Gas suspension calcining furnace main burner sub-flame combustion device

Abstract

The utility model discloses a kind of gas suspension roasting furnace main burner flame-splitting combustion device, including main furnace and burner nozzle assembly, burner nozzle assembly is arranged at least three layer regions along main furnace axial direction, at least two azimuth regions are evenly distributed in each layer region along circumference, and each azimuth region independently configures several burner nozzles.The utility model is layered and zoned by several burner nozzles on main furnace along axis, by gradient configuration of at least three layers up and down, can improve the precision of adjusting temperature, the burner nozzle of each azimuth region independent control can eliminate the temperature dead angle of traditional equipment, the dynamic combination of multilayer multi-zone burner nozzle effectively disperses flame concentration area, avoid excessive roasting of alumina due to local high temperature, reduce invalid heat loss by accurate temperature field adjustment, stable control crystal transformation process, reduce alpha-Al2O3 abnormal generation, keep product granularity uniformity, improve fuel utilization.

Description

Technical Field

[0001] This utility model relates to the field of roasting furnace technology, and specifically to a flame-dividing combustion device for the main burner of a gas suspension roasting furnace. Background Technology

[0002] In the production process of alumina, the calcination of aluminum hydroxide is the final and crucial step. Alumina is typically produced via the Bayer process, and this alumina is mainly used to manufacture metallic aluminum. When calcining is carried out in a gas suspension calciner, the calcination temperature is usually maintained between 980℃ and 1100℃. The calcination process of alumina involves a series of chemical reactions, including the loss of adsorbed water and water of crystallization from aluminum hydroxide, ultimately forming α-Al₂O₃. Electrolytic plants have strict requirements for the quality of alumina, including low loss on ignition, high specific surface area, low α-Al₂O₃ content, and low hygroscopicity. These characteristics are closely related to the calcination process.

[0003] Currently, gas suspension roasting furnaces mainly use natural gas as fuel and are equipped with a corresponding number of burners according to the designed capacity. However, when the roasting furnace is running at full load, all burners in a traditional gas suspension roasting furnace are in a fully open state. It is impossible to change the flame distribution and thermal field in the roasting furnace by dynamically adjusting the opening and closing of the burners. This may cause the flame to concentrate in a certain part, resulting in local high temperature. This not only increases heat loss and fuel consumption, but may also lead to over-roasting of alumina, affecting product particle size and electrolysis efficiency. Utility Model Content

[0004] To overcome at least one of the aforementioned drawbacks, this utility model provides a flame-dividing combustion device for the main burner of a gas suspension roasting furnace. The objective of this utility model can be achieved by adopting the following technical solution:

[0005] This application provides a flame-splitting combustion device for the main burner of a gas suspension roasting furnace, comprising:

[0006] Main furnace;

[0007] The burner assembly has at least three layers arranged along the axial direction of the main furnace, and at least two directional zones are evenly distributed in each layer along the circumference, with each directional zone independently configured with several burners.

[0008] In one possible implementation, the gas flow rate of the burners in different layers from top to bottom is the same or decreases sequentially.

[0009] In one possible implementation, the number of azimuth zones is two, three, four, or other integers, and the different azimuth zones have the same size and the included angle between adjacent azimuth zones is the same.

[0010] In one possible implementation, the number of the layer regions is three, specifically including an upper high-temperature zone, a middle transition zone, and a lower flame-stabilizing zone.

[0011] In one possible implementation, the burner gas flow rate ratio of the upper high-temperature zone, the middle transition zone, and the lower flame stabilization zone is 1.2–1.5:1:0.5–0.8.

[0012] In one possible implementation, the upper high-temperature zone burner axis is at an elevation angle of 15° to 30° with the radial direction of the main furnace, the middle transition zone burner is arranged horizontally, and the lower flame stabilization zone burner is at a depression angle of 10° to 20° with the radial direction of the main furnace.

[0013] In one possible implementation, the burners in adjacent layers are arranged longitudinally or staggered.

[0014] In one possible implementation, each azimuth zone contains 3 to 6 burners.

[0015] In one possible implementation, it further includes:

[0016] A partition controller, connected to the layer zone and / or the orientation zone, is used to adjust the burner switch state within the layer zone and / or the orientation zone.

[0017] In one possible implementation, the partition controller includes:

[0018] The PLC controller adjusts the on / off state of the burners in different layers and / or orientation zones according to the thermal field distribution in the main furnace.

[0019] The beneficial technical effects of this utility model are as follows: According to the present disclosure, the main burner flame distribution combustion device of the gas suspension roasting furnace includes a main furnace and burner assembly. By dividing several burners on the main furnace into axial layers and circumferential zones, and through a gradient configuration of at least three layers, the accuracy of temperature regulation can be improved. The burners with independent control in each direction can eliminate the temperature dead zone of traditional equipment. The dynamic combination of multi-layer and multi-zone burners effectively disperses the concentrated flame area, avoids over-roasting of alumina due to local high temperature, reduces ineffective heat loss through precise temperature field adjustment, stabilizes the crystal transformation process, reduces abnormal formation of α-Al2O3, maintains product particle size uniformity, and improves fuel utilization. Attached Figure Description

[0020] The following are given by way of example and without limitation in the accompanying drawings:

[0021] Figure 1 A schematic diagram of the structure of a flame-division combustion device according to an embodiment of this application is shown;

[0022] Figure 2 This invention illustrates a first arrangement of the burner according to an embodiment of the present application;

[0023] Figure 3 A schematic diagram of a second arrangement of the burner according to an embodiment of this application is shown;

[0024] Figure 4 A top view showing a third arrangement of the burner according to one embodiment of this application is shown;

[0025] Figure 5 A top view showing a fourth arrangement of the burner according to one embodiment of this application is shown;

[0026] Figure 6 A top view showing a fifth arrangement of the burner according to an embodiment of this application is shown;

[0027] Figure 7 A perspective view of the structure of a flame-division combustion device according to another embodiment of this application is shown;

[0028] Figure 8 A schematic diagram of the structure of a flame-division combustion device according to another embodiment of this application is shown;

[0029] Figure 9 A schematic diagram of the burner arrangement according to another embodiment of this application is shown;

[0030] Figure 10 A schematic diagram of a burner with different layers in another embodiment of this application is shown;

[0031] Figure 11 A schematic diagram of the burner in a prior art flame splitting combustion device is shown.

[0032] In the diagram: 1. Main furnace; 2. Burner; 11. Layer zone; 12. Orientation zone. Detailed Implementation

[0033] In the following detailed disclosure, these embodiments are fully described with reference to the accompanying drawings. In order to enable those skilled in the art to understand and clarify the technical solution of this utility model more clearly, the embodiments described below are not limited thereto. The present utility model will be further described in detail below with reference to the embodiments and the accompanying drawings.

[0034] In this utility model, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "join," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "join" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0035] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] like Figure 11 The traditional gas suspension roasting furnace shown has a single layer of burners that cannot form an axial temperature gradient, which easily leads to uneven heating of materials. The flame tends to concentrate in a specific area, generating local high-temperature hot spots. All burners must be opened and closed simultaneously, making it impossible to achieve precise control and difficult to eliminate temperature dead zones.

[0037] This application provides a flame-splitting combustion device for the main burner of a gas suspension roasting furnace, such as... Figures 1-10 As shown, it includes a main furnace and burner assembly. The burner assembly is arranged in at least three layers along the main furnace axis. Each layer has at least two directional zones evenly distributed along the circumference, and each directional zone is independently configured with several burners.

[0038] The gas suspension roasting furnace main burner flame distribution combustion device provided in this embodiment includes a main furnace and burner assembly. By dividing several burners on the main furnace into axial layers and circumferential zones, and through a gradient configuration of at least three layers, the accuracy of temperature regulation can be improved. The burners with independent control in each direction can eliminate the temperature dead zones of traditional equipment. The dynamic combination of multi-layer and multi-zone burners effectively disperses the concentrated flame area, avoids over-roasting of alumina due to local high temperature, reduces ineffective heat loss through precise temperature field adjustment, stabilizes the crystal transformation process, reduces abnormal formation of α-Al2O3, maintains product particle size uniformity, and improves fuel utilization.

[0039] The gas suspension roasting furnace main burner flame splitting combustion device provided in this embodiment can avoid local high temperature in the roasting furnace, reduce the generation of thermal nitrogen oxides, and help reduce the emission intensity of nitrogen oxides in the roasting furnace. While ensuring that the product loss on ignition is less than 1%, it reduces the temperature of the roasting main furnace, reduces fuel consumption, reduces production costs, reduces roasting temperature, and reduces alumina breakage (particle size difference of aluminum hydroxide roasted into alumina).

[0040] In this design, the burners in different layers from top to bottom have the same gas flow rate. This arrangement of the same flow rate helps to maintain a balanced heat load in each layer and ensures that the flame intensity in each layer is consistent. The multi-layer synchronous combustion enhances the mutual support of the flames. By adjusting the axial position of the nozzles, abnormal crystal transformation caused by local high temperature can be avoided.

[0041] In this design, the gas flow rate of the burners in different layers decreases sequentially from top to bottom. The decreasing flow rate creates a temperature gradient with higher flow rate at the top and lower flow rate at the bottom. The higher flow rate in the upper layer maintains a strong ignition ring, while the lower flow rate reduces backfire, allowing for more precise control of the α-Al2O3 formation rate and reducing over-roasting.

[0042] In one possible implementation, such as Figures 4-6 As shown, the number of azimuth zones is two, three, four, or other integers. Different azimuth zones have the same size, and adjacent azimuth zones have the same included angle.

[0043] In one possible implementation, such as Figure 2 and Figure 9 As shown, there are three layers: an upper high-temperature zone, a middle transition zone, and a lower flame-stabilizing zone.

[0044] The upper high-temperature zone is responsible for the rapid heating of materials and can be equipped with high-power burners. The flame stiffness is preferably 2 / 3 of the furnace radius. The middle transition zone realizes the key reaction of crystal transformation and the temperature fluctuation is required to be ≤±5℃. The lower flame stabilization zone maintains the slow cooling process of materials and can be equipped with low-speed burners and supplemented by a swirling flame stabilization structure.

[0045] It is understandable that a reasonable temperature difference needs to be maintained between the upper high-temperature zone, the middle transition zone, and the lower flame-stabilizing zone.

[0046] Furthermore, the ratio of burner gas flow rates in the upper high-temperature zone, the middle transition zone, and the lower flame stabilization zone is 1.2–1.5:1:0.5–0.8.

[0047] In one possible implementation, such as Figure 10 As shown, the burner axis in the upper high-temperature zone is at an elevation angle of 15° to 30° with the radial direction of the main furnace, the burners in the middle transition zone are arranged horizontally, and the burners in the lower flame stabilization zone are at a depression angle of 10° to 20° with the radial direction of the main furnace.

[0048] The burners in the upper high-temperature zone are positioned at an elevation angle of 15° to 30° to form rising flames, which enhances the high-temperature flue gas recirculation effect and improves the uniformity of the temperature field in the upper part of the main furnace. The large-angle arrangement can be used in conjunction with high-speed burners, and the flame rigidity must ensure that it penetrates more than 2 / 3 of the furnace radius. The middle transition zone is arranged horizontally, and the horizontal axis is conducive to forming a stable laminar flow, meeting the ±5° temperature control requirements of the crystal transformation zone, and achieving precise control of the flame shape. The lower flame stabilization zone is configured with a downward angle of 10° to 20° to promote the sinking of hot flue gas, forming a slow cooling environment, which can prevent the flame from floating upwards.

[0049] In one possible implementation, such as Figures 1-3As shown, the burners in adjacent layers are arranged longitudinally. This longitudinal arrangement of burners makes it easier to control the zones, and the alignment of the burner axes in each layer forms a stable axial airflow, which is beneficial for establishing a continuous thermal gradient distribution and reducing turbulence disturbances.

[0050] In one possible implementation, such as Figures 7-9 As shown, the burners in adjacent layers are arranged in an alternating pattern. This alternating arrangement means that the burners in adjacent layers are staggered by a certain distance on the horizontal plane. This staggered arrangement enhances airflow disturbance, expands the flame coverage area, reduces dead zones in the furnace, improves furnace filling, and enables more flexible heat load distribution to adapt to different heating needs.

[0051] Understandably, each azimuth zone typically contains 3 to 6 burners. Configuring 3 to 6 burners in each azimuth zone can achieve a reasonable distribution of heat load and avoid local overheating or underheating. Through the coordinated work of multiple burners, the temperature uniformity of the effective heating zone can be controlled within ±10℃.

[0052] Three burners in each azimuth zone are suitable for small roasting furnaces, four to five burners are suitable for medium-sized roasting furnaces, and six or more burners are suitable for large roasting furnaces. The number of burners must be matched with the furnace size. By adjusting the number of layers, the axial spacing between burners in different layers, the number of azimuth zones, and the number of burners in each azimuth zone, the temperature requirements for different roasting processes can be met, thus improving flexibility and adaptability.

[0053] In one possible implementation, the flame distribution combustion device of the main burner of the gas suspension roasting furnace further includes a zone controller, which is connected to the layer zone and / or orientation zone and is used to adjust the burner switching status in the layer zone and / or orientation zone.

[0054] In this embodiment, the main burner flame distribution combustion device of the gas suspension roasting furnace has a modular design for the zone controller, which can independently control the azimuth zone composed of several burners. It is linked with the layer zone control unit through PLC to form a two-level control structure of "azimuth zone - layer zone".

[0055] In one possible implementation, the zone controller includes a PLC controller, which adjusts the on / off state of burners in different layers and / or orientation zones according to the thermal field distribution in the main furnace.

[0056] The zone controller adopts a two-level control architecture of "directional zone-layer zone". Each directional zone is configured with 3-6 burners to form an independent control unit. By adjusting different combinations of burner opening, the alumina ignition loss is continuously tracked and tested. Under the condition that the main furnace temperature remains unchanged, the lower the alumina ignition loss, the optimal combination for roasting and use is selected.

[0057] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0059] In view of the detailed description above, these and other changes can be made to these embodiments. This written description includes embodiments of the best mode disclosed in this utility model. The patent scope of this utility model is defined by the claims, which are not limited by this disclosure. The protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in this utility model, based on the technical solution and concept of this utility model, are within the protection scope of this utility model.

Claims

1. A flame-dividing combustion device for the main burner of a gas suspension roasting furnace, characterized in that, include: Main furnace (1); The burner (2) assembly has at least three layers (11) arranged along the axial direction of the main furnace (1), and at least two directional zones (12) are evenly distributed in the circumferential direction in each layer (11), with each directional zone (12) independently configured with several burners (2).

2. The gas suspension calciner main burner split flame burner apparatus according to claim 1, characterized by, The gas flow rates of the burners (2) in different layers (11) from top to bottom are the same or decrease sequentially.

3. The gas suspension calciner main burner split flame burner apparatus according to claim 1, characterized by, The number of the azimuth zones (12) is two, three, four, or other integers. Different azimuth zones (12) have the same size, and adjacent azimuth zones (12) have the same included angle.

4. The gas suspension calciner main burner split flame burner apparatus according to claim 3, characterized by, The number of the layer zones (11) is three, specifically including an upper high-temperature zone, a middle transition zone, and a lower flame-stabilizing zone.

5. The gas suspension calciner main burner split flame burner apparatus according to claim 4, characterized in that, The ratio of gas flow rate for the burners in the upper high-temperature zone, the middle transition zone, and the lower flame stabilization zone is 1.2-1.5:1:0.5-0.

8.

6. The gas suspension calciner main burner split flame burner apparatus according to claim 4, wherein, The upper high-temperature zone burner (2) has an elevation angle of 15° to 30° with the radial direction of the main furnace (1), the middle transition zone burner (2) is arranged horizontally, and the lower flame stabilization zone burner (2) has a depression angle of 10° to 20° with the radial direction of the main furnace.

7. The flame-dividing combustion device for the main burner of the gas suspension roasting furnace according to claim 1, characterized in that, The burners (2) in adjacent layers (11) are arranged longitudinally or in an alternating pattern.

8. The gas suspension calciner main burner split flame burner apparatus according to claim 1, wherein, Each directional zone (12) contains 3 to 6 burners (2).

9. A gas suspension calciner main burner split flame burner device according to any one of claims 1 to 8, characterized in that, Also includes: A partition controller, which is connected to the layer zone (11) and / or the orientation zone (12), is used to adjust the on / off state of the burner (2) in the layer zone (11) and / or the orientation zone (12).

10. The gas suspension calciner main burner split flame burner apparatus according to claim 9, characterized in that, The partition controller includes: The PLC controller adjusts the on / off state of the burners (2) in different layer zones (11) and / or orientation zones (12) according to the thermal field distribution in the main furnace (1).

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