A drying equipment for paraformaldehyde production

Abstract

The present application relates to a kind of dryers for paraformaldehyde production, including the drying cylinder fixed on base frame;Drying cylinder bottom is integrally formed with the material collecting part of opening towards the axis of drying cylinder, the bottom of material collecting part is equipped with the downward discharge port in middle part;Material collecting part is provided with discharge mechanism, for the material falling into material collecting part is sent to discharge port;Drying cylinder is equipped with arc plate, arc plate and the closely sliding fit of drying cylinder inner wall;Base frame is located on one side of drying cylinder and is equipped with drive unit;Wherein, drive unit is configured as: in the first working mode, drive arc plate to material collecting part as the symmetry center, reciprocating motion around the axis of drying cylinder, and always block material collecting part;In the second working mode, it can drive arc plate to make continuous circumferential motion around the axis of drying cylinder.The equipment solves the problem that material is not discharged completely, low efficiency and material adhered to cylinder wall is difficult to clean.

Description

Technical Field

[0001] This invention relates to the field of paraformaldehyde production technology, specifically to a drying device for paraformaldehyde production. Background Technology

[0002] In the production process of paraformaldehyde, a rake dryer is usually used for the drying process. The traditional rake dryer is mainly composed of a jacketed cylinder and a stirring shaft with rake teeth. The inner wall is heated by a heat medium introduced through the jacket of the cylinder, while the stirring shaft drives the rake teeth to rotate continuously and turn the wet material in the cylinder, so that the material can fully contact the heated wall and constantly renew the surface, thereby accelerating the evaporation of moisture and finally achieving the drying of paraformaldehyde.

[0003] Since the discharge port of most traditional rake dryers is located at the bottom center of the cylinder, relying solely on the gravity of the inclined cylinder to fall naturally and the limited radial pushing force of the rake teeth, it is difficult to effectively transport the material from the dead corners such as the two ends of the cylinder, the cylinder wall and the gaps between the rake teeth to the central discharge port, resulting in incomplete discharge and low discharge efficiency.

[0004] During the drying process, some material will adhere to the inner wall of the cylinder. Traditional rake dryers rely solely on the disturbance created by the rotation of the rake teeth, which cannot completely scrape off the material adhering to the cylinder wall, resulting in a large amount of residual material on the cylinder wall and making cleaning and maintenance difficult. Summary of the Invention

[0005] Based on this, the present invention provides a drying device for the production of paraformaldehyde to solve the technical problems of incomplete material discharge, low efficiency and difficulty in cleaning material adhering to the cylinder wall in the prior art rake dryer.

[0006] This application provides a drying device for the production of paraformaldehyde, including a drying cylinder fixed on a base frame; The bottom of the drying cylinder is integrally formed with a material collection part that opens towards the axis of the drying cylinder, and a downward discharge port is provided at the middle of the bottom of the material collection part; The material collection section is equipped with a discharge mechanism to guide the material falling into the material collection section to the discharge port; An arc-shaped plate is installed inside the drying cylinder, and the arc-shaped plate slides tightly against the inner wall of the drying cylinder; A drive unit is installed on one side of the drying cylinder on the base frame; The drive unit is configured as follows: In the first working mode, the drive arc plate reciprocates around the axis of the drying cylinder with the collection section as the center of symmetry, and always blocks the collection section; In the second working mode, the arc-shaped plate can be driven to make continuous circular motion around the axis of the drying cylinder.

[0007] In one implementation, the top of the drying cylinder is provided with a feeding port for feeding materials into the drying cylinder and a water vapor outlet for discharging the dried evaporating gas; The drying cylinder is equipped with a stirring mechanism; The outer wall of the drying cylinder is fitted with jacket layers at intervals along its length, and adjacent jacket layers are arranged independently.

[0008] In one implementation, the drive unit includes a shaft, a worm gear, a worm, a driven bevel gear, a pair of driving bevel gears, a first drive motor, and a translation mechanism; The shaft is coaxially and rotatably mounted through one end of the drying cylinder, and the worm gear is fixed to the end of the shaft located outside the drying cylinder; A connecting frame is fixed on the outer wall of the drying cylinder, and the connecting frame is fixedly connected to the arc-shaped plate. The worm is rotatably mounted on the outer side wall of the drying cylinder via a bracket and meshes with the worm wheel accordingly. A U-shaped seat is provided on the base frame via a translation mechanism, and a shaft is rotatably mounted on the U-shaped seat; The driven bevel gear is fixed to one end of the worm, and the two driving bevel gears are symmetrically fixed and mounted on the shaft, with the two driving bevel gears distributed on both sides of the driven bevel gear; The first drive motor is fixed to one side of the U-shaped base, and the output shaft is fixedly connected to one end of the shaft body; The translation mechanism is used to drive the U-shaped seat to translate and adjust along the axial direction of the drying cylinder, so as to realize the first working mode in which the two driving bevel gears alternately mesh with the driven bevel gear and the second working mode in which either driving bevel gear meshes with the driven bevel gear alone.

[0009] In one implementation, the translation mechanism includes a translation pusher cylinder; A slide rail extending axially along the drying cylinder is fixed on the base frame. A saddle is slidably mounted on the upper limit of the slide rail, and a U-shaped seat is fixed on the top of the saddle. The translational push cylinder is fixed on the base frame, and the telescopic end is fixedly connected to the side of the saddle.

[0010] In one implementation, the stirring mechanism includes a stirring shaft and several rake teeth; The stirring shaft is rotatably mounted through the drying cylinder on the side away from the shaft rod. The part of the stirring shaft located inside the drying cylinder is evenly distributed with several rake teeth extending radially along the drying cylinder. The end of the stirring shaft located inside the drying cylinder is rotatably connected to the shaft rod on the same axis. A third drive motor is fixed on the base frame, and the output shaft of the third drive motor is connected to the stirring shaft via a belt assembly.

[0011] In one implementation, the surface of the arc-shaped plate facing away from the inner wall of the drying cylinder is evenly distributed with several interfering piles. The disturbance piles and rake teeth are misaligned.

[0012] In one implementation, two movable slots are symmetrically formed on the shaft, and mounting holes are formed on the inner walls of both sides of the movable slots. The two driving bevel gears are rotatably mounted on the shaft through their central holes; Key blocks extending radially along the two driving bevel gears are fixed on the inner walls of the central holes of both driving bevel gears. The two key blocks are movably embedded in the movable slot in a one-to-one correspondence, and the key blocks are in blocking transmission cooperation with the inner side wall of the movable slot; Springs are fixed on both sides of the key block, and the other end of the springs extends into the mounting hole and is fixedly connected to the end wall of the mounting hole.

[0013] In one implementation, the material discharge mechanism includes a conveyor shaft and a second drive motor; The conveyor shaft is rotatably installed inside the collection section, with one end extending through to the outside of the collection section; The second drive motor is fixed on the base frame, and its output shaft is fixedly connected to the outer end of the conveying shaft; A pair of spiral conveyor blades are provided on the conveyor shaft; Two spiral conveyor blades are symmetrically distributed around the discharge port, and are used to convey materials to the discharge port.

[0014] In one implementation, the cross-section of the jacket layer is a discontinuous circle with a notch; The gap in the jacket layer is sealed and connected to both sides of the aggregate section.

[0015] In one implementation, the jacket layer is connected to a secondary inlet pipe on the side near the collection section, and to a secondary return pipe on the other side near the collection section. The secondary inlet pipe is connected to the main inlet pipe, and the secondary return pipe is connected to the main return pipe. The main inlet pipe is connected to the outlet of the external heat medium heating equipment, and the main return pipe is connected to the return port of the external heat medium heating equipment.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The dual-mode motion of the arc-shaped plate enables the switching between blocking during the drying stage and opening during the discharge stage, replacing the independently set discharge valve in traditional drying equipment. The rake teeth are responsible for the radial stirring of the main body of the material, and the arc-shaped plate covers the blind spots at the bottom of the drying cylinder that traditional stirring cannot reach, forming a synergistic stirring effect and reducing the stirring dead corners. At the same time, the reciprocating tossing of the arc-shaped plate and the impact disturbance of the disturbance piles combine to break through the limitation of traditional rake stirring that only relies on shear force to disperse materials. It can efficiently break up the sticky agglomerates of paraformaldehyde and significantly improve the uniformity of material heating and drying rate.

[0017] During mode switching, the first drive motor does not need to be stopped and restarted. It can switch between reciprocating oscillation and continuous circular motion simply by switching the meshing state of the active bevel gear and the driven bevel gear through the translation mechanism. This avoids the inrush current and mechanical fatigue loss caused by frequent motor start-stop, reduces equipment operating energy consumption, and significantly extends the service life of the drive motor and transmission gears.

[0018] The continuous circular motion of the arc plate can scrape the entire inner wall of the drying cylinder without dead angles, thoroughly removing the paraformaldehyde material adhering to the cylinder wall and preventing the material from deteriorating due to long-term heat exposure, which would affect product quality. At the same time, the mechanical disturbance of the arc plate when passing through the opening of the collecting section can actively break up material bridging. Combined with the forced conveying of the material by the spiral conveyor blades, this solves the problems of excessive material residue and difficult cleaning and maintenance in traditional equipment. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 Another perspective view of the structure shown; Figure 3 This is a schematic diagram of a partial internal structure of the drying cylinder in this invention; Figure 4 This is a schematic diagram of the cross-sectional structure of the drying cylinder in this invention; Figure 5 This is a schematic diagram of the driving unit structure in this invention; Figure 6 This is a schematic diagram showing the distribution of the two active bevel gear structures in this invention; Figure 7 This is a schematic diagram of the assembly structure of the active bevel gear and shaft in this invention; Figure 8 This is a partial structural diagram of the bottom of the drying cylinder in this invention; Figure 9 This is a schematic diagram showing the structural distribution of the jacket layer and the material collection section in this invention; Figure 10 This is a schematic diagram of the curved plate swinging to its limit in the first working mode. Figure 11 This is a schematic diagram of the arc-shaped plate swinging to cancel the blockage of the aggregate section in the second working mode.

[0020] In the diagram: 1. Base frame; 2. Drying cylinder; 21. Collection section; 22. Feed inlet; 23. Discharge outlet; 24. Water vapor outlet; 3. Jacket layer; 31. Notch; 32. Secondary inlet pipe; 33. Main inlet pipe; 34. Secondary return pipe; 35. Main return pipe; 4. Arc-shaped plate; 41. Disturbance pile; 5. Shaft; 501. Connecting frame; 51. Worm gear; 52. Worm; 53. Driven bevel gear; 54. U-shaped 55. Base; 551. Shaft; 552. Movable groove; 553. Mounting hole; 554. Spring; 555. Drive bevel gear; 561. Center hole; 562. Key block; 57. First drive motor; 58. Slide rail; 581. Saddle; 59. Translation push cylinder; 6. Conveying shaft; 61. Spiral conveying blade; 62. Second drive motor; 7. Stirring shaft; 71. Rake teeth; 8. Third drive motor; 81. Belt assembly. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments.

[0022] Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without inventive effort should fall within the scope of protection of this application.

[0023] In the description of this application, the term "axial" generally refers to the direction parallel to the central axis of the drying cylinder 2, "radial" refers to the direction perpendicular to the axis, and "circumferential" refers to the annular direction around the axis.

[0024] "Blocking" refers to the arc-shaped plate 4 covering the opening connecting the material collection section 21 and the inner cavity of the drying cylinder 2, preventing the material from falling through the opening.

[0025] Please see Figures 1 to 10 This application provides a drying device for the production of paraformaldehyde. The drying device includes a drying cylinder 2 fixed on a base frame 1. The bottom of the drying cylinder 2 is integrally formed with a material collection part 21 with an opening facing the axis of the drying cylinder 2. The cross-section of the material collection part 21 is U-shaped.

[0026] The bottom of the collecting section 21 is provided with a downward discharge port 23 in the middle. The collecting section 21 is provided with a discharge mechanism to guide the material falling into the collecting section 21 to the discharge port 23, so as to ensure that the material falling into the collecting section 21 can be reliably discharged from the discharge port 23. The drying cylinder 2 is provided with an arc plate 4, which is tightly slidably attached to the inner wall of the drying cylinder 2.

[0027] A drive unit is provided on one side of the drying cylinder 2 on the base frame 1. The drive unit is configured to: in the first working mode, drive the arc plate 4 to reciprocate around the axis of the drying cylinder 2 with the material collection part 21 as the center of symmetry, and always block the material collection part 21; in the second working mode, drive the arc plate 4 to make continuous circular motion around the axis of the drying cylinder 2.

[0028] According to the present invention, by setting a drive unit that can switch between two working modes, the conversion of different motion forms of the arc plate 4 is realized.

[0029] Among them, the arc length of the arc plate 4 along the circumference of the drying cylinder 2 is greater than the maximum chord length of the opening of the material collection section 21.

[0030] In the first working mode, the reciprocating oscillation of the arc plate 4 and the continuous sealing of the collection section 21 ensure that the material is confined within the main body of the drying cylinder 2 for thorough drying. In the second working mode, the continuous circular motion of the arc plate 4 periodically opens the collection section 21, allowing the material to be discharged, while its movement effectively cleans the material adhering to the cylinder wall.

[0031] In some alternative embodiments, the arc plate 4 is made of a heat-conducting metal plate (such as stainless steel plate or carbon steel plate), and the heat from the inner wall of the drying cylinder 2 can be transferred to the arc plate 4, thereby facilitating auxiliary heating and drying of the material in contact with it.

[0032] In practical applications, the overall working process of this drying equipment is as follows: Wet material is added into the drying cylinder 2 through the feeding port 22. At this time, the equipment is running in the first working mode. The arc plate 4 swings back and forth to block the material collection section 21. The stirring mechanism runs at the same time to turn the material over. The heat medium is introduced into the jacket layer 3 to heat the wall of the drying cylinder 2. The material is dried in this state. Once drying is complete, the drive unit switches to the second working mode, and the arc plate 4 rotates into continuous circular motion. Under the action of gravity, the material periodically falls into the collection section 21 and is discharged from the discharge port 23 by the discharge mechanism, completing the entire drying and discharge cycle.

[0033] In some embodiments, such as Figure 1 , Figure 2 and Figure 3 As shown, the top of the drying cylinder 2 is provided with a feeding port 22 and a water vapor outlet 24. The feeding port 22 is used to feed materials into the drying cylinder 2, and the water vapor outlet 24 is used to discharge the moisture evaporated during drying.

[0034] The drying cylinder 2 is equipped with a stirring mechanism for turning and dispersing materials during the drying process. The outer wall of the drying cylinder 2 is fitted with jacket layers 3 at intervals along its length for introducing heat medium to heat the wall of the drying cylinder 2. Adjacent jacket layers 3 are arranged independently, so that the heat medium can circulate independently in each jacket layer 3, improving the flexibility and uniformity of heat utilization.

[0035] The following is an exemplary description of the driving unit mentioned above, such as... Figure 5 and Figure 6 As shown, the drive unit includes a shaft 5, a worm gear 51, a worm 52, a driven bevel gear 53, a pair of driving bevel gears 56, a first drive motor 57, and a translation mechanism.

[0036] The shaft 5 is coaxially and rotatably mounted through one end of the drying cylinder 2. The worm gear 51 is fixed to the end of the shaft 5 located outside the drying cylinder 2. A connecting frame 501 is fixed on the outer wall of the shaft 5 inside the drying cylinder 2. The connecting frame 501 is fixedly connected to the arc plate 4. The worm 52 is rotatably mounted on the outer wall of the side end of the drying cylinder 2 through the bracket and meshes with the worm gear 51.

[0037] A U-shaped seat 54 is provided on the base frame 1 via a translation mechanism. A shaft 55 is rotatably mounted on the U-shaped seat 54. A driven bevel gear 53 is fixed to one end of a worm gear 52. Two driving bevel gears 56 are symmetrically fixed and fitted onto the shaft 55, and the two driving bevel gears 56 are distributed on both sides of the driven bevel gear 53.

[0038] The first drive motor 57 is fixed to one side of the U-shaped seat 54, and its output shaft is fixedly connected to one end of the shaft body 55. The translation mechanism is used to drive the U-shaped seat 54 to translate and adjust along the axial direction of the drying cylinder 2, so as to realize the first working mode in which the two active bevel gears 56 alternately mesh with the driven bevel gear 53 and the second working mode in which any one of the active bevel gears 56 meshes with the driven bevel gear 53 alone.

[0039] During operation, the first drive motor 57 operates continuously. By adjusting the positions of the two active bevel gears 56, different operating modes can be achieved, thereby avoiding frequent shutdowns and restarts of the first drive motor 57.

[0040] Its working principle is as follows: the first drive motor 57 continuously drives the shaft 55 and the two active bevel gears 56 to rotate. When the translation mechanism drives the U-shaped seat 54 to move, so that one of the active bevel gears 56 meshes with the driven bevel gear 53, the power is transmitted to the shaft 5 through the worm 52 and the worm wheel 51.

[0041] The worm gear 51 and worm 52 mechanism has a self-locking characteristic. When the shaft 5 is subjected to resistance from the arc plate 4 and the material, it can prevent it from driving the worm 52 in the opposite direction, thereby locking the movement of the arc plate 4 in a predetermined reciprocating or continuous rotation mode.

[0042] By shifting the U-shaped seat 54 to switch the driving bevel gear 56 that meshes with the driven bevel gear 53, the rotation direction or motion mode of the shaft 5 can be changed.

[0043] In one embodiment, such as Figure 5 As shown, the translation mechanism includes a translation push cylinder 59, a slide rail 58 extending axially along the drying cylinder 2 is fixed on the base frame 1, a saddle 581 is slidably mounted on the upper limit of the slide rail 58, and a U-shaped seat 54 is fixed on the top of the saddle 581; the translation push cylinder 59 is fixed on the base frame 1, and its telescopic end is fixedly connected to the side of the saddle 581.

[0044] As a specific implementation method, the translational push cylinder 59 can be an electric push rod, a pneumatic cylinder or a hydraulic cylinder. By extending and retracting the translational push cylinder 59, the saddle 581 and the U-shaped seat 54 can be precisely controlled to slide along the slide rail 58, thereby realizing the reliable switching of the meshing state of the two active bevel gears 56 and the driven bevel gear 53.

[0045] In a further embodiment, such as Figure 3 and Figure 4 As shown, the stirring mechanism includes a stirring shaft 7 and several rake teeth 71. The stirring shaft 7 is rotatably mounted through the drying cylinder 2 on the side away from the shaft 5. Several rake teeth 71 extending radially along the drying cylinder 2 are evenly distributed on the part of the stirring shaft 7 located inside the drying cylinder 2.

[0046] The stirring shaft 7 is located inside the drying cylinder 2, and its end is coaxially rotatably connected to the shaft 5 via bearings, allowing the two to rotate independently.

[0047] like Figure 1 As shown, a third drive motor 8 is fixed on the base frame 1. The output shaft of the third drive motor 8 is connected to the stirring shaft 7 via a belt assembly 81. The belt assembly 81 includes two pulleys that are respectively fixedly mounted on the stirring shaft 7 and the output shaft of the third drive motor 8, and a transmission belt mounted on the two pulleys.

[0048] The third drive motor 8 operates, and its output shaft, driven by the belt assembly 81, drives the stirring shaft 7 and the rake teeth 71 to rotate inside the drying cylinder 2, stirring the material and ensuring that the material is heated evenly.

[0049] Preferably, such as Figure 4 As shown, a number of disturbance piles 41 are evenly distributed on the surface of the arc plate 4 away from the inner wall of the drying cylinder 2. The disturbance piles 41 are used to impact, disperse and disturb the material. These disturbance piles 41 and the rake teeth 71 in the mixing mechanism are staggered to prevent interference between the two during the movement.

[0050] As a specific implementation method, the disturbance piles 41 can be conical or cylindrical and evenly distributed on the material-facing surface of the arc plate 4.

[0051] In some embodiments, the connection method between the drive bevel gear 56 and the shaft 55 has been optimized, such as... Figure 6 and Figure 7 As shown, two movable slots 551 are symmetrically opened on the shaft 55. Mounting holes 552 are opened on the inner walls of both sides of the movable slots 551. Two active bevel gears 56 are respectively rotatably mounted on the shaft 55 through the center holes 561 on them.

[0052] Among them, key blocks 562 extending radially along the active bevel gear 56 are fixed on the inner wall of the center hole 561 of the two active bevel gears 56. The two key blocks 562 are movably embedded in the movable groove 551 in a one-to-one correspondence, and the key blocks 562 and the inner side wall of the movable groove 551 are in a blocking transmission cooperation.

[0053] Springs 553 are fixed on both sides of the key block 562. The other end of the springs 553 extends into the mounting holes 552 and is fixedly connected to the inner end wall of the mounting holes 552.

[0054] Furthermore, in conjunction with the above structure, when the U-shaped seat 54 is axially adjusted along the drying cylinder 2 to switch the meshing state of the driving bevel gear 56 and the driven bevel gear 53, the above mechanism forms an elastic floating buffer structure.

[0055] If the teeth of the driving bevel gear 56 and the tooth grooves of the driven bevel gear 53 are not fully aligned, at the moment of meshing, the key block 562 can compress the spring 553 on one side in the movable groove 551 to generate a small circumferential buffer displacement, allowing the driving bevel gear 56 to adaptively adjust the angle, thereby ensuring smooth meshing and avoiding tooth collision or interference. At the same time, the spring 553 can absorb the meshing impact and play a role in protecting the teeth.

[0056] When the key block 562 contacts and blocks the inner wall of the movable groove 551, the shaft 55 can smoothly drive the drive bevel gear 56 to rotate through the key block 562; In addition, the spring 553 on this side is compressed and completely housed in the mounting hole 552 on the same side. On the one hand, this avoids the spring 553 from blocking or interfering with the contact between the key block 562 and the inner wall of the movable groove 551. On the other hand, it can protect the spring 553 and prevent it from bending and deforming excessively.

[0057] After the driving bevel gear 56 separates from the driven bevel gear 53, the elastic restoring force of the spring 553 can drive the driving bevel gear 56 to rotate and reset, so that the key block 562 returns to the centered state in the movable groove 551, so that the driving bevel gear 56 can mesh smoothly with the driven bevel gear 53 next time.

[0058] In one embodiment, such as Figure 2 and Figure 4As shown, the material discharge mechanism includes a conveyor shaft 6 and a second drive motor 62.

[0059] The conveying shaft 6 is rotatably installed inside the collecting part 21, and one end extends through to the outside of the collecting part 21. The second drive motor 62 is fixed on the base frame 1, and its output shaft is fixedly connected to the outer end of the conveying shaft 6. The conveying shaft 6 is provided with a pair of spiral conveying blades 61, and the two spiral conveying blades 61 are symmetrically distributed with the discharge port 23 as the center.

[0060] The second drive motor 62 drives the conveyor shaft 6 to rotate, and the conveyor shaft 6 drives the two spiral conveyor blades 61 to rotate in the same direction in the collection section 21. Thus, the two symmetrically distributed spiral conveyor blades 61 can convey and collect the material falling into the collection section 21 from both sides to the discharge port 23 in the middle and discharge it.

[0061] In a further embodiment, such as Figure 9 As shown, the cross-section of the jacket layer 3 is a discontinuous circle with a notch 31. The notch 31 of the jacket layer 3 is sealed to both sides of the material collection part 21, thereby avoiding leakage of the heat medium and facilitating structural arrangement.

[0062] Specifically, in combination Figure 8 On the jacket layer 3, there are auxiliary inlet pipes 32 connected to each other on the side near the collection section 21, and auxiliary return pipes 34 connected to each other on the other side near the collection section 21. All auxiliary inlet pipes 32 are connected to a main inlet pipe 33, and all auxiliary return pipes 34 are connected to a main return pipe 35.

[0063] The main inlet pipe 33 is connected to the outlet of the external heat medium heating equipment, and the main return pipe 35 is connected to the return port of the external heat medium heating equipment.

[0064] Multiple jacket layers 3 are arranged independently to ensure high heat utilization rate of the heat medium in each jacket layer 3. Each jacket layer 3 is connected by separate secondary inlet pipes 32 and secondary return pipes 34, as well as shared main inlet pipes 33 and main return pipes 35, which ensures that an independent and parallel heat medium flow loop can be formed in each jacket layer 3, which is conducive to precise control of heat distribution.

[0065] In addition, it should be noted that in the first working mode, such as Figure 10 As shown, the arc plate 4 reciprocates against the inner wall of the drying cylinder 2 at the bottom. No matter which side it moves to the limit position, the arc plate 4 can block the opening connecting the collection part 21 and the drying cylinder 2, thereby effectively preventing the material from falling directly into the collection part 21 during the drying process.

[0066] Meanwhile, the reciprocating oscillating arc plate 4, under the action of inertia, can throw and bounce the material on it, achieving the effect of throwing the material, accelerating the dispersion of lumpy material, ensuring that the material is further heated evenly, and improving the drying effect.

[0067] Furthermore, during the process of the arc plate 4 reciprocating and throwing the material, the disturbance piles 41 on its surface have an impact and disturbance effect on the material, which can further disperse the material that has clumped together.

[0068] During the drying process, traditional rake dryers have gaps between the rake blades and the inner wall of the drum, creating dead zones for mixing. Furthermore, the rake blades are arranged at intervals, resulting in limited mixing coverage. Consequently, some materials are deposited at the bottom of the drying drum due to gravity and cannot be effectively mixed.

[0069] In this application, the arc plate 4 is mainly located at the bottom of the drying cylinder 2, which completely makes up for the lack of stirring by the rake teeth 71. The two work together to further improve the drying effect.

[0070] In the second working mode, such as Figure 11 As shown, the arc plate 4 fits against the inner wall of the drying cylinder 2 and rotates continuously around the axis of the drying cylinder 2, which can periodically remove the blockage of the opening of the collection section 21. The dried material in the drying cylinder 2 can fall into the collection section 21 at the bottom under the action of gravity.

[0071] The continuously rotating arc plate 4 can scrape off the material adhering to the inner wall of the drying cylinder 2 and cover the entire circumference of the inner wall of the drying cylinder 2, cleaning without dead corners. On the other hand, when the arc plate 4 moves to the bottom of the drying cylinder 2, it can generate a disturbance effect, which can break the bridging of the material at the opening connecting the collection part 21 and the drying cylinder 2, ensuring the smooth flow of the material.

[0072] In particular, since the material discharge can be prevented by blocking the opening of the collecting section 21 with the arc plate 4 in the first working mode, there is no need to set a separate discharge valve at the discharge port 23, which simplifies the structure.

[0073] Based on the above structure, the working principle of this drying equipment for paraformaldehyde production is as follows: Wet material is fed into the inner cavity of the drying cylinder 2 through the feeding port 22. Multiple independently arranged jacket layers 3 are circulated with heat medium to uniformly heat the wall of the drying cylinder 2. The heat is simultaneously transferred to the arc plate 4 of the heat-conducting material. The third drive motor 8 drives the stirring shaft 7 through the belt group 81 to drive the rake teeth 71 to rotate continuously, completing the mixing of the main body of the material.

[0074] The first drive motor 57 in the drive unit runs continuously throughout the entire process, and the drive shaft 55 and the two active bevel gears 56 rotate synchronously. The translation mechanism drives the U-shaped seat 54 to translate along the axis of the drying cylinder 2, so that the two active bevel gears 56 alternately mesh with the driven bevel gear 53. The power is transmitted to the shaft 5 through the worm 52 and worm wheel 51 and drives the arc plate 4 to reciprocate. The shaft 5 drives the arc plate 4 to swing back and forth around the axis of the drying cylinder 2 with the collection part 21 as the center of symmetry through the connecting frame 501. No matter which extreme position it swings to, the arc plate 4 completely blocks the communication opening between the collection part 21 and the inner cavity of the drying cylinder 2, preventing the material from entering the collection part 21 in advance.

[0075] The reciprocating arc plate 4 uses inertia to toss and throw the material, and the disturbance piles 41 on its surface simultaneously impact and disturb the material, accelerating the dispersion of lumpy material; at the same time, the movement range of the arc plate 4 covers the bottom stirring dead corner inside the drying cylinder 2, forming a stirring complement with the rake teeth 71, so that the material is heated evenly; the water vapor evaporated during the drying process is discharged from the equipment through the water vapor outlet 24.

[0076] After the material is dried, the translation mechanism drives the U-shaped seat 54 to translate axially, so that the single driving bevel gear 56 and the driven bevel gear 53 are continuously meshed. The shaft 5 drives the arc plate 4 to make continuous circular motion around the axis of the drying cylinder 2, periodically removing the blockage of the opening of the collection section 21. The dried material falls into the inner cavity of the collection section 21 under the action of gravity. The second drive motor 62 drives the conveying shaft 6 to rotate, and the two spiral conveying blades 61 arranged symmetrically convey the material on both sides of the collection section 21 to the discharge port 23 in the middle and discharge it. During the circular motion of the arc plate 4, it fits tightly against the inner wall of the drying cylinder 2, which can scrape off the material adhering to the entire inner wall of the drying cylinder 2. At the same time, the disturbance generated when the arc plate 4 passes through the opening of the collecting part 21 can destroy the bridging structure formed by the material at the opening, ensuring smooth material discharge.

[0077] The control method of the present invention is automatic control through a controller. The control program of the controller can be easily implemented by those skilled in the art through simple programming. The power supply and circuit connection are common knowledge in the art, so the present invention will not explain the control method and circuit connection in detail.

[0078] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A drying device for paraformaldehyde production, comprising a drying cylinder (2) fixed on a base frame (1), characterized in that: The bottom of the drying cylinder (2) is integrally formed with a material collection part (21) with an opening facing the axis of the drying cylinder (2), and a downward discharge port (23) is provided at the middle of the bottom of the material collection part (21). The material collection section (21) is equipped with a discharge mechanism for guiding the material falling into the material collection section (21) to the discharge port (23); The drying cylinder (2) is provided with an arc-shaped plate (4), which is in close sliding contact with the inner wall of the drying cylinder (2); A drive unit is provided on one side of the drying cylinder (2) on the base frame (1); The drive unit is configured as follows: In the first working mode, the drive arc plate (4) reciprocates around the axis of the drying cylinder (2) with the collection part (21) as the center of symmetry, and always blocks the collection part (21); In the second working mode, the arc plate (4) can be driven to make continuous circular motion around the axis of the drying cylinder (2).

2. The drying equipment for paraformaldehyde production according to claim 1, characterized in that: The top of the drying cylinder (2) is provided with a feeding port (22) for feeding materials into the drying cylinder (2) and a water vapor outlet (24) for discharging the drying evaporation gas. The drying cylinder (2) is equipped with a stirring mechanism; The drying cylinder (2) has jacket layers (3) spaced along its length on its outer wall, and adjacent jacket layers (3) are arranged independently.

3. The drying equipment for paraformaldehyde production according to claim 2, characterized in that: The drive unit includes a shaft (5), a worm gear (51), a worm (52), a driven bevel gear (53), a pair of driving bevel gears (56), a first drive motor (57), and a translation mechanism; The shaft (5) is coaxially and rotatably mounted on one end of the drying cylinder (2), and the worm gear (51) is fixed on the end of the shaft (5) located outside the drying cylinder (2); The shaft (5) is fixed to the outer wall of the drying cylinder (2) with a connecting frame (501), and the connecting frame (501) is fixedly connected to the arc plate (4); The worm (52) is rotatably mounted on the outer side wall of the drying cylinder (2) via a bracket and meshes with the worm wheel (51); A U-shaped seat (54) is provided on the base frame (1) via a translation mechanism, and a shaft (55) is rotatably mounted on the U-shaped seat (54). The driven bevel gear (53) is fixed to one end of the worm (52), and the two driving bevel gears (56) are symmetrically fixed and fitted on the shaft (55), with the two driving bevel gears (56) distributed on both sides of the driven bevel gear (53). The first drive motor (57) is fixed to one side of the U-shaped seat (54), and the output shaft is fixedly connected to one end of the shaft body (55); The translation mechanism is used to drive the U-shaped seat (54) to translate and adjust along the axial direction of the drying cylinder (2) to achieve the first working mode in which the two active bevel gears (56) alternately mesh with the driven bevel gear (53) and the second working mode in which either active bevel gear (56) meshes with the driven bevel gear (53) alone.

4. The drying equipment for paraformaldehyde production according to claim 3, characterized in that: The translation mechanism includes a translation pusher cylinder (59); A slide rail (58) extending axially along the drying cylinder (2) is fixed on the base frame (1). A saddle (581) is slidably mounted on the upper limit of the slide rail (58). The U-shaped seat (54) is fixed on the top of the saddle (581). The translational push cylinder (59) is fixed on the base frame (1), and the telescopic end is fixedly connected to the side of the saddle (581).

5. A drying device for paraformaldehyde production according to claim 3, characterized in that: The stirring mechanism includes a stirring shaft (7) and several rake teeth (71); The stirring shaft (7) is rotatably mounted on the side of the drying cylinder (2) away from the shaft (5). The portion of the stirring shaft (7) located inside the drying cylinder (2) is evenly distributed with several rake teeth (71) extending radially along the drying cylinder (2). The end of the stirring shaft (7) located inside the drying cylinder (2) is rotatably connected to the shaft (5) on the same axis; A third drive motor (8) is fixed on the base frame (1), and the output shaft of the third drive motor (8) is connected to the stirring shaft (7) via a belt group (81).

6. The drying equipment for paraformaldehyde production according to claim 5, characterized in that: The surface of the arc-shaped plate (4) facing away from the inner wall of the drying cylinder (2) is evenly distributed with several interfering piles (41). The disturbance piles (41) and the rake teeth (71) are misaligned.

7. A drying device for paraformaldehyde production according to claim 3, characterized in that: Two movable grooves (551) are symmetrically provided on the shaft (55), and mounting holes (552) are provided on the inner walls of both sides of the movable grooves (551). The two drive bevel gears (56) are respectively rotatably mounted on the shaft (55) through their center holes (561); Both of the driving bevel gears (56) have a key block (562) that extends radially along the driving bevel gear (56) fixed on the inner wall of the center hole (561). The two key blocks (562) are movably embedded in the movable groove (551) in a one-to-one correspondence, and the key blocks (562) and the inner sidewall of the movable groove (551) are in blocking transmission cooperation; Springs (553) are fixed on both sides of the key block (562). The other end of the spring (553) extends into the mounting hole (552) and is fixedly connected to the inner end wall of the mounting hole (552).

8. The drying equipment for paraformaldehyde production according to claim 1, characterized in that: The material discharge mechanism includes a conveyor shaft (6) and a second drive motor (62); The conveying shaft (6) is rotatably installed inside the collecting part (21), and one end extends through to the outside of the collecting part (21); The second drive motor (62) is fixed on the base frame (1), and its output shaft is fixedly connected to the outer end of the conveying shaft (6); The conveying shaft (6) is provided with a pair of spiral conveying blades (61); The two spiral conveyor blades (61) are symmetrically distributed around the discharge port (23) and are used to convey materials to the discharge port (23).

9. A drying device for paraformaldehyde production according to claim 2, characterized in that: The cross-section of the jacket layer (3) is a discontinuous circle with a notch (31); The notch (31) of the jacket layer (3) is sealed and connected to both sides of the material collection part (21).

10. A drying device for paraformaldehyde production according to claim 9, characterized in that: A secondary inlet pipe (32) is connected to the side of the jacket layer (3) near the collection part (21), and a secondary return pipe (34) is connected to the other side of the jacket layer (3) near the collection part (21). The secondary inlet pipe (32) is connected to the main inlet pipe (33), and the secondary return pipe (34) is connected to the main return pipe (35). The main inlet pipe (33) is connected to the outlet of the external heat medium heating device, and the main return pipe (35) is connected to the return port of the external heat medium heating device.

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