Novel kiln external temperature measurement and control method
By setting up DN50 short tubes in the blast furnace temperature measurement area and filling with high-strength cast refractory materials, the problems of inaccurate temperature measurement and burning through the furnace shell in high-temperature and high-pressure environments are solved, the temperature measurement accuracy and safety are improved, and the stable production of the blast furnace is ensured.
Patent Information
- Application Number
- CN202411808105.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-03-04
AI Technical Summary
During the blast furnace iron smelting process, the high temperature and high pressure environment of the hot air furnace leads to excessive temperature measurement, affecting the accuracy of temperature measurement, and there is a safety hazard of burning through the furnace shell.
By setting up a short DN50 tube and filling it with high-strength cast refractory material around it, the thermocouple should be prevented from contacting the hollow directly and preventing high-temperature and high-pressure gas from entering the furnace shell.
It improves the accuracy of external temperature measurement of the furnace, protects the furnace shell from being burned through by high-temperature gas, eliminates safety hazards, and ensures the stable production of the blast furnace.
Smart Images
Figure CN119553022A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of blast furnace production, and in particular to a novel method for measuring and controlling the external temperature of a furnace. Background Art
[0002] The dome of the hot blast furnace precombustion chamber of the blast furnace ironmaking plant is equipped with a DN900 manhole, and a DN50 middle hole is left in the center of the manhole for temperature measurement. Since the hot blast furnace is a high-temperature and high-pressure container, and the hot blast furnace is under pressure and high temperature during the air supply and combustion periods, the internal refractory bricks will rise or shrink, causing high-temperature gas to enter the temperature measurement part, resulting in a larger gap between the manhole cover and the refractory bricks, which in turn causes the local temperature to be too high, exceeding 200°C, thus affecting the accuracy of the furnace temperature measurement. This is a common problem in kilns in the metallurgical industry. If it is not handled in time, it will cause a major safety hazard of burning through the furnace shell. Therefore, the above problems need to be solved urgently. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a new method for measuring and controlling the temperature of the outside of a furnace. By setting a DN50 short tube, direct contact between the temperature measuring thermocouple and the hollow space is avoided. The tube is filled with high-strength cast refractory materials on all sides, which is not easily deformed by high temperature. The high-temperature and high-pressure gas in the furnace is effectively controlled to pass to the furnace shell, thereby improving the accuracy of the temperature measurement outside the furnace. At the same time, the furnace shell can be protected from being burned through by the high-temperature gas that escapes, thereby controlling the temperature of the furnace shell, thereby eliminating safety hazards and ensuring stable production of the blast furnace.
[0004] In order to solve the above technical problems, the present invention adopts the following technical solution: A novel method for measuring and controlling the temperature outside a furnace of the present invention is innovative in that it comprises the following steps: (1) When the hot blast furnace is switched to stewing mode, open the corresponding flue valve and remove the original spherical thermocouple; (2) First, a lower short joint is coaxially provided on the upper surface of the manhole cover relative to the middle hole, and a middle hole flange plate is coaxially screwed on the upper end of the lower short joint, and an upper short joint is coaxially provided on the upper surface of the middle hole flange plate; then, a channel for inserting a DN50 short pipe is coaxially embedded in the lower short joint, the middle hole flange plate and the upper short joint along the length direction; (3) First separate the middle hole flange plate from the lower short joint, then remove the manhole cover, and then remove the internal refractory material and clean it; (4) After calibrating the DN50 short tube with a level ruler, insert the DN50 short tube coaxially through the center hole for a certain distance based on the thickness of the refractory material inside the vault, and ensure that the upper end of the DN50 short tube coaxially exceeds the upper end surface of the center hole; (5) Then, high-strength cast refractory materials are used to fill the area around the DN50 short pipe relative to the area surrounded by the refractory insulation bricks, and the gap part above the refractory insulation bricks relative to the DN50 short pipe is cast; (6) After the castable solidifies slightly, fill the gap between the DN50 short pipe and the middle hole with a fiber blanket; (7) Then install the manhole cover, and make the upper half of the DN50 short pipe coaxially sleeved in the lower short joint; then install a circular thin plate coaxially horizontally in the lower short joint relative to the DN50 short pipe just above, and ensure that the upper surface of the thin plate is coaxially arranged with the upper end surface of the lower short joint; (8) The middle hole flange plate is coaxially sealed and screwed to the upper end of the lower short joint, and a temperature measuring thermocouple is also sealed and installed on the upper end of the upper short joint, and the temperature measurement and temperature control operation is then performed through the temperature measuring thermocouple.
[0005] Preferably, in the above step (2), the outer diameter of the lower short joint is larger than the diameter of the middle hole, and its lower end is coaxially sealed and welded with the upper surface of the manhole cover, and extends vertically to the lower surface of the manhole cover; a connecting flange is also coaxially sleeved and fixed on the outer circumferential surface of the lower short joint near its upper end, and the upper surface of the connecting flange is flush with the upper end surface of the lower short joint, the diameter of the middle hole flange plate matches the diameter of the connecting flange, and it is coaxial with the connecting flange from top to bottom. The two are tightly fitted and sealed and screwed together; the outer diameter of the upper short joint is larger than the diameter of the middle hole, and the lower end of the upper short joint is coaxially sealed and welded with the upper surface of the middle hole flange plate; a slot matching the DN50 short tube is coaxially embedded in the lower short joint along its length direction, the slot is coaxially arranged with the middle hole above and below, and the lower end is connected with the middle hole, and the upper end extends vertically upward out of the middle hole flange plate and the upper surface of the upper short joint in turn, thereby forming a channel for inserting the DN50 short tube.
[0006] Preferably, in the above step (3), a fiber blanket is used to block the middle hole during the removal process to prevent burns.
[0007] Preferably, in the above step (4), the DN50 short tube must be arranged coaxially with the central hole, and its insertion length is 800 mm; the upper end surface of the DN50 short tube must be kept horizontal, and the horizontal error must not be greater than 0.5-1 mm.
[0008] Preferably, in the above step (5), CN-130 castable is used to cast the void portion, and high-strength castable refractory material is used to fill the DN50 short tube around it to prevent it from being deformed by high temperature, thereby effectively controlling the high-temperature and high-pressure gas in the furnace from passing through to the furnace shell.
[0009] Preferably, in the above step (7), before installing the manhole cover, the DN50 short pipe needs to be calibrated again with a spirit level so that its upper end surface remains horizontal, and it is necessary to ensure that the horizontal error is not greater than 0.5-1 mm.
[0010] Preferably, in the above step (7), the upper end surface of the DN50 short tube is located directly below the upper end surface of the lower short joint, and the distance between the two is 3 mm.
[0011] Preferably, in the above step (7), the inner diameter of the thin plate matches the outer diameter of the DN50 short tube, and its outer diameter is smaller than the outer diameter of the lower short joint; a circular groove matching the thin plate is also coaxially and vertically embedded in the upper surface of the lower short joint, and the thin plate is coaxially placed in the circular groove so that its lower surface is coaxially pressed against the upper end surface of the DN50 short tube, and its upper surface is ensured to be in the same horizontal plane as the upper surface of the lower short joint; then the thin plate is welded to the lower short joint and the DN50 short tube respectively, and a multi-layer and multi-pass welding method is adopted during welding, and one-time welding is not allowed, and the flatness of the upper end surface of the lower short joint and the upper surface of the connecting flange after welding is ensured, so as not to affect the sealing screw connection between the connecting flange and the center hole flange plate.
[0012] The beneficial effects of the present invention are as follows: the present invention avoids direct contact between the temperature measuring thermocouple and the hollow space by arranging a DN50 short tube, and the four sides of the tube are filled with high-strength cast refractory materials, which are not easily deformed by high temperature, and effectively control the high-temperature and high-pressure gas in the furnace to pass to the furnace shell, thereby improving the accuracy of temperature measurement outside the furnace, and at the same time protecting the furnace shell from being burned through by the high-temperature gas that escapes, thereby controlling the temperature of the furnace shell, thereby eliminating safety hazards and ensuring stable production of the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0014] Figure 1 It is a structural principle diagram of the present invention.
[0015] Among them, 1-hot blast furnace body shell; 2-refractory insulation bricks; 3-high-strength castable refractory material; 4-refractory spray coating; 5-manhole steel plate; 6-manhole cover; 7-CN-130 castable; 8-DN50 short pipe; 9-thin plate; 10-lower short joint; 11-connecting flange; 12-middle hole flange plate; 13-upper short joint; 14-temperature measuring thermocouple. DETAILED DESCRIPTION
[0016] The technical solution of the present invention will be clearly and completely described below through specific implementation methods.
[0017] A novel furnace external temperature measurement and control method of the present invention is as follows: Figure 1 As shown, the following steps are included: (1) When the hot blast furnace is switched to stewing mode, open the corresponding flue valve and remove the original ball-top thermocouple.
[0018] (2) First, a lower short joint 10 is coaxially provided on the upper surface of the manhole cover plate 6 relative to the center hole position, and a center hole flange plate 12 is coaxially screwed on the upper end of the lower short joint 10, and an upper short joint 13 is coaxially provided on the upper surface of the center hole flange plate 12; then, a channel for inserting the DN50 short pipe 8 is coaxially embedded in the lower short joint 10, the center hole flange plate 12 and the upper short joint 13 along the length direction.
[0019] In the above steps, the outer diameter of the lower short joint 10 is larger than the diameter of the middle hole, and its lower end is coaxially sealed and welded with the upper surface of the manhole cover 6, and extends vertically to the lower surface of the manhole cover 6; a connecting flange 11 is coaxially sleeved and fixed on the outer circumferential surface of the lower short joint 10 near its upper end, and the upper surface of the connecting flange 11 is flush with the upper end surface of the lower short joint 10, the diameter of the middle hole flange plate 12 matches the diameter of the connecting flange 11, and it is coaxially fitted with the connecting flange 11 from top to bottom. The outer diameter of the upper short joint 13 is larger than the diameter of the middle hole, and the lower end thereof is coaxially sealed and welded with the upper surface of the middle hole flange plate 12; a slot matching the DN50 short tube 8 is coaxially embedded in the lower short joint 10 along its length direction, the slot is coaxially arranged with the middle hole up and down, and the lower end thereof is connected with the middle hole, and the upper end thereof extends vertically upward out of the middle hole flange plate 12 and the upper surface of the upper short joint 13 in sequence, thereby forming a channel for inserting the DN50 short tube 8.
[0020] (3) First separate the middle hole flange plate 12 from the lower short joint 10, then remove the manhole cover plate 6, and then remove the internal refractory material and clean it.
[0021] In the above steps, a fiber blanket should be used to block the middle hole during the removal process to prevent burns.
[0022] (4) After calibrating the DN50 short tube 8 with a level, insert the DN50 short tube 8 coaxially through the center hole to a certain distance based on the thickness of the refractory material inside the vault, and ensure that the upper end of the DN50 short tube 8 coaxially exceeds the upper end surface of the center hole.
[0023] In the above steps, the DN50 short tube 8 must be ensured to be coaxially arranged with the center hole, and its insertion length must be 800 mm; the upper end surface of the DN50 short tube 8 must be kept horizontal, and it must be ensured that the horizontal error is not greater than 0.5~1 mm.
[0024] (5) Then, high-strength cast refractory material 3 is used to fill the area around the DN50 short pipe 8 relative to the area surrounded by the refractory insulation bricks 2, and the gap part above the refractory insulation bricks 2 relative to the DN50 short pipe 8 is cast.
[0025] In the above steps, CN-130 castable 7 is used to cast the gap part, and high-strength castable refractory material 3 is used to fill the DN50 short tube 8 around it to make it less susceptible to deformation due to high temperature, and effectively control the high-temperature and high-pressure gas in the furnace to flow to the furnace shell. This not only improves the accuracy of external temperature measurement, but also protects the furnace shell from being burned through by the high-temperature gas that escapes, thereby playing a role in controlling the temperature of the furnace shell.
[0026] (6) After the castable solidifies slightly, fill the gap between the DN50 short pipe 8 and the middle hole with a fiber blanket.
[0027] (7) Then install the manhole cover 6, and make the upper half of the DN50 short pipe 8 coaxially sleeved in the lower short joint 10; then install a circular thin plate 9 coaxially horizontally in the lower short joint 10 directly above the DN50 short pipe 8, and ensure that the upper surface of the thin plate 9 is arranged in the same horizontal plane as the upper end surface of the lower short joint 10.
[0028] In the above steps, before installing the manhole cover 6, the DN50 short pipe 8 needs to be calibrated again with a level ruler to keep its upper end surface horizontal, and it is necessary to ensure that the horizontal error is not greater than 0.5~1mm.
[0029] In the above steps, the upper end surface of the DN50 short tube 8 is located directly below the upper end surface of the lower short joint 10, and the distance between the two is 3 mm.
[0030] The inner diameter of the thin plate 9 of the present invention matches the outer diameter of the DN50 short tube 8, and its outer diameter is smaller than the outer diameter of the lower short joint 10; a circular groove matching the thin plate 9 is also coaxially and vertically embedded in the upper surface of the lower short joint 10, and the thin plate 9 is coaxially placed in the circular groove so that its lower surface is coaxially tightly fitted with the upper end surface of the DN50 short tube 8, and ensure that its upper surface is in the same horizontal plane as the upper surface of the lower short joint 10; then the thin plate 9 is welded and fixed to the lower short joint 10 and the DN50 short tube 8 respectively, and a multi-layer and multi-pass welding method is adopted during welding, and one-time welding is not allowed, and the flatness of the upper end surface of the lower short joint 10 and the upper surface of the connecting flange 11 after welding is ensured, so as not to affect the sealing screw connection between the connecting flange 11 and the center hole flange plate 12, and ensure that the welding quality reaches the airtight high pressure resistance strength.
[0031] (8) The middle hole flange plate 12 is coaxially sealed and screwed to the upper end of the lower short joint 10, and a temperature measuring thermocouple 14 is also sealed and installed on the upper end of the upper short joint 13, so that the temperature measurement and temperature control operation can be performed through the temperature measuring thermocouple 14.
[0032] Beneficial effects of the present invention: The present invention avoids direct contact between the temperature measuring thermocouple 14 and the hollow space by arranging the DN50 short tube 8, and the four sides thereof are filled with high-strength cast refractory material 3, which is not easily deformed by high temperature, and effectively controls the high-temperature and high-pressure gas in the furnace to pass to the furnace shell, thereby improving the accuracy of temperature measurement outside the furnace, and at the same time can protect the furnace shell from being burned through by the high-temperature gas that escapes, thereby controlling the temperature of the furnace shell, thereby eliminating safety hazards and ensuring stable production of the blast furnace.
[0033] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering technicians in the field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the technical requirements.
Claims
1. A new method for measuring and controlling the temperature outside the furnace, characterized in that The following steps are involved: (1) When the hot blast furnace is switched to stewing mode, open the corresponding flue valve and remove the original spherical thermocouple; (2) First, a lower short joint is coaxially provided on the upper surface of the manhole cover relative to the middle hole, and a middle hole flange plate is coaxially screwed on the upper end of the lower short joint, and an upper short joint is coaxially provided on the upper surface of the middle hole flange plate; then, a channel for inserting a DN50 short pipe is coaxially embedded in the lower short joint, the middle hole flange plate and the upper short joint along the length direction; (3) First separate the middle hole flange plate from the lower short joint, then remove the manhole cover, and then remove the internal refractory material and clean it; (4) After calibrating the DN50 short tube with a level ruler, insert the DN50 short tube coaxially through the center hole for a certain distance based on the thickness of the refractory material inside the vault, and ensure that the upper end of the DN50 short tube coaxially exceeds the upper end surface of the center hole; (5) Then, high-strength cast refractory materials are used to fill the area around the DN50 short pipe relative to the area surrounded by the refractory insulation bricks, and the gap part above the refractory insulation bricks relative to the DN50 short pipe is cast; (6) After the castable solidifies slightly, fill the gap between the DN50 short pipe and the middle hole with a fiber blanket; (7) Then install the manhole cover, and make the upper half of the DN50 short pipe coaxially sleeved in the lower short joint; then install a circular thin plate coaxially horizontally in the lower short joint relative to the DN50 short pipe just above, and ensure that the upper surface of the thin plate is coaxially arranged with the upper end surface of the lower short joint; (8) The middle hole flange plate is coaxially sealed and screwed to the upper end of the lower short joint, and a temperature measuring thermocouple is also sealed and installed on the upper end of the upper short joint, and the temperature measurement and temperature control operation is then performed through the temperature measuring thermocouple.
2. A novel furnace external temperature measurement and control method according to claim 1, characterized in that: In the above step (2), the outer diameter of the lower short joint is larger than the diameter of the middle hole, and its lower end is coaxially sealed and welded with the upper surface of the manhole cover plate, and extends vertically to the lower surface of the manhole cover plate; a connecting flange is coaxially sleeved and fixed on the outer circumferential surface of the lower short joint near its upper end, and the upper surface of the connecting flange is flush with the upper end surface of the lower short joint, the diameter of the middle hole flange plate matches the diameter of the connecting flange, and it is coaxially fitted with the connecting flange up and down, and the two are sealed and screwed; the outer diameter of the upper short joint is larger than the diameter of the middle hole, and its lower end is coaxially sealed and welded with the upper surface of the middle hole flange plate; a slot matching the DN50 short pipe is coaxially embedded in the lower short joint along its length direction, the slot is coaxially arranged with the middle hole up and down, and its lower end is connected with the middle hole, and its upper end extends vertically upward from the middle hole flange plate and the upper surface of the upper short joint in sequence, thereby forming a channel for inserting the DN50 short pipe.
3. A novel furnace external temperature measurement and control method according to claim 2, characterized in that: In the above step (3), a fiber blanket is used to block the middle hole during the removal process to prevent burns.
4. A novel furnace external temperature measurement and control method according to claim 1, characterized in that: In the above step (4), the DN50 short tube must be arranged coaxially with the center hole, and its insertion length must be 800 mm; the upper end surface of the DN50 short tube must be kept horizontal, and the horizontal error must not be greater than 0.5~1 mm.
5. A novel furnace external temperature measurement and control method according to claim 1, characterized in that: In the above step (5), CN-130 castable is used to cast the gap part, and high-strength castable refractory material is used to fill the DN50 short pipe around it to make it less susceptible to deformation due to high temperature, thereby effectively controlling the high-temperature and high-pressure gas in the furnace from passing through to the furnace shell.
6. A novel furnace external temperature measurement and control method according to claim 1, characterized in that: In the above step (7), before installing the manhole cover, the DN50 short pipe needs to be calibrated again with a spirit level to keep its upper end surface level and ensure that the horizontal error is no greater than 0.5~1mm.
7. A novel furnace external temperature measurement and control method according to claim 1, characterized in that: In the above step (7), the upper end surface of the DN50 short tube is located directly below the upper end surface of the lower short joint, and the distance between the two is 3 mm.
8. A novel furnace external temperature measurement and control method according to claim 7, characterized in that: In the above step (7), the inner diameter of the thin plate matches the outer diameter of the DN50 short tube, and its outer diameter is smaller than the outer diameter of the lower short joint; a circular groove matching the thin plate is also coaxially and vertically embedded in the upper surface of the lower short joint, and the thin plate is coaxially placed in the circular groove so that its lower surface is coaxially in close contact with the upper end surface of the DN50 short tube, and its upper surface is ensured to be in the same horizontal plane as the upper surface of the lower short joint; then the thin plate is welded to the lower short joint and the DN50 short tube respectively, and a multi-layer and multi-pass welding method is adopted during welding, and one-time welding is not allowed, and the flatness of the upper end surface of the lower short joint and the upper surface of the connecting flange after welding is ensured, so as not to affect the sealing screw connection between the connecting flange and the center hole flange plate.