube when measuring temperature, due to long-term operation in the harsh environment of high temperature, high pressure, and high flow rate of 1200°C to 1450°C, the protective tube often breaks and the thermocouple is damaged, necessitating replacement of the thermocouple.

[0004] During the thermocouple replacement process, it was discovered that the thermocouple installation channel was only simply enlarged. To minimize leakage of hot air from the furnace cavity through the thermocouple installation channel, a smaller enlargement should be performed to maintain the insertion of the protective sleeve. However, due to varying degrees of hot air erosion on the walls of the thermocouple installation channel, the corresponding hole sections of each eroded wall layer were misaligned, making the protective sleeve difficult to insert into the smaller enlarged thermocouple installation channel. Specifically, when the protective sleeve is made of a high-temperature-resistant and hard material such as silicon carbide, it easily breaks during insertion. When the protective sleeve is made of a material such as stainless steel, while its toughness is improved, its resistance to high-temperature deformation is weak, making it prone to adhesion to the thermocouple installation channel, making it difficult to remove the protective sleeve later. In actual use, it was found that thermocouples installed in this manner still suffered from hot air erosion of the furnace shell, resulting in a relatively short replacement cycle.

[0005] From the above process of replacing the thermocouple, it can be seen that in order to facilitate the insertion of the thermocouple and to adapt to the degree of powdering and erosion of each layer of the wall at the same time, the hole size will inevitably increase. Based on the above situation, when replacing the thermocouple, the hole size of the thermocouple installation channel is further expanded to ensure the coaxiality of its various hole sections. Due to the increase in the hole size, the original single-layer sleeve is optimized to a double-layer sleeve, and grouting is performed between the double-layer sleeves to fill the gap between the double-layer sleeves. Although the technical problems of the difficulty in inserting the thermocouple into the thermocouple installation channel and the increase in the hole size have been solved, in actual process, the problem of the furnace shell temperature being too high still exists, which means that the problem of hot air leaking into the furnace shell through the thermocouple installation channel still exists.

[0006] The reason for this is that when replacing thermocouples in a hot blast furnace, the furnace is usually in a shut-off state, during which time the furnace body has not completely cooled down, and the temperature inside the thermocouple installation channel is not suitable for direct manual operation. During the thermocouple installation process, in order to allow the outer protective sleeve to be inserted into the thermocouple installation channel, the two are generally fitted with a clearance, resulting in a small gap between the thermocouple installation channel and the outer protective sleeve. During normal operation of the hot blast furnace, this gap can be partially filled by high-temperature expansion. However, this places high demands on the accuracy of the hole opening position of the corresponding hole section of each layer of wall in the thermocouple installation channel, resulting in extended hole opening time, and thus extended repair time. Summary of the Invention

[0007] 1. Technical problems to be solved The present invention provides a thermocouple temperature measuring device for a hot blast furnace and its installation method. This solution utilizes a slurry overflow hole in the outer protective sleeve of the thermocouple temperature measuring device. Slurry is injected into the thermocouple installation channel through the overflow hole to fill the gap between the thermocouple installation channel and the outer protective sleeve, thereby reducing the need for hole expansion in the thermocouple installation channel. Furthermore, this solution can also fill powdered areas on the walls of the thermocouple installation channel.

[0008] 2. Technical solutions adopted In order to achieve the above object, the technical solution provided by the present invention is: A first aspect of the present invention provides a thermocouple temperature measuring device for a hot blast stove, comprising an outer protective sleeve, an inner protective sleeve, a thermocouple and two sealing rings, wherein the inner protective sleeve is nested on the outside of the thermocouple; the outer protective sleeve is nested on the outside of the inner protective sleeve, and two sealing rings are provided between the inner cavity of the outer protective sleeve and the inner protective sleeve and are spaced apart along their axis to form a grouting cavity between the outer protective sleeve and the inner protective sleeve; a grouting hole is provided at one end of the outer protective sleeve for injecting slurry into the grouting cavity; and a plurality of overflow holes are provided at the other end and are spaced apart along its axial direction, and the overflow holes are used to introduce the slurry in the grouting cavity into the thermocouple installation channel.

[0009] Furthermore, except for the furnace shell layer, the remaining walls in the thermocouple installation channel are all provided with corresponding overflow holes, and the overflow holes corresponding to each layer of the wall are all arranged at the thickness center of the wall layer.

[0010] Furthermore, each layer of the wall is provided with four grouting holes that are evenly distributed around the axis of the outer protective sleeve.

[0011] Furthermore, the gap between the inner protective sleeve and the thermocouple is 3-8 mm; the gap between the outer protective sleeve and the inner protective sleeve is 7-37 mm.

[0012] Furthermore, two sealing rings are respectively arranged at both ends of the inner cavity of the outer protective sleeve; the end of the inner protective sleeve close to the working end of the thermocouple is flush with the end of the outer protective sleeve, the length of the outer protective sleeve is greater than the length of the thermocouple installation channel and less than the length of the inner protective sleeve, and the injection hole is opened in the axial section of the outer protective sleeve located outside the thermocouple installation channel.

[0013] Furthermore, the thickness of the sealing ring is 5-8 mm.

[0014] The second aspect of the present invention provides a method for installing any of the above-mentioned thermocouple temperature measuring devices for hot blast furnaces, comprising the following steps: S1, removing the thermocouple and its external protective sleeve; S2, using a reamer to expand the thermocouple installation channel to match the outer diameter of the outer protective sleeve, and ensuring that the working end of the thermocouple can be inserted into the furnace cavity through the opening in the silica brick layer of the furnace wall, and cleaning the expanded thermocouple installation channel; S3, pairing the outer protective sleeve, inner protective sleeve, sealing ring and inner sleeve. The flange is assembled and then inserted into the thermocouple installation channel, and the end of the outer protective sleeve is tightly fitted into the silica brick layer in the furnace wall, and then the outer protective sleeve is welded to the furnace shell layer in the furnace wall; S4, grouting liquid is poured into the grouting cavity through the grouting hole, and the slurry fills the gap between the inner and outer protective sleeves and flows into the thermocouple installation channel through the overflow hole; S5, the end of the thermocouple is wrapped with ceramic fiber packing, and then inserted into the inner protective sleeve, and finally the thermocouple matching flange is fixed to the inner sleeve matching flange.

[0015] Furthermore, the expanded thermocouple installation channel in S2 is coaxially arranged with the opening in the silicon brick layer; or a water-cooled reamer is used for reaming in S2.

[0016] Furthermore, in S4, the grouting pressure during the grouting process is detected, and the grouting pressure is controlled to be maintained at 0.05-0.2 MPa.

[0017] Furthermore, the raw materials of the slurry used in S4 include corundum mullite castable and silica sol.

[0018] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: (1) The present invention optimizes the design of the outer protective sleeve. Specifically, a grouting hole and a plurality of overflow holes are respectively opened at both ends of the outer protective sleeve. The slurry overflows from the overflow holes into the gap between the outer protective sleeve and the thermocouple installation channel to automatically fill the gap between the two, thereby greatly reducing the relative position accuracy requirements between the aperture of the corresponding section of each layer of wall in the thermocouple installation channel and the outer diameter of the outer protective sleeve, thereby facilitating the opening of holes and greatly shortening the emergency repair time.

[0019] (2) The present invention further optimizes the design of the opening position through the outer protective sleeve. Specifically, the outer protective sleeve is provided with overflow holes corresponding to each layer of the wall in the thermocouple installation channel, which can prevent the adjacent wall layers from being separated due to uneven powdering, so that the slurry can flow to the hole sections corresponding to each layer of the wall.

[0020] (3) The present invention further optimizes the relative position between the outer protective sleeve and the inner protective sleeve. Specifically, the gap between the inner protective sleeve and the thermocouple is 3 to 8 mm, thereby providing sufficient protection space for the thermocouple; the gap between the outer protective sleeve and the inner protective sleeve is 7 to 37 mm, thereby forming a grouting cavity with a suitable space. Furthermore, two sealing rings are respectively provided at both ends of the inner cavity of the outer protective sleeve, thereby fully utilizing the inner cavity length of the outer protective sleeve to form the grouting cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a schematic structural diagram of a thermocouple temperature measuring device for a hot blast stove according to an embodiment of the present invention when in use.

[0022] Figure 2 This is a schematic cross-sectional view of the outer protective sleeve in a thermocouple temperature measuring device for a hot blast stove according to an embodiment of the present invention.

[0023] Description of labels: 1. Thermocouple; 2. Thermocouple matching flange; 3. Inner protective casing; 4. Outer protective casing; 5. Irrigation tube; 6. Furnace shell layer; 7. Spray coating; 8. Thermal insulation board layer; 9. Lightweight clay brick layer, 10. Lightweight silica brick layer; 11. Silica brick layer; 12. Sealing ring; 13. Overflow hole; 14. Inner casing matching flange. DETAILED DESCRIPTION

[0024] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0025] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology. They are not used to limit the conditions for implementation of the present invention and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, terms such as "upper", "lower", "left", "right", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation. Changes or adjustments in their relative relationships should also be considered as the scope of implementation of the present invention without substantially changing the technical content.

[0026] The explanation of the names of the two ends of the thermocouple 1 is as follows: the working end of the thermocouple 1 refers to the end thereof extending into the furnace cavity, and the other end is called the cold end.

[0027] Typically, the outermost layer of the furnace wall in a hot blast furnace is the furnace shell 6. The furnace wall comprises, arranged in order from the outside inward, a spray coating layer 7, an insulation board layer 8, a lightweight clay brick layer 9, a lightweight silica brick layer 10, and a silica brick layer 11. The silica brick layer 11 has good heat resistance and is less deformed by the impact of the hot air inside the furnace cavity. The "thermocouple installation channel" referred to in the present invention refers to the "channel extending from the furnace shell 6 to the lightweight silica brick layer 10." The length of the thermocouple installation channel is the sum of the thicknesses of the furnace shell 6, the lightweight silica brick layer 10, and the multi-layer wall located therebetween, i.e., the sum of the thicknesses of the furnace shell 6, the spray coating layer 7, the insulation board layer 8, the lightweight clay brick layer 9, and the lightweight silica brick layer 10. The silica brick layer 11 is provided with an opening that connects to the thermocouple installation channel. The opening has an inner diameter smaller than the aperture of the thermocouple installation channel and is used to insert the working end of the thermocouple into the furnace cavity.

[0028] This embodiment provides a thermocouple temperature measuring device for a hot blast stove, referring to Figure 1As shown, the thermocouple temperature measuring device includes an outer protective sleeve 4, an inner protective sleeve 3, a thermocouple 1 and two sealing rings 12. The inner protective sleeve 3 is nested on the outside of the thermocouple 1; the outer protective sleeve 4 is sleeved on the outside of the inner protective sleeve 3, and two sealing rings 12 are provided between the inner cavity of the outer protective sleeve 4 and the inner protective sleeve 3 and spaced apart along their axes to form a grouting cavity between the outer protective sleeve 4 and the inner protective sleeve 3, which is used to inject slurry into the grouting cavity; and a plurality of overflow holes 13 are provided at the other end and spaced apart along their axial directions, and the overflow holes 13 are used to introduce the slurry in the grouting cavity into the thermocouple installation channel.

[0029] In the temperature measuring device, the thermocouple 1 passes through the interior of the thermocouple matching flange 2 and is fixedly connected to it. The inner sleeve matching flange 14 is sleeved on the outside of the inner protective sleeve 3. The inner sleeve matching flange 14 is sleeved on the outside of the inner protective sleeve 3. This part adopts the existing technology and will not be repeated here.

[0030] In response to the problems existing in the thermocouple replacement process mentioned in the background technology, the inventors conducted in-depth research on the problem of thermocouple replacement and found that by opening an overflow hole 13 in the outer protective sleeve 4, the slurry overflows from the overflow hole 13 into the gap between the outer protective sleeve 4 and the thermocouple installation channel, and the gap between the two can be automatically filled, thereby greatly reducing the relative position accuracy requirements between the aperture of the corresponding section of each layer of wall in the thermocouple installation channel and the outer diameter of the outer protective sleeve 4. Specifically, during installation, only the dimensional accuracy of the opening of the furnace shell layer 6 is required. The thickness of the furnace shell layer 6 is relatively small and it is farthest from the furnace cavity. The aperture of the corresponding hole section of the furnace shell layer 6 in the thermocouple installation channel is easy to adjust, that is, the accuracy of its opening position is relatively easy to control. The thermocouple temperature measuring device can be inserted into the thermocouple installation channel, and the end of the outer protective sleeve 4 is against the silica brick layer 12. The remaining walls in the thermocouple installation channel, namely the spray coating layer 7, the insulation board layer 8, the lightweight clay brick layer 9, and the lightweight silica brick layer 10, the gaps between the corresponding hole sections in these wall layers and the outer protective sleeve 4 can be filled with slurry, thereby greatly reducing the requirements for the expansion size and hole expansion accuracy of the thermocouple installation channel, thereby facilitating hole opening and greatly shortening the emergency repair time.

[0031] When replacing traditional thermocouples, the problem of thermal deformation of the thermocouple installation channel is not taken into consideration. Some high-temperature gases will take the opportunity to enter the thermocouple channel. Under the dual effects of high temperature and stress, the refractory material near the furnace shell layer 6 will gradually become powdered, which will further cause the local furnace shell temperature of the hot blast furnace to be too high, thereby seriously affecting the service life of the furnace shell and posing a severe challenge to the safe and stable operation of the entire hot blast furnace system. The study also found that the slurry overflowed from the overflow hole 13 into the gap between the outer protective sleeve 4 and the thermocouple installation channel. The slurry can repair the powdered part of the wall in the thermocouple installation channel, reducing the risk of hot air leaking from the powdered part of the wall. By reinforcing the thermocouple installation channel, not only the replacement cycle of the thermocouple is extended, but also the problem of excessive temperature of the furnace shell near the thermocouple installation channel can be effectively solved.

[0032] Specifically, with the exception of the furnace shell 6, the remaining walls in the thermocouple installation channel each have corresponding grouting holes 13. Accordingly, the outer protective sleeve 4 is provided with grouting holes 13 corresponding to the spray coating layer 7, the insulation board layer 8, the lightweight clay brick layer 9, and the lightweight silica brick layer 10. The grouting holes 13 corresponding to each of these wall layers are positioned directly at the center of the thickness of that wall layer. By carefully designing the locations of the multiple grouting holes, it is possible to prevent the adjacent wall layers from being blocked due to uneven pulverization, allowing the slurry to flow to the corresponding hole sections of each wall layer.

[0033] More specifically, refer to Figure 2 As shown, each layer of the wall is provided with four overflow holes 13 evenly spaced around the axis of the outer protective sleeve 4. When in use, two of the overflow holes 13 are arranged in the vertical direction, which is conducive to better flow of slurry to the thermocouple installation channel.

[0034] Further preferably, the gap between the inner protective sleeve 3 and the thermocouple 1 is 3~8mm, so that the inner protective sleeve 3 can provide sufficient protection space for the thermocouple; the gap between the outer protective sleeve 4 and the inner protective sleeve 3 is 7~37mm, thereby forming a grouting cavity with a suitable space.

[0035] More preferably, the diameter of the inner protective sleeve 3 is selected to be φ60×5mm to φ76×8mm, where φ60 represents the outer diameter of the inner protective sleeve 3, and 5mm and 8mm represent the wall thickness of the inner protective sleeve 3. The diameter of the outer protective sleeve 4 is selected to be φ100×5mm to φ150×8mm. The diameter selection is mainly based on the size of the thermocouple 1 and the size of the grouting cavity. In addition, the wall thickness of both the inner protective sleeve 3 and the outer protective sleeve 4 is selected to be 5mm to 8mm, which effectively ensures the strength and durability of the outer protective sleeve 4 and the inner protective sleeve 3, allowing both to withstand internal pressure and external environmental influences.

[0036] As a further preferred embodiment of any of the above embodiments, two sealing rings 12 are respectively provided at both ends of the inner cavity of the outer protective sleeve 4, and the end of the inner protective sleeve 3 close to the working end of the thermocouple 1 is flush with the end of the outer protective sleeve 4. The length of the outer protective sleeve 4 is greater than the length of the thermocouple installation channel and less than the length of the inner protective sleeve 3. The grouting hole 13 is opened in the axial section of the outer protective sleeve 4 located outside the thermocouple installation channel to facilitate grouting operations. More preferably, the grouting hole is located below the axis of the outer protective sleeve 4. To facilitate grouting operations, a grouting pipe 5 is inserted into the grouting hole.

[0037] Among them, the two sealing rings 12 are respectively arranged at the two ends of the inner cavity of the outer protective sleeve 4, so that the inner cavity length of the outer protective sleeve 4 can be fully utilized to form a grouting cavity, thereby better providing a grouting cavity that meets the length of the thermocouple channel and provides sufficient space for the flow of repair materials.

[0038] As an expansion solution, the distance between the grouting hole and the outer surface of the furnace shell layer 6 is preferably greater than 100 mm, so as to facilitate the operator to perform the grouting repair material operation, thereby improving the convenience and safety of the grouting operation.

[0039] As a further development solution, the length of the outer protective sleeve 4 along its axis is 150-250 mm greater than the length of the thermocouple channel.

[0040] As a preferred embodiment of the sealing ring 12, the end of the sealing ring 12 closest to the silica brick layer 11 contacts the side of the silica brick layer 11 away from the interior of the furnace chamber, so that the sealing ring 12 abuts the side of the silica brick layer 11, thereby helping to prevent the sealing ring 12 from shifting during the grouting process. It should be noted that the outer ring of the end of the sealing ring 12 only needs to contact the side of the silica brick layer 11, and the rest of the position is not required.

[0041] More preferably, the thickness of the sealing ring 12 is 5-8 mm. The thickness of the sealing ring 12 refers to its dimension along the axis of the outer protective sleeve 4. This thickness is designed to effectively ensure that the sealing ring 12 fits tightly between the inner protective sleeve 3 and the outer protective sleeve 4, while not being too thick and heavy to affect the assembly and use of the entire device.

[0042] The installation method of the thermocouple temperature measuring device of the present invention specifically includes the following steps: S1, removing the thermocouple 1 and its external protective sleeve; S2, using a reamer to expand the thermocouple installation channel to ensure that the outer protective sleeve 4 can be inserted into the thermocouple installation channel and the working end of the thermocouple can be inserted into the furnace cavity through the opening in the furnace wall silicon brick layer 11, and cleaning the expanded thermocouple installation channel; S3, installing the outer protective sleeve 4, the inner protective sleeve 3, the sealing ring 12 and the inner sleeve. Assemble the flange 14 and then insert it into the thermocouple installation channel, and the end of the outer protective sleeve 4 is tightly fitted into the silica brick layer 11 in the furnace wall, and then the outer protective sleeve 4 is welded to the furnace shell layer 6 in the furnace wall; S4, pour slurry into the grouting cavity through the pouring hole, and flow into the thermocouple installation channel through the overflow hole 13; S5, wrap the ceramic fiber packing around the end of the thermocouple, and then insert it into the inner protective sleeve 3, and finally fix the thermocouple matching flange 2 and the inner sleeve matching flange 14.

[0043] Preferably, during the hole expansion process of S2, it should be ensured as much as possible that the thermocouple installation channel is coaxial with the opening in the silicon brick layer 11.

[0044] Further preferably, in the S2 hole expanding process, a water-cooled hole expander is used for hole expanding.

[0045] More preferably, during the grouting process S4, the grouting pressure is detected and the grouting pressure is controlled to be maintained at 0.05-0.2 MPa.

[0046] During the S4 grouting process, the grouting speed is preferably increased when the grouting pressure is below 0.05 MPa, and decreased when the pressure approaches 0.2 MPa. Grouting is stopped when the grouting pressure reaches 0.2 MPa to prevent deformation and loss of hot blast furnace wall bricks due to excessive pressure.

[0047] In the S4 grouting process, preferably, the raw materials used for the slurry include corundum mullite castable and silica sol.

[0048] Among them, in S5, when inserting the thermocouple 1 into the inner protective sleeve 3, it is necessary to pay special attention to the insertion depth and position accuracy of the thermocouple 1 to ensure that it is in the best measurement position, and then the thermocouple matching flange 2 and the inner sleeve matching flange 14 are sealed and fastened.

[0049] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs a structure and embodiment similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A thermocouple temperature measuring device for a hot blast stove, characterized in that: The invention comprises an outer protective sleeve (4), an inner protective sleeve (3), a thermocouple (1) and two sealing rings (12), wherein the inner protective sleeve (3) is nested outside the thermocouple (1); the outer protective sleeve (4) is nested outside the inner protective sleeve (3), and two sealing rings (12) are provided between the inner cavity of the outer protective sleeve (4) and the inner protective sleeve (3) and are spaced apart along the axis thereof, so as to form a grouting cavity between the outer protective sleeve (4) and the inner protective sleeve (3); One end of the outer protective sleeve (4) is provided with a grouting hole for injecting slurry into the grouting cavity; and the other end is provided with a plurality of overflow holes (13) spaced apart along its axial direction, the overflow holes (13) being used to introduce the slurry in the grouting cavity into the thermocouple installation channel.

2. The thermocouple temperature measuring device for hot blast stove according to claim 1, characterized in that: Except for the furnace shell layer (6), the remaining walls in the thermocouple installation channel are all provided with corresponding overflow holes (13), and the overflow holes (13) corresponding to each layer of the wall are all arranged at the thickness center of the wall layer.

3. The thermocouple temperature measuring device for hot blast stove according to claim 2, characterized in that: Each wall layer is provided with four grouting holes (13) evenly spaced around the axis of the outer protective sleeve (4).

4. The thermocouple temperature measuring device for hot blast stove according to claim 1, characterized in that: The gap between the inner protective sleeve (3) and the thermocouple (1) is 3 to 8 mm; the gap between the outer protective sleeve (4) and the inner protective sleeve (3) is 7 to 37 mm.

5. The thermocouple temperature measuring device for a hot blast stove according to any one of claims 1 to 4, characterized in that: Two sealing rings (12) are respectively arranged at both ends of the inner cavity of the outer protective sleeve (4); one end of the inner protective sleeve (3) close to the working end of the thermocouple (1) is flush with the end of the outer protective sleeve (4); the length of the outer protective sleeve (4) is greater than the length of the thermocouple installation channel and less than the length of the inner protective sleeve (3), and the injection hole is opened in the shaft section of the outer protective sleeve (4) located outside the thermocouple installation channel.

6. The thermocouple temperature measuring device for hot blast stove according to claim 5, characterized in that: The thickness of the sealing ring (12) is 5-8 mm.

7. A method for installing a thermocouple temperature measuring device for a hot blast stove according to any one of claims 1 to 6, characterized in that: The steps include: S1, remove the thermocouple (1) and its external protective sleeve; S2, using a reamer to expand the thermocouple installation channel to match the outer diameter of the outer protective sleeve (4), and ensure that the working end of the thermocouple can be inserted into the furnace cavity through the opening in the silicon brick layer (11), and clean the expanded thermocouple installation channel; S3, assembling the outer protective sleeve (4), the inner protective sleeve (3), the sealing ring (12) and the inner sleeve matching flange (14), and then inserting them into the thermocouple installation channel, with the end of the outer protective sleeve (4) tightly fitting the silica brick layer (11) in the furnace wall, and then welding the outer protective sleeve (4) to the furnace shell layer (6); S4, pouring grout into the grouting cavity through the pouring hole, the grout fills the gap between the inner protective sleeve (3) and the outer protective sleeve (4), and flows into the thermocouple installation channel through the overflow hole (13); S5, wrap the end of the thermocouple (1) with ceramic fiber packing, then insert it into the inner protective sleeve (3), and finally fix the thermocouple matching flange (2) and the inner sleeve matching flange (14).

8. The installation method according to claim 7, characterized in that: The expanded thermocouple installation channel in S2 is coaxially arranged with the opening in the silicon brick layer (11); Alternatively, a water-cooled reamer is used to reame the hole in S2.

9. The installation method according to claim 8, characterized in that: In the step S4, the grouting pressure during the grouting process is detected and the grouting pressure is controlled to be maintained at 0.05-0.2 MPa.

10. The installation method according to claim 8, characterized in that: The raw materials of the slurry used in S4 include corundum mullite castable and silica sol.

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