Rotary kiln and activation device for preparing activated carbon

Abstract

This invention relates to the field of industrial kiln (rotary kiln) technology, specifically disclosing a rotary kiln and an activation device for preparing activated carbon, enabling more controlled material reactions within the rotary kiln. The rotary kiln includes a rotating body and a spiral material guide channel. The spiral material guide channel is located within the rotating body and arranged spirally around the center line of rotation of the rotating body. The spiral material guide channel includes a main reaction section, the cross-section of which is closed. The main reaction section also includes at least one positive pressure reaction section connected to an air inlet structure. During operation, the material flowing at both ends of the at least one positive pressure reaction section in the axial direction of the main reaction section forms air-tight material piles at the bottom of the rotating body. This effectively solves the problem of difficulty in accurately predicting and controlling the material movement trajectory and residence time in existing rotary kilns.

Description

Technical Field

[0001] This invention relates to the field of industrial kiln (rotary kiln) technology, specifically to a rotary kiln and an activation device for preparing activated carbon. Background Technology

[0002] Rotary kilns are important industrial heat treatment equipment, widely used in industries such as cement, metallurgy, and chemicals. They are used for processes such as sintering, roasting, and calcining of materials, and have advantages such as continuous production and high thermal efficiency. Existing rotary kilns mainly consist of a rotating drum, support devices (such as tires and rollers), a transmission system (such as gears and motors), a kiln tail feeding device, a kiln head discharging device, and a heating device.

[0003] The rotary drum is the core component of the entire rotary kiln. It is cylindrical and installed at a slight incline. A tire is mounted on the outside of the rotary drum, and support rollers are located below the tire to support the weight of the drum. The transmission system drives the tire, which in turn rotates the rotary drum. The kiln tail feed device is located at the high end of the rotary drum (kiln tail) and is sealed to the kiln tail. The kiln head discharge device is located at the low end of the rotary drum (kiln head) and is sealed to the kiln head. In externally heated rotary kilns, the heating element is located outside the rotary drum; in internally heated rotary kilns, the heating element is located inside the rotary drum. During operation, the rotary drum rotates slowly, causing the material to roll forward along the inner wall of the drum under gravity, while simultaneously exchanging heat fully with the heat source of the heating element.

[0004] In existing rotary kilns, materials move primarily within the rotating drum due to gravity and centrifugal force generated by the drum's rotation. This movement pattern is easily affected by various factors, such as the material's physical properties (particle size, viscosity, etc.), the kiln's tilt angle, and rotational speed. Consequently, the actual trajectory and residence time of the material are difficult to predict and control precisely, resulting in a wide range of actual residence times within the kiln. Some materials may have excessively short residence times, while others may have excessively long residence times. This limits the refinement of heat treatment processes and reduces the rotary kiln's adaptability when processing certain special materials.

[0005] For example, in the production of activated carbon, the carbonized material needs to be activated. To improve the performance of activated carbon, the activation process often requires more refined design and control. However, the limited control over the flow of carbonized material within the rotary drum restricts the feasibility of using a rotary kiln to achieve refined improvements in the activation process.

[0006] Furthermore, the sealing performance of existing rotary kilns is insufficient. When using rotary kilns to process certain special materials, air leakage can affect the processing effect. For example, in the activation stage of activated carbon production, it is often desirable for the carbonized material to be in a positive pressure environment (this usually increases the porosity and specific surface area of ​​activated carbon, enhancing its adsorption performance). However, the insufficient sealing performance of existing rotary kilns results in the positive pressure environment required for activation not reaching the desired level, thus affecting the quality of activated carbon. Summary of the Invention

[0007] The purpose of this invention is to improve the structure of existing rotary kilns so that materials can react in a more controlled manner within the rotary kiln, and to provide an activation device for preparing activated carbon based on the improved rotary kiln.

[0008] In the first aspect, a rotary kiln includes a rotating body and a spiral material guide channel, the spiral material guide channel being located in the rotating body and arranged spirally around the rotation centerline of the rotating body; the spiral material guide channel includes a main reaction section, the cross-section of the main reaction section being closed; the main reaction section further includes at least one positive pressure reaction section connected to an air inlet structure, wherein during operation, the material flowing at both ends of the at least one positive pressure reaction section in the axial direction of the main reaction section forms an air-tight material pile at the bottom of the rotating body.

[0009] As an optimization and / or instantiation of the rotary kiln in the first aspect mentioned above, a further specific scheme for the rotary kiln is as follows: during operation, an air-tight material pile is formed in the region located at the bottom of the rotating body in each spiral section of the main reaction section.

[0010] As an optimization and / or instantiation of the rotary kiln in the first aspect mentioned above, a further specific scheme for the rotary kiln is as follows: the main reaction section includes at least two reaction sections with different pitch settings for the central spiral of the channel; at least one of the at least two reaction sections belongs to the positive pressure reaction section.

[0011] As an optimization and / or instantiation of the rotary kiln in the first aspect mentioned above, a further specific scheme for the rotary kiln is as follows: the main reaction section includes an intermediate reaction section and end reaction sections located at both ends of the intermediate reaction section; the pitch of the central spiral of the channel of the end reaction section is smaller than the pitch of the central spiral of the channel of the intermediate reaction section connected to the corresponding end reaction section.

[0012] As an optimization and / or instantiation of the rotary kiln in the first aspect mentioned above, a further specific scheme for the rotary kiln is as follows: the rotating body is a rotary cylinder; an inner spiral guide plate is provided on the inner wall of the rotary cylinder, and the outer contour line of the inner spiral guide plate is attached to the inner wall of the rotary cylinder to separate a spiral guide channel in the rotary cylinder; the part of the cavity corresponding to the main reaction section in the cavity formed by the inner contour line of the inner spiral guide plate is fitted with an inner cylinder, and the main reaction section of the spiral guide channel is wrapped around the inner cylinder.

[0013] As an optimization and / or instantiation of the rotary kiln in the first aspect mentioned above, a further specific scheme for the rotary kiln is as follows: the air inlet structure is set in the inner cylinder and the required gas is delivered to the positive pressure reaction section through the air inlet opened on the inner cylinder.

[0014] As an optimization and / or instantiation of the rotary kiln in the first aspect mentioned above, a further specific solution for the rotary kiln is: the rotating body adopts a spiral tube, and a spiral material guiding channel is formed inside the spiral tube.

[0015] As an optimization and / or instantiation of the rotary kiln in the first aspect mentioned above, a further specific solution for the rotary kiln is: the spiral tube is formed by sequentially connecting multiple spiral tube sections.

[0016] Secondly, an activation apparatus for preparing activated carbon is provided, which employs the rotary kiln described in the first aspect above.

[0017] As an optimization and / or instantiation of the activation device for preparing activated carbon in the second aspect mentioned above, a further specific scheme is as follows: the rotating body is a rotary drum; an inner spiral guide plate is provided on the inner wall of the rotary drum, and the outer contour line of the inner spiral guide plate is attached to the inner wall of the rotary drum, thereby separating a spiral guide channel in the rotary drum; the portion of the cavity corresponding to the main reaction section in the cavity formed by the inner contour line of the inner spiral guide plate is fitted with an inner cylinder, and the main reaction section of the spiral guide channel is wrapped around the inner cylinder; the air inlet structure is set in the inner cylinder and delivers the required gas to the positive pressure reaction section through the air inlet opened on the inner cylinder.

[0018] As an optimization and / or instantiation of the activation device for preparing activated carbon in the second aspect above, a further specific solution is: the rotating body adopts a spiral tube, and a spiral material guiding channel is formed inside the spiral tube.

[0019] Because the spiral feed channel includes the main reaction section, and the cross-section of the main reaction section is closed, the flow of material in the main reaction section is confined within the spiral feed channel. This effectively solves the problem of accurately predicting and controlling the material movement trajectory and residence time in existing rotary kilns. Through the forced guidance of the spiral feed channel, the material flows orderly along a preset spiral path, making the actual residence time more controllable and avoiding the problem of some materials having too short or too long a residence time. This lays the foundation for refined control of the heat treatment process.

[0020] The closed cross-section of the main reaction section creates the necessary conditions for the formation of the positive pressure reaction section. Furthermore, since the main reaction section includes at least one positive pressure reaction section connected to the air intake structure, during operation, the material flowing at both ends of the axial direction of at least one positive pressure reaction section in the main reaction section forms air-tight material piles at the bottom of the rotating body. These air-tight material piles act as a natural seal, effectively preventing gas leakage and ensuring a stable positive pressure environment is maintained within the positive pressure reaction section.

[0021] In the process of activated carbon preparation, a stable positive pressure activation environment can promote full contact and reaction between the activator and the carbonized material, improve the porosity and specific surface area of ​​activated carbon, and enhance the adsorption performance and product quality of activated carbon.

[0022] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, are used to aid in understanding the invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the invention, but do not constitute an undue limitation of the invention.

[0024] Figure 1 This is a schematic diagram of the external structure of the rotary kiln in Embodiment 1 of the present invention.

[0025] Figure 2 for Figure 1 The diagram shows the internal structure of the rotary drum in the rotary kiln after it has been made transparent.

[0026] Figure 3 for Figure 2 The diagram shows a gas-tight material pile formed at the bottom of the rotary drum.

[0027] Figure 4 This is a schematic diagram of the spiral tube structure of the rotary kiln in Embodiment 2 of the present invention.

[0028] Figure 5 For use in constructing Figure 4 A schematic diagram of the external structure of a spiral tube section.

[0029] Figure 6 for Figure 4 The image shows a side view of the spiral tube forming an air-tight material pile at its bottom.

[0030] Figure 7 for Figure 4 The image shows an axial view of the air-tight material pile formed at the bottom of the spiral tube.

[0031] The following are labeled in the diagram: Rotating body 1; Heating device 2; Kiln tail feeding device 3; Kiln head discharging device 4; Gas-proof material pile 5; Rotary cylinder 11; Inner cylinder 12; Rotation center line 13; Spiral tube 14; Spiral tube section 141; Spiral material guide channel 101; End reaction section 101a; Intermediate reaction section 101b; Inner spiral guide plate 111. Detailed Implementation

[0032] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0033] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0034] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0035] Regarding the terminology and units in this specification: The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Furthermore, other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0036] Figure 1 This is a schematic diagram of the external structure of the rotary kiln in Embodiment 1 of the present invention. Figure 2 for Figure 1 The diagram shows the internal structure of the rotary drum in the rotary kiln after it has been made transparent. Figure 3 for Figure 2 The diagram shows a gas-tight material pile formed at the bottom of the rotary drum. Figures 1-3 As shown, the rotary kiln includes a rotating body 1 and a heating device 2, which is located outside the rotating body 1. A kiln tail feed device 3 is provided at the high end (kiln tail) of the rotating body 1, and a kiln head discharge device 4 is provided at the bottom end (kiln head) of the rotating body 1. This rotary kiln serves as an activation device for preparing activated carbon.

[0037] The rotating body 1 has a spiral material guiding channel 101, which is arranged in a spiral shape around the rotation center line 13 of the rotating body 1.

[0038] In this embodiment, the rotating body 1 is specifically a rotating drum 11; an inner spiral guide plate 111 is provided on the inner wall of the rotating drum 11, and the outer contour line of the inner spiral guide plate 111 is attached to the inner wall of the rotating drum 11, thereby separating a spiral guide channel 101 in the rotating drum 11.

[0039] An inner cylinder 12 is also fitted inside the cavity formed by the inner contour line of the inner spiral guide plate 111. The spiral guide channel 101 is basically completely wrapped around the inner cylinder 12. The part of the spiral guide channel 101 wrapped around the inner cylinder 12 constitutes the main reaction section, and the cross-section of the main reaction section is closed.

[0040] "Channel cross-section" refers to the cross-section of the spiral material guide channel perpendicular to the direction of material flow. In the main reaction section, since the inner cylinder 12 closes the side of the corresponding channel cross-section facing the rotation center line 13 of the rotary cylinder 11, the channel cross-section of the main reaction section is closed.

[0041] During operation, an air-sealing stockpile 5 is formed in the region at the bottom of the rotating body 1 within each spiral segment of the main reaction section. The air-sealing stockpile 5 is formed by the material (carbonized material) accumulated in the region at the bottom of the rotating body 1 within each spiral segment of the main reaction section. This material (carbonized material) completely seals off some of the cross-sectional areas of the channels, thereby isolating the airflow. Therefore, the reaction chamber between two adjacent air-sealing stockpiles 5 in the main reaction section is highly sealed.

[0042] The inner cylinder 12 is provided with an air intake structure. The air intake structure delivers gas to the reaction chambers between two adjacent gas-isolated material piles 5 in the main reaction section through the air intake port opened on the inner cylinder 12 (located above the inner cylinder 12, not shown in the figure), thereby forming positive pressure reaction sections for these reaction chambers respectively.

[0043] The inner cylinder 12 is equipped with an air inlet pipe at one end of the kiln head discharge device 4. The air inlet pipe is connected to the air inlet structure inside the inner cylinder 12 to provide stable activation gas for each positive pressure reaction section.

[0044] In addition, the main reaction section can be divided into an intermediate reaction section 101b and end reaction sections 101a located at both ends of the intermediate reaction section 101b; the pitch of the channel center helix of the end reaction section 101a is smaller than the pitch of the channel center helix of the part of the intermediate reaction section 101b connected to the corresponding end reaction section.

[0045] Because the pitch of the central spiral of the channel in the end reaction section 101a is smaller than the pitch of the central spiral of the channel in the middle reaction section 101b connected to the corresponding end reaction section, the width of the channel cross-section of the end reaction section 101a is smaller than the width of the channel cross-section of the middle reaction section 101b. As a result, the gas-barrier material pile 5 in the end reaction section 101a is more compact and better isolates the airflow.

[0046] The pitch of the central spiral lines in the channels of the intermediate reaction section 101b does not need to be uniform; it can be adjusted according to the reaction requirements. By adjusting the pitch of the central spiral lines in different regions of the intermediate reaction section 101b, the residence time of the carbonized material in each region can be differentiated, thereby meeting the different requirements of reaction time and reaction conditions at different stages of the activation process.

[0047] For example, a smaller pitch can be used in areas where the reaction time needs to be extended, while a larger pitch can be used in areas where rapid passage is required. This enables the refined design and control of the activation process, further improving the adaptability and process control precision of the rotary kiln in the processing of special materials such as activated carbon preparation.

[0048] In a preferred embodiment, the intermediate reaction section 101b is designed as two reaction sections with different pitches of the spiral line at the center of the channel: the first reaction section uses a smaller pitch, so that the carbonized material stays in this area for a longer time, ensuring that the carbonized material and the activator are fully mixed and undergo a preliminary activation reaction; the second reaction section uses a larger pitch, so that the preliminarily activated carbonized material can quickly complete the deep activation reaction in a high-temperature environment, avoiding over-reaction caused by excessive residence time.

[0049] Because the spiral material guide channel 101 includes the main reaction section, and the cross-section of the main reaction section is closed, the flow of material in the main reaction section is confined within the spiral material guide channel 101. This effectively solves the problem of accurately predicting and controlling the material movement trajectory and residence time in existing rotary kilns. Through the forced guidance of the spiral material guide channel 101, the material flows orderly along a preset spiral path, making the actual residence time more controllable and avoiding the problem of some materials having too short or too long a residence time. This lays the foundation for refined control of the heat treatment process.

[0050] The closed cross-section of the main reaction section creates the necessary conditions for the formation of the positive pressure reaction section. Furthermore, since the main reaction section includes at least one positive pressure reaction section connected to the air intake structure, during operation, the material flowing at both ends of the axial direction of at least one positive pressure reaction section in the main reaction section forms air-tight material piles 5 at the bottom of the rotating body 1. These air-tight material piles 5 act as a natural seal, effectively preventing gas leakage and ensuring a stable positive pressure environment is maintained within the positive pressure reaction section.

[0051] In the process of activated carbon preparation, a stable positive pressure activation environment can promote full contact and reaction between the activator and the carbonized material, improve the porosity and specific surface area of ​​activated carbon, and enhance the adsorption performance and product quality of activated carbon.

[0052] Figure 4This is a schematic diagram of the spiral tube structure of the rotary kiln in Embodiment 2 of the present invention. Figure 5 For use in constructing Figure 4 A schematic diagram of the external structure of a spiral tube section. Figure 6 for Figure 4 The image shows a side view of the spiral tube forming an air-tight material pile at its bottom. Figure 7 for Figure 4 The image shows an axial view of the air-tight material pile formed at the bottom of the spiral tube.

[0053] like Figures 4-7 As shown, in the rotary kiln of Embodiment 2, the rotating body 1 adopts a spiral tube 14, and a spiral material guiding channel 101 is formed inside the spiral tube 14.

[0054] The spiral pipe 14 is formed by sequentially connecting multiple spiral pipe sections 141, each spiral pipe section 141 being formed by a spiral pipe bending machine. These spiral pipe sections 141 are connected by a flange connection structure to form a complete spiral pipe 14.

[0055] An air inlet structure is connected to the outside of the spiral tube 14. The air inlet structure can be an air inlet manifold that extends along the axial direction of the spiral tube 14 and rotates with the spiral tube 14. The air inlet manifold is used to deliver activation gas to each positive pressure reaction section in the spiral material guide channel 101.

[0056] During operation, the material (carbonized material) flows spirally along the spiral guide channel 101, forming an air-tight material pile 5 at the bottom region of each spiral tube section 141. For example... Figure 6 and Figure 7 As shown, the air-barrier material pile 5 forms a continuous sealing strip at the bottom of the spiral tube 14, completely isolating the channels between adjacent air-barrier material piles 5 and forming an independent positive pressure reaction section.

[0057] The wall of the spiral tube 14 itself forms a closed channel cross section, eliminating the need for additional complex structures such as the inner spiral guide plate 111 and the inner cylinder 12. At the same time, the modular design of the spiral tube section 141 facilitates processing, manufacturing, and on-site installation. When a spiral tube section 141 is worn or damaged, it can be replaced individually, reducing maintenance costs.

[0058] The present invention has been described above. Those skilled in the art will be able to implement the present invention based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of patent protection.

Claims

1. Rotary kiln, including the rotating body; Its features are: It also includes a spiral material guiding channel, which is located in the rotating body and is spirally arranged around the rotation center line of the rotating body; The spiral material guide channel includes a main reaction section, the cross-section of which is closed. The main reaction section also includes at least one positive pressure reaction section connected to an air inlet structure. During operation, the material flowing at both ends of the at least one positive pressure reaction section in the axial direction of the main reaction section forms an air-barrier material pile at the bottom of the rotating body. During operation, an air-barrier material pile is formed in the region at the bottom of the rotating body in each spiral segment of the main reaction section. The air-barrier material pile is formed by the material accumulated in the region at the bottom of the rotating body in each spiral segment of the main reaction section. This material completely seals the cross-section of the channel in the region, thereby creating an airflow barrier. The rotating body is a rotary cylinder; an inner spiral guide plate is provided on the inner wall of the rotary cylinder, and the outer contour line of the inner spiral guide plate is attached to the inner wall of the rotary cylinder to separate the spiral guide channel in the rotary cylinder; an inner cylinder body is fitted in the cavity formed by the inner contour line of the inner spiral guide plate corresponding to the main reaction section, and the main reaction section of the spiral guide channel is wrapped around the inner cylinder body; the air inlet structure is set in the inner cylinder body and supplies the required gas to the positive pressure reaction section through the air inlet opened on the inner cylinder body; Alternatively, the rotating body may be a spiral tube, with a spiral material guide channel formed inside the spiral tube, and the air intake structure connected to the outside of the spiral tube.

2. The rotary kiln as described in claim 1, characterized in that: The main reaction section includes at least two reaction sections with different pitches of the channel center spiral; at least one of the at least two reaction sections belongs to the positive pressure reaction section.

3. The rotary kiln as described in claim 2, characterized in that: The main reaction section includes an intermediate reaction section and end reaction sections located at both ends of the intermediate reaction section; the pitch of the channel center helix of the end reaction section is smaller than the pitch of the channel center helix of the intermediate reaction section connected to the corresponding end reaction section.

4. The rotary kiln as described in claim 1, characterized in that: When the rotating body adopts a helical tube, the helical tube is formed by sequentially connecting multiple helical tube sections.

5. An activation apparatus for preparing activated carbon, characterized in that: It employs a rotary kiln as described in any one of claims 1-4.

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