A wet product ammonium chloride drying and recovery system

Abstract

The present application relates to the field of ammonium chloride drying, and discloses a wet ammonium chloride drying and recycling system, which comprises a centrifugal discharge bin, a bidirectional horizontal scraper conveyor and a conical mixer, the discharge end of the centrifugal discharge bin is connected with a first air lock fan, the discharge port of the first air lock fan is opposite to the bidirectional horizontal scraper conveyor, the discharge end of the bidirectional horizontal scraper conveyor is communicated with the conical mixer, the discharge port of the conical mixer is connected with a second air lock fan and a third air lock fan, the discharge end of the third air lock fan is connected with a vacuum paddle dryer, the discharge port of the vacuum paddle dryer is connected with a fourth air lock fan and a fifth air lock fan, the discharge port of the fifth air lock fan is provided with a ton bag, and the gas outlet end of the vacuum paddle dryer is connected with a heat exhaust pipe and a circulating recycling mechanism. The wet ammonium chloride drying and recycling system can fully dry and recycle ammonium chloride with low energy consumption, safety and environmental protection, and can not release dust and gas during the drying process, and can cool, purify and recycle mixed volatile gas.

Description

Technical Field

[0001] This invention belongs to the field of ammonium chloride drying, and specifically relates to a wet ammonium chloride drying and recovery system. Background Technology

[0002] Centrifugation of the TMOF alcoholysis solution produces wet ammonium chloride, with the following composition: 90% ammonium chloride, 7.8%–8.2% o-dichlorobenzene, 0.1%–0.3% methanol, 1.2%–1.6% trimethyl orthoformate, 0.05%–0.2% methyl formate, and <0.1% triazine. The wet ammonium chloride needs to be dried and dehumidified until the product reaches the required moisture content.

[0003] Currently, wet ammonium chloride is typically dried using a circulating fluidized bed dryer. A circulating fluidized bed dryer mainly consists of a heater, a fluidized bed dryer, a cooling-condenser, a gas-liquid separator, a circulating fan, and a low-dew-point nitrogen source (or a low-dew-point compressed air source). In closed-loop drying operation, wet ammonium chloride is metered into the agitated fluidized bed dryer via a feeder. Under the action of hot air (nitrogen or air), the moisture content of the wet ammonium chloride is continuously evaporated and separated. The drying medium repeatedly undergoes moisture loading and dehumidification processes in the closed-loop drying system until the product reaches the required moisture content. Fine powder raised during the drying process is captured by a bag filter at the top of the drying chamber and, through an automatic vibration mechanism, detaches from the filter bag surface and returns to the material layer in the drying chamber. Volatile matter evaporated from the material layer is carried out of the dryer with the drying medium and condensed into liquid in the subsequent cooling-condenser for recycling. Non-condensable drying media are reheated and recycled. When a leak occurs in the closed-loop dry operating system or other reasons cause pressure fluctuations, the nitrogen tank will automatically replenish the system with an appropriate amount of nitrogen.

[0004] Existing circulating fluidized bed dryers can dry wet ammonium chloride, but the moisture content of the dried ammonium chloride is greater than 1%, resulting in substandard product quality and low market price. Furthermore, the temporary storage areas for wet ammonium chloride in bulk bags and the surrounding drying areas release flammable, explosive, and toxic gases such as methanol, methyl formate, trimethyl orthoformate, and o-dichlorobenzene, causing significant odors and environmental pollution at the storage sites and surrounding areas.

[0005] Therefore, the present invention provides a wet ammonium chloride drying and recovery system with better drying effect and safer and more stable operation. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a wet ammonium chloride drying and recovery system. This invention aims to solve the problems of poor drying effect and lack of treatment of harmful gases such as o-dichlorobenzene in existing ammonium chloride drying devices.

[0007] To achieve the above objectives, the present invention provides a wet ammonium chloride drying and recovery system, comprising a centrifugal discharge hopper, a bidirectional horizontal scraper conveyor, and a conical mixer. The centrifugal discharge hopper is used to store and discharge the wet ammonium chloride obtained after centrifugation of TMOF alcoholysis liquid. A first airlock fan is connected to the discharge end of the centrifugal discharge hopper. A sealing shell is fitted around the outside of the bidirectional horizontal scraper conveyor. The discharge port of the first airlock fan communicates with the sealing shell. The end of the sealing shell near the conical mixer is connected to the conical mixer. The discharge port is connected to a second shut-off fan, the discharge port of the second shut-off fan is connected to a third shut-off fan, the discharge end of the third shut-off fan is connected to a vacuum paddle dryer, the vacuum paddle dryer is used to dry wet ammonium chloride, the discharge port of the vacuum paddle dryer is connected to a fourth shut-off fan, the discharge port of the fourth shut-off fan is connected to a fifth shut-off fan, the discharge port of the fifth shut-off fan is equipped with a ton bag, the air outlet of the vacuum paddle dryer is connected to a heat exhaust duct, and the discharge end of the heat exhaust duct is connected to a circulation and recovery mechanism.

[0008] Furthermore, the vacuum paddle dryer includes a shell and a heating cylinder disposed at the center of the shell. A motor is provided on one side of the shell, and the output end of the motor is connected to a rotating shaft. The rotating shaft is connected to the heating cylinder via gears. Paddles are provided on the outer side of the heating cylinder. Both the shell and the heating cylinder are provided with heating chambers. A connecting pipe is provided at the end of the shell away from the motor and is rotatably connected to the heating cylinder. The heating chamber of the heating cylinder communicates with the connecting pipe. A steam insulation pipe is connected to the connecting pipe and the heating chamber of the shell. A control valve, a pressure transmitter, and a temperature transmitter are provided on the steam insulation pipe. A steam condensation insulation pipe is connected to the lower end of the connecting pipe and the heating chamber of the shell. A control valve is provided on the steam condensation insulation pipe.

[0009] Furthermore, the recycling mechanism includes an absorption tower connected to the outlet of the exhaust duct. Several nozzles are installed in the upper part of the inner cavity of the absorption tower. The water inlet of each nozzle is connected to a spray pipe, which is connected to a spray liquid circulation mechanism. An exhaust pipe is connected to the top of the absorption tower, and an oxygen content analyzer is installed on the exhaust pipe. A power unit is connected to the outlet of the exhaust pipe. A drain pipe is connected to the bottom of the absorption tower, and a primary hydrocyclone is connected to the outlet of the drain pipe. A delivery pipe is connected to the outlet of the primary hydrocyclone, and a secondary hydrocyclone is connected to the outlet of the delivery pipe. A liquid supply unit is connected to the outlet of the secondary hydrocyclone. The system includes a supply pipe, a solvent storage tank connected to the outlet of the supply pipe, a partition inside the solvent storage tank, a solvent inlet pipe connected to the upper end of the solvent storage tank, a solvent preparation pump on the solvent inlet pipe, discharge pipes connected to the lower outlets of the primary and secondary hydrocyclones, a discharge pipe connected to the sedimentation section of the partition of the solvent storage tank, a discharge pipe connected to the discharge end of the discharge pipe and the discharge pipe connected to the same return pipe, the discharge end of the return pipe extending into the high-level centrifuge tank of the alcoholysis liquid, a transfer pump on the return pipe, and control valves on the spray pipe, exhaust pipe, discharge pipe, supply pipe, solvent inlet pipe, discharge pipe, discharge pipe and return pipe.

[0010] Furthermore, the spray liquid circulation mechanism includes a solvent riser pipe connected to the solvent storage tank, an absorption circulation cooler connected to the outlet end of the solvent riser pipe, an absorption liquid circulation pump, a control valve and a pressure transmitter on the solvent riser pipe, an outlet at the upper end of the absorption circulation cooler connected to the spray pipe, and a temperature transmitter on the spray pipe.

[0011] Furthermore, the power assembly includes a solvent delivery pipe connected to a solvent storage tank. The outlet end of the solvent delivery pipe is connected to a vacuum circulation cooler. The solvent delivery pipe is equipped with a vacuum circulation pump, a control valve, and a pressure transmitter. The outlet end of the vacuum circulation cooler is connected to a solvent guide pipe. The outlet end of the solvent guide pipe is connected to a venturi tower. The outlet end of the venturi tower is connected to a solvent circulation pipe. The outlet end of the solvent circulation pipe is connected to the solvent storage tank. The exhaust pipe is connected to the side of the venturi tower. The solvent guide pipe, the solvent circulation pipe, and the exhaust pipe are equipped with control valves.

[0012] Furthermore, the wet ammonium chloride drying and recovery system is also equipped with a tail gas emission pipe. The tail gas emission pipe is provided with tail gas emission branch pipes connected to the centrifugal discharge bin, the sealing shell of the bidirectional horizontal scraper conveyor, the conical mixer and the solvent storage tank. The tail gas emission pipe is equipped with a tail gas emission fan, and the exhaust end of the tail gas emission pipe is equipped with a tail gas absorption tower.

[0013] Furthermore, the drying chamber and the discharge pipe of the vacuum paddle dryer are connected to a nitrogen pipe, and a control valve is provided on the nitrogen pipe.

[0014] Furthermore, a ton bag is also provided at the end of the sealing shell away from the conical mixer.

[0015] Furthermore, the drying chamber of the vacuum paddle dryer has a drying temperature ≤100℃ and an oxygen content <0.5%.

[0016] Beneficial effects:

[0017] 1. The present invention provides a wet ammonium chloride drying and recovery system comprising a centrifugal discharge hopper, a bidirectional horizontal scraper conveyor, a conical mixer, a first shut-off fan, a second shut-off fan, a third shut-off fan, a vacuum paddle dryer, a fourth shut-off fan, a fifth shut-off fan, and a heating cylinder. This system maintains a vacuum in the drying chamber of the vacuum paddle dryer, allowing for negative pressure distillation of the wet ammonium chloride within the drying chamber, resulting in more thorough drying. The moisture content of the dried ammonium chloride is <0.5%. Furthermore, the drying and recovery system utilizes waste heat from the production process via a steam pipe to heat and dry the wet ammonium chloride, further reducing energy consumption.

[0018] 2. The wet ammonium chloride drying and recovery system of the present invention is equipped with a pressure transmitter, a temperature transmitter and an oxygen content analyzer, which can monitor the pressure and temperature of each pipeline in real time, thus improving safety.

[0019] 3. The wet ammonium chloride drying and recovery system of the present invention is equipped with an absorption tower, a primary hydrocyclone, a secondary hydrocyclone, a solvent storage tank, a transfer pump, an absorption circulation cooler, an absorption liquid circulation pump, a vacuum circulation cooler, a vacuum circulation pump, and a venturi tower. It can cool and purify the hot waste gas after material drying. The spray liquid can be recycled again, with little impact on the external environment. The solid-liquid mixture after solid-liquid separation is returned to the high-level centrifuge tank of alcoholysis liquid for subsequent centrifugation and secondary drying and recovery.

[0020] 4. The present invention provides a wet ammonium chloride drying and recovery system with an overall sealed drying environment and is equipped with a tail gas exhaust fan and a tail gas absorption tower. It can centrally treat the methanol, methyl formate, trimethyl orthoformate, o-dichlorobenzene and other gases generated by the volatilization of wet ammonium chloride during the drying process, making it safer and more environmentally friendly.

[0021] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a wet ammonium chloride drying and recovery system according to the present invention;

[0023] Figure 2This is a front view of a partial cross-section of a vacuum paddle dryer;

[0024] Figure 3 This is a flowchart of a wet ammonium chloride drying and recovery system according to the present invention;

[0025] The attached diagram is labeled as follows: 1. Centrifugal discharge hopper; 2. Bidirectional horizontal scraper conveyor; 3. Conical mixer; 4. First shut-off fan; 5. Second shut-off fan; 6. Third shut-off fan; 7. Vacuum paddle dryer; 8. Fourth shut-off fan; 9. Fifth shut-off fan; 10. Heating cylinder; 11. Absorption tower; 12. First-stage hydrocyclone; 13. Second-stage hydrocyclone; 14. Solvent storage tank; 15. Transfer pump; 16. Absorption circulation cooler; 17. Absorption liquid circulation pump; 18. Vacuum circulation cooler; 19. Vacuum circulation pump; 20. Venturi tower; 21. Tail gas exhaust fan; 22. Bag centrifuge. Detailed Implementation

[0026] To make the technical solutions, advantages, and objectives of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of this application.

[0027] like Figure 1-3 As shown, the present invention provides a wet ammonium chloride drying and recovery system, including a centrifugal discharge bin 1, a bidirectional horizontal scraper conveyor 2, and a conical mixer 3. The centrifugal discharge bin 1 is used to store and discharge the wet ammonium chloride obtained after centrifugation of TMOF alcoholysis liquid. The discharge end of the centrifugal discharge bin 1 is connected to a first shut-off fan 4. A sealing shell is fitted on the outside of the bidirectional horizontal scraper conveyor 2. The discharge port of the first shut-off fan 4 is directly connected to the bidirectional horizontal scraper conveyor 2 and the sealing shell. The right end of the sealed shell is connected to the conical mixer 3. The discharge port of the conical mixer 3 is connected to a second shut-off fan 5. The discharge port of the second shut-off fan 5 is connected to a third shut-off fan 6. The discharge end of the third shut-off fan 6 is connected to a vacuum paddle dryer 7, which is used to dry wet ammonium chloride. The discharge port of the vacuum paddle dryer 7 is connected to a fourth shut-off fan 8. The discharge port of the fourth shut-off fan 8 is connected to a fifth shut-off fan 9. A ton bag is installed below the discharge port of the fifth shut-off fan 9. A ton bag is also installed on the left end of the sealed shell. The air outlet of the vacuum paddle dryer 7 is connected to a heat exhaust duct, and the discharge end of the heat exhaust duct is connected to a circulation and recovery mechanism.

[0028] The vacuum paddle dryer 7 includes a shell and a heating cylinder 10 located at the center of the shell. A motor is installed on the left side of the shell, and a rotating shaft is fixedly connected to the output end of the motor. The rotating shaft is connected to the heating cylinder 10 via a transmission gear. The heating cylinder 10 is rotatably connected to the shell of the vacuum paddle dryer 7 in a sealed manner. Paddles are installed on the outer side of the heating cylinder 10 corresponding to the drying chamber of the vacuum paddle dryer 7. Both the shell and the heating cylinder 10 of the vacuum paddle dryer 7 are provided with heating chambers. A connecting pipe is fixedly connected to the right end of the shell and rotatably connected to the heating cylinder 10. The heating chamber of the heating cylinder 10 communicates with the connecting pipe. A steam insulation pipe is connected to the right end of the connecting pipe and the upper end of the heating chamber of the shell. A control valve, a pressure transmitter, and a temperature transmitter are installed on the steam insulation pipe. A steam condensation insulation pipe is connected to the lower end of the connecting pipe and the heating chamber of the shell. A control valve is installed on the steam condensation insulation pipe.

[0029] The recycling mechanism includes an absorption tower 11 connected to the outlet of a heat exhaust duct. Several nozzles are installed on the upper part of the inner cavity of the absorption tower 11. The water inlet of each nozzle is connected to a spray pipe, which is connected to a spray liquid circulation mechanism. An exhaust pipe is connected to the top of the absorption tower 11, and an oxygen content analyzer is installed on the exhaust pipe. A power unit is connected to the outlet of the exhaust pipe. A drain pipe is connected to the bottom of the absorption tower 11, and a primary hydrocyclone 12 is connected to the outlet of the drain pipe. A delivery pipe is connected to the outlet of the primary hydrocyclone 12, and a secondary hydrocyclone 13 is connected to the outlet of the delivery pipe. A supply pipe is connected to the outlet of the secondary hydrocyclone 13. The outlet end of the pipe is connected to a solvent storage tank 14. A baffle is installed inside the solvent storage tank 14. A solvent inlet pipe is connected to the upper end of the solvent storage tank 14. A solvent preparation pump is installed on the solvent inlet pipe. The discharge ports at the lower ends of the first-stage hydrocyclone 12 and the second-stage hydrocyclone 13 are both connected to discharge pipes. A discharge pipe is connected to the sedimentation part of the baffle of the solvent storage tank 14. The discharge pipe and the discharge end of the discharge pipe are connected to the same return pipe. The discharge end of the return pipe extends into the high-level centrifuge tank of the alcoholysis liquid. A transfer pump 15 is installed on the return pipe. Control valves are installed on the spray pipe, exhaust pipe, liquid discharge pipe, liquid supply pipe, solvent inlet pipe, discharge pipe, discharge pipe and return pipe.

[0030] The spray liquid circulation mechanism includes a solvent riser pipe connected to the solvent storage tank 14. The outlet end of the solvent riser pipe is connected to an absorption circulation cooler 16. An absorption liquid circulation pump 17, a control valve, and a pressure transmitter are installed on the solvent riser pipe. The outlet at the upper end of the absorption circulation cooler 16 is connected to the spray pipe. A temperature transmitter is installed on the spray pipe.

[0031] The power assembly includes a solvent delivery pipe connected to a solvent storage tank 14. The outlet of the solvent delivery pipe is connected to a vacuum circulating cooler 18. A vacuum circulating pump 19, a control valve, and a pressure transmitter are installed on the solvent delivery pipe. The outlet of the vacuum circulating cooler 18 is connected to a solvent guide pipe. The outlet of the solvent guide pipe is connected to a venturi 20. The outlet of the venturi 20 is connected to a solvent circulation pipe. The outlet of the solvent circulation pipe is connected to the solvent storage tank 14. An exhaust pipe is connected to the side of the venturi 20. Control valves are installed on the solvent guide pipe, the solvent circulation pipe, and the exhaust pipe.

[0032] The wet ammonium chloride drying and recovery system is also equipped with a tail gas emission pipe. The tail gas emission pipe is equipped with a tail gas emission branch pipe connected to the centrifugal discharge bin 1, the shell of the bidirectional horizontal scraper conveyor 2, the conical mixer 3 and the solvent storage tank 14. A tail gas emission fan 21 is installed on the tail gas emission pipe, and the exhaust end of the tail gas emission pipe is connected to a tail gas absorption tower.

[0033] As a preferred embodiment, the drying chamber and the discharge pipe of the vacuum paddle dryer 7 are connected to a nitrogen pipe, and a control valve is provided on the nitrogen pipe.

[0034] As a preferred embodiment, during the drying of wet ammonium chloride, the environment of the drying chamber of the vacuum paddle dryer 7 is controlled as follows: drying temperature ≤100℃, oxygen content <0.5%.

[0035] The operation process of the wet ammonium chloride drying and recovery system of the present invention is as follows: The TMOF alcoholysis liquid is centrifuged by a bag centrifuge 22 to obtain wet ammonium chloride. The wet ammonium chloride falls onto a bidirectional horizontal scraper conveyor 2 through a centrifuge discharge bin 1 and a first air blower 4. Then, it is lifted by the bidirectional horizontal scraper conveyor 2 to a conical mixer 3 for stirring and mixing. After stirring and mixing, the wet ammonium chloride enters a vacuum paddle dryer 7 through a second air blower 5 and a third air blower 6. The vacuum paddle dryer 7 dries the wet ammonium chloride. During the drying process, the wet ammonium chloride will generate mixed volatile gas, which is discharged to the circulation and recovery mechanism through a heat exhaust duct. After the drying process is complete, ammonium chloride with a moisture content of <0.5% is obtained. Then, the motor on the left side of the vacuum paddle dryer 7 is started. The motor drives the heating cylinder 10 to rotate through the shaft and transmission gear. The paddles rotate synchronously with the heating cylinder 10, thus spirally pushing the ammonium chloride with a moisture content of <0.5% towards the discharge port of the vacuum paddle dryer 7. After that, the dried ammonium chloride falls into the ton bag through the fourth shut-off fan 8 and the fifth shut-off fan 9. When wet ammonium chloride enters the vacuum paddle dryer 7 and when ammonium chloride with a moisture content of <0.5% leaves the vacuum paddle dryer 7, the corresponding shut-off fans are adjusted to minimize the entry of outside air into the vacuum paddle dryer 7, maintain the vacuum degree of the vacuum paddle dryer 7, improve the heating effect, and reduce energy consumption.

[0036] After the bidirectional horizontal scraper conveyor 2 has been running for a period of time, some wet ammonium chloride will adhere to the surface of the bidirectional horizontal scraper conveyor 2. When there is a lot of wet ammonium chloride, the bidirectional horizontal scraper conveyor 2 can be driven to run to the left in order to remove the excess wet ammonium chloride.

[0037] The heat required for drying in the vacuum paddle dryer 7 comes from the steam insulation pipe. The steam generated during the production process in the factory enters the heating chamber of the vacuum paddle dryer 7 shell and the heating cylinder 10 through the steam insulation pipe. Through heat transfer, the wet ammonium chloride is heated from the surroundings and the center at the same time. After the steam in the vacuum paddle dryer 7 shell and the heating chamber of the heating cylinder 10 is condensed, it is discharged to the outside through the steam condensation insulation pipe at the lower end.

[0038] The process of the recycling mechanism for handling mixed volatile gases is as follows: the vacuum circulation pump 19 lifts the solvent from the clean side of the partition of the solvent storage tank 14 to the vacuum circulation cooler 18. The vacuum circulation cooler 18 cools the solvent. After cooling, the solvent is discharged to the venturi tower 20 and then flows back into the solvent storage tank 14. When the solvent flows in the venturi tower 20, it will generate a traction force, thereby driving the mixed volatile gases to flow along the heat exhaust pipe, the absorption tower 11, and the exhaust pipe to the venturi tower 20. When the mixed volatile gases enter the absorption tower 11, they flow from bottom to top, making full contact with the spray liquid from the nozzles. The spray liquid cools and absorbs the mixed volatile gases. After absorption, the spray liquid containing impurities is separated into solid and liquid phases by cyclone separation in the first-stage hydrocyclone 12 and the second-stage hydrocyclone 13, and then enters the solvent storage tank 14. Under the action of the baffles in the solvent storage tank 14, it undergoes weight sedimentation, ultimately yielding clear solvent (spray liquid). The high-concentration turbid liquid discharged from the discharge port of the first-stage hydrocyclone 12 and the second-stage hydrocyclone 13, as well as the impurities in the sedimentation section of the baffles in the solvent storage tank 14, are returned to the high-level tank of the alcoholysis liquid centrifuge via the return pipe and the transfer pump 15, awaiting subsequent centrifugation. The solvent on the clean side of the solvent storage tank 14 is lifted to the absorption circulation cooler 16 by the action of the absorption liquid circulation pump 17. The absorption circulation cooler 16 cools the solvent, and after cooling, the solvent is discharged towards the nozzles.

[0039] In the wet ammonium chloride drying and recovery system, when a leak occurs in the closed-loop drying system or pressure fluctuations occur due to other reasons, an appropriate amount of nitrogen is automatically replenished to the system via a nitrogen pipeline. After the wet ammonium chloride has been dried, the drying chamber of the vacuum paddle dryer can be dried using nitrogen.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A wet ammonium chloride drying and recovery system, characterized in that: The system includes a centrifugal discharge bin (1), a bidirectional horizontal scraper conveyor (2), and a conical mixer (3). The centrifugal discharge bin (1) is used to store and discharge wet ammonium chloride obtained after centrifugation of TMOF alcoholysis liquid. The discharge end of the centrifugal discharge bin (1) is connected to a first airlock fan (4). A sealing shell is fitted on the outside of the bidirectional horizontal scraper conveyor (2). The discharge port of the first airlock fan (4) is connected to the sealing shell. The end of the sealing shell near the conical mixer (3) is connected to the conical mixer (3). The discharge port of the conical mixer (3) is connected to a second airlock fan (5). The discharge port of the second shut-off blower (5) is connected to the third shut-off blower (6), the discharge end of the third shut-off blower (6) is connected to the vacuum paddle dryer (7), the vacuum paddle dryer (7) is used to dry wet ammonium chloride, the discharge port of the vacuum paddle dryer (7) is connected to the fourth shut-off blower (8), the discharge port of the fourth shut-off blower (8) is connected to the fifth shut-off blower (9), the discharge port of the fifth shut-off blower (9) is equipped with a ton bag, the air outlet of the vacuum paddle dryer (7) is connected to the heat exhaust pipe, and the discharge end of the heat exhaust pipe is connected to the circulation and recycling mechanism. The vacuum paddle dryer (7) includes a shell and a heating cylinder (10) located in the center of the shell. A motor is provided on one side of the shell, and the output end of the motor is connected to a rotating shaft. The rotating shaft is connected to the heating cylinder (10) via gears. Paddles are provided on the outside of the heating cylinder (10). Both the shell and the heating cylinder (10) are provided with heating chambers. A connecting pipe is provided at the end of the shell away from the motor and is rotatably connected to the heating cylinder (10). The heating chamber of the heating cylinder (10) is connected to the connecting pipe. A steam insulation pipe is connected to the connecting pipe and the heating chamber of the shell. A control valve, a pressure transmitter, and a temperature transmitter are provided on the steam insulation pipe. A steam condensation insulation pipe is connected to the lower end of the connecting pipe and the heating chamber of the shell. A control valve is provided on the steam condensation insulation pipe. The recycling mechanism includes an absorption tower (11) connected to the outlet of the exhaust duct. Several nozzles are provided on the upper part of the inner cavity of the absorption tower (11). A spray pipe is connected to the water inlet of each nozzle, and the spray pipe is connected to a spray liquid circulation mechanism. An exhaust pipe is connected to the top of the absorption tower (11), and an oxygen content analyzer is installed on the exhaust pipe. A power assembly is connected to the outlet of the exhaust pipe. A drain pipe is connected to the bottom of the absorption tower (11), and a primary hydrocyclone (12) is connected to the outlet of the primary hydrocyclone (12). A delivery pipe is connected to the outlet of the delivery pipe, and a secondary hydrocyclone (13) is connected to the outlet of the secondary hydrocyclone (13). A liquid supply system is connected to the outlet of the secondary hydrocyclone (13). The supply pipe is connected to a solvent storage tank (14) at its outlet end. The solvent storage tank (14) is equipped with a baffle plate. The upper end of the solvent storage tank (14) is connected to a solvent inlet pipe. The solvent inlet pipe is equipped with a solvent preparation pump. The outlets of the first-stage hydrocyclone (12) and the second-stage hydrocyclone (13) at their lower ends are both connected to discharge pipes. The sedimentation part of the baffle plate of the solvent storage tank (14) is connected to a discharge pipe. The discharge pipe and the discharge end of the discharge pipe are connected to the same return pipe. The discharge end of the return pipe extends into the high-level centrifuge tank of the alcoholysis liquid. The return pipe is equipped with a delivery pump (15). The spray pipe, exhaust pipe, discharge pipe, supply pipe, solvent inlet pipe, discharge pipe, discharge pipe and return pipe are all equipped with control valves. The spray liquid circulation mechanism includes a solvent riser pipe connected to the solvent storage tank (14), an absorption circulation cooler (16) connected to the outlet end of the solvent riser pipe, an absorption liquid circulation pump (17), a control valve and a pressure transmitter on the solvent riser pipe, an outlet at the upper end of the absorption circulation cooler (16) connected to the spray pipe, and a temperature transmitter on the spray pipe. The power assembly includes a solvent delivery pipe connected to a solvent storage tank (14), a vacuum circulation cooler (18) connected to the outlet end of the solvent delivery pipe, a vacuum circulation pump (19), a control valve and a pressure transmitter provided on the solvent delivery pipe, a solvent guide pipe connected to the outlet end of the vacuum circulation cooler (18), a venturi tower (20) connected to the outlet end of the venturi tower (20), a solvent circulation pipe connected to the outlet end of the solvent circulation pipe, a solvent storage tank (14) connected to the outlet end of the solvent storage tank (14), an exhaust pipe connected to the side of the venturi tower (20), and a control valve provided on the solvent guide pipe, the solvent circulation pipe and the exhaust pipe.

2. The wet ammonium chloride drying and recovery system according to claim 1, characterized in that: The wet ammonium chloride drying and recovery system is also equipped with a tail gas emission pipe. The tail gas emission pipe is provided with a tail gas emission branch pipe connected to the centrifugal discharge bin (1), the sealing shell of the bidirectional horizontal scraper conveyor (2), the conical mixer (3) and the solvent storage tank (14). The tail gas emission pipe is equipped with a tail gas emission fan (21), and the exhaust end of the tail gas emission pipe is equipped with a tail gas absorption tower.

3. The wet ammonium chloride drying and recovery system according to claim 2, characterized in that: The drying chamber and discharge pipe of the vacuum paddle dryer (7) are connected to a nitrogen pipe, and a control valve is provided on the nitrogen pipe.

4. The wet ammonium chloride drying and recovery system according to claim 1, characterized in that: The end of the sealing shell away from the conical mixer (3) is also equipped with a ton bag.

5. The wet ammonium chloride drying and recovery system according to claim 1, characterized in that: The vacuum paddle dryer (7) drying chamber has a drying temperature of ≤100℃ and an oxygen content of <0.5%.

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