A method and system for detecting the shape of material surface in a kiln

Abstract

The present application discloses a method for detecting the shape of a material surface in a kiln, comprising: applying liquid from the material surface of the charge in the kiln to a predetermined area of ​​the material surface upward; and acquiring a thermal image of the material surface with a thermal imager. The temperature of the liquid is lower than the temperature of the charge, so that the charge in the predetermined area that receives the liquid appears as a recognizable low-temperature zone in the thermal image; and the predetermined area is selected so that its shape can reflect the local or overall shape of the material surface, so that the shape of the low-temperature zone in the thermal image correspondingly reflects the local or overall shape of the material surface. According to another aspect of the present application, a system for detecting the shape of a material surface in a kiln is provided, comprising: a liquid spraying device for applying liquid from the material surface of the charge in the kiln to a predetermined area of ​​the material surface upward; and a thermal imager for acquiring a thermal image of the material surface, wherein the charge in the predetermined area of ​​the material surface that receives the liquid appears as a recognizable low-temperature zone in the thermal image.

Description

Technical Field

[0001] The present application relates to a detection device, and more particularly to a method and system for detecting the shape of a material surface in a kiln. Background Art

[0002] Closed industrial furnaces such as blast furnaces have high temperature, high pressure, high dust, high humidity and other furnace environments, so it is difficult to observe through the observation window with human eyes. To this end, various detection devices have been proposed to obtain information inside the furnace.

[0003] In the prior art, a thermal imager is used to obtain an infrared image of the material surface in the furnace, and thereby obtain the temperature distribution information of each part of the material surface. However, this method can only be used to observe and monitor the production situation in the furnace. Since there is no coordinate data, the shape and position information of the material surface cannot be obtained.

[0004] Several distance measurement methods are also used in the prior art to obtain the shape information of the material surface. For example, the material surface is scanned with infrared, microwave, ultrasonic and other ray distance measurement equipment to obtain the distances of multiple points on the material surface relative to the distance measurement equipment, thereby obtaining the shape and position information of the material surface. Such distance measurement equipment requires complex ray emission and receiving devices, and cannot work for a long time in the harsh furnace environment. Therefore, it can only be temporarily inserted into the blast furnace for a short time or under specific conditions to obtain furnace information. Moreover, the high dust environment in the furnace will also affect the emission and reception of rays, resulting in inaccurate measurement results.

[0005] In the prior art, a laser scanning device is also used to irradiate the laser onto the material surface in the furnace, forming a laser bright spot on the material surface, and using a camera to capture an image containing the laser bright spot. Since the position of the laser bright spot on the material surface reflects the position of the material surface at its location, the shape information and even the position information of the material surface can be obtained by acquiring the pattern of the laser bright spot at multiple positions on the material surface. However, when the dust in the blast furnace is particularly high, the laser is severely reflected and scattered by the dust, and it may not be able to move forward to the material surface at all. Moreover, even if the laser reaches the material surface, the brightness of the laser point on the material surface is very weak and difficult to detect. In addition, the laser bright spot formed outside the material surface due to dust scattering, the local bright spot formed by the burning charge, and the splashing bright charge will also interfere with the extraction of the laser bright spot from the image. Summary of the invention

[0006] The purpose of the present application is to provide a novel method and system for detecting the shape of the material surface in a kiln.

[0007] Compared with the laser scanning device in the prior art which uses laser to form a "bright spot" on the material surface to indicate the position of the material surface at the bright spot, the inventor of the present application uses the opposite method to form a "dark spot" or "dark area" on the material surface to indicate the position of the material surface at that location.

[0008] According to one aspect of the present application, a method for detecting the shape of a material surface in a kiln is provided, comprising: applying liquid from above the material surface of the charge in the kiln to a predetermined area of ​​the material surface; and acquiring a thermal image of the material surface with a thermal imager; wherein the temperature of the liquid is lower than the temperature of the charge, so that the charge in the predetermined area receiving the liquid appears as a recognizable low-temperature area in the thermal image; and, the predetermined area is selected so that its shape can reflect the local or overall shape of the material surface, so that the shape of the low-temperature area in the thermal image correspondingly reflects the local or overall shape of the material surface.

[0009] According to another aspect of the present application, a system for detecting the shape of a material surface in a kiln is provided, comprising: a liquid spraying device for applying liquid from the material surface of the charge in the kiln upward to a predetermined area of ​​the material surface; and a thermal imager for acquiring a thermal image of the material surface, wherein the charge in the predetermined area of ​​the material surface that receives the liquid appears as a recognizable low-temperature area in the thermal image. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 An embodiment of the system for detecting the shape of the material surface in the kiln furnace of the present application is shown;

[0011] Figure 2 Shows Figure 1 A liquid spraying device in a system;

[0012] Figure 3 Shows Figure 1 The installation status of the thermal imager in the system;

[0013] Figure 4 yes Figure 1 One embodiment of a thermal image acquired by the system shown; and

[0014] Figure 5 is from Figure 4 The image of the low temperature area extracted from the thermal image shown. DETAILED DESCRIPTION

[0015] The technical solution of the present application is described in detail below in conjunction with the accompanying drawings and embodiments. In these drawings, the same or similar components are marked with the same or similar reference numerals.

[0016] Figure 1 A blast furnace 10 is shown as an example of a furnace to which the present application is applicable. Figure 1As shown, the blast furnace 10 may have a furnace shell 11. The charge 20 is arranged in the blast furnace 10, and its surface forms a charge surface 21. The shape and position information of the charge surface 21 is important in-furnace information that is expected to be detected, because it helps to understand the distribution and consumption of the charge 20 in the furnace. In other embodiments, the method and system of the present application can be applied to other types of kilns other than blast furnaces.

[0017] The furnace shell 11 of the blast furnace 10 is generally symmetrically shaped along the central axis L, and the material surface 21 of the charge 20 therein is also generally symmetrically shaped along the central axis L. In this case, the undulating shape extending along one or more linear or strip-shaped paths of the material surface 21 can reflect the shape of the entire material surface. Therefore, as long as the shape of the one or more linear or strip-shaped paths is obtained, the shape of the entire material surface 21 can be basically inferred. Among the one or more linear or strip-shaped paths, it is best to have at least one path pass through the rotation center of the material surface 21.

[0018] In particular, if Figure 1 As shown, when the furnace shell 11 of the blast furnace 10 and the material surface 21 therein are circular in a plane perpendicular to the axis L, or in other words, the material surface 21 is roughly rotationally symmetrical around the axis L at any angle, it is only necessary to obtain the shape of the material surface 21 along a diameter or even a radius of the blast furnace 10 in the horizontal plane to basically reflect or infer the shape of the entire material surface 21. Figure 1 This diameter is schematically indicated by the dotted line D in FIG.

[0019] The idea of ​​the present application is to use a liquid spray device 30 to spray a relatively low-temperature liquid 40 above the material surface 21 of the charge 20 to a predetermined area of ​​the material surface 21, and then use a thermal imager to obtain a thermal image of the material surface 21. The charge 20 that receives the liquid 40 in the predetermined area appears as a recognizable low-temperature area in the thermal image, because the low-temperature area appears in a different color in the thermal image than the material surface area that does not receive the low-temperature liquid, usually a darker "dark area". Since the position and shape of the predetermined area can be selected so that the shape of the material surface can be reflected by the shape of the predetermined area, the shape of the low-temperature area corresponding to the predetermined area in the thermal image obtained by the thermal imager reflects the shape of the material surface. Figure 1 In the embodiment, two liquid spraying devices 30 are arranged on opposite sides of the furnace shell 11 of the blast furnace 10 along the diameter D so as to apply liquid to the material surface 21 along the diameter D.

[0020] In order to make the predetermined area (for example Figure 1The low temperature area corresponding to the material surface area along the diameter D in the middle of the material surface 21 is easily identified in the thermal image, and the temperature of the liquid 40 applied to the material surface 21 is usually significantly lower than the temperature of the charge 20. In this way, the temperature of the portion of the charge 20 that receives the liquid 40 is significantly lower than the portion of the charge 20 that does not receive the liquid 40, making the difference between the color of the low temperature area in the thermal image and the color of other material surface areas more obvious, so that the low temperature area can be more easily identified from the thermal image.

[0021] For a blast furnace in operation, the charge 20 is usually at a high temperature of more than 1000 degrees, so it is convenient to select water at room temperature as the liquid 40 to be applied. Even for a blast furnace that has just stopped working, the charge 20 may have a high temperature of several hundred degrees, and it is also feasible to use water at room temperature as the liquid 40. Of course, in this case, water that has been cooled can also be used as the liquid 40 to increase the temperature difference between it and the charge 20, so that it can be more easily identified from the thermal image that the low temperature zone is connected. For a blast furnace that has been shut down for a period of time, as long as its temperature is still significantly higher than the ambient temperature, it is still possible to identify the desired low temperature zone in the thermal image when using water at room temperature or water that has been cooled as the liquid 40. Therefore, the method proposed in this application can be used to detect the shape of the material surface 21 in the blast furnace when it is working or stopped. In other non-blast furnace application scenarios, as long as a recognizable low temperature zone can be formed in the thermal image of the detected material surface by applying a liquid, the method of this application is feasible. In other embodiments, other applicable liquids can be used to replace water.

[0022] The predetermined area to which the liquid 40 is applied can be, for example, one or more linear or strip-shaped paths that can be used to reflect or infer the overall shape of the material surface as mentioned above, or a diameter or radius in the case of a circular material surface. Of course, if only the local shape of the material surface 21 is of interest, the predetermined area can also be selected as one or more linear or strip-shaped paths that can reflect the local material surface shape of interest. In other words, as long as the shape of the predetermined area is known, the overall shape of the material surface 21 or the local shape of interest therein is also known.

[0023] Figure 2 Shows Figure 1A liquid spraying device 30 is provided in the embodiment of the present invention. The liquid spraying device 30 may include a spray gun 31. The spray gun 31 may be simply formed as a tubular object in which the liquid to be sprayed can be transported. The left end of the spray gun 31 is an inlet end, which can be connected to a liquid supply pipe 32 via an electromagnetic valve 33. The liquid supply pipe 32 can transport liquid from a liquid source (not shown) into the spray gun 31. The liquid source may be, for example, a water source or other liquid source, and preferably a pressurized liquid. The electromagnetic valve 33 can selectively connect and disconnect the liquid passage between the liquid supply pipe 32 and the spray gun 31. The diameter of the spray gun 31 is preferably smaller than the diameter of the liquid supply pipe 32, so that an increased hydraulic pressure can be generated in the spray gun 31, so that the sprayed liquid 40 can have a sufficient speed to spray the liquid 40 to a desired sufficiently far distance.

[0024] The flange short pipe 34 can be used as a mounting base for the spray gun 31, and it can have a tubular portion 341 and a flange portion 342. Figure 1 As shown, the tubular portion 341 of the flange short pipe 34 can extend through the furnace shell 11 of the blast furnace 10 and be fixed at the furnace shell 11, and the flange portion 342 is located outside the blast furnace 10. Figure 2 The spray gun 31 may be fixedly connected with a flange portion 311. The spray gun 31 is inserted into the flange short tube 34, and its flange portion 311 and the flange portion 342 of the flange short tube 34 are fixedly connected to each other, so that the spray gun 31 is fixedly mounted to the flange short tube 34.

[0025] When it is necessary to spray liquid onto the material surface 21 in the blast furnace 10 , the solenoid valve 33 is controlled to open the passage between the liquid supply pipe 32 and the spray gun 31 , and the liquid 40 is transmitted into the blast furnace 10 via the spray gun 31 and sprayed onto the material surface 21 of the charge 20 at the outlet end of the spray gun 31 .

[0026] The charge 20 receiving the liquid 40 sprayed by the spray gun 31 will have a lower temperature than other surrounding charge materials, which will appear as a recognizable low temperature area in the thermal image. Figure 1 The dotted circle schematically indicates the position of the thermal imager 50, which is installed at the furnace shell 11 of the blast furnace 10, outside the vertical plane where the diameter D is located and facing the vertical plane, so as to be able to observe the undulating state of the low-temperature zone along the material surface. Figure 3 The installation position and state of the thermal imager 50 are shown from another angle. Figure 1 The diameter D in Figure 3 It is represented by a black dot D, which is a diameter extending perpendicular to the paper surface. Figure 3 The solid circle also indicates Figure 1 The position of one of the spray devices 30 is shown, and the other spray device 30 is located on the other side of the spray device shown along the diameter D. Figure 3 The thermal imager 50 can be easily observed in this position. Figure 1 The undulating state of the material surface 21 in the image is extended along the diameter D. In other embodiments, when other predetermined areas are selected to reflect the shape of the material surface, the thermal imager 50 is correspondingly arranged at a position where the undulating state of the material surface in the predetermined area can be conveniently observed.

[0027] It should also be noted that after the liquid 40 is sprayed onto the material surface 21 by the liquid spraying device 30, the liquid 40 may be evaporated in a short time, and the furnace material 20 receiving the liquid 40 will return to its original high temperature state. Therefore, after the liquid spraying device 30 sprays the liquid, the thermal imager 50 should be started in time to obtain a thermal image.

[0028] Figure 4 1 is a thermal image obtained by the thermal imager 50 after the spraying operation is performed along a diameter of the blast furnace 10. In this thermal image, a linear or strip-shaped low-temperature zone extending along the surface of the material can be clearly identified in the dotted rectangular area. Figure 5 By observing the extended undulation state of the low temperature zone, the shape of the material surface 21 can be known. In addition, based on the installation position and angle of the thermal imager 50 and other parameters, the absolute position of each point in the low temperature zone relative to the blast furnace can be further calculated, thereby obtaining a more accurate material surface shape curve.

[0029] It should be noted that, for the one or more linear or strip-shaped paths mentioned above, in practice, the liquid spraying device 30 may not strictly and continuously apply the liquid 40 along the path when spraying the liquid, but may form multiple discrete areas along the path. This does not affect the implementation of the technical solution of the present application, as long as these discrete areas can define a predetermined linear or strip-shaped path in the thermal image finally obtained. Furthermore, the predetermined area for receiving the liquid 40 itself can be composed of multiple discrete areas, such as multiple point-shaped areas, as long as these discrete areas can reflect the local or overall shape of the material surface 21 as a whole.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A method for detecting the shape of a material surface in a kiln, comprising: Applying liquid from above the material surface of the charge in the kiln to a predetermined area of ​​the material surface; and Acquire a thermal image of the material surface using a thermal imager; The temperature of the liquid is lower than the temperature of the charge, so that the charge in the predetermined area receiving the liquid appears as a identifiable low-temperature zone in the thermal image; and the predetermined area is selected so that its shape can reflect the local or overall shape of the charge surface, so that the shape of the low-temperature zone in the thermal image correspondingly reflects the local or overall shape of the charge surface.

2. The method according to claim 1, characterized in that The predetermined area includes one or more predetermined linear or strip-shaped paths.

3. The method according to claim 1, characterized in that The predetermined area includes a plurality of discrete areas located on one or more predetermined linear or strip-shaped paths, and the plurality of discrete areas can define the one or more predetermined linear or strip-shaped paths.

4. The method according to any one of claims 2 to 3, characterized in that: The material surface is rotationally symmetric around a vertical central axis, and at least one of the one or more linear or belt-shaped paths passes through the rotation center of the material surface.

5. The method according to claim 4, characterized in that The material surface is a circle surrounding the rotation center, and at least one of the one or more linear or belt-shaped paths is a diameter or a radius of the circle.

6. The method according to claim 5, characterized in that The thermal imager acquires the thermal image outside a vertical plane passing through the diameter or radius and facing the vertical plane.

7. The method according to claim 1, characterized in that The liquid is water.

8. The method according to claim 7, characterized in that The water is room temperature water or water that has been cooled.

9. A system for detecting the shape of a material surface in a kiln, comprising: A liquid spraying device for applying liquid from the surface of the charge in the kiln upward to a predetermined area of ​​the surface; wherein the predetermined area is selected to have a shape that can reflect a partial or overall shape of the surface of the charge; and The thermal imager is used to obtain a thermal image of the material surface, and the furnace charge in the predetermined area of ​​the material surface that receives the liquid appears as a recognizable low-temperature area in the thermal image.

10. The system according to claim 9, characterized in that The liquid spraying device comprises a spray gun.

11. The system according to claim 10, characterized in that The injection gun penetrates the furnace shell of the kiln.

12. The system according to claim 9, characterized in that The thermal imager is located outside a vertical plane passing through the predetermined area and faces the vertical plane.

Images