An oxidizer for producing formaldehyde

Abstract

The application provides an oxidizer for preparing formaldehyde and relates to the field of formaldehyde preparation. The oxidizer for preparing formaldehyde comprises an outer cylinder shell, a self-cleaning cooling device, a bottom water injection tank installed at the bottom of the outer cylinder shell, a bottom water injection pipeline for injecting cold water installed at the bottom of the bottom water injection tank and a top water discharge tank installed at the top of the outer cylinder shell. During the up-and-down movement of the sliding clamping block, the slope of the pushing surface also pushes the steam bubbles close to the surface of the cooling outer pipe to flow outward, thereby preventing the steam from flowing upward along the position close to the cooling outer pipe and affecting the cooling efficiency of the cooling outer pipe due to the close distance between the steam and the cooling outer pipe when the steam contacts the cold water, so that the cooling effect is improved, the surface of the cooling outer pipe and the outer heat dissipation plate are cleaned, the cooling efficiency is improved, and the uniformity of cooling is improved under the effect of the turbulence when the raw gas flows and cools.

Description

Technical Field

[0001] This invention relates to the field of formaldehyde preparation technology, specifically to an oxidizer for preparing formaldehyde. Background Technology

[0002] Formaldehyde has a wide range of applications in the petrochemical, pharmaceutical, textile, biochemical, energy, and transportation industries. It can be used as a disinfectant and preservative, and can also be used to prepare a variety of products such as phenolic resin, urea-formaldehyde resin, melamine resin, hexamethylenetetramine, and pentaerythritol.

[0003] The invention patent with application number CN201910666541.0 discloses a high-efficiency formaldehyde oxidizer. The oxidizer includes a first cylinder, a second cylinder, a third cylinder, and a fourth cylinder connected in sequence. The first cylinder is provided with a reaction gas inlet. The second cylinder includes a reaction chamber, a first cooling chamber, and a second cooling chamber. The oxidizer cools the gas simultaneously through a sleeve and a finned tube, which accelerates the gas cooling rate and increases the concentration of formaldehyde generated by the reaction.

[0004] During the cooling process, the horizontal placement of the cooling fins on the outer surface of the finned tube affects the flow efficiency and processing efficiency. Furthermore, during continuous operation, water in contact with the finned tube surface is easily heated and forms a layer of impurities on the finned tube surface, affecting the heat conduction effect. During the cooling process, bubbles generated on the surface of the finned tube float upwards along the surface and near the finned tube. These bubbles are composed of high-temperature steam, and their proximity to the finned tube also affects the cooling effect. In addition, when the raw material flows along the finned tube, the raw material near the finned tube cools down at a high rate, while the raw material far from the finned tube cools down at a slow rate, resulting in poor cooling uniformity. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides an oxidizer for the preparation of formaldehyde, which solves the problems of poor cooling uniformity, easy formation of dirt on the surface of finned tubes affecting cooling efficiency, and steam generated by finned tubes flowing along the finned tubes affecting the cooling efficiency of the finned tubes.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: an oxidizer for formaldehyde preparation, comprising an outer shell and a self-cleaning cooling device. A bottom water tank is installed at the bottom of the outer shell, and a bottom water pipe for injecting cold water is installed at the bottom of the bottom water tank. A top drain tank is installed at the top of the outer shell, and a top drain pipe for discharging hot water is installed at the top of the top drain tank. A bottom sealing inner tube support plate is installed on the inner wall of the outer shell near the bottom, and a top sealing inner tube support plate is installed on the inner wall of the outer shell near the top. A catalyst for catalytic reaction is installed on the inner wall of the outer shell below the top sealing inner tube support plate. A catalyst plate layer is installed on the inner wall of the outer shell, below the catalyst plate layer. A top-sealing outer tube support plate is installed between the top-sealing inner tube support plate and the top-sealing outer tube support plate to form an injection chamber for dispersing gaseous raw materials. A bottom-sealing outer tube support plate is installed on the inner wall of the outer shell, above the bottom-sealing inner tube support plate. A discharge chamber is formed between the bottom-sealing inner tube support plate and the bottom-sealing outer tube support plate for collecting and discharging cooled gas. A catalyst plate layer is installed on the inner wall of the outer shell, below the top-sealing inner tube support plate. A partition plate is installed on the inner wall of the outer shell, above the bottom-sealing outer tube support plate. A cold water injection chamber for diffusing injected cold water is formed between the sealing outer tube support plate and the partition plate. A cooling chamber for cooling is formed between the top sealing outer tube support plate and the partition plate. A cooling outer tube for heat dissipation is installed between the bottom sealing outer tube support plate and the top sealing outer tube support plate. A connecting pipe for introducing cold water from the cold water injection chamber into the cooling chamber is installed on the surface of the partition plate and outside the cooling outer tube. A self-cleaning cooling device with self-cleaning function is provided on the outside of the cooling outer tube to improve cooling efficiency. A cooling inner tube for auxiliary cooling from the inside of the cooling outer tube is installed between the bottom sealing inner tube support plate and the top sealing inner tube support plate. The discharge pipe is installed on the outer wall of the outer cylinder shell and communicates with the inside of the discharge chamber. The injection pipe is installed on the outer wall of the outer cylinder shell and communicates with the inside of the injection chamber. The side water injection pipe is installed on the outer wall of the outer cylinder shell and communicates with the inside of the cold water injection chamber. The side drainage pipe is installed on the outer wall of the outer cylinder shell and communicates with the inside of the cooling chamber. The partition ring is installed on the inner wall of the outer cylinder shell and above the side drainage pipe. The pressure relief and exhaust pipe is installed on the outer wall of the outer cylinder shell and above the partition ring. The pressure relief and exhaust pipe communicates with the inside of the cooling chamber. A sewage pipe is installed on the outer wall of the outer cylinder shell and close to the upper side of the partition plate. A valve for controlling the switch during cleaning is installed at the end of the sewage pipe.

[0009] Preferably, the self-cleaning cooling device includes an inner heat-conducting plate, a first turbulence-dissipating plate, a second turbulence-dissipating plate, an outer heat dissipating plate, a sliding block, a lower limit ring seat, a positioning support frame, an upper limit ring seat, a moving rail frame, and a power blade. The inner heat-conducting plate is installed on the inner wall of the inner cooling tube. The first turbulence-dissipating plate is installed on the outer wall of the inner cooling tube and located inside the outer cooling tube. The second turbulence-dissipating plate is installed on the outer wall of the inner cooling tube and located below the first turbulence-dissipating plate. The outer heat dissipating plate is installed on the outer wall of the outer cooling tube. The sliding block is movably engaged in the gap between adjacent outer heat dissipating plates. The lower limit ring seat, used to block and limit the downward movement range of the sliding block, is installed on the outer wall of the outer cooling tube and located at the bottom of the outer heat dissipating plate. The positioning support frame is installed on the outer surface of the sliding block. The upper limit ring seat is rotatably installed on the outer wall of the outer cooling tube and located above the outer heat dissipating plate via a bearing. The power blade is installed on the outer wall of the upper limit ring seat. The top end of the moving rail frame is connected to the upper limit ring seat.

[0010] Preferably, the actuating rail frame is spiral in shape, with the upper end of the actuating rail frame having a "C"-shaped bend, and the top of the actuating rail frame being installed on the outer wall of the upper limit ring seat.

[0011] Preferably, there are several external heat dissipation plates evenly arranged on the outer wall of the cooling outer pipe, and the outer side thickness of the external heat dissipation plate is greater than the inner side thickness.

[0012] Preferably, both the first and second turbulence heat dissipation plates are spiral-shaped, and the spiral directions of the first and second turbulence heat dissipation plates are opposite. A buffer space is provided between the bottom end of the first and second turbulence heat dissipation plates and the top end of the second turbulence heat dissipation plates are offset.

[0013] Preferably, the sliding block is adapted to the groove formed between the adjacent external heat dissipation plate, and the thickness of the sliding block on the side closer to the cooling outer tube is greater than the thickness on the side farther away from the cooling outer tube.

[0014] Preferably, the top of the partition plate has an upward conical protrusion, and the top of the connecting tube extends above the partition plate.

[0015] Preferably, the bottom of the top sealing outer tube frame plate has a downward conical protrusion.

[0016] Preferably, the top of the bottom water tank, the bottom of the top drainage tank, the surface of the bottom sealing inner tube frame plate, and the surface of the top sealing inner tube frame plate are all provided with through holes for the cooling inner tube to flow through.

[0017] Preferably, the horizontal interface shape of the inner heat-conducting plate is "*".

[0018] (III) Beneficial Effects

[0019] This invention provides an oxidizer for the preparation of formaldehyde. It has the following beneficial effects:

[0020] 1. This formaldehyde oxidizer uses upward-flowing water and upward-surging steam to contact the power blades, causing them to rotate. The power blades drive the upper limit ring seat to rotate, which in turn drives the actuating rail frame to rotate. As the actuating rail frame rotates, it pushes the sliding block to slide upward along the inner side of the outer heat dissipation plate via the positioning support frame. This upward sliding motion of the outer heat dissipation plate scrapes and cleans the surface of the cooling outer pipe and the outer heat dissipation plate, thus preventing dirt from forming on the surface of the cooling outer pipe and the outer heat dissipation plate, which would affect the heat conduction efficiency and thus the cooling efficiency.

[0021] 2. In this oxidizer for formaldehyde preparation, when the raw material flows between the inner and outer cooling pipes, the raw material is fully mixed and comes into contact with the inner and outer cooling pipes, as well as the first and second turbulence heat dissipation plates, under the turbulence effect of the first and second turbulence heat dissipation plates to achieve cooling, thereby improving the uniformity of cooling of the raw material.

[0022] 3. In this oxidizer for formaldehyde preparation, the first turbulence heat dissipation plate, the second turbulence heat dissipation plate, and the outer heat dissipation plate are all arranged longitudinally. This reduces the resistance encountered by the raw materials and coolant when they flow longitudinally, thereby increasing the flow rate of the coolant, improving the cooling effect, and also accelerating the flow rate of the raw materials, thus improving the efficiency of transmission and processing.

[0023] 4. In this oxidizer for formaldehyde preparation, the reaction gas raw material flows through the injection chamber, cooling chamber, cold water injection chamber and discharge chamber in one go, and after entering the interior, it comes into contact with the bottom sealed inner tube frame plate. The four-stage cooling method improves the cooling efficiency and cooling effect.

[0024] 5. In this oxidizer for formaldehyde preparation, as the sliding block moves up and down, the inclined surface of the pushing surface also pushes the steam bubbles near the surface of the cooling outer tube to flow outward. This prevents the steam from flowing upward along the position near the cooling outer tube and getting too close to the cooling outer tube, which would affect the contact between the cooling outer tube and the cold water and reduce the cooling efficiency of the cooling outer tube, thereby improving the cooling effect. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a schematic cross-sectional view of the present invention;

[0027] Figure 3 For the present invention Figure 2 Enlarged view of the structure at point A in the middle;

[0028] Figure 4 This is a schematic diagram of the self-cleaning cooling device of the present invention;

[0029] Figure 5 For the present invention Figure 4 Enlarged view of the structure at point B in the middle;

[0030] Figure 6 This is a schematic diagram of the installation structure of the internal heat-conducting plate, the first turbulence heat dissipation plate, and the second turbulence heat dissipation plate of the present invention.

[0031] The components include: 1. Outer shell; 11. Bottom sealing inner tube frame plate; 12. Top sealing inner tube frame plate; 13. Separator plate; 14. Top sealing outer tube frame plate; 15. Bottom sealing outer tube frame plate; 16. Catalyst plate layer; 17. Connecting pipe; 2. Bottom water injection tank; 21. Bottom water injection pipe; 3. Top drainage tank; 31. Top drainage pipe; 41. Discharge chamber; 42. Cold water injection chamber; 43. Cooling chamber; 44. Injection chamber; 51. Discharge pipe; 52. Injection pipe 53. Sewage pipe; 54. Side water injection pipe; 55. Side drainage pipe; 56. Pressure relief and exhaust pipe; 57. Separating ring; 6. Inner cooling pipe; 7. Outer cooling pipe; 8. Self-cleaning cooling device; 81. Inner heat conduction plate; 82. First turbulence heat dissipation plate; 83. Second turbulence heat dissipation plate; 84. Outer heat dissipation plate; 85. Sliding block; 86. Lower limit ring seat; 87. Positioning support rod frame; 88. Upper limit ring seat; 89. Actuating rail frame; 90. Power blade. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] Please see Figures 1-6This invention provides a technical solution: an oxidizer for formaldehyde preparation, comprising an outer shell 1 and a self-cleaning cooling device 8. A bottom water tank 2 is installed at the bottom of the outer shell 1, and a bottom water pipe 21 for injecting cold water is installed at the bottom of the bottom water tank 2. A top drain tank 3 is installed at the top of the outer shell 1, and a top drain pipe 31 for discharging hot water is installed at the top of the top drain tank 3. A bottom sealing inner tube support plate 11 is installed on the inner wall of the outer shell 1 near the bottom, and a top sealing inner tube support plate 12 is installed on the inner wall of the outer shell 1 near the top. A catalyst plate layer 16 for catalytic reaction is installed on the inner wall of the outer shell 1 below the top sealing inner tube support plate 12. A catalyst plate layer 16 for catalytic reaction is installed on the inner wall of the outer shell 1 below the catalyst plate layer 16. The outer shell 1 is equipped with a top-sealed outer tube support plate 14. A material injection chamber 44 for dispersing gaseous raw materials is formed between the top-sealed inner tube support plate 12 and the top-sealed outer tube support plate 14. A bottom-sealed outer tube support plate 15 is installed on the inner wall of the outer shell 1 above the bottom-sealed inner tube support plate 11. A discharge chamber 41 for collecting and discharging cooled gas is formed between the bottom-sealed inner tube support plate 11 and the bottom-sealed outer tube support plate 15. A catalyst plate layer 16 is installed on the inner wall of the outer shell 1 below the top-sealed inner tube support plate 12. A partition plate 13 is installed on the inner wall of the outer shell 1 above the bottom-sealed outer tube support plate 15. A cold water injection chamber for diffusing injected cold water is formed between the bottom-sealed outer tube support plate 15 and the partition plate 13. A cooling chamber 43 for cooling is formed between cavity 42, top sealing outer tube frame plate 14 and partition plate 13. A cooling outer tube 7 for heat dissipation is installed between bottom sealing outer tube frame plate 15 and top sealing outer tube frame plate 14. A connecting pipe 17 for introducing cold water into the cooling chamber 43 is installed on the surface of partition plate 13 and outside the cooling outer tube 7. A self-cleaning cooling device 8 with self-cleaning function is provided on the outside of the cooling outer tube 7 to improve cooling efficiency. A cooling inner tube 6 for auxiliary cooling from the inside of the cooling outer tube 7 is installed between bottom sealing inner tube frame plate 11 and top sealing inner tube frame plate 12. A heat insulation sleeve for heat insulation is provided on the outer wall of the cooling inner tube 6 and above the catalyst plate layer 16, so that the raw material The gas will not be cooled before it reacts. The discharge pipe 51 is installed on the outer wall of the outer shell 1 and communicates with the inside of the discharge chamber 41. The injection pipe 52 is installed on the outer wall of the outer shell 1 and communicates with the inside of the injection chamber 44. The side water injection pipe 54 is installed on the outer wall of the outer shell 1 and communicates with the inside of the cold water injection chamber 42. The side drainage pipe 55 is installed on the outer wall of the outer shell 1 and communicates with the inside of the cooling chamber 43. The partition ring 57 is installed on the inner wall of the outer shell 1 and above the side drainage pipe 55. The pressure relief and exhaust pipe 56 is installed on the outer wall of the outer shell 1 and above the partition ring 57, and communicates with the inside of the cooling chamber 43. A drain pipe 53 is installed on the outer wall of the outer shell 1, close to the upper side of the partition plate 13.A valve is installed at the end of the sewage pipe 53 to control its operation during cleaning.

[0034] In this embodiment, the self-cleaning cooling device 8 includes an inner heat-conducting plate 81, a first turbulent heat dissipation plate 82, a second turbulent heat dissipation plate 83, an outer heat dissipation plate 84, a sliding block 85, a lower limit ring seat 86, a positioning support frame 87, an upper limit ring seat 88, a moving rail frame 89, and a power blade 90. The inner heat-conducting plate 81 is installed on the inner wall of the inner cooling pipe 6. The first turbulent heat dissipation plate 82 is installed on the outer wall of the inner cooling pipe 6 and located inside the outer cooling pipe 7. The second turbulent heat dissipation plate 83 is installed on the outer wall of the inner cooling pipe 6 and located below the first turbulent heat dissipation plate 82. The outer heat dissipation plate 84... 4. The sliding block 85 is installed on the outer wall of the cooling outer tube 7 and is movably engaged in the gap between the adjacent outer heat dissipation plates 84. The lower limit ring seat 86, which is used to block and limit the downward movement range of the sliding block 85, is installed on the outer wall of the cooling outer tube 7 and at the bottom of the outer heat dissipation plate 84. The positioning support frame 87 is installed on the outer surface of the sliding block 85. The upper limit ring seat 88 is rotatably installed on the outer wall of the cooling outer tube 7 and above the outer heat dissipation plate 84 through a bearing. The power blade 90 is installed on the outer wall of the upper limit ring seat 88. The top of the actuating rail frame 89 is connected to the upper limit ring seat 88.

[0035] For details, see attached. Figures 3-6 As shown, the self-cleaning cooling device 8 cools and lowers the temperature of the raw material gas flowing between the inner cooling pipe 6 and the outer cooling pipe 7, and also turbulents the flowing gas to further improve the uniformity of cooling.

[0036] In this embodiment, the actuating rail frame 89 is spiral in shape, and the upper end of the actuating rail frame 89 is bent in a "C" shape. The top end of the actuating rail frame 89 is installed on the outer wall of the upper limit ring seat 88.

[0037] For details, see attached. Figure 3 and Figure 4 As shown, when the actuating rail frame 89 rotates, the positioning support frame 87 actuates the sliding block 85 to slide upward along the inner side of the outer heat dissipation plate 84. When the positioning support frame 87 moves to a position close to the top of the actuating rail frame 89, the positioning support frame 87 moves past the actuating rail frame 89 through the upper C-shaped notch position of the actuating rail frame 89. Then the sliding block 85 falls under the action of gravity, thereby causing the sliding block 85 to move up and down repeatedly.

[0038] In this embodiment, there are several external heat dissipation plates 84, which are evenly arranged on the outer wall of the cooling outer pipe 7. The outer thickness of the external heat dissipation plate 84 is greater than the inner thickness.

[0039] For details, see attached. Figure 4As shown, the outer opening of the opening formed by the adjacent outer heat dissipation plates 84 is smaller than the inner opening, and the sliding block 85 is engaged so that the sliding block 85 can only slide up and down along the gap formed by the adjacent outer heat dissipation plates 84.

[0040] In this embodiment, both the first turbulence heat dissipation plate 82 and the second turbulence heat dissipation plate 83 are spiral-shaped, and the spiral directions of the first turbulence heat dissipation plate 82 and the second turbulence heat dissipation plate 83 are opposite. A buffer space is provided between the bottom end of the first turbulence heat dissipation plate 82 and the top end of the second turbulence heat dissipation plate 83. The bottom end of the first turbulence heat dissipation plate 82 and the top end of the second turbulence heat dissipation plate 83 are misaligned.

[0041] For details, see attached. Figure 6 As shown, the raw material gas flowing in the gap between the inner cooling pipe 6 and the outer cooling pipe 7 will be deflected under the constraint of the first turbulence heat dissipation plate 82 and the second turbulence heat dissipation plate 83, thereby achieving the effect of turbulence and improving the uniformity of cooling. Furthermore, the first turbulence heat dissipation plate 82 and the second turbulence heat dissipation plate 83 also increase the contact area with the raw material gas for cooling, thereby improving the cooling efficiency.

[0042] In this embodiment, the sliding block 85 is adapted to the groove formed between the adjacent external heat dissipation plate 84, and the thickness of the sliding block 85 on the side closer to the cooling outer pipe 7 is greater than the thickness on the side farther away from the cooling outer pipe 7.

[0043] For details, see attached. Figure 3 As shown, when the sliding block 85 slides, it pushes the dirt and steam bubbles on its moving side to the outside, preventing dirt from adhering to the surface of the cooling outer pipe 7 and the outer heat dissipation plate 84, and preventing steam bubbles from getting close to the cooling outer pipe 7, which would cause the water temperature near the cooling outer pipe 7 to rise and affect the cooling effect.

[0044] In this embodiment, the top of the partition plate 13 is provided with an upward conical protrusion, and the top of the connecting pipe 17 extends above the partition plate 13.

[0045] For details, see attached. Figure 2 As shown, when dirt settles downwards, it flows outwards along the conical protrusion at the top of the partition plate 13, preventing dirt from accumulating in the middle. There are several connecting pipes 17 arranged in a circumferential array on the outside of the cooling outer pipe 7. Cooling water is evenly supplied to the outside of the cooling outer pipe 7 through the connecting pipes 17. The end of the connecting pipe 17 extends above the partition plate 13, effectively preventing dirt from entering the interior of the connecting pipe 17 along the surface of the partition plate 13.

[0046] In this embodiment, the bottom of the top sealing outer tube frame plate 14 is provided with a downward conical protrusion.

[0047] For details, see attached. Figure 2As shown, the conical protrusion at the bottom of the top sealing outer pipe rack plate 14 allows steam to automatically diffuse outward after flowing to the top, facilitating the discharge of steam through the pressure relief exhaust pipe 56.

[0048] In this embodiment, the top of the bottom water tank 2, the bottom of the top drainage tank 3, the surface of the bottom sealing inner tube frame plate 11, and the surface of the top sealing inner tube frame plate 12 are all provided with through holes for the cooling inner tube 6 to flow through.

[0049] For details, see attached. Figure 2 As shown, cold water inside the bottom water tank 2 flows into the cooling inner tube 6 through the through hole, and the cooling water flows upward along the cooling inner tube 6 and flows into the top drain tank 3 through the through hole at the top for collection.

[0050] In this embodiment, the horizontal interface shape of the inner heat-conducting plate 81 is "*".

[0051] For details, see attached. Figure 6 As shown, the inner heat-conducting plate 81 increases the contact area between the cooling water flowing inside the inner cooling pipe 6 and the inner cooling pipe 6 for heat conduction, thereby improving the cooling effect of the inner cooling pipe 6.

[0052] The working principle and usage process of this invention are as follows: The cold water supply pipe is connected to the bottom water injection pipe 21 and the end of the side water injection pipe 54; the hot water recovery pipe is connected to the side drainage pipe 55 and the top drainage pipe 31; the raw material gas supply pipe is connected to the injection pipe 52; and the raw material receiving pipe is connected to the discharge pipe 51. Cold water enters the bottom water injection tank 2 through the bottom water injection pipe 21. Under pressure, the cold water inside the bottom water injection tank 2 flows upward into the cooling inner pipe 6 and upward along the cooling inner pipe 6, eventually flowing upward along the cooling inner pipe 6 into the top drainage tank 3, and then being discharged through the top drainage pipe 31. The cold water entering the cold water injection chamber 42 through the side water injection pipe 54 flows upward along the connecting pipe 17 to the cooling chamber 43. The raw material gas flows upward along the outside of the outer cooling pipe 7 and is finally discharged outward through the side drain pipe 55. The high-temperature raw material gas is discharged into the inner filling chamber 44 through the filling pipe 52. The raw material gas flows downward and contacts the catalyst plate 16 to react. After flowing below the catalyst plate 16, the raw material gas first contacts the inner cooling pipe 6 for initial cooling, and then enters the inner cooling pipe 7 through the top of the outer cooling pipe 7 and flows downward along the inner cooling pipe 7. When the raw material gas flows along the inner cooling pipe 7, it will swirl in two directions under the obstruction of the first turbulence heat dissipation plate 82 and the second turbulence heat dissipation plate 83, thereby achieving a turbulence effect, so that the raw material gas can fully react with the inner cooling pipe 6, the first turbulence heat dissipation plate 82, and the second turbulence heat dissipation plate 83. 83 and the surface of the cooling outer pipe 7 are in contact. The raw material gas transfers heat to the cooling inner pipe 6 through the first turbulence heat dissipation plate 82 and the second turbulence heat dissipation plate 83, and then exchanges heat with the water flowing inside the cooling inner pipe 6. The water flowing inside the cooling inner pipe 6 absorbs the heat, thereby achieving cooling. At the same time, the first turbulence heat dissipation plate 82 and the second turbulence heat dissipation plate 83 also transfer the heat of the reacting gas to the cooling outer pipe 7. The cooling outer pipe 7 transfers heat to the outer heat dissipation plate 84. Through the cooperation of the cooling outer pipe 7 and the outer heat dissipation plate 84, heat conduction and cooling are carried out by the cold water in contact with the outside. The upward flowing water and the upward surging steam on the outside of the cooling outer pipe 7 contact with the power blade 90, driving the power blade 90 to rotate. The power blade 90 drives the upper limit. The upper limit ring seat 88 rotates, causing the actuating rail frame 89 to rotate. When the actuating rail frame 89 rotates, it pushes the sliding block 85 upward along the inner side of the outer heat dissipation plate 84 through the positioning support frame 87. The upward sliding of the outer heat dissipation plate 84 scrapes and cleans the surface of the cooling outer tube 7 and the surface of the outer heat dissipation plate 84, thereby preventing dirt from forming on the surface of the cooling outer tube 7 and the outer heat dissipation plate 84 and affecting the heat conduction efficiency. After the sliding block 85 and the positioning support frame 87 move to the top position, they disengage from the support of the actuating rail frame 89 through the C-shaped bend position of the actuating rail frame 89, causing the sliding block 85 to fall. During the up and down movement of the sliding block 85, the inclined surface of the pushing surface also pushes the steam bubbles near the surface of the cooling outer tube 7 to flow outward.This prevents the steam from flowing upwards near the cooling outer pipe 7, which would be too close to the cooling outer pipe 7 and affect its contact with the cold water, thus reducing the cooling efficiency of the cooling outer pipe 7. After being cooled by the self-cleaning cooling device 8, the raw material gas continues to flow downwards into the cold water injection chamber 42. The low-temperature cold water inside the cold water injection chamber 42 further cools the cooling outer pipe 7. The cooled raw material gas then enters the discharge chamber 41, where it is further cooled by the cooling inner pipe 6 and the cold water inside it. After cooling is complete inside the discharge chamber 41, the raw material gas is discharged through the discharge pipe 51.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An oxidizer for preparing formaldehyde, comprising an outer shell (1) and a self-cleaning cooling device (8), characterized in that: A bottom water tank (2) is installed at the bottom of the outer shell (1), and a bottom water pipe (21) for injecting cold water is installed at the bottom of the bottom water tank (2). A top drain tank (3) is installed at the top of the outer shell (1), and a top drain pipe (31) for discharging hot water is installed at the top of the top drain tank (3). A bottom sealing inner tube support plate (11) is installed on the inner wall of the outer shell (1) near the bottom, and a top sealing inner tube support plate (12) is installed on the inner wall of the outer shell (1) near the top. A catalyst plate layer (16) for catalytic reaction is installed on the inner wall of the outer shell (1) below the top sealing inner tube support plate (12). A top sealing outer tube frame plate (14) is installed below (16). A filling chamber (44) for dispersing gaseous raw materials is formed between the top sealing inner tube frame plate (12) and the top sealing outer tube frame plate (14). A bottom sealing outer tube frame plate (15) is installed on the inner wall of the outer shell (1) above the bottom sealing inner tube frame plate (11). A discharge chamber (41) for collecting and discharging cooled gas is formed between the bottom sealing inner tube frame plate (11) and the bottom sealing outer tube frame plate (15). A catalyst plate layer (16) is installed on the inner wall of the outer shell (1) below the top sealing inner tube frame plate (12). A catalyst plate layer (16) is installed on the inner wall of the outer shell (1) above the bottom sealing outer tube frame plate (15). A partition plate (13) is installed at the square position. A cold water injection chamber (42) for diffusing injected cold water is formed between the bottom sealing outer pipe support plate (15) and the partition plate (13). A cooling chamber (43) for cooling is formed between the top sealing outer pipe support plate (14) and the partition plate (13). A cooling outer pipe (7) for heat dissipation is installed between the bottom sealing outer pipe support plate (15) and the top sealing outer pipe support plate (14). A connecting pipe (17) for introducing cold water from the cold water injection chamber (42) into the cooling chamber (43) is installed on the surface of the partition plate (13) and outside the cooling outer pipe (7). A self-cleaning function that improves cooling efficiency is provided on the outside of the cooling outer pipe (7). A cooling device (8) is provided, wherein a cooling inner pipe (6) for auxiliary cooling by the inside of the cooling outer pipe (7) is installed between the bottom sealing inner pipe support plate (11) and the top sealing inner pipe support plate (12); a discharge pipe (51) is installed on the outer wall of the outer cylinder shell (1) and communicates with the inside of the discharge chamber (41); a filling pipe (52) is installed on the outer wall of the outer cylinder shell (1) and communicates with the inside of the filling chamber (44); a side water filling pipe (54) is installed on the outer wall of the outer cylinder shell (1) and communicates with the inside of the cold water injection chamber (42); a side drain pipe (55) is installed on the outer wall of the outer cylinder shell (1) and communicates with the inside of the cooling chamber (43); and a partition ring (57) is installed on the inner wall of the outer cylinder shell (1) and above the side drain pipe (55).A pressure relief exhaust pipe (56) is installed on the outer wall of the outer cylinder shell (1) and above the partition ring (57). The pressure relief exhaust pipe (56) is connected to the interior of the cooling chamber (43). A drain pipe (53) is installed on the outer wall of the outer cylinder shell (1) and above the partition plate (13). A valve for controlling the opening and closing during cleaning is installed at the end of the drain pipe (53). The self-cleaning cooling device (8) includes an inner heat-conducting plate (81), a first turbulent heat dissipation plate (82), a second turbulent heat dissipation plate (83), an outer heat dissipation plate (84), a sliding block (85), a lower limit ring seat (86), a positioning support rod (87), an upper limit ring seat (88), a moving rail frame (89), and a power blade (90). The inner heat-conducting plate (81) is installed on the inner wall of the inner cooling tube (6). The first turbulent heat dissipation plate (82) is installed on the outer wall of the inner cooling tube (6) and located inside the outer cooling tube (7). The second turbulent heat dissipation plate (83) is installed on the outer wall of the inner cooling tube (6) and located below the first turbulent heat dissipation plate (82). The outer heat dissipation plate (84)... The sliding block (85) is installed on the outer wall of the cooling outer tube (7), and the sliding block (85) is movably engaged in the gap between adjacent outer heat dissipation plates (84). The lower limit ring seat (86) used to block and limit the downward movement range of the sliding block (85) is installed on the outer wall of the cooling outer tube (7) and at the bottom of the outer heat dissipation plate (84). The positioning support frame (87) is installed on the outer surface of the sliding block (85). The upper limit ring seat (88) is rotatably installed on the outer wall of the cooling outer tube (7) and above the outer heat dissipation plate (84) through a bearing. The power blade (90) is installed on the outer wall of the upper limit ring seat (88). The top of the actuating rail frame (89) is connected to the upper limit ring seat (88). The entire actuating rail frame (89) is spiral-shaped, with the upper end of the actuating rail frame (89) bent in a "C" shape. The top of the actuating rail frame (89) is installed on the outer wall of the upper limit ring seat (88), and the positioning support frame (87) moves past the actuating rail frame (89) through the C-shaped notch at the upper end of the actuating rail frame (89). There are several external heat dissipation plates (84) and they are evenly arranged on the outer wall of the cooling outer tube (7). The outer side thickness of the external heat dissipation plate (84) is greater than the inner side thickness. The first turbulence heat sink (82) and the second turbulence heat sink (83) are both spiral-shaped, and the spiral directions of the first turbulence heat sink (82) and the second turbulence heat sink (83) are opposite. A buffer space is provided between the bottom end of the first turbulence heat sink (82) and the top end of the second turbulence heat sink (83). The bottom end of the first turbulence heat sink (82) and the top end of the second turbulence heat sink (83) are misaligned. The sliding block (85) is adapted to the groove formed between the adjacent external heat dissipation plate (84), and the thickness of the sliding block (85) on the side closer to the cooling outer tube (7) is greater than the thickness on the side farther away from the cooling outer tube (7). The horizontal interface shape of the inner heat-conducting plate (81) is "*".

2. The oxidizer for preparing formaldehyde according to claim 1, characterized in that: The top of the partition plate (13) has an upward conical protrusion, and the top of the connecting pipe (17) extends above the partition plate (13).

3. The oxidizer for preparing formaldehyde according to claim 1, characterized in that: The bottom of the top sealing outer tube frame plate (14) is provided with a downward conical protrusion.

4. An oxidizer for preparing formaldehyde according to claim 1, characterized in that: The top of the bottom water tank (2), the bottom of the top drain tank (3), the surface of the bottom sealing inner tube frame plate (11), and the surface of the top sealing inner tube frame plate (12) are all provided with through holes for the cooling inner tube (6) to flow through.

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