Melamine drying drum

Abstract

The application discloses a melamine drying roller, which comprises a roller body, a feeding head arranged at one end of the roller body, a discharging mechanism arranged at the other end of the roller body, a plurality of circle heating pipe assemblies arranged in the roller body, and a steam shunt device arranged at one end of the roller body and used for supplying gas to each heating pipe assembly. The inner wall of the roller body is arranged to be inclined along one end of the discharging mechanism. The axis of the heating pipe assembly is arranged to be parallel to the inner wall of the roller body. A plurality of supporting rings are arranged in the inner wall of the roller body. Wet melamine fed by the feeding head is conveyed to the end of the discharging mechanism through the rolling of the roller body. The wet melamine conveyed forward is separated into different areas by the supporting rings. The wet melamine in different areas is synchronously heated and dried to different depths by the heating pipe assemblies. The application can solve the problems that the existing drying roller is unevenly heated when the product is heated and dried, and the drying efficiency is low due to the fact that the roller cannot be heated in different temperature intervals.

Description

Technical Field

[0001] This invention relates to the technical field of chemical equipment, specifically to a melamine drying drum. Background Technology

[0002] Melamine is an important organic chemical intermediate, primarily used in industrial applications for the condensation polymerization of melamine with formaldehyde to produce melamine-formaldehyde resin. In China, melamine synthesis and production generally uses urea as a raw material. After centrifugation, the melamine typically contains approximately 10-15% water, thus requiring drying of the wet melamine.

[0003] Currently, melamine is generally dried using small-scale drying equipment. When the quantity is large, agitation-type drying equipment is generally ineffective and inefficient. For large-scale drying of melamine, current drying equipment typically uses drum or agitation-type dryers, employing long drying drums or conveyor belts. The heat source for these large drying drums is usually hot air or steam. The hot air or steam heats the inner cavity of the drum, while the drum itself allows for better contact between the melamine and the heat source, thus achieving drying. When using hot air as the heat source, a fan typically delivers hot air into the drying drum, where the rotating drum heats and dries the melamine. Agitator blades or similar structures are usually incorporated into the drum wall for auxiliary drying. When using steam as the heat source, high-temperature steam heats the drum wall, allowing the melamine to dry through contact with the rotating drum.

[0004] Whether using hot air drying, steam heating of the drum wall, or a combination of both, the problem of localized heating and drying of melamine within the mixing drum persists. For example, with an air-drying structure, only the exposed surface layer of melamine is effectively dried; other areas remain undried. The same applies to drum wall heating, where the drying area is limited to the perimeter of the drum wall, resulting in uneven heat distribution. This prevents simultaneous heating of the accumulated melamine at different depths, leaving central areas unheated and leading to uneven drying, low efficiency, excessively long drying times, and poor uniformity. Therefore, effective drying can only be achieved by reducing the thickness of the melamine buildup or increasing the frequency of stirring and drying time. Furthermore, due to the sealed interior of the drum, the internal temperature is difficult to control during prolonged drying, potentially leading to overheating and reactions within the melamine. Therefore, improvements to existing melamine drying equipment are necessary. Summary of the Invention

[0005] In order to solve one or more technical problems existing in the prior art, the purpose of this application is to provide a melamine drying drum that can solve the problem of uneven heating and inability to heat the drum in different temperature zones when heating and drying products, resulting in low drying efficiency.

[0006] To solve the aforementioned technical problems, this application adopts the following technical solution:

[0007] A melamine drying drum includes a drum body, a feed head at one end of the drum body, a discharge mechanism at the other end of the drum body, several rings of heating tube assemblies arranged within the drum body, and a steam diversion device at one end of the drum body for supplying air to each of the heating tube assemblies. High-pressure steam is rapidly and evenly diverted through the steam diversion device to the air inlet of each heating tube assembly. The inner wall of the drum body is inclined along one end of the discharge mechanism. The axis of the heating tube assembly is parallel to the inner wall of the drum body. Several support rings are arranged around the inner wall of the drum body, and the heating tube assemblies are supported and fixed by the support rings. The wet melamine fed in by the feed head is conveyed to the discharge mechanism by the rolling of the drum body. The forward conveyed wet melamine is divided into different areas by the support rings, and the wet melamine in different areas is simultaneously heated and dried to different depths by the heating tube assemblies.

[0008] Preferably, the discharge mechanism includes a plurality of discharge ports arranged around one side wall of the roller body, a discharge hood arranged around the outside of the roller body, and a discharge guide port arranged at the bottom of the discharge hood. The discharge ports are located inside the discharge hood. A sealing rotation structure is provided between the discharge hood and the roller body. The roller body and the discharge hood are sealed and rotated relative to each other through the sealing rotation structure. Melamine flowing out through the discharge ports is discharged downward from the discharge guide port.

[0009] Preferably, the sealing rotation structure includes two limiting flanges with a fixed ring on the outside of the drum body, buffer devices on both sides of the unloading hood, and a wear-resistant ring on the outside of the buffer devices. The outside of the buffer devices is sealed to the inside of the limiting flanges through the wear-resistant ring.

[0010] Preferably, the buffer device includes a metal connecting ring disposed between the unloading hood and the limiting flange, and expansion rings disposed on both sides between the unloading hood and the metal connecting ring, the expansion rings being outwardly convex arc-shaped structures, and the metal connecting rings being fixedly connected to the side of the unloading hood through the expansion rings.

[0011] Preferably, a sealing ring is provided at each of the two connecting points of the expansion ring, and the inner ring of the sealing ring is in contact with the outer wall of the roller body.

[0012] Preferably, the buffer device is provided with a plurality of support screws, and an L-shaped bracket is provided on the support screw. A roller is provided at the bottom of the bracket. A spring is provided on the support screw to press the L-shaped bracket inward. The roller extends outward through the support screw and the L-shaped bracket and contacts the outer roller body of the limiting flange.

[0013] Preferably, the unloading hood is also provided with an air inlet, which is connected to the discharge port. Gas that enters the drum body through the air inlet is discharged from the feed head.

[0014] Preferably, the steam diversion device includes a cylindrical steam feed chamber coaxially disposed in the middle of the drum body, a steam transition chamber disposed outside the feed end of the heating tube assembly, and a plurality of first connecting pipes uniformly arranged in a ring between the steam feed chamber and the steam transition chamber. A rotary joint is connected to the air inlet on one side of the steam feed chamber. After high-pressure steam enters the steam feed chamber, it enters the steam transition chamber uniformly through the first connecting pipes and is diverted to the heating tube assembly for heating.

[0015] Preferably, the heating tube assembly includes several steam tubes arranged in a ring within the drum body. Each steam tube includes an inlet pipe with one end connected to the steam transition chamber and a condenser return pipe sleeved on the outside of the steam tube. The inlet pipe and the condenser return pipe are connected by a bracket. The end of the condenser return pipe is a sealed structure. High-temperature steam flows into each inlet pipe through the steam transition chamber and then into the condenser return pipe through the inlet pipe to heat and dry the wet melamine.

[0016] Preferably, both the steam feed chamber and the steam transition chamber are provided with a partition plate. The steam transition chamber forms a first concentrate collection chamber with the side wall of the drum body through the partition plate, and the steam feed chamber forms a second concentrate collection chamber with the side wall of the drum body through the partition plate. A plurality of second connecting pipes are provided between the first concentrate collection chamber and the second concentrate collection chamber. A water outlet pipe extending outward is provided in the middle of the second connecting pipe. One end of the condensate return pipe is connected to the first concentrate collection chamber. The liquid condensed after high-pressure steam cooling flows back into the first concentrate collection chamber through the condensate return pipe and flows into the second concentrate collection chamber through the second connecting pipe. The liquid in the second concentrate collection chamber is discharged through the water outlet pipe.

[0017] Preferably, the diameter of the steam pipe located inside the drum body decreases sequentially from the outside to the inside.

[0018] Preferably, the support ring is composed of 4 to 10 arc-shaped partition plates, with adjacent partition plates arranged alternately.

[0019] Preferably, the outer surface of the roller body is provided with a plurality of riding rings and at least one toothed ring. The roller body is mounted on an external frame via the riding rings and is connected to an external drive mechanism for rotation via the toothed ring.

[0020] Preferably, the inclination of the roller body is tg1.5 to 2.0.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. Because the inner wall of the drum body is inclined along one end of the discharge mechanism, the melamine entering the drum body can flow slowly forward during the drum's rotation, preventing local accumulation. Simultaneously, several support rings are arranged on the inner wall of the drum body. These support rings not only support and fix the various heat pipe components but also separate the heating zones. This creates multiple relatively independent spaces within the drum body, allowing the melamine to flow slowly and sequentially into the next heating zone as the drum rotates and flows forward. This ensures that the melamine that enters first will preferentially enter the next heating zone, thereby controlling the temperature range within the drum body and preventing local accumulation and mixing of wet and dry melamine during forward transport.

[0023] 2. By dividing the interior of the drum body into different heating zones, the total amount of melamine in each heating zone can be precisely controlled, ensuring that the melamine discharged from the discharge mechanism is drier and eliminating the problem of wet melamine.

[0024] 3. Because the heating tube assembly is installed in a ring-shaped multi-ring structure along the axis of the drum body, heating tube assemblies are distributed in spaces of different diameters inside the drum body. When melamine is heated inside the drum body, it is no longer dried by heating the drum wall, but by heating assemblies in spaces of different diameters to simultaneously heat melamine in different depth areas. This effectively solves the problem of uneven heat distribution in existing heated drum bodies during drying, which makes it impossible to simultaneously heat and dry melamine at different depths. It enables melamine to dry more evenly and with higher drying efficiency. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of the overall structure of the present invention;

[0026] Figure 2 This is a partially enlarged view of the connection between the drum body and the air inlet via a sealed rotating structure in this invention;

[0027] Figure 3 This is a cross-sectional view of the connection between the steam diversion device and the heating tube assembly in this invention;

[0028] Figure 4 This is a schematic diagram of the heating tube assembly in this invention;

[0029] In the diagram: 1. Feed head; 2. Riding ring; 3. Toothed ring; 4. Drum body; 5. Support ring; 6. Heating tube assembly; 7. Discharge mechanism; 8. Air inlet; 9. Steam diversion device; 10. Discharge guide; 11. Discharge port; 12. Sealing rotating structure; 13. Discharge hood; 14. Buffer device; 15. Metal connecting ring; 16. Spring; 17. Support screw; 18. L-shaped bracket; 19. Roller; 20. Limiting flange; 21. Wear-resistant ring; 22. Expansion ring; 23. Sealing ring; 24. Second connecting pipe; 25. First connecting pipe; 26. Second concentrate manifold; 27. Water outlet pipe; 28. Steam feed chamber; 29. ​​Dividing plate; 30. First concentrate manifold; 31. Steam pipe; 32. Condensate return pipe; 33. Steam inlet pipe; 34. Steam transition chamber; 35. Divider plate. Detailed Implementation

[0030] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0031] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0033] Example 1:

[0034] like Figure 1 As shown, a melamine drying drum includes a drum body 4, a feed head 1 at one end of the drum body 4, a discharge mechanism 7 at the other end of the drum body 4, several rings of heating tube assemblies 6 arranged within the drum body 4, and a steam diversion device 9 at one end of the drum body 4 for supplying air to each of the heating tube assemblies 6. High-pressure steam is rapidly and evenly diverted to the air inlet end of each heating tube assembly 6 through the steam diversion device 9. The inner wall of the drum body 4 is inclined along one end of the discharge mechanism 7. The axis of the heating tube assembly 6 is parallel to the inner wall of the drum body 4. Several support rings 5 ​​are arranged around the inner wall of the drum body 4, and the heating tube assemblies 6 are supported and fixed by the support rings 5. The wet melamine fed in by the feed head 1 is conveyed to the discharge mechanism 7 by the rolling of the drum body 4. The forward conveyed wet melamine is divided into different areas by the support rings 5, and the wet melamine in different areas is simultaneously heated and dried to different depths by the heating tube assemblies 6.

[0035] In the actual processing, wet melamine is fed into the feed head 1 through a screw feeder and flows into the interior of the drum body 4. At the same time, high-pressure steam is connected to the steam distribution device 9 through a rotary joint, so that the high-pressure steam entering the steam distribution device 9 can be quickly and evenly injected into each heat pipe assembly for uniform heating. Since the inner wall of the drum body 4 is inclined along one end of the discharge mechanism 7, the melamine after entering the drum body 4 can flow forward slowly during the rolling process of the drum body 4, and there will be no local accumulation. Meanwhile, since several support rings 5 ​​are arranged on the inner wall of the drum body 4, the support can not only support and fix each heat pipe assembly, but also separate the heating areas. This allows the interior of the drum body 4 to form multiple relatively independent spaces through the support rings 5. As the melamine rotates and flows forward through the drum body 4, it can slowly flow into the next heating area in sequence, ensuring that the melamine that enters first will preferentially enter the next heating area. This achieves the purpose of controlling the temperature range inside the drum body 4, avoiding the problem of local accumulation and dry-wet mixing of melamine during forward conveying. It also ensures precise control of the total amount of melamine in each heating space, ensuring that the melamine discharged from the discharge mechanism 7 is drier and no longer contains wet melamine. Meanwhile, since the heating tube assembly 6 is installed in a ring-shaped multi-ring structure along the axis of the drum body 4, the heating tube assembly 6 is distributed in spaces of different diameters inside the drum body 4. When melamine is heated inside the drum body 4, it is no longer dried by heating the drum wall, but by heating the melamine in different depth areas simultaneously through the heating tube assembly 6 in spaces of different diameters. This effectively solves the problem that the existing heating drum body 4 has uneven heat distribution during drying and cannot simultaneously heat and dry melamine at different depths. It can make the drying of melamine more uniform and the drying efficiency higher.

[0036] Further improvements include, for example Figure 2 As shown, the discharge mechanism 7 includes a plurality of discharge ports 11 arranged around one side wall of the roller body 4, a discharge cover 13 arranged around the outside of the roller body 4, and a discharge guide port 10 located at the bottom of the discharge cover 13. The discharge ports 11 are located inside the discharge cover 13. A sealing rotation structure 12 is provided between the discharge cover 13 and the roller body 4. The roller body 4 and the discharge cover 13 are sealed and rotated relative to each other through the sealing rotation structure 12. The melamine flowing out through the discharge ports 11 is discharged downward uniformly from the discharge guide port 10.

[0037] When melamine is dried by rolling inside the drum body 4 and flows into the discharge mechanism 7 at the other end, the dried melamine can be discharged outward through one or more discharge ports 11 at the bottom. When the melamine is discharged through the discharge port 11 into the unloading hood 13, it can be directly transported to the outside for packaging through the unloading guide port 10 at the bottom of the unloading hood 13. Multiple discharge ports 11 are provided around one side wall of the drum body 4, which allows the drum body 4 to discharge material through the corresponding discharge port 11 no matter what angle it rotates to. This makes it easier and more effective to discharge the dried melamine outward, avoiding the phenomenon of accumulation at the end. Moreover, the structure is simple and effectively solves the problem of the existing drum discharge ports 11 being single and fixed, resulting in insufficient discharge flexibility. Meanwhile, during the discharge process via the discharge mechanism 7, the discharge hood 13 can seal and block the outside of the discharge port 11 where no material needs to be discharged, preventing the entry of outside air and avoiding the environmental pollution caused by melamine being discharged from outside the discharge guide port 10. Furthermore, the discharge hood 13 is connected to the roller body 4 via a sealed rotating structure 12, allowing the discharge hood 13 to be fixedly mounted on the frame. During the rotation of the roller body 4, the discharge hood 13 will not rotate with the roller body 4, resulting in better stability of the discharge guide port 10 position.

[0038] A further improvement is made to the sealing rotation structure 12, which includes two limiting flanges 20 with a fixed ring on the outside of the drum body 4, a buffer device 14 on both sides of the unloading cover 13, and a wear-resistant ring 21 on the outside of the buffer device 14. The outside of the buffer device 14 is sealed to the inside of the limiting flange 20 through the wear-resistant ring 21.

[0039] When connecting the unloading hood 13 and the drum body 4 via the sealing rotating structure 12, two limiting flanges 20 are located on both sides of the discharge port 11. The limiting flanges 20 on both sides can also effectively position the buffer device 14 to prevent it from swaying left and right. The buffer device 14 is fixedly installed on both sides of the unloading hood 13, and the wear-resistant ring 21 is installed on the side of the buffer device 14 by screws, etc., so that the buffer device 14 contacts the limiting flange 20 through the wear-resistant ring 21. The wear-resistant ring 21 can not only seal the sealing rotating structure 12 to prevent melamine from flowing out due to gaps, but also buffer the buffer device 14 to prevent direct friction between the buffer device 14 and the limiting flange 20. When the wear-resistant ring 21 wears out, the replacement cost is also lower. Meanwhile, the buffer device 14 can also compensate for the gap between the roller body 4 and the unloading cover 13 and reduce vibration during the vibration process, so as to avoid the problem of large gap and the impact of vibration on the sealing when the two are connected by the sealing rotation structure 12. This allows the two to have better buffering and shock absorption function while being filled by the buffer device 14, making the structure simpler and the rotation flexibility and stability better after installation.

[0040] A further improvement is made to the buffer device 14, which includes a metal connecting ring 15 disposed between the unloading hood 13 and the limiting flange 20, and expansion rings 22 disposed on both sides between the unloading hood 13 and the metal connecting ring 15. The expansion rings 22 are arc-shaped structures that bulge outwards. The metal connecting ring 15 is fixedly connected to the side of the unloading hood 13 through the expansion rings 22. A sealing ring 23 is provided at the connection point on both sides of the expansion ring 22. The inner ring of the sealing ring 23 contacts the outer wall of the roller body 4.

[0041] The expansion ring 22, with its arc-shaped outward protrusion, allows for a larger gap compensation coefficient between the roller body 4 and the unloading cover 13, better preventing gaps after installation. It also features a simple structure, better contractility under vibration, and a longer service life. Furthermore, a metal connecting ring 15 is installed on one side of the expansion ring 22, facilitating the installation and fixing of the wear-resistant ring 21 and preventing it from falling off. It also facilitates the installation of the sealing ring 23 on one side. An inner ring and a sealing ring 23 are clamped and fixed at the connection points on both sides of the expansion ring 22. The inner sealing ring 23 can directly seal the side of the discharge port 11, thereby preventing melamine from flowing into the buffer device 14. The outer sealing ring 23 can perform a secondary seal, thereby isolating melamine that has entered the buffer device 14 and preventing the product from flowing out. In particular, when combined with the wear-resistant ring 21 on the side, it can prevent melamine from being discharged outdoors, resulting in better safety and environmental hygiene.

[0042] The buffer device 14 is provided with a plurality of support screws 17, and L-shaped brackets 18 are provided on the support screws 17. Rollers 19 are provided at the bottom of the brackets. Springs 16 are provided on the support screws 17 to press the L-shaped brackets 18 inward. The rollers 19 extend outward through the support screws 17 and the L-shaped brackets 18 and contact the outer roller body 4 of the limiting flange 20.

[0043] When connected via the buffer device 14, since the roller body 4 and the wear ring 21 are in rotational contact, if the wear ring 21 is not released from the limiting flange 20, it will not achieve the effect of buffering and sealing. If the interference between the two is too large, the wear ring 21 is prone to wear, or even tearing and breaking. As a result, the width requirement of the buffer device 14 is high, the process is difficult, and during operation, the surface contact rotation is adopted, resulting in excessive friction. Therefore, when the buffer device 14 dampens the discharge hood 13 during the rotation of the drum body 4, in order to ensure the buffer device 14 has good stability and avoid tilting or shaking, and also to avoid the discharge hood 13 shaking and sealing problems when there is a certain gap between the wear ring 21 and the limiting flange 20, several support screws 17 are installed in a ring on the metal connecting ring 15 of the buffer device 14. An L-shaped bracket 18, pressed inward by a spring 16, is installed on the support screw 17. A roller 19 is installed at the bottom of the bracket. By rotating the nut at one end of the support screw 17, the contact between the outer roller 19 and the limiting flange 20 can be controlled. When the inner wear-resistant ring 21 is in contact with the side of the limiting flange 20, the roller 19 presses the L-shaped bracket 18 against the outer wall of the limiting flange 20 through the spring 16, thus achieving a tight clamping fit between the roller 19 and the wear-resistant ring 21 on both sides. This allows the roller body 4 to rotate relative to the roller 19 during rotation, ensuring the flexibility of the roller, and also allows the clamping distance between the roller 19 and the wear-resistant ring 21 to be adjusted through the cooperation of the spring 16 and the support screw 17. This ensures that the wear-resistant ring 21 not only provides a seal but also prevents rapid wear. This effectively solves the problem of the wear-resistant ring 21 wearing too quickly when the relative distance between the two is not adjustable when using a sealing structure connection, thus extending its service life.

[0044] Example 2:

[0045] A further improvement based on Embodiment 1 is that the unloading hood 13 is also provided with an air inlet 8, which is connected to the discharge port 11. Gas that enters the drum body 4 through the air inlet 8 is discharged from the feed head 1.

[0046] During the drying process, to prevent excessive internal heat from causing a reaction in the melamine and to ensure timely removal of moisture, an air inlet 8 is provided above the discharge hood 13. When the air inlet pipe is connected to the air inlet duct, an external fan blows gas into the air inlet 8. The gas then flows into the drum body 4 through the discharge port 11. This simplifies the structure, eliminating the need for additional structures and enabling simultaneous rotation and air delivery. Simultaneously, as the drum body 4 rotates, some of the gas is discharged through the discharge port 11, which connects to the discharge guide 10. This gas also helps to feed the melamine, preventing slow melamine discharge and ensuring efficient output. Furthermore, heated hot air can be introduced through the discharge port 11. After being delivered into the drum body 4 by the hot air, the internal temperature of the drum can be controlled to avoid the problem of the internal temperature being too low or too high, thereby ensuring the drying efficiency of melamine. The internal temperature control accuracy is higher and the temperature uniformity is better, avoiding the occurrence of local overcooling or overheating.

[0047] Example 3:

[0048] Further improvements can be made based on Example 1 or Example 2, such as... Figure 3 As shown, the steam diversion device 9 includes a cylindrical steam feed chamber 28 coaxially arranged in the middle of the drum body 4, a steam transition chamber 34 located outside the feed end of the heating tube assembly 6, and a plurality of first connecting pipes 25 uniformly arranged in a ring between the steam feed chamber 28 and the steam transition chamber 34. A rotary joint is connected to the air inlet on one side of the steam feed chamber 28. After high-pressure steam enters the steam feed chamber 28, it enters the steam transition chamber 34 uniformly through the first connecting pipes 25 and is diverted to the heating tube assembly 6 for heating.

[0049] Because the drum body 4 of large-scale drying equipment is generally large in length and diameter (e.g., the diameter of this drum body 4 is about 23 meters and the diameter is about 3 meters), it is difficult to evenly distribute the high-pressure steam to each area of ​​the heating tube assembly 6 when injecting it. This can easily lead to insufficient internal pressure and steam supply in some heating tube assemblies 6 during high-pressure steam delivery, thus affecting the drying effect. Therefore, a cylindrical steam feed chamber 28 and a steam transition chamber 34 are installed on one side of the drum body 4. Both the steam feed chamber 28 and the steam transition chamber 34 are cylindrical and coaxially arranged with the drum body 4. During drum rotation, the drum body 4 drives the steam feed chamber 28 and the steam transition chamber 34 to rotate coaxially. The air inlet on one side of the steam feed chamber 28 is generally coaxial with the drum body 4. Thus, after connecting the rotary joint, when connected to the external steam pipe 31 through the rotary joint, the steam feed chamber can be fed even without the rotary joint rotating. The rotation of the drum body 4 and the steam feed chamber 28 simplifies the supply of steam to the steam feed chamber 28. To prevent uneven distribution of steam into each heating tube assembly 6 after entering the steam feed chamber 28, a steam transition chamber 34 is installed on the outside of the feed end of the heating tube assembly 6. The steam feed chamber 28 and the steam transition chamber 34 are connected by 4-6 first connecting pipes 25. The first connecting pipes 25 allow for a smaller volume of the steam feed chamber 28 and the steam transition chamber 34, making internal pressure control more convenient and avoiding insufficient pressure. When high-pressure steam enters the steam feed chamber 28, it buffers the high-pressure steam and balances the internal pressure. Then, through the first connecting pipes 25 on the side wall of the steam feed chamber 28, it is evenly injected into various areas of the steam transition chamber 34 from all directions. This results in a more uniform distribution of steam when entering the heating tube assembly 6, preventing uneven temperature distribution in the heating tube assembly 6 and making the temperature inside the drum body 4 more uniform.

[0050] Further improvements include, for example Figure 4 As shown, the heating tube assembly 6 includes several steam pipes 31 arranged in a ring within the drum body 4. Each steam pipe 31 includes a steam inlet pipe 33 connected at one end to the steam transition chamber 34 and a condensation return pipe 32 sleeved on the outside of the steam pipe 31. The steam inlet pipe 33 and the condensation return pipe 32 are connected by a bracket. The end of the condensation return pipe 32 is a sealed structure. High-temperature steam flows into each of the steam inlet pipes 33 through the steam transition chamber 34, and then flows into the condensation return pipe 32 through the steam inlet pipes 33 to heat and dry the wet melamine. The diameter of the steam pipes 31 within the drum body 4 decreases sequentially from the outside to the inside.

[0051] High-pressure steam is injected through one end of the steam inlet pipe 33, flows out from the other end, and re-enters the condenser return pipe 32. It then flows back to the outlet end through the condenser return pipe 32. As the high-pressure steam travels through the steam transition chamber 34 into the drum body 4, it heats the steam pipe 31, thus achieving internal drying. Currently, high-pressure steam heating typically uses a circulating pipe structure. Steam enters through one end of the pipe, circulates, and flows out from the other end. While this structure can achieve heating, it suffers from overheating at the inlet and undercooling at the outlet, making internal temperature control difficult. Therefore, the steam pipe 31 that makes up the heating pipe assembly 6 consists of two interlocking steam inlet pipes 33 and a condensation return pipe 32. The end of the return pipe is sealed, which allows the high-pressure steam to travel a longer distance and stay in the drum for a longer time, resulting in higher heat utilization. The single-pipe, independently circulating steam pipe 31 structure avoids the phenomenon of insufficient temperature at the feed end and insufficient temperature at the discharge end that exists in multi-pipe circulating structures. The two are connected by a bracket, which makes the internal gap uniform. One end of each steam inlet pipe 33 is directly connected to the steam transition chamber 34, thereby achieving the goal of directly connecting each steam pipe 31 to the high-pressure steam and making its heating uniformity better. Since the drum body 4 has a circular structure, in order to ensure the uniformity of heating inside the drum body 4, the diameter of the steam pipe 31 gradually decreases from the outside to the inside. This makes the gap between each steam pipe 31 more uniform and can accommodate a higher temperature of melamine. As a result, the heating of melamine in each area is more uniform. This ensures that the melamine near the side wall of the drum body 4 is heated evenly, and that the melamine on the surface is also heated evenly. It also prevents melamine from accumulating on the pipes due to the excessively large internal pipe diameter.

[0052] A further improvement is made in that both the steam feed chamber 28 and the steam transition chamber 34 are provided with a partition plate 29. The steam transition chamber 34 forms a first concentrate collection chamber 30 with the side wall of the drum body 4 through the partition plate 29. The steam feed chamber 28 forms a second concentrate collection chamber 26 with the side wall of the drum body 4 through the partition plate 29. A plurality of second connecting pipes 24 are provided between the first concentrate collection chamber 30 and the second concentrate collection chamber 26. A water outlet pipe 27 extending outward is provided in the middle of the second connecting pipe 24. One end of the condensate return pipe 32 is connected to the first concentrate collection chamber 30. The liquid condensed after high-pressure steam cooling flows back into the first concentrate collection chamber 30 through the condensate return pipe 32 and flows into the second concentrate collection chamber 26 through the second connecting pipe 24. The liquid in the second concentrate collection chamber 26 is discharged through the water outlet pipe 27.

[0053] Because condensate forms during the flow of high-pressure steam in the steam pipe 31, this condensate is discharged outward along the condensate return pipe 32. Simultaneously, the gas flowing out through the condensate return pipe 32 also experiences a temperature drop. Directly injecting this gas into the steam transition chamber 34 can easily lower the steam temperature inside the steam transition chamber 34, making it more difficult to raise the internal temperature of the drum body 4. Therefore, to solve the drainage and venting problems, and also to reduce structural complexity, a partition plate 29 is installed in both the steam feed chamber 28 and the steam transition chamber 34. This allows the steam transition chamber 34 to form a first concentrate collection chamber 30 by combining with the side wall of the drum body 4 through the partition plate 29, and the steam feed chamber 28 to form a second concentrate collection chamber 26 by combining with the side wall of the drum body 4 through the partition plate 29. The first concentrate collection chamber 30 and the second concentrate collection chamber 26 are connected by several second connecting pipes 24. A water outlet pipe 27 extending outward along the axis is installed in the middle of the second connecting pipe 24. After the condensed liquid and gas are discharged from the condensate return pipe 32, they can enter the first concentrate manifold 30 separately, and then flow into the second concentrate manifold 26 through the second connecting pipe. Finally, they are discharged outward through the water outlet pipe 27 on one side of the second concentrate manifold 26. The overall structure is simple and the production cost is lower. At the same time, it effectively ensures the stable output of condensate and cooled gas during the rotation of the drum body 4. The structure is simple and the cost is low.

[0054] Example 4:

[0055] A further improvement based on Embodiment 1 is that the support ring 5 is composed of 4 to 10 arc-shaped partition plates 35, with adjacent partition plates 35 arranged alternately.

[0056] When melamine is heated in the various sections separated by the support ring 5, the wet melamine, when transported to one side of the support ring 5, is easily obstructed, causing it to be unable to be transported forward in a timely manner, resulting in some melamine lingering in one area for a long time. Therefore, to avoid the phenomenon of local long-term accumulation of melamine due to the closed structure of the support ring 5 during forward transport, the support ring 5 is divided into 4 to 10 arc-shaped partition plates 35, and the two partition plates 35 are staggered. Thus, during the rotary transport of melamine, the staggered partition plates 35 not only separate the areas but also avoid long-term material obstruction, allowing the adhered melamine to be transported forward better along the gaps. Generally, the roller body 4 with a diameter of 2.5 to 3 meters is equipped with 8 arc-shaped partition plates 35 inside, which can make the material obstruction and transition more stable and less prone to problems of being too fast or too slow.

[0057] A further improvement is that the outer surface of the roller body 4 is provided with several riding rings 2 and at least one toothed ring 3. The roller body 4 is mounted on an external frame through the riding rings 2 and connected to an external drive mechanism for rotation through the toothed ring 3. The inclination of the roller body 4 is tg1.5~2.0.

[0058] The drum body 4 is mounted on the support roller of the external frame via the riding ring 2. It can be connected to the external drive gear via the toothed ring 3, thereby realizing the rotation of the drum. The inclination of the drum body 4 is tg1.5~2.0. When the melamine is rolled and conveyed forward by the drum body 4, it can move slowly, which not only ensures the internal heating and drying time and efficiency, but also solves the problem of automatic flow of melamine.

[0059] The above embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of protection of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application shall fall within the scope of protection claimed by this application.

Claims

1. A melamine drying drum, characterized in that: The device includes a drum body (4), a feed head (1) at one end of the drum body (4), a discharge mechanism (7) at the other end of the drum body (4), several rings of heating tube assemblies (6) arranged inside the drum body (4), and a steam diversion device (9) at one end of the drum body (4) for supplying air to each of the heating tube assemblies (6). High-pressure steam is rapidly and evenly diverted to the air inlet of each heating tube assembly (6) through the steam diversion device (9). The inner wall of the drum body (4) is inclined along one end of the discharge mechanism (7). The heating tube assembly (6) is arranged parallel to the inner wall of the drum body (4). Several support rings (5) are arranged around the inner wall of the drum body (4). The heating tube assembly (6) is supported and fixed by the support rings (5). The wet melamine fed in by the feed head (1) is conveyed to the discharge mechanism (7) by the rolling of the drum body (4). The forward conveyed wet melamine is divided into different areas by the support rings (5). The wet melamine in different areas is synchronously heated and dried to different depths by the heating tube assembly (6). The discharge mechanism (7) includes a discharge cover (13) surrounding the drum body (4). A sealing rotation structure (12) is provided between the discharge cover (13) and the drum body (4). The sealing rotation structure (12) includes two limiting flanges (20) with fixed rings on the outside of the drum body (4), buffer devices (14) on both sides of the discharge cover (13), and a wear-resistant ring (21) on the outside of the buffer device (14). The outside of the buffer device (14) is sealed by contact between the wear-resistant ring (21) and the inside of the limiting flange (20). The buffer device (14) includes a metal connecting ring (15) disposed between the unloading hood (13) and the limiting flange (20), and expansion rings (22) disposed on both sides between the unloading hood (13) and the metal connecting ring (15). The expansion ring (22) is an outwardly convex arc-shaped structure. The metal connecting ring (15) is fixedly connected to the side of the unloading hood (13) through the expansion ring (22). A sealing ring (23) is provided at the connection point on both sides of the expansion ring (22). The inner ring of the sealing ring (23) contacts the outer wall of the roller body (4). The buffer device (14) is provided with a plurality of support screws (17), and an L-shaped bracket (18) is provided on the support screws (17). A roller (19) is provided at the bottom of the bracket. A spring (16) is provided on the support screws (17) to press the L-shaped bracket (18) inward. The roller (19) extends outward through the support screws (17) and the L-shaped bracket (18) and contacts the outer roller body (4) of the limiting flange (20).

2. The melamine drying drum according to claim 1, characterized in that: The discharge mechanism (7) includes a plurality of discharge ports (11) arranged around one side wall of the roller body (4) and a discharge guide port (10) located at the bottom of the discharge hood (13). The discharge ports (11) are located inside the discharge hood (13). The roller body (4) and the discharge hood (13) are sealed and rotated relative to each other through the sealing rotation structure (12). The melamine flowing out through the discharge ports (11) is discharged downward from the discharge guide port (10).

3. A melamine drying drum according to claim 2, characterized in that: The unloading hood (13) is also provided with an air inlet (8), which is connected to the discharge port (11). The gas that enters the drum body (4) through the air inlet (8) is discharged from the feed head (1).

4. A melamine drying drum according to any one of claims 1 to 3, characterized in that: The steam diversion device (9) includes a cylindrical steam feed chamber (28) coaxially arranged in the middle of the drum body (4), a steam transition chamber (34) arranged outside the feed end of the heating tube assembly (6), and a plurality of first connecting pipes (25) uniformly arranged in a ring between the steam feed chamber (28) and the steam transition chamber (34). A rotary joint is connected to the air inlet on one side of the steam feed chamber (28). After the high-pressure steam enters the steam feed chamber (28), it enters the steam transition chamber (34) uniformly through the first connecting pipes (25) and is diverted to the heating tube assembly (6) for heating.

5. A melamine drying drum according to claim 4, characterized in that: The heating tube assembly (6) includes several steam tubes (31) arranged in a ring within the drum body (4). Each steam tube (31) includes a steam inlet pipe (33) connected at one end to the steam transition chamber (34) and a condensation return pipe (32) sleeved on the outside of the steam tube (31). The steam inlet pipe (33) and the condensation return pipe (32) are connected by a bracket. The end of the condensation return pipe (32) is a sealed structure. High-temperature steam flows into each steam inlet pipe (33) through the steam transition chamber (34) and then into the condensation return pipe (32) through the steam inlet pipe (33) to heat and dry the wet melamine.

6. A melamine drying drum according to claim 5, characterized in that: Both the steam feed chamber (28) and the steam transition chamber (34) are provided with a partition plate (29). The steam transition chamber (34) forms a first concentrate collection chamber (30) with the side wall of the drum body (4) through the partition plate (29). The steam feed chamber (28) forms a second concentrate collection chamber (26) with the side wall of the drum body (4) through the partition plate (29). Several second connecting pipes (2) are provided between the first concentrate collection chamber (30) and the second concentrate collection chamber (26). 4) A water outlet pipe (27) extending outward is provided in the middle of the second connecting pipe (24). One end of the condensate return pipe (32) is connected to the first concentrate collection chamber (30). The liquid condensed after high-pressure steam cooling flows back to the first concentrate collection chamber (30) through the condensate return pipe (32) and flows into the second concentrate collection chamber (26) through the second connecting pipe (24). The liquid in the second concentrate collection chamber (26) is discharged through the water outlet pipe (27).

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