Multi-tubular externally heated activated converter

Abstract

The present application relates to the technical fields of activated converter, and discloses a multi-tube external heating activated converter, which comprises a converter body, the converter body is driven to rotate through a driving device, the inner wall of the converter body is uniformly provided with heating pipes, the heating pipes are fixed through pipe plates arranged on the inner wall of the converter body, the pipe plates are provided with through holes for the heating pipes to pass through, one end of the heating pipe is fixed through a stainless steel plate and is provided with a sealing element and a gas delivery pipe for air isolation, non-reactive gas is input into the heating pipe, the other end of the heating pipe is provided with an end sleeve, the end sleeve is fixed to the end of the converter body far away from the sealing element, and the inner diameter of the end sleeve is larger than the outer diameter of the heating pipe, so that when the heating pipe longitudinally expands, there is an expansion space for the heating pipe in the end sleeve, the inner wall of the converter body is provided with an air pipe for supplying gas to the inside of the converter body, and the air pipe is arranged in the gap between adjacent heating pipes.

Description

Technical Field

[0001] This invention relates to the field of activation converter technology, specifically a multi-tube external heating activation converter. Background Technology

[0002] A thermal activation converter is an industrial piece of equipment used to produce activated carbon. It involves heating raw materials (such as wood, coconut shells, and coal) at high temperatures under oxygen-deficient conditions to pyrolyze and activate them, forming porous activated carbon. In recent years, with increasingly stringent requirements for activated carbon quality, externally heated activation converters have been widely used in activated carbon production to improve product surface quality, prevent surface erosion, and increase product yield. The main components of an externally heated activation converter include: the converter body, a steam injection system, an oxygen supply system, an induced draft system, and a waste heat recovery system.

[0003] Currently, the widely used external heating activation furnaces adopt a single-tube external heating method. This equipment has a small heat exchange area for raw materials, resulting in high energy consumption and low production capacity. At the same time, the single-tube structure causes uneven heat distribution along the axial and circumferential directions, resulting in a large temperature difference inside the furnace. Uneven heating of materials leads to component segregation or incomplete reaction, resulting in insufficient finished product qualification rate. Summary of the Invention

[0004] (a) Technical problem to be solved: In view of the shortcomings of the existing technology, the present invention provides a multi-tube external heat activation converter with the advantages of high-efficiency heat conduction and uniform activation, and solves the problem of insufficient heating surface of the activation converter.

[0005] (II) Technical Solution: To achieve the above-mentioned goals of efficient heat conduction and uniform activation, the present invention provides the following technical solution: A multi-tube external heat activation converter, comprising a converter body, the converter body being driven to rotate by a driving device, heating tubes being uniformly arranged on the inner wall of the converter body, the heating tubes being fixed by a tube plate on the inner wall of the converter body, the tube plate having through holes for the heating tubes to pass through, one end of the heating tube being fixed by a stainless steel plate and having a sealing element and a gas supply pipe for isolating air, and non-reactive gas being introduced into the heating tube, the other end of the heating tube having an end sleeve, the end sleeve being fixed in the converter body at the end away from the sealing element, and the inner diameter of the end sleeve being larger than the outer diameter of the heating tube, so that when the heating tube expands longitudinally, there is a space for the expansion and contraction of the heating tube in the end sleeve, and an air pipe for supplying gas to the interior of the converter body is provided on the inner wall of the converter body, the air pipe being disposed in the gap between adjacent heating tubes.

[0006] The tube sheets are arranged in a circumferential array along the inner wall of the converter body, and two adjacent tube sheets are staggered in the direction of rotation. The staggered tube sheets form a group, and there are at least three groups arranged in the direction of rotation along the inner wall of the converter body.

[0007] The tube sheet is provided with a connecting plate on its side, which connects adjacent tube sheets that are staggered front to back.

[0008] The length of the air pipe is greater than that of the tube sheet, so that the air pipe opening is closer to the rotation axis of the converter body than the heating pipe.

[0009] An annular gasket is provided in the through hole through which the heating tube passes on the tube sheet.

[0010] The tube sheet is provided with tube sheet reinforcing ribs, and a sealing end reinforcing rib is provided between the stainless steel plate at one end of the heating tube and the converter body.

[0011] The inner wall of the heating tube inlet end is provided with a spiral guide groove, and the guide groove is arranged in a circumferential array.

[0012] The guide channel is only provided at the inlet end of the heating tube, the length of the guide channel is twice the inner diameter of the heating tube, and a distribution ring is provided at the end of the guide channel, the distribution ring being provided on the inner wall of the heating tube.

[0013] The material distribution ring has a serrated cross-section.

[0014] (III) Beneficial Effects: Compared with the prior art, the present invention provides a multi-tube externally heated converter with the following beneficial effects: 1. The multi-tube externally heated converter uses a tube sheet to fix multiple circumferentially distributed heating tubes to form a radiant heat transfer network. One end of the heating tube is rigidly fixed to a sealing element by a stainless steel plate, and the other end is connected by a floating end sleeve, forming a "single-end fixed + single-end free expansion and contraction" layout. The three-dimensional nested design of the heating tube and the combustion chamber inside the converter allows the high-temperature gas to directly surround the tube wall, shortening the heat transfer path and reducing the radiation loss of traditional external heating. The matching design of the end sleeve and the through hole of the tube sheet allows the heating tube to expand freely along the axial direction when heated. By limiting radial displacement, the tube body is prevented from twisting, solving the problem of cracking caused by thermal stress. When the converter rotates at low speed, the material inside the heating tube rolls tightly against the tube wall under the action of centrifugal force. Simultaneously, the axial slippage caused by the converter's tilt angle creates a "rolling-sliding" composite motion mode. Centrifugal force forces the material to fully contact the tube wall, eliminating the contact thermal resistance of traditional static heating. Rolling friction causes the material to continuously tumble, exposing fresh surfaces to enhance reaction kinetics. The air pipe is embedded in the gap between the heating tubes and injects combustion gas into the furnace. The flame directly wraps around the outer wall of the heating tube. After being heated inside the tube, the material undergoes a reforming reaction with water vapor to generate CO / H2. The combustible gas returns to the combustion zone through the pipe to participate in secondary combustion. The combustion heat energy is directly transferred to the material through the tube wall, avoiding the multiple energy conversion losses of traditional indirect heating. The reducing gas generated by the reaction serves as supplementary fuel, reducing external energy consumption and forming a "heat absorption-heat release" self-balancing cycle. The staggered arrangement of the air pipe and heating tube creates turbulent disturbances, extending the residence time of high-temperature flue gas and improving combustion efficiency.

[0015] 2. In this multi-tube externally heated converter, the staggered tube sheets form a "spatial cross-truss network" through connecting plates. This transforms the linear thermal expansion stress borne by the traditional single-row tube sheet into multi-directional stress components. Through the staggered arrangement of the stepped tube sheet groups, the thermal expansion displacement of adjacent tube sheets cancels each other out at the connecting plates, avoiding unidirectional cumulative deformation. The connecting plates convert the circumferential tension generated by centrifugal force into a combination of compressive or tensile loads at the truss nodes. The stepped distribution breaks the continuous ring structure, suppressing overall radial expansion out-of-roundness. The stepped tube sheets form an asymmetric heat conduction path. When the converter rotates, the thermal expansion of the tube sheets in the high-temperature zone is transferred to the low-temperature zone through the connecting plates, forming a self-balancing temperature compensation. The phase difference arrangement of adjacent tube sheet groups causes the peaks and troughs of thermal deformation to cancel each other out, reducing the overall thermal deformation. The stepped tube sheets destroy the axial continuous thermal bridge, forcing heat to be transferred along a "zigzag" path, extending the heat flow trajectory. The connecting plates form a transverse heat conduction channel, establishing a radial-axial composite heat transfer mode, which improves the circumferential temperature uniformity.

[0016] 3. This multi-tube externally heated converter, with the air pipe opening close to the converter axis, forms a centripetal jet when the gas is injected. Coupled with the converter's rotation direction, it generates a forced vortex effect. The air pipe extends beyond the tube sheet to form a cantilevered injection structure. The gas flame directly penetrates the gap between the heating tubes, forming a "tube bundle interpenetrating combustion" mode. This eliminates the high-temperature edge zone caused by traditional sidewall combustion. The elastic modulus of the ceramic fiber gasket is significantly lower than that of the metal tube sheet. During thermal expansion, it absorbs displacement differences through flexible deformation, avoiding fretting wear caused by hard metal contact.

[0017] 4. This multi-tube externally heated converter uses a spiral guide channel to induce a spiral centrifugal motion in the material. This forced spiral centrifugal motion disrupts the thermal boundary layer, increasing the convective heat transfer coefficient. Simultaneously, the guide channel increases the inner wall surface area, reducing unit energy consumption. The guide channel guides the material to form a spiral-ring composite motion, eliminating localized overheating or low-temperature dead zones and preventing quality fluctuations due to temperature differences. The spiral structure at the feed end divides the material flow into multiple fine streams, preventing large-scale accumulation. The serrated structure applies shear stress to agglomerated materials, ensuring material dispersion. The kinetic energy of the material colliding with the distribution ring is converted into tube wall vibration energy, exciting standing wave resonance to peel off scale and reduce cleaning energy consumption. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the internal structure of the converter of the present invention. Figure 1 .

[0020] Figure 3 This is a schematic diagram of the internal structure of the converter of the present invention. Figure 2 .

[0021] Figure 4 This is a schematic diagram of the internal structure of the converter of the present invention. Figure 3 .

[0022] Figure 5 This is a detailed schematic diagram of the end sleeve of the present invention.

[0023] Figure 6 This is a schematic diagram of the internal structure of the converter of the present invention. Figure 4 .

[0024] Figure 7 This is a schematic diagram of the reinforcing rib structure at the sealing end of the present invention.

[0025] Figure 8 This is a schematic diagram of the flow channel structure of the present invention.

[0026] Figure 9 This is a schematic cross-sectional view of the heating tube of the present invention.

[0027] In the diagram: 1. Converter body; 2. Heating tube; 3. Sealing element; 11. Air pipe; 12. Tube sheet; 13. End sleeve; 21. Guide groove; 22. Material distribution ring; 31. Gas supply pipe; 32. Sealing end reinforcing rib; 121. Tube sheet reinforcing rib; 122. Gasket; 123. Connecting plate. Detailed Implementation

[0028] 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. 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.

[0029] Please see Figures 1-5 A multi-tube externally heated converter includes a converter body 1, which is driven to rotate by a drive device. Heating tubes 2 are evenly arranged on the inner wall of the converter body 1. The heating tubes 2 are fixed by a tube plate 12 on the inner wall of the converter body 1. The tube plate 12 has through holes for the heating tubes 2 to pass through. One end of the heating tube 2 is fixed by a stainless steel plate and is equipped with a sealing element 3 and a gas supply pipe 31 to isolate air and input non-reactive gas into the heating tube 2. The other end of the heating tube 2 is equipped with an end sleeve 13. The end sleeve 13 is fixed inside the converter body 1 at the end away from the sealing element 3, and the inner diameter of the end sleeve 13 is larger than the outer diameter of the heating tube 2, so that when the heating tube 2 expands longitudinally, there is a space for the heating tube 2 to expand and contract. An air pipe 11 is provided on the inner wall of the converter body 1 to supply gas into the converter body 1. The air pipe 11 is set in the gap between adjacent heating tubes 2.

[0030] The converter body 1 injects fuel gas into the heating tube 2 through air pipe 11 for combustion. The material moves within the heating tube 2 as the converter rotates, absorbing heat through the tube wall for indirect heating, avoiding direct contact with the flame and preventing oxidation or burn-off. Inert gases such as nitrogen and argon are introduced into the heating tube 2 through gas pipe 31 to isolate oxygen and prevent high-temperature oxidation of the material. Upon reaching a certain temperature, these gases react with water vapor to produce carbon monoxide and hydrogen. The carbon monoxide and hydrogen react with oxygen to generate heat, which then heats the heating tube 2, thus recycling the energy. The drive device drives the converter body 1 to rotate at a low speed. The material rolls along the wall within the heating tube 2 under centrifugal force, while simultaneously moving slowly axially. Traditional single-tube external heating methods rely on external heating... The traditional method heats the entire converter body 1 by placing the material directly inside the converter body 1. However, this application heats the material inside the converter body 1 by placing it in the heating tubes 2, avoiding direct contact with the heat source. Compared with the traditional structure, with the same inner diameter of the converter body 1, the heating area of ​​the traditional single-tube external heating method is: S=πDL, where D is the inner diameter of the converter body 1. In this application, the heating area is S=nπdL, where n is the number of heating tubes 2 and d is the diameter of the heating tubes 2. The array arrangement of the heating tubes greatly increases the heating area. At the same time, in terms of heat exchange area, the traditional single-tube heat exchange area is S=πDL, where D is the inner diameter of the converter body 1. In this application, the heat exchange area is S=nπdL, where n is the number of heating tubes 2 and d is the diameter of the heating tubes 2, significantly increasing the heat exchange area. In this application, one end of the heating tube 2 is provided with an end sleeve 13, and a space is provided for the expansion and contraction of the heating tube 2 under heat, avoiding tearing caused by heating expansion and cooling contraction.

[0031] See Figures 4-6 The tube sheet 12 is arranged in a circumferential array along the inner wall of the converter body 1, and two adjacent tube sheets 12 are staggered in the direction of rotation. The staggered tube sheets 12 form a group. There are at least three groups arranged in the direction of rotation on the inner wall of the converter body 1. The tube sheet 12 is provided with a connecting plate 123 on its side, and the connecting plate 123 connects the adjacent and staggered tube sheets 12.

[0032] When the converter operates at high temperatures, the tube sheet 12 and heating tube 2 undergo significant deformation due to thermal expansion. The coefficient of thermal expansion of stainless steel is approximately 18 × 10⁻⁶. -6 / °C, if the tube sheets 12 are arranged in a uniform single row, the accumulation of axial thermal expansion will lead to local stress concentration, causing weld cracking or deformation of the tube sheets 12. The tube sheets 12 are staggered back and forth along the converter axis to form a "stepped" distribution. The thermal expansion force is transferred to the adjacent tube sheets 12 through the connecting plate to avoid single-point stress concentration. The staggered tube sheets 12 form a spatial truss structure. The centrifugal force and thermal expansion force during converter rotation are dispersed to multiple sets of tube sheets 12, which improves the overall bending resistance. In addition, the staggered tube sheets 12 form a discontinuous thermal bridge, which blocks the straight transfer of axial heat flow, forces heat to diffuse in multiple directions, reduces the axial temperature difference, and multiple sets of tube sheets form a thermal network. The heating tubes are heated more evenly in the circumferential and axial directions. The tube sheets 12 are connected by welding using the connecting plate 123 to form a rigid frame, which can effectively resist the centrifugal force generated when the converter body 1 rotates and the impact load of the material in the heating tubes 2.

[0033] The length of the air pipe 11 is greater than that of the tube sheet 12, so that the opening of the air pipe 11 is closer to the rotation axis of the converter body 1 than the heating pipe 2.

[0034] The tube sheet 12 has an annular gasket 122 in the through hole through which the heating tube 2 passes. For example, a high-temperature resistant ceramic fiber gasket is used to resist high temperature while effectively increasing the contact area, reducing collisions during rotation and expansion and compression caused by heating, and avoiding direct metal contact.

[0035] See Figure 4 and Figure 7 The tube sheet 12 is provided with tube sheet reinforcing ribs 121, and a sealing end reinforcing rib 32 is provided between the stainless steel plate at one end of the heating tube 2 and the converter body 1.

[0036] See Figures 8-9 The inner wall of the inlet end of the heating tube 2 is provided with a spiral guide groove 21, and the guide groove 21 is arranged in a circumferential array. The guide groove 21 is only provided at the inlet end of the heating tube 2. The length of the guide groove 21 is twice the inner diameter of the heating tube 2. A distribution ring 22 is provided at the end of the guide groove 21. The distribution ring 22 is set on the inner wall of the heating tube 2 and fixed by welding. The cross-section of the distribution ring 22 is sawtooth-shaped. The spiral guide groove 21 increases the surface area of ​​the inner wall of the pipe, directly improving the heat transfer efficiency. When the converter body 1 rotates, the newly added material generates a spiral motion along the guide groove 21 in the heating tube 2, generating centrifugal slinging and secondary flow, breaking the boundary layer, improving heat exchange, and effectively preventing the newly added material from accumulating and blocking. When the material starts to move under centrifugal force, the obstruction of the distribution ring 22 causes the material to break the static accumulation after impact, disperse it along the circular trajectory, and generate a shearing effect on the agglomerated material, reducing adhesion.

[0037] Working principle: The converter body 1 injects fuel gas into the heating tube 2 through air pipe 11 for combustion. The material moves inside the heating tube 2 with the converter's rotation, absorbing heat through the tube wall for indirect heating, avoiding direct contact with the flame and preventing oxidation or burn-off. Inert gases such as nitrogen and argon are introduced into the heating tube 2 through gas pipe 31 to isolate oxygen and prevent high-temperature oxidation of the material. After reaching a certain temperature, these gases react with water vapor to produce carbon monoxide and hydrogen. The carbon monoxide and hydrogen react with oxygen to generate heat, which then heats the heating tube 2, thus recycling the energy. The drive device drives the converter body 1 to rotate at a low speed. The material rolls along the wall inside the heating tube 2 under centrifugal force, while moving slowly along the axial direction. Traditional single-tube external heating methods use external... In traditional methods, a heat source heats the entire converter body 1, with materials placed directly inside. However, this application heats the material within the converter body 1, placing it in heating tubes 2 to avoid direct contact with the heat source. Compared to conventional structures, with the same inner diameter of the converter body 1, the heating area of ​​a traditional single-tube external heating system is S = πDL, where D is the inner diameter of the converter body 1. In this application, the heating area is S = nπdL, where n is the number of heating tubes 2 and d is the diameter of the heating tubes 2. The array arrangement of the heating tubes significantly increases the heating area. Furthermore, in terms of heat exchange area, the traditional single-tube system has a heat exchange area of ​​S = πDL, where D is the inner diameter of the converter body 1, while this application's heat exchange area is S = nπdL. n represents the number of heating tubes 2, and d represents the diameter of the heating tubes 2, significantly increasing the heat exchange area. In this application, one end of the heating tube 2 is provided with an end sleeve 13, and a space is provided for the expansion and contraction of the heating tube 2 under heat, avoiding tearing caused by heating expansion and cooling contraction. The tube sheet 12 is arranged circumferentially along the inner wall of the converter body 1, and two adjacent tube sheets 12 are staggered along the direction of rotation. The staggered tube sheets 12 form a group. At least three groups are arranged along the direction of rotation on the inner wall of the converter body 1. The tube sheet 12 is provided with a connecting plate 123 on its side, which connects adjacent staggered tube sheets 12. When the converter is running at high temperature, the tube sheet 12 and the heating tubes 2 deform significantly due to thermal expansion. The coefficient of thermal expansion of stainless steel is approximately 18 × 10⁻⁶. -6 / °C, if the tube sheets 12 are arranged in a uniform single row, the accumulation of axial thermal expansion will lead to local stress concentration, causing weld cracking or deformation of the tube sheets 12. The tube sheets 12 are staggered back and forth along the converter axis to form a "stepped" distribution. The thermal expansion force is transferred to the adjacent tube sheets 12 through the connecting plate to avoid single-point stress concentration. The staggered tube sheets 12 form a spatial truss structure. The centrifugal force and thermal expansion force during converter rotation are dispersed to multiple sets of tube sheets 12, which improves the overall bending resistance. In addition, the staggered tube sheets 12 form a discontinuous thermal bridge, which blocks the straight transfer of axial heat flow and forces heat to diffuse in multiple directions, reducing the axial temperature difference. Multiple sets of tube sheets form a "honeycomb" thermal network, and the heating tubes are heated more evenly in the circumferential and axial directions. The tube sheets 12 are connected by welding using the connecting plate 123 to form a rigid frame, which can effectively resist the centrifugal force generated when the converter body 1 rotates and the impact load of the material in the heating tubes 2.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-tubular externally heated activated converter comprising a converter body (1) which is rotated by a driving device, characterized in that: The converter body (1) inner wall is uniformly arranged with heating pipes (2), the heating pipes (2) are fixed by setting a pipe plate (12) on the inner wall of the converter body (1), the pipe plate (12) is provided with a through hole for the heating pipe (2) to pass through, one end of the heating pipe (2) is fixed by a stainless steel plate, and a sealing element (3) and a gas delivery pipe (31) are arranged for air isolation, and non-reactive gas is input into the heating pipe (2), the other end of the heating pipe (2) is provided with an end sleeve (13), the end sleeve (13) is fixed at the end of the converter body (1) away from the sealing element (3), and the inner diameter of the end sleeve (13) is greater than the outer diameter of the heating pipe (2), so that when the heating pipe (2) expands longitudinally, there is an expansion space for the heating pipe (2) in the end sleeve (13), the inner wall of the converter body (1) is provided with an air pipe (11) for supplying gas to the inside of the converter body (1), the air pipe (11) is arranged in the gap between adjacent heating pipes (2), the pipe plate (12) is arranged along the circumference of the inner wall of the converter body (1), and the two adjacent pipe plates (12) are staggered forward and backward along the extension direction of the rotation axis, the forward and backward staggered pipe plates (12) form a group, there are at least three groups of pipe plates (12) arranged along the extension direction of the rotation axis on the inner wall of the converter body (1), and the side of the pipe plate (12) is provided with a connecting plate (123), the connecting plate (123) connects the adjacent and staggered pipe plates (12).

2. A multi-tubular externally heated activated converter according to claim 1, wherein: The length of the air pipe (11) is greater than that of the pipe plate (12), so that the air pipe (11) is closer to the rotation axis of the converter body (1) than the heating pipe (2).

3. A multi-tubular externally heated activated converter according to claim 1, wherein: The through hole of the pipe plate (12) for the heating pipe (2) to pass through is provided with an annular gasket (122).

4. A multiple-tube external heating activated converter according to claim 1, characterized in that: The pipe plate (12) is provided with a pipe plate reinforcing rib (121), and a sealing end reinforcing rib (32) is arranged between the stainless steel plate at one end of the heating pipe (2) and the converter body (1).

5. A multi-tubular externally heated activated converter according to any one of claims 1 to 4, wherein: The inner wall of the inlet end of the heating pipe (2) is provided with a spiral flow guide groove (21), and the flow guide groove (21) is arranged along the circumference.

6. A multiple-tube external heating activated converter according to claim 5, characterized in that: The flow guide groove (21) is only arranged at the inlet end of the heating pipe (2), the length of the flow guide groove (21) is 2 times the inner diameter of the heating pipe (2), and a distribution ring (22) is arranged at the end of the flow guide groove (21), and the distribution ring (22) is arranged on the inner wall of the heating pipe (2).

7. A multiple-tube external heating activated converter according to claim 6, characterized in that: The cross section of the distribution ring (22) is sawtooth-shaped.

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