Oxidation method for waste heat recovery and utilization device in the oxidation section of oxalic acid production

Abstract

The present invention discloses a waste heat recovery and utilization device for the oxidation section in the production of oxalic acid by the oxidation method, which relates to the field of waste heat recovery. A heat exchanger is used to exchange heat between the NO gas generated in the production of oxalic acid and the air passing through the inside of the heat exchanger. x An oxidation tube is used to send the NO gas generated in the production of oxalic acid into the inside of the heat exchanger. x A drying tower is used to send the dried and dehumidified air to the inside of the heat exchanger to exchange heat with the NO gas. x An absorption tower is used to purify the cooled NO gas. x A dryer is used to receive the heated air to dry the oxalic acid inside it. The waste heat recovery and utilization device for the oxidation section in the production of oxalic acid by the oxidation method realizes the effect of making full use of the waste heat generated in the oxalic acid production reaction, avoids the problem that the large temperature difference between the gas and the tube bundle is likely to cause damage and leakage of the tube bundle, reduces the amount of external impurities attached to the tube bundle, and reduces the problem that the heat exchange effect is affected due to more impurities attached to the outside of the tube bundle.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat recovery, and particularly to a device for recovering and utilizing waste heat in the oxidation section of oxalic acid production by the oxidation method. Background Art

[0002] Oxalic acid is an organic compound and a metabolite of organisms. It is widely distributed in plants, animals, and fungi, and plays different functions in different living organisms. The reaction in the oxidation section of oxalic acid production by the oxidation method is an exothermic reaction. When NO generated by the oxidation reaction contacts oxygen, NO2 is formed and a large amount of reaction heat is released. Calculated based on an oxalic acid production capacity of 180,000 tons / year, the NO X mixed gas is about 33,445 m³ / h (standard conditions: 273.15 K, 1 standard atmosphere). When the effective utilization rate is 69.6%, the recoverable heat energy is about 833,920 kcal / h.

[0003] Due to the strong corrosiveness of NO x gas, large leakage risk, and high difficulty in recovery and utilization, most current manufacturers of oxalic acid production by the oxidation method use the traditional water cooling method for temperature reduction, with almost no recovery, resulting in a large waste of waste heat. Therefore, the present solution proposes a device for recovering and utilizing waste heat in the oxidation section of oxalic acid production by the oxidation method. Summary of the Invention

[0004] The purpose of the present invention is to provide a device for recovering and utilizing waste heat in the oxidation section of oxalic acid production by the oxidation method, so as to solve the problems in the prior art that due to the strong corrosiveness of NO x gas, large leakage risk, high difficulty in recovery and utilization, most current manufacturers of oxalic acid production by the oxidation method use the traditional water cooling method for temperature reduction, with almost no recovery, resulting in a large waste of waste heat.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A device for recovering and utilizing waste heat in the oxidation section of oxalic acid production by the oxidation method, including a heat exchanger, which is used for heat exchange between the NO x gas generated by oxalic acid production and the air passing through the inside of the heat exchanger;

[0006] An oxidation tube, which is connected to the heat exchanger and is used for sending the NO x gas generated by oxalic acid production into the inside of the heat exchanger;

[0007] A drying tower, which is connected to the heat exchanger and is used for sending the dried and dehumidified air to the inside of the heat exchanger for heat exchange with the NO x gas;

[0008] An absorption tower, which is connected to the heat exchanger through a fan and is used for purifying the cooled NO x gas;

[0009] A dryer, which is connected to a heat exchanger and is used to receive heated air to dry the oxalic acid inside it.

[0010] Furthermore, the heat exchanger includes a shell, two tube sheets fixedly connected inside the shell, a plurality of tube bundles fixedly connected to the two tube sheets, two heads respectively installed at both ends of the shell, an inflow port installed on one side of the top of the shell, and an outflow port installed on one side of the bottom of the shell. A distribution chamber is provided between the tube sheet and the head.

[0011] Furthermore, one of the heads is connected to a drying tower, the other head is connected to the dryer, the inflow port is connected to an oxidation tube, and the outflow port is connected to a fan.

[0012] Furthermore, the heat exchanger further includes a plurality of baffle plates. The plurality of baffle plates are sequentially installed inside the heat exchanger along the length direction of the shell. The baffle plates are fixedly connected to the inside of the shell and fixedly sleeved outside the plurality of tube bundles. The baffle plates are of a segmental structure, and the plurality of baffle plates are sequentially arranged in a staggered manner along the length direction of the shell;

[0013] A buffer mechanism, which is arranged on the tube sheet near the drying tower side and is used to reduce the impact force on the tube bundle;

[0014] A tube wall cleaning mechanism, which is arranged outside the tube bundle and is connected to the buffer mechanism, and is used to clean the impurities on the outer wall of the tube bundle;

[0015] A wind direction adjusting mechanism, which is arranged between the head and the buffer mechanism and is used to adjust the wind direction of the air entering the distribution chamber;

[0016] A filtering mechanism, the number of which is multiple. The multiple filtering mechanisms are sequentially arranged at the bottom along the length direction of the shell and are used to collect and filter the solid particles inside the shell.

[0017] Furthermore, the buffer mechanism includes a plurality of sliding rods slidably connected inside the shell along the length direction of the shell, a plurality of buffer plates respectively fixedly connected to one ends of the plurality of sliding rods located inside the distribution chamber, and a plurality of springs respectively sleeved outside the plurality of sliding rods. The plurality of sliding rods respectively correspond to the plurality of tube bundles. The sliding rods sequentially penetrate through the tube sheet and the plurality of baffle plates and are slidably connected to the tube sheet and the plurality of baffle plates respectively. One end of the spring is fixedly connected to the buffer plate, and the other end of the spring is fixedly connected to the outer wall of the tube sheet.

[0018] Furthermore, the tube wall cleaning mechanism includes a plurality of scraping rings slidably sleeved outside the tube bundle in sequence along the axial direction of the tube bundle. The plurality of scraping rings are all fixedly connected to the outer wall of the sliding rod.

[0019] Further, the wind direction adjusting mechanism includes a driving shaft rotatably connected inside the distribution chamber, a guide plate fixedly sleeved outside the driving shaft, and a motor installed outside the housing. The output end of the motor is in transmission connection with one end of the driving shaft.

[0020] Further, the filtering mechanism includes an aggregate pipe fixedly connected to the bottom of the housing, a filter cylinder arranged inside the aggregate pipe, a connecting pipe installed on one side of the aggregate pipe, and a reflux pipe installed at the other end of the connecting pipe. The top end of the reflux pipe extends into the housing. The aggregate pipe and the reflux pipe are respectively arranged on both sides of the baffle plate. A detachable sealing cover is installed at the bottom end of the aggregate pipe.

[0021] Compared with the prior art, the waste heat recovery and utilization device for the oxidation section in oxalic acid production provided by the present invention has the following beneficial effects:

[0022] NO generated in acid production x The gas is sent into the heat exchanger through the inflow port. The air after being dried by the drying tower enters the left distribution chamber through the left head. The two gases exchange heat without contact inside the heat exchanger. The cooled NO x gas is sent into the absorption tower for purification treatment. The heated air is sent into the dryer to dry the oxalic acid inside, thereby achieving the effect of making full use of the waste heat of the oxalic acid production reaction;

[0023] Through the cooperation between the wind direction adjusting mechanism and the buffer mechanism, the problem that the gas impacts the tube bundle 9 greatly is avoided. The setting of the buffer plate and the adjustment of the wind direction by the wind direction adjusting mechanism can increase the flow distance of the gas after entering the distribution chamber, so that the gas enters the tube bundle only after the temperature rises inside the distribution chamber, avoiding the problem that the large temperature difference between the gas and the tube bundle is likely to cause damage and leakage of the tube bundle;

[0024] Through the cooperation between the buffer mechanism and the tube wall cleaning mechanism, a plurality of scraping rings can be driven to move back and forth along the outer wall of the tube bundle, reducing the amount of impurities attached to the outside of the tube bundle and reducing the problem that the heat exchange effect is affected due to more impurities attached to the outside of the tube bundle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0026] Figure 1 is the overall structural schematic diagram of the present invention;

[0027] Figure 2Schematic diagram of the external structure of the heat exchanger of the present invention;

[0028] Figure 3 Schematic diagram of the internal structure of the heat exchanger of the present invention;

[0029] Figure 4 For the present invention Figure 3 Enlarged schematic diagram of the structure at location A in the present invention;

[0030] Figure 5 For the present invention Figure 3 Enlarged schematic diagram of the structure at location B in the present invention;

[0031] Figure 6 Schematic diagram of the structure of the filtering mechanism of the present invention.

[0032] Explanation of reference numerals:

[0033] 1. Heat exchanger; 2. Oxidation tube; 3. Drying tower; 4. Absorption tower; 5. Dryer; 6. Fan; 7. Shell; 8. Tube sheet; 9. Tube bundle; 10. Head; 11. Inflow port; 12. Outflow port; 13. Distribution chamber; 14. Baffle; 15. Slide bar; 16. Buffer plate; 17. Spring; 18. Scraping ring; 19. Drive shaft; 20. Guide plate; 21. Motor; 22. Aggregate pipe; 23. Filter cylinder; 24. Connecting pipe; 25. Return pipe; 26. Sealing cover. Detailed implementation manners

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further introduced in detail below in conjunction with the accompanying drawings. Embodiment

[0035] Please refer to Figure 1 , the waste heat recovery and utilization device for the oxidation section of oxalic acid production by the oxidation method, including a heat exchanger 1, which is used to exchange heat between the NO x gas generated in oxalic acid production and the air passing through the inside of the heat exchanger 1;

[0036] An oxidation tube 2, which is connected to the heat exchanger 1 and is used to send the NO x gas generated in oxalic acid production into the inside of the heat exchanger 1. The reaction in the oxidation section of oxalic acid production by the oxidation method is an exothermic reaction. When the NO generated by the oxidation reaction contacts oxygen, NO2 is generated and a large amount of reaction heat is released. The NO gas generated by the oxidation is fully oxidized and exothermic in a closed pipeline;

[0037] A drying tower 3, which is connected to the heat exchanger 1 and is used to send the dried and dehumidified air to the inside of the heat exchanger 1 to exchange heat with the NO x gas;

[0038] An absorption tower 4, which is connected to the heat exchanger 1 through a fan 6 and is used to cool the NO xPurify the gas;

[0039] A dryer 5, which is connected to the heat exchanger 1 and is used to receive the heated air to dry the oxalic acid inside it, making full use of the waste heat of the oxalic acid production reaction for subsequent oxalic acid drying work. Embodiment

[0040] Please refer to Figures 2 - 6 , on the basis of Embodiment 1, this embodiment provides a technical solution: The heat exchanger 1 includes a housing 7, two tube sheets 8 fixedly connected inside the housing 7, a plurality of tube bundles 9 fixedly connected to the two tube sheets 8, two heads 10 respectively installed at both ends of the housing 7, an inflow port 11 installed on one side of the top of the housing 7, and an outflow port 12 installed on one side of the bottom of the housing 7. A distribution chamber 13 is provided between the tube sheet 8 and the head 10. One of the heads 10 is connected to the drying tower 3, and the other head 10 is connected to the dryer 5. The inflow port 11 is connected to the oxidation tube 2, and the outflow port 12 is connected to the fan 6. The dried air enters the interior of the left distribution chamber 13 through the left head 10, and the gas inside the distribution chamber 13 flows through the plurality of tube bundles 9 into the interior of the right distribution chamber 13. During this process, the NO x gas transfers heat to the gas inside the tube bundle 9, and the gas inside the right distribution chamber 13 is discharged through the right head 10.

[0041] The heat exchanger 1 further includes a plurality of baffle plates 14. The plurality of baffle plates 14 are sequentially installed inside the heat exchanger 1 along the length direction of the housing 7. The baffle plates 14 are fixedly connected to the inside of the housing 7 and fixedly sleeved outside the plurality of tube bundles 9. The baffle plates 14 are of a segmental structure. The plurality of baffle plates 14 are sequentially arranged in a staggered manner along the length direction of the housing 7. The NO x gas sequentially passes through the notches of the baffle plates 14 in a winding manner, thereby increasing the residence time of the NO x gas inside the housing 7 and improving the heat exchange effect.

[0042] The buffer mechanism is arranged on the tube sheet 8 near the drying tower 3 to reduce the impact force on the tube bundle 9. The buffer mechanism includes a plurality of slide bars 15 slidingly connected to the interior of the shell 7 along the length direction, a plurality of buffer plates 16 respectively fixed to one end of the plurality of slide bars 15 located inside the distribution chamber 13, and a plurality of springs 17 respectively sleeved on the outside of the plurality of slide bars 15. The plurality of slide bars 15 respectively correspond to the plurality of tube bundles 9. The slide bars 15 are sequentially arranged through the tube sheet 8 and the plurality of baffles 14 and are respectively slidably connected to the tube sheet 8 and the plurality of baffles 14. One end of the spring 17 It is fixedly connected to the buffer plate 16, and the other end of the spring 17 is fixedly connected to the outer wall of the tube sheet 8. When the gas inside the distribution chamber 13 directly blows the tube bundle 9, the buffer plate 16 on the left side of the tube bundle 9 can block the directly blown gas to avoid a large impact of the gas on the tube bundle 9. The setting of the buffer plate 16 and the adjustment of the wind direction by the wind direction adjustment mechanism can increase the distance the gas flows after entering the distribution chamber 13, so that the gas enters the tube bundle 9 only after the temperature rises after entering the distribution chamber 13, avoiding the problem of damage and leakage of the tube bundle 9 caused by a large temperature difference between the gas and the tube bundle 9.

[0043] The tube wall cleaning mechanism is arranged on the outside of the tube bundle 9 and is connected to the buffer mechanism. It is used to clean impurities on the outer wall of the tube bundle 9. The tube wall cleaning mechanism includes a plurality of scraper rings 18 that are slidably sleeved on the outside of the tube bundle 9 in sequence along the axial direction. The plurality of scraper rings 18 are all fixed to the outer wall of the slide rod 15. When the slide rod 15 is driven to move back and forth, it drives the plurality of scraper rings 18 to move back and forth along the outer wall of the tube bundle 9, which will reduce the amount of impurities attached to the outside of the tube bundle 9 and reduce the problem of the heat exchange effect of the tube bundle 9 being affected by the large amount of impurities attached to the outside of the tube bundle 9.

[0044] The wind direction adjustment mechanism is arranged between the head 10 and the buffer mechanism, and is used to adjust the wind direction of the air entering the distribution chamber 13. The wind direction adjustment mechanism includes a drive shaft 19 rotatably connected to the inside of the distribution chamber 13, a guide plate 20 fixedly sleeved on the outside of the drive shaft 19, and a motor 21 installed on the outside of the shell 7. The output end of the motor 21 is connected to one end of the drive shaft 19. After the external dry air enters the distribution chamber 13 through the head 10, the drive shaft 19 is driven to rotate back and forth within a range of 90 degrees by controlling the motor 21, and the guide plate 20 is fixedly sleeved on the outside of the drive shaft 19. The plate 20 rotates accordingly, thereby circulating the gas entering the distribution chamber 13 in the upper, middle and lower directions. When the gas blows directly on the buffer plate 16, the buffer plate 16 is blocked and moves toward the tube plate 8, and the slide bar 15 slides accordingly, and the spring 17 is compressed accordingly, and the wind direction is adjusted accordingly. After the buffer plate 16 at this location is not directly blown by the gas, the rebound force of the spring 17 drives the slide bar 15 and the buffer plate 16 to reset, thereby achieving the effect of cyclically driving the buffer plates 16 and the slide bar 15 to move back and forth by adjusting the wind direction inside the distribution chamber 13.

[0045] Filtering mechanism, the number of which is multiple. The multiple filtering mechanisms are sequentially arranged at the bottom of the housing 7 along the length direction thereof, and are used for collecting and filtering solid particles inside the housing 7. The filtering mechanism includes an aggregate pipe 22 fixedly connected to the bottom of the housing 7, a filtering cylinder 23 arranged inside the aggregate pipe 22, a connecting pipe 24 installed on one side of the aggregate pipe 22, and a reflux pipe 25 installed at the other end of the connecting pipe 24. The top end of the reflux pipe 25 extends into the housing 7. The aggregate pipe 22 and the reflux pipe 25 are respectively arranged on both sides of the baffle 14. A detachable sealing cover 26 is installed at the bottom end of the aggregate pipe 22 and can be connected to the aggregate pipe 22 by bolts. The aggregate pipe 22 is located on one side of the connection between the bottom of the arc-shaped baffle 14 and the inner wall of the bottom of the housing 7. That is to say, the filtering mechanism is not arranged at the position where the incomplete part of the baffle 14 is removed. Therefore, through the interception effect of the bottom of the baffle 14, the solid impurities at the bottom of the housing 7 can enter the aggregate pipe 22 and are filtered by the filtering cylinder 23, and the gas returns to the housing 7 through the reflux pipe 25. The solid impurities inside the filtering cylinder 23 need to be cleaned regularly. Only by removing the sealing cover 26 can the filtering cylinder 23 be taken out for cleaning.

[0046] Working principle: During use, the NO x gas is sent into the heat exchanger 1 through the inflow port 11. The air after being dried by the drying tower 3 enters the left distribution chamber 13 through the left end head 10. By controlling the motor 21 to drive the drive shaft 19 to reciprocate within a range of 90°, the guide plate 20 rotates accordingly, so as to circulate and guide the gas entering the distribution chamber 13 upward, middle and downward. When the gas blows directly against the buffer plate 16, the buffer plate 16 is blocked and moves towards the tube sheet 8, the slide bar 15 slides accordingly, and the spring 17 is compressed accordingly. With the adjustment of the wind direction, after the buffer plate 16 at this place is not blown directly by the gas, through the rebounding force of the spring 17, the slide bar 15 and the buffer plate 16 are driven to reset. The buffer plate 16 on the left side of the tube bundle 9 can block the directly blown gas, avoiding large impact on the tube bundle 9. The setting of the buffer plate 16 and the adjustment of the wind direction by the wind direction adjustment mechanism can increase the flow distance of the gas after entering the distribution chamber 13, so that the temperature of the gas rises before entering the tube bundle 9 after entering the distribution chamber 13, avoiding the problem that the large temperature difference between the gas and the tube bundle 9 is likely to cause damage and leakage of the tube bundle 9. By adjusting the wind direction inside the distribution chamber 13, the effect of circularly driving each buffer plate 16 and the slide bar 15 to reciprocate is achieved. During the reciprocating movement of the slide bar 15 driven, a plurality of scraping rings 18 are driven to move back and forth along the outer wall of the tube bundle 9, reducing the attachment amount of impurities outside the tube bundle 9 and reducing the problem that the heat exchange effect of the tube bundle 9 is affected due to more attached impurities outside the tube bundle 9.

[0047] It should be noted that the device structure and the attached drawings of the present invention mainly describe the principle of the present invention. Based on the technical principle of this design, the settings of the power mechanism, power supply system, control system, etc. of the device are not fully described clearly. However, on the premise that those skilled in the art understand the principle of the above-mentioned invention, the specific details of its power mechanism, power supply system and control system can be clearly obtained. The control method of the application document is automatically controlled by a controller, and the control circuit of the controller can be realized by simple programming by those skilled in the art; only some exemplary embodiments of the present invention are described above by way of illustration. Undoubtedly, for those of ordinary skill in the art, without departing from the spirit and scope of the present invention, the described embodiments can be modified in various different ways. Therefore, the above-mentioned drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the attached drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0049] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more unless otherwise specifically defined. In addition, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Claims

1. The waste heat recovery and utilization device for the oxidation section in the production of oxalic acid by the oxidation method is characterized in that, including a heat exchanger (1) for exchanging heat between the NO gas generated in oxalic acid production and the air passing through the interior of the heat exchanger (1); x and a heat exchanger (1) for exchanging heat between the NO gas generated in oxalic acid production and the air passing through the interior of the heat exchanger (1). An oxidation tube (2), which is connected to a heat exchanger (1) and is used to send NO generated in oxalic acid production into the interior of the heat exchanger (1). x The gas is sent into the interior of the heat exchanger (1). The drying tower (3), which is connected to the heat exchanger (1) and is used to send the dried and dehumidified air to the inside of the heat exchanger (1) for heat exchange with NO x gas; Absorption tower (4), which is connected to the heat exchanger (1) through a fan (6) and is used to purify the cooled NO x gas; A dryer (5), which is connected to a heat exchanger (1) and is used to receive the heated air to dry the oxalic acid inside it; Wherein, The heat exchanger (1) includes a housing (7), two tube sheets (8) fixedly connected inside the housing (7), a plurality of tube bundles (9) fixedly connected to the two tube sheets (8), two heads (10) respectively installed at both ends of the housing (7), an inflow port (11) installed on one side of the top of the housing (7), and an outflow port (12) installed on one side of the bottom of the housing (7). A distribution chamber (13) is provided between the tube sheet (8) and the head (10); One of the heads (10) is connected to the drying tower (3), the other head (10) is connected to the dryer (5), the inflow port (11) is connected to the oxidation tube (2), and the outflow port (12) is connected to the fan (6); The heat exchanger (1) further includes a plurality of baffle plates (14). The plurality of baffle plates (14) are sequentially installed inside the heat exchanger (1) along the length direction of the housing (7). The baffle plates (14) are fixedly connected to the inside of the housing (7) and fixedly sleeved outside the plurality of tube bundles (9). The baffle plates (14) are of a segmental structure, and the plurality of baffle plates (14) are sequentially arranged in a staggered manner along the length direction of the housing (7); A buffer mechanism, which is arranged on the tube sheet (8) on the side close to the drying tower (3) and is used to reduce the impact force on the tube bundle (9); A tube wall cleaning mechanism, which is arranged on the outer side of the tube bundle (9) and is connected to the buffer mechanism and is used to clean the impurities on the outer wall of the tube bundle (9); A wind direction adjusting mechanism, which is arranged between the head (10) and the buffer mechanism and is used to adjust the wind direction of the air entering the distribution chamber (13); Filter mechanisms, the number of which is multiple. The multiple filter mechanisms are sequentially arranged at the bottom of the housing (7) along the length direction of the housing (7) and are used to collect and filter the solid particles inside the housing (7).

2. The waste heat recovery and utilization device for the oxidation section in the production of oxalic acid by the oxidation method according to claim 1, wherein, The buffer mechanism includes a plurality of sliding rods (15) slidably connected inside the housing (7) along the length direction of the housing (7), a plurality of buffer plates (16) respectively fixedly connected to one ends of the plurality of sliding rods (15) located inside the distribution chamber (13), and a plurality of springs (17) respectively sleeved outside the plurality of sliding rods (15). The plurality of sliding rods (15) respectively correspond to the plurality of tube bundles (9). The sliding rods (15) sequentially penetrate through the tube sheet (8) and the plurality of baffle plates (14) and are slidably connected to the tube sheet (8) and the plurality of baffle plates (14). One end of the spring (17) is fixedly connected to the buffer plate (16), and the other end of the spring (17) is fixedly connected to the outer wall of the tube sheet (8).

3. The waste heat recovery and utilization device for the oxidation section in the production of oxalic acid by the oxidation method according to claim 1, characterized in that, The tube wall cleaning mechanism includes a plurality of scraping rings (18) slidably sleeved outside the tube bundle (9) in sequence along the axial direction of the tube bundle (9). The plurality of scraping rings (18) are all fixedly connected to the outer wall of the sliding rod (15).

4. The waste heat recovery and utilization device for the oxidation section in the production of oxalic acid by the oxidation method according to claim 1, characterized in that, The wind direction adjusting mechanism includes a driving shaft (19) rotatably connected inside the distribution chamber (13), a guide plate (20) fixedly sleeved outside the driving shaft (19), and a motor (21) installed outside the housing (7). The output end of the motor (21) is in transmission connection with one end of the driving shaft (19).

5. The waste heat recovery and utilization device for the oxidation section in the production of oxalic acid by the oxidation method according to claim 1, characterized in that, The filtering mechanism includes an aggregate pipe (22) fixedly connected to the bottom of the housing (7), a filter cylinder (23) arranged inside the aggregate pipe (22), a connecting pipe (24) installed on one side of the aggregate pipe (22), and a reflux pipe (25) installed at the other end of the connecting pipe (24). The top end of the reflux pipe (25) extends into the housing (7). The aggregate pipe (22) and the reflux pipe (25) are respectively arranged on both sides of the baffle plate (14). A detachable sealing cover (26) is installed at the bottom end of the aggregate pipe (22).

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