Coal-to-ethylene glycol nitric acid reduction purification equipment

Abstract

The present invention discloses a nitric acid reduction and purification device for coal-based ethylene glycol, which relates to the technical field of nitric acid reduction and purification. The device comprises a tank body, wherein a main shaft, a motor, a mounting shaft, a transmission control assembly, and a pressure balancing assembly are arranged in the tank body. The main shaft is coaxially rotatable and arranged in the tank body. The transmission control assembly comprises a plurality of air cylinders fixedly arranged on the outer wall of the main shaft, wherein a sealing plate is provided in the air cylinder for sealing and sliding, and a resistance structure for balancing air pressure is provided between the sealing plate and the air cylinder; the pressure balancing assembly comprises a plurality of vacuum cylinders radially arranged on the outer wall of the mounting shaft, wherein a piston 1 is provided in the vacuum cylinder for sealing and sliding, and a connecting rod is fixedly provided at one end of the piston 1 away from the mounting shaft. The present invention controls the reaction pressure, improves the conversion rate of the reaction, changes the equilibrium position of the reaction, and promotes the reduction reaction to shift toward the generation direction of nitrous acid and nitrogen, thereby improving the reduction efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of nitric acid reduction and purification, in particular to nitric acid reduction and purification equipment for coal-based ethylene glycol. Background Art

[0002] Ethylene glycol (EG) is a key raw material in the organic chemical industry, primarily used in the production of polyester resins and antifreeze fluids, with limited applications in unsaturated polyester resins, lubricants, plasticizers, and nonionic surfactants. Currently, there are two primary methods for producing EG worldwide: petroleum-based and non-petroleum-based. Given my country's resource constraints of being "poor in oil, rich in coal, and limited in natural gas," non-petroleum coal-to-EG technology is a key area of ​​future research and development.

[0003] The coal-to-ethylene glycol process mainly includes: coal gasification, separation and purification, coupling reaction, regeneration reaction, hydrogenation reaction, etc. In the regeneration reaction process, the regenerated liquid waste contains a large amount of nitric acid, which has certain hazards to the environment and human health. For the wastewater generated after regeneration, the nitric acid is generally reduced to nitrous acid and nitrogen by adding a reducing agent.

[0004] The reduction reaction of nitric acid is generally carried out in a reactor. Existing reduction equipment is usually connected to an exhaust gas collection pipe, and the nitrogen generated by the reduction is directly pumped away. The entire equipment is operated at normal pressure. According to Le Chatelier's principle, the reaction reaches equilibrium when the gas phase pressures of the reactants and products are equal. At normal pressure, the pressures of the gas phase reactants and products are relatively low, and the reaction equilibrium position may be biased towards the side with more reactants, resulting in a low conversion rate. At normal pressure, the energy of the reactant molecules is low, and side reactions or product decomposition are likely to occur during the reaction, which may lead to low product selectivity and difficulty in obtaining high-purity products. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem in the prior art that the nitric acid reduction reaction is carried out under normal pressure, the reaction equilibrium position may be biased towards the side with more reactants, resulting in low conversion rate and low product selectivity, making it difficult to obtain high-purity products. The present invention proposes a nitric acid reduction and purification device for coal-based ethylene glycol.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] Coal-to-ethylene glycol nitric acid reduction purification equipment, including a tank body, wherein the tank body is provided with:

[0008] A main shaft is coaxially rotatably arranged in the tank body, and a plurality of stirring rods are equidistantly arranged on the outer circumference of the main shaft;

[0009] The motor is fixedly arranged at the bottom of the tank body, and the output end of the motor is connected to the main shaft through a reducer;

[0010] An installation shaft is rotatably arranged on the top of the tank body, and the installation shaft is coaxially rotatably connected with the main shaft;

[0011] The transmission control assembly includes a plurality of air cylinders fixedly mounted on the outer wall of the main shaft, a sealing sheet is provided in a sealing and sliding manner in the air cylinder, a resistance structure for balancing the air pressure is provided between the sealing sheet and the air cylinder, a plug rod is fixedly provided near one end of the mounting shaft of the sealing sheet, and a socket adapted for the plug rod is provided on the outer wall of the mounting shaft;

[0012] The pressure balancing assembly includes a plurality of vacuum cylinders radially arranged on the outer wall of the mounting shaft, a piston 1 is sealingly and slidingly arranged in the vacuum cylinder, a connecting rod is fixedly arranged at one end of the piston away from the mounting shaft, a driving mechanism for driving the connecting rod to move axially is arranged in the tank body, the air inlet and outlet ends of the vacuum cylinder are both arranged near one end of the mounting shaft, and a one-way valve 1 is provided at the air inlet and outlet ends of the vacuum cylinder, so that when the piston 1 reciprocates, the driving gas flows in one direction.

[0013] Preferably, the resistance structure includes a resistance spring, one end of the resistance spring is fixedly connected to the bottom of the air pressure cylinder, and the other end of the resistance spring is fixedly connected to the sealing sheet.

[0014] Preferably, the resistance structure includes a magnet 1 fixedly arranged at the bottom of the air pressure cylinder, an adjusting rod is threadedly connected to the sealing plate, a magnet 2 is fixedly arranged at the end of the adjusting rod, and the magnet 1 and magnet 2 are arranged correspondingly and have the same magnetic poles at one end facing each other.

[0015] Preferably, the driving mechanism includes a guide plate fixedly arranged on the inner wall of the tank body, a guide groove is provided on the guide plate, and a guide rod 1 is fixedly arranged on the end of the connecting rod, and the guide rod 1 extends into the guide groove and abuts against the inner wall of the guide groove.

[0016] Preferably, the guide groove is an annular groove with a wavy profile.

[0017] Preferably, a sealing connection ring is provided on the top of the mounting shaft, and a coaxially arranged sealing cavity one and a sealing cavity two are opened in the sealing connection ring. A sealing disk is provided on the top of the sealing connection ring for sealing rotation, and an air collecting pipe is fixedly provided on the top of the sealing disk. The air collecting pipe and the output end of the vacuum cylinder are both connected to the sealing cavity one.

[0018] Preferably, it also includes a liquid extraction tube fixedly arranged on the outer wall of the mounting shaft, wherein a second piston is sealingly and slidingly arranged in the liquid extraction tube, a push rod is fixedly arranged on the side wall of the second piston, and a second guide rod is fixedly arranged on the end of the push rod, and the second guide rod extends into the guide groove and abuts against the inner wall of the guide groove.

[0019] Preferably, the output end and input end of the liquid extraction pipe are both provided with a second one-way valve, the top of the tank body is provided with a storage tank for storing the reducing agent, and the output end of the storage tank and the input end of the liquid extraction pipe are both connected to the second sealed chamber.

[0020] Preferably, a flow channel extending into the mounting shaft is provided on the main shaft, the output end of the liquid extraction tube is connected to the flow channel, and the stirring rod is provided with a plurality of drainage holes connected to the flow channel.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The present invention performs a nitric acid reduction reaction in a sealed tank body. By arranging an air pressure cylinder, a sealing plate and a resistance spring to cooperate with each other, the nitrogen generated by the nitric acid reduction reaction is used to increase the pressure in the tank body. The increased air pressure pushes the sealing plate to move, so that the insertion rod is inserted into the insertion hole, and the installation shaft and the main shaft are driven. The pressure balance component is controlled to release the pressure, so that the tank body is maintained at a reasonable pressure reaction environment. After the reaction pressure is increased, the collision frequency of the reactants increases, thereby promoting the reaction. Increasing the pressure can change the equilibrium position of the reaction, causing the reduction reaction to shift toward the generation direction of nitrous acid and nitrogen, thereby improving the reduction efficiency. Nitric acid is a strong oxidant with high explosiveness. In the nitric acid reduction purification process, increasing the pressure can reduce the volatility of nitric acid and reduce the release of oxidants, thereby improving the safety of the equipment.

[0023] 2. The present invention supplements the reducing agent by providing a liquid suction pipe. After the internal pressure of the tank body increases, it means that the reducing agent has reacted and the nitric acid has not reacted completely. At this time, the installation shaft and the main shaft are driven to drive the second piston to move and draw the reducing agent in the storage tank into the tank body for reaction, thereby adding the reducing agent in batches, which can better control the progress of the reaction and avoid the reaction being out of control due to adding too much reducing agent at one time. The reaction rate and temperature can be better controlled, and the selectivity and yield of the reaction can be improved. In order to completely react the nitric acid, it is usually necessary to add an excess of reducing agent to ensure that the nitric acid is completely reduced. The air pressure generated by the reaction drives the installation shaft to rotate, thereby controlling the addition of the reducing agent. After the nitric acid in the waste liquid has reacted completely, no nitrogen gas is generated and the air pressure inside the tank body no longer changes. Therefore, excessive addition of reducing agent will not occur, which is conducive to accurate control of the amount of reducing agent used.

[0024] 3. The present invention provides a stirring rod with a drainage hole, and the reducing agent is added directly to different depths of the waste liquid through the drainage hole. Under the stirring action of the stirring rod, the reducing agent and the reactants are fully mixed, thereby improving the uniformity and effect of the reaction. At the same time, in the nitric acid reduction reaction, the reaction releases heat, causing the temperature of the reaction system to rise. Stirring can make the temperature of the reaction system more evenly distributed. Through stirring, the heat can be evenly dispersed, avoiding the generation of local areas with excessively high temperatures, reducing the occurrence of side reactions, preventing the aggregation and accumulation of precipitates in the reaction system, and maintaining the uniform dispersion of the reactants and the reducing agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the appearance and structure of the nitric acid reduction and purification equipment for coal-to-ethylene glycol proposed in the present invention;

[0026] Figure 2 This is a schematic cross-sectional view of the nitric acid reduction and purification equipment for coal-based ethylene glycol proposed in the present invention;

[0027] Figure 3 This is a schematic diagram of the internal structure of the nitric acid reduction purification equipment for coal-to-ethylene glycol proposed in the present invention;

[0028] Figure 4 This is a schematic structural diagram of the main shaft in the nitric acid reduction purification equipment for coal-to-ethylene glycol proposed by the present invention;

[0029] Figure 5 This is a schematic diagram of the central cross-sectional structure of the nitric acid reduction purification equipment for coal-to-ethylene glycol proposed by the present invention;

[0030] Figure 6 for Figure 5 Enlarged view of part A;

[0031] Figure 7 This is a schematic structural diagram of the pressure balance assembly in the nitric acid reduction and purification equipment for coal-to-ethylene glycol proposed by the present invention;

[0032] Figure 8 This is a schematic top view of the structure of the pressure balance assembly in the nitric acid reduction and purification equipment for coal-to-ethylene glycol proposed by the present invention;

[0033] Figure 9 This is a schematic structural diagram of Example 2 of the present invention.

[0034] In the figure: 1. Tank body; 11. Storage tank; 2. Main shaft; 21. Stirring rod; 22. Flow channel; 23. Drain hole; 3. Mounting shaft; 31. Plug hole; 32. Liquid extraction pipe; 33. Piston 2; 34. Push rod; 35. Guide rod 2; 4. Transmission control assembly; 41. Air cylinder; 42. Sealing plate; 43. Insert rod; 44. Resistance spring; 45. Magnet 1; 46. Adjustment rod; 47. Magnet 2; 5. Pressure balance assembly; 51. Vacuum cylinder; 52. Piston 1; 53. Connecting rod; 54. Guide plate; 55. Guide groove; 56. Guide rod 1; 6. Motor; 7. Connecting ring; 71. Sealing chamber 1; 72. Sealing chamber 2; 73. Sealing disk; 74. Gas collecting pipe. DETAILED DESCRIPTION

[0035] Example 1

[0036] Reference Figure 1-3 The nitric acid reduction and purification equipment for coal-based ethylene glycol includes a tank body 1, in which a main shaft 2, a motor 6, a mounting shaft 3, a transmission control component 4 and a pressure balance component 5 are arranged. The tank body 1 is a sealed tank body, and a feed pipe and a discharge pipe are arranged on the tank body 1. The waste liquid containing nitric acid is transported into the tank body 1 through the feed pipe and then closed. Nitric acid and the reducing agent react to produce nitrogen, which increases the internal air pressure of the tank body 1. The pressure balance component 5 can control the internal pressure of the tank body 1 to be maintained at a high level. After the reaction pressure is increased, the collision frequency of the reactants increases, thereby promoting the reaction. Increasing the pressure can change the equilibrium position of the reaction, prompting the reduction reaction to shift towards the generation direction of nitrous acid and nitrogen, thereby improving the reduction efficiency. Nitric acid is a strong oxidant with high explosiveness. In the nitric acid reduction and purification process, increasing the pressure can reduce the volatility of nitric acid and reduce the release of oxidants, thereby improving the safety of the equipment.

[0037] The main shaft 2 is coaxially rotated and arranged in the tank body 1. A plurality of stirring rods 21 are equidistantly arranged on the outer peripheral surface of the main shaft 2. The main shaft 2 rotates and drives the stirring rods 21 to stir the material in the tank body 1. Stirring can make the reactants and the reducing agent more evenly mixed together, increase the contact area between them, which helps to accelerate the reaction rate and promote the progress of the reaction. At the same time, in the nitric acid reduction reaction, the reaction will release heat, causing the temperature of the reaction system to rise. Stirring can make the temperature of the reaction system more evenly distributed. Through stirring, the heat can be evenly dispersed, avoiding the generation of local areas with excessively high temperatures, reducing the occurrence of side reactions, preventing the aggregation and accumulation of precipitates in the reaction system, and maintaining the uniform dispersion of the reactants and the reducing agent.

[0038] The motor 6 is fixedly mounted at the bottom of the tank 1. The output end of the motor 6 is connected to the main shaft 2 via a speed reducer. The motor 6 provides power, and the speed reducer reduces the rotational speed of the motor 6 output. It should be noted that during the nitric acid reduction reaction, the stirring conditions need to be adjusted according to the specific reaction system and requirements. Excessive stirring may cause gas escape or excessive foaming, affecting the reaction. Therefore, the speed reducer is used to control the main shaft 2 to maintain a reasonable speed to ensure the effectiveness and safety of the reaction.

[0039] The mounting shaft 3 is rotatably arranged on the top of the tank body 1, and the mounting shaft 3 is coaxially rotatably connected with the main shaft 2. The transmission purpose between the mounting shaft 3 and the main shaft 2 is controlled by the transmission control component 4. When the air pressure inside the tank body 1 does not reach the calibrated pressure, the mounting shaft 3 and the main shaft 2 do not transmit. When the pressure inside the tank body 1 exceeds the calibrated pressure, the main shaft 2 and the mounting shaft 3 are effectively transmitted to drive the mounting shaft 3 to rotate. When the mounting shaft 3 rotates, the pressure balance component 5 is driven to operate to release the pressure, so that the tank body 1 is maintained at a reasonable pressure response environment.

[0040] Reference Figure 4-6 The transmission control assembly 4 includes a plurality of air cylinders 41 fixedly arranged on the outer wall of the main shaft 2. A sealing sheet 42 is provided in the air cylinder 41 for sealing and sliding. A resistance structure for balancing the air pressure is provided between the sealing sheet 42 and the air cylinder 41. The sealed cavity formed between the air cylinder 41 and the sealing sheet 42 is at normal pressure. After the nitric acid in the tank body 1 is reacted to generate nitrogen, the air pressure on the inner wall of the tank body 1 increases, and a pressure difference is formed inside and outside the air cylinder 41. The air pressure inside the tank body 1 will apply thrust to the sealing sheet 42, and the resistance structure acts on the sealing. The resistance on the sheet 42 is equal to the thrust caused to the sealing sheet 42 under the calibrated pressure. When the air pressure in the tank body 1 exceeds the calibrated air pressure, the sealing sheet 42 will be pushed to move. The sealing sheet 42 is fixed with an insertion rod 43 near one end of the mounting shaft 3. The outer wall of the mounting shaft 3 is provided with a socket 31 adapted to the insertion rod 43. When the sealing sheet 42 moves, it drives the insertion rod 43 forward, so that the insertion rod 43 is inserted into the socket 31, so that the mounting shaft 3 and the main shaft 2 are circumferentially limited. Therefore, the main shaft 2 can effectively transmit the mounting shaft 3.

[0041] Reference Figure 6 The resistance structure includes a resistance spring 44, one end of which is fixedly connected to the bottom of the air pressure cylinder 41, and the other end of the resistance spring 44 is fixedly connected to the sealing plate 42. The sealing plate 42 is blocked by the elastic force of the resistance spring 44. Only when the thrust generated by the air pressure difference is greater than the elastic force of the resistance spring 44, the driving rod 43 is inserted into the socket 31, and after the air pressure is reduced, the resistance spring 44 drives the sealing plate 42 to rebound, thereby disengaging the rod 43 from the socket 31, making the transmission of the mounting shaft 3 and the main shaft 2 invalid.

[0042] Reference Figure 7-8When the piston 1 is in the air-conditioning state, the air in the air-conditioning valve 51 is in the air-conditioning state, and the air inlet and outlet ends of the air-conditioning valve 51 are respectively provided with one-way valves 1 and 2. When the piston 1 is in the air-conditioning state, the air in the air-conditioning valve 51 is driven to flow in one direction. The air inlet and outlet ends of the air-conditioning valve 51 are both provided near one end of the air-conditioning valve 51. The installation directions of the two one-way valves 1 are opposite. When the piston 1 is in the air-conditioning valve 51, the air in the air-conditioning valve 51 is sucked in from the air inlet end and discharged from the air outlet end. The piston 1 is fixed with a connecting rod 53 at one end away from the installation shaft 3. The connecting rod 53 is used to control the movement of the piston 1 52. A driving mechanism for driving the connecting rod 53 to move axially is provided in the tank body 1. When the installation shaft 3 and the main shaft 2 are effectively transmitted, and under the action of the driving mechanism, the connecting rod 53 drives the piston 1 52 to reciprocate in the air-conditioning valve 51.

[0043] Reference Figure 3 and 8 The driving mechanism includes a guide plate 54 fixedly arranged on the inner wall of the tank body 1. When the vacuum cylinder 51 and the connecting rod 53 rotate with the installation shaft 3, they move relative to the guide plate 54. A guide groove 55 is provided on the guide plate 54. The guide groove 55 is an annular groove with a wavy outline. A guide rod 1 56 is fixedly provided at the end of the connecting rod 53. The guide rod 1 56 extends into the guide groove 55 and abuts against the inner wall of the guide groove 55. The guide rod 1 56 rotates with the connecting rod 53 and moves along the outline of the guide groove 55 under the limiting action of the guide groove 55, so that the connecting rod 53 reciprocates in the radial direction of the installation shaft 3, driving the piston 1 52 to reciprocate in the vacuum cylinder 51 to extract and exhaust.

[0044] Reference Figure 5 and 7 A sealing connection ring 7 is provided on the top of the installation shaft 3, and a coaxial sealing chamber 71 and a sealing chamber 2 72 are opened in the sealing connection ring 7. A sealing disk 73 is provided on the top of the sealing connection ring 7 for sealing rotation. A gas collecting pipe 74 is fixedly provided on the top of the sealing disk 73. The gas collecting pipe 74 and the output end of the vacuum cylinder 51 are both connected to the sealing chamber 71. When the vacuum cylinder 51 is exhausted, the gas is transported to the sealing chamber 71, and the gas is collected in the sealing chamber 71 and discharged through the gas collecting pipe 74. Since the gas collecting pipe 74 needs to be connected to an external gas collection device, the gas collecting pipe 74 is connected to the sealing chamber 71 by connecting with the sealing disk 73. When the installation shaft 3 rotates, it will not affect the position of the gas collecting pipe 74, and prevent the gas collecting pipe 74 from being entangled and twisted.

[0045] Reference Figure 3 、 7and 8, and also include a liquid extraction tube 32 fixedly arranged on the outer wall of the mounting shaft 3, and a one-way valve 2 is provided at the output end and the input end of the liquid extraction tube 32, and the two one-way valves 2 are set in opposite directions, and a piston 2 33 is sealed and slidably arranged in the liquid extraction tube 32. Under the action of the one-way valve 2, the piston 2 33 drives the liquid to flow in one direction when it reciprocates along the liquid extraction tube 32, and a push rod 34 is fixedly arranged on the side wall of the piston 2 33, and a guide rod 2 35 is fixedly arranged at the end of the push rod 34, and the guide rod 2 35 extends into the guide groove 55 and resists the inner wall of the guide groove 55. When the liquid extraction tube 32 rotates with the mounting shaft 3, the position of the guide rod 2 35 in the guide groove 55 changes continuously, so that the guide rod 2 35 moves along the contour of the guide groove 55, driving the piston 2 33 to reciprocate in the liquid extraction tube 32 to extract liquid.

[0046] Reference Figure 1-3 A storage tank 11 for storing the reducing agent is provided on the top of the tank body 1. The output end of the storage tank 11 and the input end of the liquid extraction pipe 32 are both connected to the sealed chamber 2 72. The reducing agent in the storage tank 11 flows into the sealed chamber 2 72. When the liquid extraction pipe 32 extracts liquid, the reducing agent in the sealed chamber 2 72 is extracted into the tank body 1. The output end of the storage tank 11 is connected to the sealed chamber 2 72 through the sealing disk 73 to prevent the rotation of the mounting shaft 3 from affecting the connection part of the storage tank 11.

[0047] When reducing and purifying waste liquid, some reducing agent needs to be added through the feed pipe to start the reaction. In the subsequent reaction, the internal pressure of the tank body 1 increases, causing the installation shaft 3 and the main shaft 2 to drive, driving the liquid extraction pipe 32 to draw the reducing agent in the storage tank 11 into the tank body 1 to replenish the reducing agent. This method of adding the reducing agent in batches can better control the progress of the reaction, avoid adding too much reducing agent at one time and causing the reaction to run away, and can better control the reaction rate and temperature, thereby improving the selectivity and yield of the reaction. In order to completely react nitric acid, an excess amount of reducing agent is usually required. After the internal pressure of the tank body 1 increases, it means that the nitric acid has not reacted completely. To ensure that the nitric acid is completely reduced, the gas pressure generated by the reaction causes the main shaft 2 to drive the installation shaft 3 to rotate, thereby controlling the addition of reducing agent. After the nitric acid in the waste liquid has reacted completely, the small amount of reducing agent added can no longer react to produce nitrogen gas, and the internal pressure of the tank body 1 no longer changes. Therefore, the main shaft 2 and the installation shaft 3 cannot be driven again, and excessive addition of reducing agent will not occur, which is conducive to accurately controlling the amount of reducing agent and judging the degree of reaction.

[0048] Reference Figure 5A flow channel 22 extending into the mounting shaft 3 is provided on the main shaft 2, and the flow channel 22 extends vertically from the mounting shaft 3 into the main shaft 2. When the mounting shaft 3 and the main shaft 2 rotate relative to each other, the connectivity of the flow channel 22 is not affected. The output end of the liquid extraction tube 32 is connected to the flow channel 22, and a plurality of drainage holes 23 connected to the flow channel 22 are provided on the stirring rod 21. When the liquid extraction tube 32 draws in and outputs the reducing agent, the reducing agent enters the flow channel 22 and is directly added to different depths of the waste liquid through different drainage holes 23. Under the stirring action of the stirring rod 21, the reducing agent and the reactant are fully mixed, thereby improving the uniformity and effect of the reaction.

[0049] Example 2

[0050] Reference Figure 9 The resistance structure includes a magnet 1 45 fixedly arranged at the bottom of the air pressure cylinder 41, an adjusting rod 46 is threadedly connected to the sealing plate 42, and a magnet 2 47 is fixedly arranged at the end of the adjusting rod 46. The magnet 1 45 and the magnet 2 47 are correspondingly arranged and have the same magnetic poles at one end facing each other. The thrust generated by the pressure difference between the inside and outside of the air pressure cylinder 41 is balanced by the repulsive force between the magnet 1 45 and the magnet 2 47. By rotating the adjusting rod 46, the initial distance between the magnet 1 45 and the magnet 2 47 can be controlled, thereby realizing the adjustment of the initial size of the repulsive force. By changing the initial size of the repulsive force, the thrust balance point generated by the pressure difference can be controlled, thereby realizing the control of the calibration pressure.

[0051] The specific working principle of the present invention is as follows:

[0052] During use, the waste liquid containing nitric acid is transported into the tank body 1 through the feed pipe, and a small amount of reducing agent is added into the tank body 1 to start the reaction. The motor 6 is started, and the main shaft 2 is driven to rotate at a low speed in conjunction with the reducer to stir the reactants so that the reactants and the reducing agent are mixed more evenly and the contact area between them is increased, which helps to accelerate the reaction rate.

[0053] Nitric acid reacts with the reducing agent to produce nitrogen, which increases the internal pressure of the tank body 1. When the pressure in the tank body 1 exceeds the calibrated pressure, the pressure difference between the inside and outside of the air cylinder 41 exerts a thrust on the sealing piece 42, pushing the sealing piece 42 to move, so that the insertion rod 43 is inserted into the insertion hole 31, so that the circumferential limit between the installation shaft 3 and the main shaft 2 is effectively transmitted;

[0054] The mounting shaft 3 rotates along with the main shaft 2, driving the vacuum cylinder 51 and the liquid extraction pipe 32 to rotate, so that the guide rod 1 56 and the guide rod 2 35 move along the contour of the guide groove 55 under the action of the guide groove 55, driving the piston 1 52 to reciprocate in the vacuum cylinder 51 to extract and exhaust gas, which is discharged to the external gas collection device through the collecting pipe 74, so that the internal air pressure of the tank body 1 is reduced, and at the same time, the piston 2 33 is driven to reciprocate in the liquid extraction pipe 32 to extract liquid, and the reducing agent is drawn into the tank body 1 for replenishment. After the air pressure drops to the calibrated pressure, the sealing plate 42 is pushed outward under the action of the resistance spring 44, so that the insertion rod 43 is separated from the insertion hole 31. At this time, the mounting shaft 3 is disengaged from the main shaft 2;

[0055] After the last gas extraction and reducing agent replenishment, the gas pressure does not rise for a long time, indicating that the nitric acid has completely reacted. The equipment can be stopped and the reactants can be discharged.

Claims

1. A nitric acid reduction purification device for coal-based ethylene glycol, comprising a tank body (1), characterized in that: The tank body (1) is provided with: A main shaft (2) is coaxially rotatably disposed in the tank body (1), and a plurality of stirring rods (21) are equidistantly disposed on the outer circumference of the main shaft (2); A motor (6) is fixedly arranged at the bottom of the tank body (1), and an output end of the motor (6) is connected to the main shaft (2) via a speed reducer; A mounting shaft (3) is rotatably mounted on the top of the tank body (1), wherein the mounting shaft (3) is coaxially rotatably connected to the main shaft (2); The transmission control assembly (4) includes a plurality of air cylinders (41) fixedly arranged on the outer wall of the main shaft (2), a sealing sheet (42) is provided in a sealing and sliding manner in the air cylinder (41), a resistance structure for balancing air pressure is provided between the sealing sheet (42) and the air cylinder (41), an insertion rod (43) is fixedly provided near one end of the sealing sheet (42) near the installation shaft (3), and a socket (31) adapted to the insertion rod (43) is provided on the outer wall of the installation shaft (3); The pressure balancing assembly (5) comprises a plurality of vacuum cylinders (51) radially arranged on the outer wall of the mounting shaft (3), a piston 1 (52) being sealingly and slidingly arranged in the vacuum cylinder (51), a connecting rod (53) being fixedly arranged at one end of the piston 1 (52) away from the mounting shaft (3), a driving mechanism for driving the connecting rod (53) to move axially is arranged in the tank body (1), the air inlet end and the air outlet end of the vacuum cylinder (51) are both arranged near one end of the mounting shaft (3), and a one-way valve 1 is arranged at the air inlet end and the air outlet end of the vacuum cylinder (51), so that when the piston 1 (52) reciprocates, the driving gas flows in one direction.

2. The nitric acid reduction purification equipment for coal-to-ethylene glycol according to claim 1, characterized in that: The resistance structure includes a resistance spring (44), one end of the resistance spring (44) is fixedly connected to the bottom of the air pressure cylinder (41), and the other end of the resistance spring (44) is fixedly connected to the sealing sheet (42).

3. The nitric acid reduction purification equipment for coal-to-ethylene glycol according to claim 1, characterized in that: The resistance structure includes a magnet 1 (45) fixedly arranged at the bottom of the air pressure cylinder (41), an adjusting rod (46) is threadedly connected to the sealing plate (42), and a magnet 2 (47) is fixedly arranged at the end of the adjusting rod (46), and the magnet 1 (45) and the magnet 2 (47) are correspondingly arranged and have the same magnetic poles at one end facing each other.

4. The nitric acid reduction purification equipment for coal-to-ethylene glycol according to claim 1, characterized in that: The driving mechanism comprises a guide plate (54) fixedly arranged on the inner wall of the tank body (1), a guide groove (55) being provided on the guide plate (54), a guide rod (56) being fixedly arranged at the end of the connecting rod (53), and the guide rod (56) extending into the guide groove (55) and abutting against the inner wall of the guide groove (55).

5. The nitric acid reduction purification equipment for coal-to-ethylene glycol according to claim 4, characterized in that: The guide groove (55) is an annular groove with a wavy profile.

6. The nitric acid reduction purification equipment for coal-to-ethylene glycol according to claim 1, characterized in that: A sealing connection ring (7) is provided on the top of the installation shaft (3), and a coaxially arranged sealing chamber 1 (71) and a sealing chamber 2 (72) are provided in the sealing connection ring (7). A sealing disk (73) is provided on the top of the sealing connection ring (7) for sealing rotation, and a gas collecting pipe (74) is fixedly provided on the top of the sealing disk (73). The gas collecting pipe (74) and the output end of the vacuum cylinder (51) are both connected to the sealing chamber 1 (71).

7. The nitric acid reduction purification equipment for coal-to-ethylene glycol according to claim 4, characterized in that: It also includes a liquid extraction tube (32) fixedly arranged on the outer wall of the mounting shaft (3), wherein the output end and the input end of the liquid extraction tube (32) are both provided with a one-way valve 2, a piston 2 (33) is sealingly and slidably provided in the liquid extraction tube (32), a push rod (34) is fixedly provided on the side wall of the piston 2 (33), and a guide rod 2 (35) is fixedly provided at the end of the push rod (34), and the guide rod 2 (35) extends into the guide groove (55) and abuts against the inner wall of the guide groove (55).

8. The nitric acid reduction and purification equipment for coal-to-ethylene glycol according to claim 7, characterized in that: A storage tank (11) for storing the reducing agent is provided on the top of the tank body (1), and the output end of the storage tank (11) and the input end of the liquid extraction pipe (32) are both connected to the second sealed chamber (72).

9. The nitric acid reduction and purification equipment for coal-to-ethylene glycol according to claim 7, characterized in that: The main shaft (2) is provided with a flow channel (22) extending into the mounting shaft (3); the output end of the liquid extraction tube (32) is connected to the flow channel (22); and the stirring rod (21) is provided with a plurality of liquid discharge holes (23) connected to the flow channel (22).

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