Monitoring system for ring formation and refractory falling in rotary kiln

Abstract

The invention discloses a rotary kiln inner ring forming and refractory material falling monitoring system which comprises a rotary kiln, a transmission device, at least one supporting foundation, at least one marking strip, at least one camera, at least one thermal imager and an electric control system, the transmission device and the supporting foundation are both arranged on the outer wall of the rotary kiln, the supporting foundation is used for supporting the rotary kiln, and the marking strip is arranged on the outer wall of the rotary kiln. The marking strip is arranged on the edge of one side of the outer wall of the rotary kiln body, and the camera is arranged on the outer side, corresponding to the rotary kiln body, of the marking strip and used for collecting image information of the marking strip. The device has the beneficial effects that manual monitoring of the temperature state of the outer wall of the rotary kiln carcass is replaced by intelligent and automatic means such as a machine vision technology and a video stitching technology, the ring forming and refractory material falling conditions in the rotary kiln are automatically analyzed according to thermal imaging images, the abnormal state can be found in time, and the working efficiency is improved. And timely adjustment of process production parameters or production halt maintenance is facilitated, production quality and equipment safety are guaranteed, and production benefits are increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgical pellet production equipment state monitoring, in particular to a rotary kiln ring formation and refractory falling monitoring system. BACKGROUND

[0002] In steel production, the finished product of pellet production is called pellet, which is an important raw material for blast furnace ironmaking. The rotary kiln is one of the main equipment in the metallurgical pellet chain-returning ring-oxidation roasting process, which is used to solidify the pellet discharged from the tail of the chain grate machine and perform high-temperature roasting operation. The rotary kiln cylinder is made of metal material, and the kiln lining is arranged in the cylinder. The kiln lining is a refractory material inlaid on the inner surface of the rotary kiln cylinder, which plays a role in heat insulation, protects the cylinder from high temperature damage, and reduces heat loss.

[0003] In the production process, the inner wall of the rotary kiln at high temperature is prone to ring-like adhesion of the furnace charge. The slight adhesion phenomenon is called kiln skin, and if the adhesion is more serious, it is called ring formation. In addition, refractory cracking and falling also occur from time to time. When ring formation and refractory falling are serious, they will directly affect pellet production and even damage the equipment, which needs to be discovered and handled in time. Therefore, it is necessary to monitor the relevant state of the rotary kiln in real time to provide decision basis for adjusting the process production parameters or stopping production for maintenance.

[0004] At present, there are two kinds of traditional monitoring methods. One is manual monitoring by temperature gun, but the rotary kiln is large in size and always rotating, so manual detection is difficult, and single-point temperature detection will cause missed detection. The other is to use a thermal imaging system to monitor the overall temperature of the outer wall of the rotary kiln body, but manual observation of the image is often required for identification. If ring formation and refractory falling are not discovered in time, it will lead to reduced production efficiency, decreased product quality, and increased equipment maintenance cost.

[0005] A new type of scanning equipment and system for rotary kiln body is disclosed in the prior art with publication number CN118603325A. Multiple movable scanning units and dynamic trajectory planning concepts are introduced. The scanning units are distributed along the axial and circumferential directions of the rotary kiln body. The motion path of the scanning unit is adjusted in real time to adapt to the rotary speed of the rotary kiln. The temperature data collected by the infrared temperature sensor is used to construct a body temperature field model, realizing dynamic tracking and data visualization display of the temperature of different regions of the rotary kiln body. However, this technical solution does not associate the feature recognition of temperature abnormal areas with the fault mechanism of ring formation and refractory falling in the rotary kiln. It can only output temperature distribution data and cannot automatically determine the fault type corresponding to the abnormal temperature. It cannot achieve accurate identification, regional positioning and fault level division of ring formation and refractory falling, and still needs to rely on manual analysis of temperature data combined with production experience, resulting in lag and subjectivity in fault judgment, which cannot meet the needs of real-time early warning and automatic monitoring of rotary kiln faults.

[0006] An existing technology discloses an online analysis device for thermal imaging infrared scanning of kiln shells, with publication number CN218411447U. It introduces multiple sets of infrared thermal imaging sensor arrays and the concept of real-time data transmission. The infrared thermal imaging sensors are arranged in layers along the circumference and axial direction of the kiln shell. The sensors synchronously collect temperature radiation signals from different areas of the kiln shell, which are converted into temperature values ​​by the data processing module and transmitted to the terminal display interface. This enables real-time scanning, data recording, and preliminary labeling of temperature anomaly areas on the outer wall of the kiln shell. However, this technical solution does not associate the characteristics of abnormal temperature areas (such as temperature gradient, area morphology, and duration) with the specific fault mechanisms of ring formation and refractory shedding in the rotary kiln. It can only simply identify areas where the temperature exceeds the preset threshold. It cannot distinguish whether the abnormal temperature is caused by ring formation (low temperature barrier) or refractory shedding (high temperature conduction). It cannot achieve automatic identification, accurate location, and quantitative assessment of the fault types of ring formation and refractory shedding. It still requires manual judgment based on production experience to identify the marked abnormal areas, resulting in a delayed fault response and making it difficult to meet the needs of rapid handling of critical faults in the rotary kiln production process. Summary of the Invention

[0007] To overcome the problems of traditional manual temperature gun monitoring being difficult and prone to missed detection, and conventional thermal imaging systems requiring manual identification and not being able to detect faults in a timely manner, this invention provides a monitoring system for ring formation and refractory material shedding in rotary kilns.

[0008] The technical solution adopted by the present invention to achieve the above objectives is as follows: It includes a rotary kiln, a transmission device, at least one supporting foundation, at least one marking strip, at least one camera, at least one thermal imager, and an electrical control system; the transmission device and the supporting foundation are both installed on the outer wall of the rotary kiln, and the supporting foundation is used to support the rotary kiln; the marking strip is installed on one edge of the outer wall of the rotary kiln body; the camera is installed on the outer side of the rotary kiln body corresponding to the marking strip, and is used to collect image information of the marking strip; the thermal imager is installed axially along the outer side of the rotary kiln body, and is used to collect thermal imaging images of the rotary kiln body; both the camera and the thermal imager are electrically connected to the electrical control system via control cables; the electrical control system uses machine vision technology to determine the current rotation position of the rotary kiln based on the marking strip image information collected by the camera.

[0009] Preferably, the electronic control system obtains a complete thermal imaging image of the rotary kiln by combining thermal imaging images acquired by at least two thermal imagers using video stitching technology.

[0010] Preferably, the marking strips include four different marking strips (first, second, third, and fourth) evenly distributed radially; the supporting foundation includes a first supporting foundation and a second supporting foundation; the rotary kiln has a cylindrical structure and rotates axially during production.

[0011] Preferably, the electric control system automatically generates a temperature distribution map of the outer wall of the barrel based on the complete thermal imaging image; the temperature distribution map of the outer wall of the barrel is a two-dimensional map, the vertical axis corresponds to the radial position of the outer wall of the barrel of the rotary kiln, and the horizontal axis corresponds to the axial position of the outer wall of the barrel of the rotary kiln; in the temperature distribution map of the outer wall of the barrel, the marks corresponding to the first marking strip, the second marking strip, the third marking strip and the fourth marking strip respectively correspond to the vertical axis positions of the first marking strip, the second marking strip, the third marking strip and the fourth marking strip, the temperature-free area corresponding to the transmission device corresponds to the horizontal axis position of the transmission device, the temperature-free areas corresponding to the first support foundation and the second support foundation respectively correspond to the horizontal axis positions of the first support foundation and the second support foundation, and there is no temperature data in the area surrounded by the horizontal axis corresponding width and the entire vertical axis in the temperature distribution map of the outer wall of the barrel.

[0012] Preferably, the electric control system divides the vertical axis of the temperature distribution map of the outer wall of the barrel into m segments and the horizontal axis into n segments according to the working conditions of the rotary kiln, forming m×n matrix squares, where both m and n are positive integers.

[0013] Preferably, the specific determination condition for the electric control system to determine the rotation position of the rotary kiln is that the image collected by the camera contains two marking strips, and the center points of the two marking strips are on the center line of the rotary kiln image.

[0014] Preferably, when the rotation position determination condition of the rotary kiln is satisfied, the electric control system updates the thermal imaging images of the vertical axis positions corresponding to the two marking strips and the entire horizontal axis surrounded area on the temperature distribution map of the outer wall of the barrel.

[0015] Preferably, the electric control system also uses machine vision technology to obtain the temperature Ti,j of the outer wall of the barrel corresponding to each matrix square except the positions where the transmission device and the support foundation are located according to the complete thermal imaging image, where i∈0~m and j∈0~n.

[0016] Preferably, the electric control system judges whether A<(Ti,j×2) / (Ti-1,j+Ti+1,j)<B holds; when this inequality does not hold, the corresponding matrix square is marked as a temperature abnormal point; where A and B are temperature deviation coefficients, and the values of A and B are obtained through on-site debugging.

[0017] Preferably, when several surrounded areas are formed by the matrix squares corresponding to all temperature abnormal points, the electric control system uses machine vision technology to compare the thermal imaging images inside and outside the surrounded area to judge whether the surrounded area belongs to a low-temperature area or a high-temperature area; when the surrounded area belongs to a low-temperature area, this area is marked as the area where a ring formation occurs; when the surrounded area belongs to a high-temperature area, this area is marked as the area where refractory peeling occurs.

[0018] The beneficial effects of this invention are that it uses intelligent and automated means such as machine vision technology and video splicing technology to replace manual monitoring of the temperature of the outer wall of the rotary kiln, and automatically analyzes the ring formation and refractory shedding in the rotary kiln based on thermal imaging images. This enables timely detection of abnormal conditions, which is conducive to timely adjustment of process production parameters or shutdown for maintenance, ensuring production quality and equipment safety, and increasing production efficiency. Attached Figure Description

[0019] Figure 1 A schematic diagram of the axial structure of the rotary kiln when the center points of the first and second marker bars are located on the center line of the rotary kiln image; Figure 2 A schematic diagram of the radial structure of a rotary kiln when the center points of the first and second marker bars are located on the center line of the rotary kiln image; Figure 3 This is a temperature distribution diagram of the outer wall of the rotary kiln shell when the center points of the first and second marker bars are located on the center line of the rotary kiln image. Figure 4 A schematic diagram of the axial structure, a schematic diagram of the radial structure, and a temperature distribution diagram of the outer wall of the rotary kiln when the center points of the second and third marker bars are located on the center line of the rotary kiln image; Figure 5 A schematic diagram of the axial structure, a schematic diagram of the radial structure, and a temperature distribution diagram of the outer wall of the rotary kiln when the center points of the third and fourth marker bars are located on the center line of the rotary kiln image; Figure 6 A schematic diagram of the axial structure, a schematic diagram of the radial structure, and a temperature distribution diagram of the outer wall of the rotary kiln when the center points of the fourth and first marker bars are located on the center line of the rotary kiln image; Figure 7 This is a composite diagram showing the temperature distribution at all locations on the outer wall of the rotary kiln shell of the present invention. Figure 8 This is a flowchart of the electrical control system of the rotary kiln ring formation and refractory material shedding monitoring system of the present invention.

[0020] In the diagram: 1. Rotary kiln; 2. Transmission device; 31. First support foundation; 32. Second support foundation; 41. First marker strip; 42. Second marker strip; 43. Third marker strip; 44. Fourth marker strip; 5. Camera; 6. Thermal imager; 11. Mark corresponding to the first marker strip; 12. Mark corresponding to the second marker strip; 13. Mark corresponding to the third marker strip; 14. Mark corresponding to the fourth marker strip; 15. Temperature-free zone corresponding to the transmission device; 16. Temperature-free zone corresponding to the first support foundation; 17. Temperature-free zone corresponding to the second support foundation. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Example 1: As Figures 1-3 As shown, this embodiment provides a rotary kiln ring formation and refractory material shedding monitoring system, including a rotary kiln 1, a transmission device 2 on the outer wall of the rotary kiln 1, and at least one support foundation, wherein the support foundation includes a first support foundation 31 and a second support foundation 32. The rotary kiln 1 is a cylinder that rotates along the axial direction during production. The rotary kiln 1 has four different marking strips 41, 42, 43 and 44 evenly distributed radially along one edge of the outer wall of the carcass. A camera 5 is provided on the outside of the carcass where the four marking strips are located. The rotary kiln 1 has several thermal imagers 6 arranged axially on the outer side of the body. The camera 5 and the thermal imager 6 are electrically connected to the electronic control system via control cables; The electronic control system uses machine vision technology to determine the current rotation position of the rotary kiln 1 by using the image information of the marking strips on the rotary kiln 1 collected by the camera 5. The electronic control system obtains a complete thermal imaging image of the rotary kiln 1 through several thermal imagers 6 and video stitching technology.

[0025] like Figures 3-7As shown in the figure, the monitoring system for ring formation and refractory peeling in the rotary kiln automatically generates the temperature distribution map of the outer wall of the barrel through thermal imaging images; The temperature distribution map of the outer wall of the barrel is a two-dimensional map, where the vertical axis represents the radial position of the outer wall of the barrel of the rotary kiln, and the horizontal axis represents the axial position of the outer wall of the barrel of the rotary kiln; In the temperature distribution map of the outer wall of the barrel, the marks 11 corresponding to the first marking strip, the marks 12 corresponding to the second marking strip, the marks 13 corresponding to the third marking strip, and the marks 14 corresponding to the fourth marking strip are the vertical axis positions corresponding to the four marking strips, namely the first marking strip 41, the second marking strip 42, the third marking strip 43, and the fourth marking strip 44; In the temperature distribution map of the outer wall of the barrel, the temperature-free area 15 corresponding to the drive device is the horizontal axis position corresponding to the drive device 2, and the temperature-free areas 16 corresponding to the first support foundation and the temperature-free area 17 corresponding to the second support foundation are the horizontal axis positions corresponding to the first support foundation 31 and the second support foundation 32. There is no temperature data in the area surrounded by the horizontal axis corresponding width and the entire vertical axis; In the temperature distribution map of the outer wall of the barrel, according to the working conditions of the rotary kiln 1, the vertical axis is evenly divided into m segments, and the horizontal axis is evenly divided into n segments, and finally m×n matrix grids are formed.

[0026] Example 2: As Figure 8 shown in the figure, this embodiment is based on the previous embodiment. The difference from the previous embodiment is that the control method of the monitoring system for ring formation and refractory peeling in the rotary kiln includes the following steps: S1. The system starts; S2. Using machine vision technology, determine whether the marking strip reaches the specified position, that is, there are two marking strips in the image of the camera 5, and the center points of the two marking strips are on the center line of the image of the rotary kiln 1. If the result is no, execute S2 again. If the result is yes, continue to execute S3; S3. Through video stitching technology, obtain the complete thermal imaging image of the rotary kiln 1, and update the vertical axis positions corresponding to the two marking strips and the thermal imaging image of the area surrounded by the entire horizontal axis on the temperature distribution map of the outer wall of the barrel; S4. According to the thermal imaging image, using machine vision technology, obtain the temperature Ti,j of the outer wall of the barrel corresponding to each matrix grid (i∈0~m, j∈0~n) except for the positions of the drive device 2 and the support foundation; S5. Determine whether A<(Ti,j×2) / (Ti-1,j + Ti+1,j)<B holds. If it does not hold, this matrix grid is marked as a temperature anomaly point, where A and B are temperature deviation coefficients obtained through on-site debugging; S6. All temperature anomaly points form a matrix of squares that enclose several areas. Using machine vision technology, the thermal imaging images inside and outside the enclosed areas are compared to determine whether the enclosed area belongs to a low-temperature area or a high-temperature area. When the enclosed area belongs to a low-temperature area, this area is marked as the area where the ring formation occurs. When the enclosed area belongs to a high-temperature area, this area is marked as the area where the refractory material falls off.

[0027] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. For example, changes in the number of marker strips, cameras, and thermal imagers, any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A monitoring system for ring formation and refractory material shedding in a rotary kiln, characterized in that: The system includes a rotary kiln (1), a transmission device (2), at least one support base, at least one marker strip, at least one camera (5), at least one thermal imager (6), and an electrical control system. The transmission device (2) and the support base are both located on the outer wall of the rotary kiln (1), and the support base is used to support the rotary kiln (1). The marker strip is located on one edge of the outer wall of the rotary kiln (1). The camera (5) is located on the outer side of the rotary kiln (1) corresponding to the marker strip and is used to collect image information of the marker strip. The thermal imager (6) is axially arranged along the outer side of the rotary kiln (1) and is used to collect thermal imaging images of the rotary kiln (1). The camera (5) and the thermal imager (6) are both electrically connected to the electrical control system through control cables. The electrical control system uses machine vision technology to determine the current rotation position of the rotary kiln (1) based on the marker strip image information collected by the camera (5).

2. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 1, characterized in that: The electronic control system obtains a complete thermal imaging image of the rotary kiln (1) by combining thermal imaging images collected by at least two thermal imagers (6) through video splicing technology.

3. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 2, characterized in that: The marking strips include four different marking strips (41), (42), (43), and (44) that are evenly distributed radially; the supporting base includes a first supporting base (31) and a second supporting base (32); the rotary kiln (1) is a cylindrical structure and rotates axially during production.

4. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 3, characterized in that: The electronic control system automatically generates a temperature distribution map of the outer wall of the kiln body based on a complete thermal imaging image. The temperature distribution map of the outer wall of the kiln body is a two-dimensional map, with the vertical axis corresponding to the radial position of the outer wall of the rotary kiln body and the horizontal axis corresponding to the axial position of the outer wall of the rotary kiln body. In the temperature distribution map of the outer wall of the kiln body, the marker (11) corresponding to the first marker bar, the marker (12) corresponding to the second marker bar, the marker (13) corresponding to the third marker bar, and the marker (14) corresponding to the fourth marker bar correspond to the vertical axis positions of the first marker bar (41), the second marker bar (42), the third marker bar (43), and the fourth marker bar (44), respectively. The temperature-free zone (15) corresponding to the transmission device corresponds to the horizontal axis position of the transmission device (2). The temperature-free zone (16) corresponding to the first support foundation and the temperature-free zone (17) corresponding to the second support foundation correspond to the horizontal axis positions of the first support foundation (31) and the second support foundation (32), respectively. The area enclosed by the width of the horizontal axis and the entire vertical axis has no temperature data in the temperature distribution map of the outer wall of the kiln body.

5. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 4, characterized in that: According to the working conditions of the rotary kiln (1), the electrical control system divides the vertical axis of the temperature distribution map of the outer wall of the carcass into m segments and the horizontal axis into n segments, forming m×n matrix squares, where m and n are both positive integers.

6. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 5, characterized in that: The specific conditions for the electronic control system to determine the rotation position of the rotary kiln (1) are as follows: the image captured by the camera (5) contains two marker bars, and the center point of the two marker bars is located on the center line of the image of the rotary kiln (1).

7. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 6, characterized in that: When the rotation position determination condition of the rotary kiln (1) is met, the electrical control system updates the thermal imaging image of the two marker bars corresponding to the vertical axis position and the entire horizontal axis enclosed area on the temperature distribution map of the outer wall of the carcass.

8. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 7, characterized in that: The electronic control system also uses machine vision technology to obtain the temperature Ti,j of the outer wall of the cylinder corresponding to each matrix grid except for the positions of the transmission device (2) and the support foundation according to the complete thermal imaging image, where i ∈ 0~m and j ∈ 0~n.

9. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 8, characterized in that: The electronic control system determines whether A < (Ti,j × 2) / (Ti-1,j + Ti+1,j) < B holds; when this inequality does not hold, the corresponding matrix grid is marked as a temperature anomaly point; where A and B are temperature deviation coefficients, and the values of A and B are obtained through on-site debugging.

10. The rotary kiln ring formation and refractory material shedding monitoring system according to claim 9, characterized in that: When several enclosed areas are formed by the matrix grids corresponding to all temperature anomaly points, the electronic control system uses machine vision technology to compare the thermal imaging images inside and outside the enclosed area to determine whether the enclosed area belongs to a low-temperature area or a high-temperature area; when the enclosed area belongs to a low-temperature area, this area is marked as the area where the ring formation occurs; when the enclosed area belongs to a high-temperature area, this area is marked as the area where the refractory falls off.

Images