A low temperature drying apparatus

Abstract

The utility model belongs to chemical equipment technical field discloses a kind of low-temperature drying equipment.The equipment includes primary drying unit and secondary drying unit, primary drying unit includes spray dryer, primary cyclone separator, secondary cyclone separator and cloth bag dust collector connected in order pipeline, and spray dryer is connected with glass lining reaction kettle discharge end;Peristaltic pump for conveying material is equipped on the feed pipeline between glass lining reaction kettle and spray dryer, and spray dryer and primary cyclone separator are connected by first pipeline;Special turnover drum is respectively arranged in primary cyclone separator and secondary cyclone separator discharge port;Secondary drying unit uses double-cone vacuum dryer, and the material collected by special turnover drum enters double-cone vacuum dryer and carries out secondary drying, and dry finished product is obtained.The utility model contains drying unit and cleaning unit, and the effective separation of material and ethanol aqueous solution in ethanol-sulfuric acid solvent system is realized.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a low-temperature drying device suitable for drying sulfuric acid ethanol solvent systems. Background Technology

[0002] In the pharmaceutical and fine chemical industries, the materials in the sulfuric acid ethanol solvent system are key intermediates, and their drying treatment has a significant impact on the quality and yield of subsequent products. Currently, traditional drying processes have many limitations: on the one hand, conventional hot air drying easily exposes sulfuric acid ethanol to oxygen, triggering side reactions such as oxidation and degradation, damaging the chemical structure of the material, reducing product purity and activity, and failing to meet the high-purity intermediate requirements of advanced pharmaceuticals; on the other hand, single-stage separation drying equipment has low efficiency in material collection and drying, easily causing material loss, and cannot accurately control the degree of drying, resulting in uneven drying and affecting the consistency of downstream production.

[0003] Meanwhile, the cleaning of equipment and pipelines after drying is often overlooked, and residual materials can easily cross-contaminate with materials used in subsequent production. This is especially problematic in the pharmaceutical industry, where stringent GMP requirements mean that incomplete cleaning can directly lead to product quality risks. Furthermore, traditional drying processes have low energy efficiency, and inert gases (such as nitrogen) are mostly consumed only once, without being recycled, increasing production costs and environmental pressures.

[0004] Therefore, developing a complete integrated process for drying sulfuric acid ethanol materials, including efficient drying, precise separation, and clean closed-loop cleaning, to address the pain points of existing technologies such as material oxidation, uneven drying, inadequate cleaning, and energy waste, has become an urgent need in the pharmaceutical and chemical industry to improve product quality and production efficiency. Utility Model Content

[0005] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide a low-temperature drying device. This device includes a drying unit and a cleaning unit, enabling effective separation of materials and ethanol-water solutions in a sulfuric acid-ethanol solvent system.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A low-temperature drying device for drying materials inside a glass-lined reactor includes a drying unit comprising a primary drying unit and a secondary drying unit. The primary drying unit includes a spray dryer, a first-stage cyclone separator, a second-stage cyclone separator, and a bag filter connected in sequence via pipelines. The spray dryer is connected to the discharge end of the glass-lined reactor. A peristaltic pump for conveying materials is installed on the feed pipeline between the glass-lined reactor and the spray dryer. The spray dryer and the first-stage cyclone separator are connected via a first pipeline. Dedicated transfer containers are respectively installed at the discharge ports of the first-stage and second-stage cyclone separators.

[0008] The secondary drying unit uses a double cone vacuum dryer. The material collected in the special turnover bucket enters the double cone vacuum dryer for secondary drying to obtain the dried finished product.

[0009] The primary drying unit further includes a gas drying unit, which includes a first nitrogen filter and a second nitrogen filter. The outlet of the first nitrogen filter is connected to the inlet of the bag filter. The outlet of the second nitrogen filter is connected in sequence to a blower for the spray dryer and a blower heating device for the air supply through a pipeline. The outlet of the blower heating device is connected to the inlet of the spray dryer.

[0010] Nitrogen gas is supplied by the spray dryer's blower and heating device. After passing through the hot air distributor at the top of the spray dryer, it enters the drying tower in a spiral shape. Simultaneously, the material to be dried is slowly conveyed to the centrifugal atomizer (nozzle) at the top of the tower by a peristaltic pump. Due to the high-speed rotation of the atomizing disc, the liquid material forms extremely small droplets upon contact with the disc, greatly increasing the specific surface area in contact with the hot air. The sprayed droplets fall in parallel with the hot air, and the moisture evaporates rapidly. The material is dried into powder or granular products in a very short time (a few seconds) and collected at the bottom of the primary and secondary cyclone separators. The humid exhaust gas is filtered by a bag filter before being discharged to the outside. The extremely short contact time between the material and the hot air, along with the rapid temperature drop due to moisture evaporation, prevents the material from overheating during drying. Therefore, the spray dryer is characterized by high speed and efficiency, and is particularly suitable for heat-sensitive materials.

[0011] The inner walls of the hot air ducts, inlet volutes, hot air distributors, centrifugal atomizers, inner walls of the main tower, primary cyclone separators, secondary cyclone separators, primary and secondary silos, inner walls of the bag filter, flow areas of the blower and induced draft fan of the spray dryer, coolers, dehydrators, nitrogen replenishment, exhaust, and venting pipes, as well as various valves, of the spray dryer are made of 316L stainless steel with a smooth, intact mirror-like surface that is easy to clean.

[0012] During the drying process, sensors monitor in real time the temperature and pressure inside the spray dryer, the material collection volume of the primary and secondary cyclone separators, and the vacuum degree and temperature of the double cone vacuum dryer. Feedback is used to adjust the speed of the spray dryer's blower and induced draft fan, as well as the operating parameters of the vacuum dryer. An oxygen meter and differential pressure indicator are installed on the nitrogen output pipeline of the bag filter.

[0013] Furthermore, the drying unit also includes a gas circulation unit to improve gas utilization. The gas circulation unit includes a spray dryer induced draft fan connected to the outlet of the bag filter. The outlet of the spray dryer induced draft fan is connected in sequence to a finned surface cooler and a baffle-type water separator via pipelines. The outlet of the baffle-type water separator is connected to the inlet of the spray dryer blower.

[0014] Furthermore, it also includes a cleaning unit for cleaning the entire drying equipment, which includes an equipment rinsing unit and an equipment drying unit;

[0015] The equipment rinsing unit includes a stainless steel rinsing tank for storing purified water. The outlet of the stainless steel rinsing tank is connected in sequence to a high-pressure pump and a water distributor for a spray dryer. The water distributor for the spray dryer is equipped with several rinsing pipes, which are connected to the top inlet of the spray dryer, the top and bottom inlets of the first-stage cyclone separator, the top and bottom inlets of the second-stage cyclone separator, and both ends of the first pipe.

[0016] The equipment flushing unit (such as the stainless steel cleaning tank) and its pipelines, the air heater housing and its pipelines, the internal steam pipelines of the bag filter, the high-efficiency filter housing, etc., are made of 304 stainless steel with a smooth and intact surface for easy cleaning. The duct gaskets, manual and automatic butterfly valve gaskets and other sealing parts are made of polytetrafluoroethylene.

[0017] Furthermore, the drying unit of the equipment includes a combined rotary dehumidifier unit, the air outlet of which is connected to the air inlet of the spray dryer's blower via a pipeline.

[0018] Furthermore, a heater is provided between the high-pressure pump and the spray dryer water distributor.

[0019] Furthermore, the spray dryer's water distributor is connected to a compressed air filter at its air inlet end, and the compressed air filter is equipped with a compressed air inlet end.

[0020] Furthermore, the combined rotary dehumidifier unit has a built-in cold water pipeline, with a cold water inlet valve installed at the inlet and a cold water outlet valve installed at the outlet. The combined rotary dehumidifier unit also has a built-in regeneration heater, which is equipped with a steam inlet pipe and a drain pipe. A first steam valve is installed on the steam inlet pipe, and a first drain valve is installed on the drain pipe. A manual outlet valve and a rotary dehumidifier outlet valve are installed on the pipeline between the combined rotary dehumidifier unit and the spray dryer blower, with the rotary dehumidifier outlet valve located close to the spray dryer blower.

[0021] Furthermore, the spray dryer is provided with an exhaust pipe at the outlet end of the induced draft fan, and a circulation pipe and a vent pipe are provided on the exhaust pipe. The circulation pipe is connected to the finned surface cooler, and a condenser inlet valve is provided on the circulation pipe. A vent valve and a gas release valve are connected in parallel on the exhaust pipe.

[0022] Furthermore, both the primary cyclone separator and the secondary cyclone separator are equipped with a hopper at their discharge ports. The lower end of the hopper is equipped with a discharge valve, and the upper valve and the lower valve are located above the hopper.

[0023] Furthermore, a drain valve is provided on the first pipeline, and the drain valve is located near the outlet of the spray dryer.

[0024] The beneficial effects of this utility model are as follows: This utility model has a simple structure and reasonable design, and has the following advantages:

[0025] (1) A gas circulation unit is adopted, and nitrogen is used in the drying process to provide an inert protective atmosphere for the material, which effectively prevents isaconazole sulfate from being oxidized in the high-temperature drying environment, ensuring the purity and quality of the product and meeting the strict requirements of the pharmaceutical industry for the high purity of pharmaceutical raw materials.

[0026] (2) Multi-stage separation and drying system: The material is processed sequentially through a spray dryer, a primary cyclone separator, a secondary cyclone separator, and a bag filter. This system enables the gradual separation and drying of materials with different particle sizes, ensuring uniform heating of the material throughout the drying process. This effectively avoids local over-drying or insufficient drying, ensuring uniformity of drying and improving the consistency of product quality. The combination of multi-stage cyclone separator and bag filter utilizes centrifugal force and filtration principles to efficiently separate and collect materials with different particle sizes, greatly improving the material collection efficiency and reducing material loss during the drying process, thereby increasing the overall drying yield.

[0027] (3) In the gas circulation unit, nitrogen is recycled through the coordinated operation of equipment such as the spray dryer blower, the spray dryer induced draft fan, the finned surface cooler, and the baffle dehydrator, which reduces nitrogen consumption and lowers production costs.

[0028] (4) A complete cleaning process, including air replacement, purified water rinsing and equipment drying, can thoroughly remove residual materials and impurities in equipment and pipelines, avoid cross-contamination between different batches of production, and strictly comply with the requirements of pharmaceutical industry GMP.

[0029] (5) During the drying and cleaning process, key parameters are monitored in real time by setting up a variety of sensors (such as temperature sensors, pressure sensors, nitrogen concentration sensors, flow sensors, humidity sensors, etc.), and the operating parameters of each equipment are adjusted according to the monitoring data feedback. This enables timely detection and resolution of fluctuations in the process, ensuring the stability and reliability of the entire drying and cleaning process. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the drying unit in this utility model;

[0032] Figure 2 This is a schematic diagram of the cleaning unit in this utility model.

[0033] In the diagram: 1. Glass-lined reactor, 2. Spray dryer, 3. Primary cyclone separator, 4. Secondary cyclone separator, 5. Bag filter, 6. Double cone vacuum dryer, 7. Air supply and heating device, 8. First nitrogen filter, 9. Baffle-type desiccant, 10. Finned surface cooler, 11. Spray dryer blower, 12. Spray dryer induced draft fan, 13. Peristaltic pump, 14. Second nitrogen filter, 15. Combined rotary dehumidifier unit, 16. Heater, 17. Stainless steel cleaning tank, 18. High-pressure pump, 19. Spray dryer water distributor, 20. Compressed air filter, 2 1. Cold water inlet valve, 22. Cold water return valve, 23. Manual valve for air outlet, 24. First steam valve, 25. First drain valve, 26. Vent valve, 27. Second drain valve, 28. Vent valve, 30. Dehumidifier outlet valve, 31. Desiccant outlet valve, 32. Condenser inlet valve, 33. Nitrogen replenishment valve, 34. Upper valve, 35. Lower valve, 36. Special turnover bucket, 37. First pipeline, 38. Discharge valve, 39. Hopper, 40. Cleaning inlet valve, 41. Second steam valve, 42. Bottom valve, 43. Drain valve, 46. Cleaning valve, 47. Exhaust pipeline, 48. Circulation pipeline. Detailed Implementation

[0034] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0037] A low-temperature drying device for drying materials inside a glass-lined reactor 1, comprising a drying unit, such as... Figure 1 shown. Figure 1 The red pipes represent the material flow lines inside the glass-lined reactor 1, while the black pipes are gas drying lines. A bottom valve 42 is located at the bottom of the glass-lined reactor 1.

[0038] This low-temperature drying equipment also includes a cleaning unit for cleaning the entire drying equipment, such as... Figure 2 As shown. The cleaning unit includes an equipment rinsing unit and an equipment drying unit; the equipment rinsing unit includes a stainless steel cleaning tank 17 for storing purified water. The outlet end of the stainless steel cleaning tank 17 is connected in sequence to a high-pressure pump 18 and a spray dryer water distributor 19. The spray dryer water distributor 19 is equipped with several rinsing pipes, each of which is equipped with a cleaning valve 46. The rinsing pipes are respectively connected to the top inlet end of the spray dryer 2, the top and bottom inlet ends of the first-stage cyclone separator 3, the top and bottom inlet ends of the second-stage cyclone separator 4, and both ends of the first pipe 37. Figure 1 The red pipes represent the material flow pipes inside the glass-lined reactor 1, the black pipes are the gas drying pipes used for equipment drying, and the cyan pipes are the purified water rinsing pipes used for equipment flushing.

[0039] Figure 1 The drying unit includes a primary drying unit and a secondary drying unit.

[0040] The primary drying unit includes a spray dryer 2, a primary cyclone separator 3, a secondary cyclone separator 4, and a bag filter 5 connected in sequence by pipelines. The spray dryer 2 is connected to the discharge end of the glass-lined reactor 1. A peristaltic pump 13 for conveying materials is installed on the feed pipeline between the glass-lined reactor 1 and the spray dryer 2. The spray dryer 2 and the primary cyclone separator 3 are connected by a first pipeline 37. Dedicated transfer buckets 36 are respectively installed at the discharge ports of the primary cyclone separator 3 and the secondary cyclone separator 4. The secondary drying unit adopts a double cone vacuum dryer 6. The materials collected in the dedicated transfer buckets 36 enter the double cone vacuum dryer 6 for secondary drying to obtain the dried finished product.

[0041] The primary drying unit also includes a gas drying unit, which includes a first nitrogen filter 8 and a second nitrogen filter 14. The outlet of the first nitrogen filter 8 is connected to the inlet of the bag filter 5. The outlet of the second nitrogen filter 14 is connected in sequence to a spray dryer blower 11 and a blower heating device 7 through a pipeline. The outlet of the blower heating device 7 is connected to the inlet of the spray dryer 2.

[0042] The drying unit also includes a gas circulation unit to improve gas utilization. The gas circulation unit includes a spray dryer induced draft fan 12 connected to the outlet of the bag filter 5. The outlet of the spray dryer induced draft fan 12 is connected in sequence to a finned surface cooler 10 and a baffle-type water separator 9 via pipelines. The outlet of the baffle-type water separator 9 is connected to the inlet of the spray dryer blower 11. A water separator outlet valve 31 is installed on the pipeline connecting the baffle-type water separator 9 and the spray dryer blower 1.

[0043] Both the primary cyclone separator 3 and the secondary cyclone separator 4 have a hopper 39 at their discharge ports. The lower end of the hopper 39 is equipped with a discharge valve 38. The upper valve 34 and the lower valve 35 are located above the hopper 39, with the upper valve 34 positioned at the lower valve 35.

[0044] A drain valve 43 is provided on the first pipeline 37, and the drain valve 43 is located near the outlet of the spray dryer 2.

[0045] Figure 2 In this unit, the drying unit includes a combined rotary dehumidifier unit 15, the outlet of which is connected to the inlet of the spray dryer blower 11 via a pipeline. A heater 16 is provided between the high-pressure pump 18 and the spray dryer water distributor 19.

[0046] The spray dryer water distributor 19 is connected to a compressed air filter 20 at its air inlet end, and the compressed air filter 20 is provided with a compressed air inlet end.

[0047] The combined rotary dehumidifier unit 15 has a built-in cold water pipeline. The inlet of the cold water pipeline is equipped with a cold water inlet valve 21, and the outlet of the cold water pipeline is equipped with a cold water outlet valve 22. The combined rotary dehumidifier unit 15 has a built-in regeneration heater. The regeneration heater is equipped with a steam inlet pipe and a drain pipe. The steam inlet pipe is equipped with a first steam valve 24, and the drain pipe is equipped with a first drain valve 25. The pipeline between the combined rotary dehumidifier unit 15 and the spray dryer blower 11 is equipped with an air outlet manual valve 23 and a rotary dehumidifier outlet valve 30. The rotary dehumidifier outlet valve 30 is located close to the spray dryer blower 11.

[0048] The spray dryer has an exhaust pipe 47 at the outlet of the induced draft fan 12. The exhaust pipe 47 is equipped with a circulation pipe 48 and a vent pipe. The circulation pipe 48 is connected to the finned surface cooler 10. The circulation pipe 48 is equipped with a condenser inlet valve 32. The exhaust pipe 47 is equipped with a vent valve 26 and a venting valve 28 in parallel.

[0049] A cleaning ball valve 40 is installed on the flushing pipe connected to the top of the spray dryer 2.

[0050] This low-temperature drying equipment, after the material is dried, first undergoes air replacement, then equipment purification and rinsing, and then further drying, before starting the drying of new material, and so on, in a continuous cycle. The specific working processes of the drying unit, air replacement unit, equipment rinsing unit, and equipment drying unit are as follows:

[0051] The working process of the drying unit is as follows:

[0052] Before drying the material, it is necessary to confirm that all valves are in the correct state. Specifically: the cold water inlet valve 21, cold water return valve 22, and manual air outlet valve 23 of the combined rotary dehumidifier unit 15 should all be open. Confirm that the second steam valve 41 and second condensate valve 27 on the regeneration air supply section, air supply heating device 7, and bag filter 5 of the combined rotary dehumidifier unit 15 are all open. Turn on the power to the spray dryer 2, enter the system operation interface, select open circuit mode on the PLC control panel, and confirm that the vent valve 28, vent valve 26, and rotary dehumidifier outlet valve 30 are all open. Confirm that the desiccant outlet valve 31 and the cold water return valve 22 are open. Condenser inlet valve 32 and nitrogen replenishment valve 33 are both closed; finned surface cooler 10 and baffle precipitator 9 are manually and automatically set to OFF; combined rotary dehumidifier unit 15 is turned on; primary cyclone separator 3 and secondary cyclone separator 4 are manually and automatically set to OFF; upper valve 34 and lower valve 35 of primary and secondary cyclone separators are opened; discharge valve 38 of primary and secondary cyclone separators is confirmed to be closed; top cleaning inlet valve 40, bottom drain valve 43 and all cleaning valves 46 of the spray dryer main tower are confirmed to be closed.

[0053] Set the main tower inlet air temperature of spray dryer 2 to 110℃, turn on the spray dryer blower 11 and the spray dryer exhaust fan 12, and adjust the frequency of the spray dryer blower 11 and the spray dryer exhaust fan 12 to make the main tower pressure 100-300Pa, preheating spray dryer 2 for at least 30 minutes; after preheating, adjust the frequency of the spray dryer blower 11 and the spray dryer exhaust fan 12 to make the main tower pressure -100 to -200Pa, start the atomizer, and confirm that the internal temperature of the main tower is 70-100℃. With the main tower inlet air temperature at 100-120℃, manually and automatically adjust both the primary cyclone separator 3 and the secondary cyclone separator 4 to the ON state, manually and automatically adjust the peristaltic pump 13 to the OFF state, turn on the pulse and peristaltic pump 13 of the bag filter 5, first spray purified water into the spray dryer 2 tower, adjust the outlet air temperature to 60-65℃, then turn on the bottom valve of the glass-lined reactor 1 and the main tower lighting, observe that the mist droplets in the main tower are normal, then gradually adjust the frequency of the peristaltic pump 13, and at the same time, confirm that the main tower outlet air temperature is not lower than 60℃;

[0054] Slowly pump the liquid material in the glass-lined reactor 1 into the spray dryer 2 until it is completely dried. During this process, record the inlet and outlet air temperatures of the spray dryer 2 every hour. Manually and automatically switch the primary cyclone separator 3 to the OFF state, open the discharge valve 38, collect the material into a double-layer pharmaceutical low-density polyethylene bag, tie the bag tightly, and place it into a special turnover bucket 36. After spray drying is completed, manually and automatically switch both the primary cyclone separator 3 and the secondary cyclone separator 4 to the OFF state, open the discharge valve 38, collect the material into a double-layer pharmaceutical low-density polyethylene bag, tie the bag tightly, and place it into a turnover bucket.

[0055] The drying unit adopts a closed-loop nitrogen circulation mode. If the solvent content in the liquid to be dried is too high, the concentration of flammable gas volatilized during drying will reach the explosion limit, which will cause safety hazards. The closed-loop circulation system includes a finned surface cooler 10, a baffle-type water separator 9, and a second nitrogen filter 14 for supplementing nitrogen. Cooling water is circulated inside the finned surface cooler 10. After the humid nitrogen passes through the finned surface cooler 10, the temperature drops, and the moisture in the nitrogen condenses into small droplets. Some of these droplets flow directly into the water storage tank (with a level gauge) below the finned surface cooler 10. The remaining mist is removed by the baffle-type water separator 9, and nitrogen can be supplemented through the nitrogen replenishment valve 33.

[0056] The system is set to PLC automatic control in closed-loop mode. The vent valve 28, vent valve 26, and rotary dehumidifier outlet valve 30 are automatically closed, while the desiccant outlet valve 31, condenser inlet valve 32, and nitrogen replenishment valve 33 are automatically opened. The working time of the primary and secondary cyclone upper valve 34 and lower valve 35, as well as the interval between the upper and lower valves, can be freely adjusted according to the drying requirements. The working time of the upper and lower drain valves of the baffle-type desiccant 9, as well as the interval between the upper and lower valves, can be freely adjusted according to the drying and dehydration effect.

[0057] In the drying unit, to remove any remaining powder not removed by the primary cyclone separator 3 and the secondary cyclone separator 4, and to prevent powder from clogging the detection probes in the system, the bag filter 5 has a heating plate on the outside of the filter bags to prevent condensation of high-humidity gas and the resulting blockage caused by condensate adhering to the filter bags. The bag filter 5 is equipped with six pulse solenoid valves for blowing away powder from the filter bags. A second steam valve 41 is located at the steam inlet pipe of the heating plate, and a second drain valve 27 is located at the drain pipe of the heating plate.

[0058] The system is equipped with safety alarm functions. When the inlet air temperature Tin of the spray dryer 2 reaches the high temperature alarm value, a high inlet air temperature alarm is triggered; when the outlet air temperature Tout of the main tower reaches the high temperature alarm value, a high outlet air temperature alarm is triggered; when the main tower pressure Pt reaches the high pressure alarm value, a high pressure alarm is triggered; when the main tower pressure Pt reaches the low pressure alarm value, a low pressure alarm is triggered; when the differential pressure PΔ of the bag filter 5 reaches the high differential pressure alarm value, a high differential pressure alarm is triggered; when the system oxygen content CO2 reaches the high oxygen content alarm value, a high oxygen content alarm is triggered.

[0059] The inner wall of the rotary tank of the spray-dried double cone vacuum dryer 6 is made of glass. When the tank is under high vacuum, hot water is introduced into the jacket. The heat comes into contact with the wet material through the inner wall of the tank. The solvent or water vapor evaporated after the wet material absorbs heat is drawn away by the vacuum pump through the vacuum exhaust pipe. Because the tank is under vacuum and the rotation of the tank causes the material to move up and down and inside and out, the material does not accumulate on the wall, the heat transfer coefficient is high, the drying efficiency of the material is improved, and the purpose of uniform drying is achieved.

[0060] The air replacement process is as follows: fresh air is introduced into the combined rotary dehumidifier unit 15, and nitrogen from the spray dryer 2, the first-stage cyclone separator 3, the second-stage cyclone separator 4, and the bag filter 5 is discharged from the exhaust pipe 47 through the cooperation of the spray dryer blower 11 and the spray dryer exhaust fan 12.

[0061] The working process of the equipment flushing unit is as follows:

[0062] The stainless steel cleaning tank 17 is connected to the peristaltic pump 13 via a pipeline. The peristaltic pump 13 sprays purified water into the spray dryer 2 to clean the feed pipe, peristaltic pump 13, and atomizing disc. After cleaning, the atomizer, peristaltic pump 13, and combined rotary dehumidifier unit 15 are turned off, and the steam valve of the air heater is closed. After 30 minutes, the pulse of the bag filter 5 is turned off, and the manual and automatic switches of the primary cyclone separator 3 and the secondary cyclone separator 4 are both turned off. The induced draft fan 12 and the air supply fan 11 of the spray dryer are turned off. It is confirmed that the bottom valve of the stainless steel cleaning tank 17 and the drain valve 43 at the bottom of the main tower of the spray dryer 2 are both open. The cleaning switch is turned on, and the upper valve 34 and lower valve 35 of the primary cyclone separator 3 and the secondary cyclone separator 4 are confirmed. Both the discharge valve 38 and the main tower cleaning manual / automatic valve are in the open state; turn the main tower cleaning automatic valve to the ON state, turn on the main tower cleaning automatic valve, and confirm that the main tower cleaning inlet valve 40, the cleaning pipe lifting cylinder, and the main tower cleaning valve 46 are all in the open state; open the steam regulating valve of the heater 16, set the cleaning water temperature to 40℃, start the high pressure pump 18, clean the inner wall of the main tower of the spray dryer 2 for about 3 minutes, then turn off the high pressure pump 18 and turn off the main tower cleaning automatic valve; after the main tower is cleaned, turn on the cleaning valves of the secondary cyclone separator 4, the primary cyclone separator 3, the air duct and the silo 39 and the high pressure pump 18 in sequence, clean the inner walls of the secondary cyclone separator 4, the primary cyclone separator 3, the air duct and the silo 39 for about 2 minutes, then turn off the high pressure pump 18 and the corresponding cleaning valve 46.

[0063] The working process of the equipment drying unit is as follows:

[0064] After cleaning, turn on the combined rotary dehumidifier unit 15, set the main tower inlet air temperature of spray dryer 2 to 110℃, turn on the spray dryer blower 11 and spray dryer induced draft fan 12, and adjust the frequency of the spray dryer blower 11 and spray dryer induced draft fan 12 to make the main tower pressure between 50 and 350 Pa, and dry the main tower, primary cyclone separator 3, secondary cyclone separator 4, air duct and hopper 38 of spray dryer 2; after drying, turn off the main tower lighting, turn off the cleaning switch, and check the primary cyclone separator 3 and secondary cyclone separator 4. After the upper valve 34, lower valve 35 and discharge valve 38 of 4 are all closed, turn off the spray dryer blower 11, spray dryer induced draft fan 12 and combined rotary dehumidifier unit 15. Select closed-loop mode on the PLC control panel, confirm that the vent valve 28, vent valve 26 and rotary dehumidifier outlet valve 30 are all closed, turn off the spray dryer blower 11, spray dryer induced draft fan 12 and atomizer, turn off the rotary dehumidifier cold water inlet and outlet valves, and turn off the steam and condensate valves of the rotary dehumidifier regeneration air supply section, air supply heater and bag filter dust collector.

[0065] In summary, this invention employs a gas circulation unit and uses nitrogen during the drying process to provide an inert protective atmosphere for the material, effectively preventing the oxidation of isaconazole sulfate under high-temperature drying conditions, ensuring the purity and quality of the product, and meeting the stringent requirements of the pharmaceutical industry for high purity of pharmaceutical raw materials.

[0066] Furthermore, this invention employs a multi-stage separation and drying system, where the material sequentially passes through a spray dryer 2, a primary cyclone separator 3, a secondary cyclone separator 4, and a bag filter 5. This system enables the gradual separation and drying of materials with different particle sizes, ensuring uniform heating throughout the drying process and effectively preventing localized over-drying or insufficient drying. This guarantees the uniformity of drying and improves the consistency of product quality. The combination of the multi-stage cyclone separator and the bag filter utilizes centrifugal force and filtration principles to efficiently separate and collect materials of different particle sizes, significantly improving material collection efficiency, reducing material loss during the drying process, and thus increasing the overall drying yield.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A low-temperature drying device for drying materials inside a glass-lined reactor (1), characterized in that: The system includes a drying unit, which comprises a primary drying unit and a secondary drying unit. The primary drying unit includes a spray dryer (2), a primary cyclone separator (3), a secondary cyclone separator (4), and a bag filter (5) connected in sequence by pipelines. The spray dryer (2) is connected to the discharge end of the glass-lined reactor (1). A peristaltic pump (13) for conveying materials is provided on the feed pipeline between the glass-lined reactor (1) and the spray dryer (2). The spray dryer (2) and the primary cyclone separator (3) are connected by a first pipeline (37). The discharge ports of the primary cyclone separator (3) and the secondary cyclone separator (4) are respectively equipped with special turnover buckets (36). The secondary drying unit uses a double cone vacuum dryer (6). The material collected in the special turnover bucket (36) enters the double cone vacuum dryer (6) for secondary drying to obtain the dried finished product. The primary drying unit also includes a gas drying unit, which includes a first nitrogen filter (8) and a second nitrogen filter (14). The outlet of the first nitrogen filter (8) is connected to the inlet of the bag filter (5). The outlet of the second nitrogen filter (14) is connected in sequence to a spray dryer blower (11) and a blower heating device (7) through a pipeline. The outlet of the blower heating device (7) is connected to the inlet of the spray dryer (2).

2. The low-temperature drying equipment according to claim 1, characterized in that: The drying unit also includes a gas circulation unit to improve gas utilization. The gas circulation unit includes a spray dryer induced draft fan (12) connected to the outlet of the bag filter (5). The outlet of the spray dryer induced draft fan (12) is connected in sequence to a finned surface cooler (10) and a baffle-type water separator (9) through pipelines. The outlet of the baffle-type water separator (9) is connected to the inlet of the spray dryer blower (11).

3. The low-temperature drying equipment according to claim 2, characterized in that: It also includes a cleaning unit for cleaning the entire drying equipment, which includes an equipment rinsing unit and an equipment drying unit; The equipment rinsing unit includes a stainless steel rinsing tank (17) for storing purified water. The outlet end of the stainless steel rinsing tank (17) is connected in sequence to a high-pressure pump (18) and a spray dryer water distributor (19). The spray dryer water distributor (19) is provided with several rinsing pipes. The rinsing pipes are respectively connected to the top inlet end of the spray dryer (2), the top and bottom inlet ends of the first-stage cyclone separator (3), the top and bottom inlet ends of the second-stage cyclone separator (4), and both ends of the first pipe (37).

4. The low-temperature drying equipment according to claim 3, characterized in that: The equipment drying unit includes a combined rotary dehumidifier unit (15), the air outlet of which is connected to the air inlet of the spray dryer blower (11) via a pipeline.

5. The low-temperature drying equipment according to claim 3, characterized in that: A heater (16) is provided between the high-pressure pump (18) and the spray dryer water distributor (19).

6. The low-temperature drying equipment according to claim 3, characterized in that: The spray dryer water distributor (19) is connected to a compressed air filter (20) at its air inlet end, and the compressed air filter (20) is provided with a compressed air inlet end.

7. The low-temperature drying equipment according to claim 4, characterized in that: The combined rotary dehumidifier unit (15) has a built-in cold water pipeline. A cold water inlet valve (21) is installed at the inlet of the cold water pipeline, and a cold water outlet valve (22) is installed at the outlet of the cold water pipeline. The combined rotary dehumidifier unit (15) has a built-in regeneration heater. The regeneration heater is equipped with a steam inlet pipe and a drain pipe. A first steam valve (24) is installed on the steam inlet pipe, and a first drain valve (25) is installed on the drain pipe. An air outlet manual valve (23) and a rotary dehumidifier outlet valve (30) are installed on the pipeline between the combined rotary dehumidifier unit (15) and the spray dryer blower (11). The rotary dehumidifier outlet valve (30) is located close to the spray dryer blower (11).

8. A low-temperature drying device according to claim 2, characterized in that: The spray dryer has an exhaust pipe (47) at the outlet end of the induced draft fan (12). The exhaust pipe (47) is equipped with a circulation pipe (48) and a vent pipe. The circulation pipe (48) is connected to the finned surface cooler (10). The circulation pipe (48) is equipped with a condenser inlet valve (32). The exhaust pipe (47) is equipped with a vent valve (26) and a venting valve (28) in parallel.

9. A low-temperature drying device according to claim 1, characterized in that: Both the primary cyclone separator (3) and the secondary cyclone separator (4) are equipped with a hopper (39) at their discharge ports. The lower end of the hopper (39) is equipped with a discharge valve (38). The upper valve (34) and the lower valve (35) are located above the hopper (39), with the upper valve (34) positioned at the lower valve (35).

10. A low-temperature drying device according to claim 3, characterized in that: A drain valve (43) is provided on the first pipeline (37), and the drain valve (43) is located near the outlet of the spray dryer (2).

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