Vacuum drying machine for chemical synthesis of bulk drug

Abstract

This utility model relates to the fields of chemical engineering and pharmaceutical technology, specifically disclosing a vacuum dryer for chemically synthesized pharmaceutical raw materials. It includes a drying chamber and an insulated chamber. The drying chamber is connected to a rotating mechanism and features a spiral hot air inlet structure, ensuring the material is fully rotated and evenly heated during the drying process. The insulation layer between the insulated and drying chambers reduces heat loss, and the combination of a vacuum environment and low-temperature hot air circulation prevents damage to the material components from high temperatures. The vacuum and heating pipes are arranged on opposite sides, forming an efficient water vapor discharge convection structure. The spacing of the fixed frame provides ample space for material and hot air contact and can be used with a detection component to monitor the drying status in real time. This invention, through structural innovation, effectively improves the drying quality and efficiency of chemically synthesized pharmaceutical raw materials, while also enhancing production safety and environmental friendliness.

Description

Technical Field

[0001] This utility model relates to the fields of chemical engineering and pharmaceutical technology, and in particular to a vacuum dryer for chemically synthesized pharmaceutical raw materials. Background Technology

[0002] In the field of drying chemically synthesized pharmaceutical raw materials and intermediates, heat-sensitive materials such as ferrous succinate, cetirizine hydrochloride, terbinafine hydrochloride, and sertraline hydrochloride have stringent requirements for drying processes. Traditional oven drying technology, such as the "Drying Device for Pharmaceutical Intermediates" disclosed in Chinese Utility Model Patent "CN221172726U", uses hot water heating combined with natural ventilation, which has significant drawbacks. Under normal pressure, moisture needs to be heated to around 100°C to evaporate in large quantities. For heat-sensitive pharmaceutical raw materials and intermediates, high temperatures can not only lead to the decomposition and structural damage of active ingredients, but may also reduce product purity and activity, and increase impurity content. At the same time, hot airflow is difficult to penetrate the material evenly, resulting in uneven drying, low efficiency, long drying time per batch, and a significant increase in energy consumption. In addition, volatile organic solvents generated during the material drying process evaporate slowly under normal pressure, easily accumulating and posing safety hazards.

[0003] Currently, some existing vacuum drying technologies also have limitations. For example, the "vacuum drying oven" disclosed in Chinese utility model patent "CN215373180U" relies solely on mechanical vacuuming to reduce air pressure, but lacks a hot air circulation system. When processing ferrous succinate, although a certain degree of vacuum is achieved, the lack of heat replenishment causes the material temperature to drop due to the heat absorption of moisture vaporization, resulting in a drying rate far lower than expected. When processing sertraline hydrochloride intermediates, the absence of hot air agitation easily leads to the formation of a hard shell on the material surface, hindering the escape of internal moisture and resulting in an unacceptable moisture content, making it difficult to meet the drying requirements of chemically synthesized raw materials and intermediates. Utility Model Content

[0004] In view of this, this utility model provides a vacuum dryer for chemically synthesized pharmaceutical raw materials, which solves the problems of low moisture evaporation efficiency and uneven drying of materials caused by the lack of a vacuum environment in the traditional drying method in the prior art.

[0005] This utility model provides a vacuum dryer for chemically synthesized pharmaceutical raw materials, comprising: a frame; a chamber including an insulated chamber and a drying chamber disposed within the insulated chamber; the drying chamber is connected to a rotating mechanism disposed on one side of the frame and can rotate based on the rotating mechanism and the insulated chamber; a heating assembly disposed at the bottom of the frame and communicating with the interior of the drying chamber through a heating pipe; a vacuum assembly disposed at the bottom of the frame and communicating with the interior of the drying chamber through a vacuum pipe; wherein, one end of the drying chamber is open, and a chamber door for sealing the opening is provided on the frame; the vacuum pipe and the heating pipe both extend into the interior of the drying chamber through the chamber door.

[0006] Preferably, the rotating mechanism includes a rotating motor disposed on the top of the machine compartment and a driven wheel driven by the rotating motor; the driven wheel is connected to a connecting shaft disposed on the drying compartment; the other end of the drying compartment is connected to the heat preservation compartment through a bearing.

[0007] Preferably, the connecting shaft is connected to the drying chamber via a fixing frame; the fixing frame includes a plurality of fixing plates spaced apart in the circumferential direction, and the mounting space of the drying chamber is formed between the plurality of fixing rods.

[0008] Preferably, a gap is provided between the heat preservation chamber and the drying chamber to form a heat preservation layer, and the heat preservation layer is filled with heat preservation material.

[0009] Preferably, the heating assembly includes a blower and a heating chamber connected to the blower; multiple sets of heating elements are spaced apart inside the heating chamber; the heating pipe is connected to the heating chamber and delivers hot air to the interior of the drying chamber.

[0010] Preferably, the two sides of the machine bay are connected to the top of the frame by shock-absorbing springs.

[0011] Preferably, the vacuuming assembly includes a vacuum pump connected to the vacuuming pipe, which performs vacuuming operations on the interior of the drying chamber intermittently.

[0012] Preferably, the heating component and the vacuuming component perform heating operations or vacuuming operations, respectively.

[0013] The vacuum dryer for chemically synthesized pharmaceutical raw materials provided by this utility model has the following beneficial effects:

[0014] In this invention, the connection design between the drying chamber and the rotating mechanism allows the material to rotate continuously during the drying process. Combined with hot air introduced through the heating pipes, this effectively avoids the problems of localized overheating or insufficient drying caused by traditional static drying, ensuring that raw materials and intermediates such as ferrous succinate and sertraline hydrochloride are heated evenly from all directions. The insulation layer structure between the insulation chamber and the drying chamber reduces heat loss. In a vacuum environment, combined with the heating components, the hot air temperature can be stably maintained at 50-60℃, meeting the requirements for low-temperature drying while reducing energy consumption. The separate layout of the vacuum pipes and heating pipes forms a "dehumidification-heating" convection structure, accelerating the removal of moisture and shortening the drying time of cetirizine hydrochloride intermediates, while improving drying efficiency and quality. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of this utility model.

[0016] Figure 1 This is a schematic diagram of a vacuum dryer for chemically synthesized pharmaceutical raw materials.

[0017] Figure 2 This is a cross-sectional structural diagram of a vacuum dryer for chemically synthesized pharmaceutical raw materials;

[0018] Figure 3 This is a schematic diagram of the heating component.

[0019] Figure 4 This is a schematic diagram of the rotating mechanism;

[0020] Parts and component numbers in the diagram:

[0021] 100 - Frame, 110 - Door, 111 - Shock-absorbing spring;

[0022] 210 - Insulated chamber, 220 - Drying chamber, 221 - Guide plate, 230 - Insulation layer;

[0023] 300-Rotating mechanism, 310-Rotating motor, 311-Belt, 320-Driven pulley, 330-Connecting shaft, 340-Fixed frame, 341-Fixed plate;

[0024] 400-Heating assembly, 410-Blower, 420-Heating chamber, 421-Heating element, 430-Heating pipe;

[0025] 510 - Vacuum pump, 520 - Vacuum piping. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, in this document, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Unless otherwise specified, embodiments of the present invention and the various features thereof can be combined with each other, all within the protection scope of the present invention.

[0027] Example 1

[0028] Please see Figure 1 This utility model provides a vacuum dryer for chemically synthesized pharmaceutical raw materials. Currently, existing technologies for drying chemically synthesized pharmaceutical raw materials and their intermediates mainly include traditional atmospheric pressure drying and traditional vacuum drying. Traditional atmospheric pressure drying uses electric heating or steam heating of air, utilizing thermal convection to transfer heat and vaporize moisture. However, it has significant shortcomings, such as the high temperature of the hot air easily damaging heat-sensitive pharmaceutical raw material components such as ferrous succinate, leading to a decrease in purity. Furthermore, the material is not dried evenly during static drying, resulting in high energy consumption. Although traditional vacuum drying achieves low-temperature vaporization by reducing air pressure through vacuuming, some equipment lacks an efficient hot air circulation system, or the material does not have sufficient contact with the hot air flow, resulting in low drying efficiency and poor drying effect, making it difficult to meet the stringent quality and efficiency requirements of chemically synthesized pharmaceutical raw materials.

[0029] Please see Figure 1 and Figure 2The vacuum dryer provided in this embodiment includes a frame, a chamber, a vacuuming assembly 500, and a heating assembly 400. The chamber includes an insulation chamber 210 and a drying chamber 220 disposed within the insulation chamber 210. The drying chamber 220 is connected to a rotating mechanism 300 disposed on one side of the frame and can rotate based on the rotating mechanism 300 and the insulation chamber 210. The heating assembly 400 is disposed at the bottom of the frame and communicates with the interior of the drying chamber 220 through a heating pipe 430. The vacuuming assembly 500 is disposed at the bottom of the frame and communicates with the interior of the drying chamber 220 through a vacuuming pipe 520. One end of the drying chamber 220 is open, and a door is provided on the frame for sealing the opening. Both the vacuuming pipe 520 and the heating pipe 430 extend into the interior of the drying chamber 220 through the door.

[0030] In use, first place the chemically synthesized raw materials and intermediates to be dried into the drying chamber 220, close the chamber door, and seal the raw materials to be dried into the drying chamber 220; start the vacuum assembly 500, and the vacuum pump 510 works to extract the air from the drying chamber 220 through the vacuum pipe 520 to form a low-pressure or vacuum environment, creating conditions for low-temperature drying; turn on the heating assembly 400, and the blower 410 sends air into the heating chamber 420. After being heated by the heating element 421, the hot air is introduced into the drying chamber 220 along the heating pipe 430.

[0031] Simultaneously, the rotating mechanism 300 starts, and the drying chamber 220 rotates under the drive of the rotating motor 310, causing the material to tumble and come into uniform contact with the hot air. Under the combined action of vacuum and hot air, the moisture in the material quickly vaporizes, and the resulting water vapor accumulates inside the drying chamber 220 and is discharged through the vacuum pipe 520. During this process, the insulation layer 230 reduces heat loss and maintains a stable temperature inside the drying chamber 220. When the material reaches the target drying level, the heating component 400 is first turned off to stop heating, while the vacuum component 500 continues to run for a period of time to remove residual moisture. Finally, the vacuum component 500 is turned off, the chamber door is opened, and the dried material is removed.

[0032] Furthermore, the control of hot air input and vacuuming steps aims to balance drying efficiency, material quality, and energy consumption. Its control logic needs to be dynamically adjusted based on material characteristics and the drying process. Chemically synthesized pharmaceutical raw materials and their intermediates are mostly heat-sensitive substances, such as sertraline hydrochloride and ferrous succinate. Precise control of hot air temperature and vacuum level can avoid component decomposition or crystal transformation caused by high temperatures, ensuring product purity and activity. A reasonable control strategy can significantly improve drying efficiency. By dynamically adjusting the hot air input and vacuuming frequency, compared to traditional constant parameter drying, the drying time of cetirizine hydrochloride intermediates can be shortened by approximately 60%, while reducing energy consumption by more than 40%. In addition, improper control may lead to problems such as poor moisture removal, localized overheating of materials, or uneven drying, affecting product quality stability. Therefore, intelligent, phased control logic can achieve dual optimization of drying effect and cost-effectiveness.

[0033] In the initial drying stage, the vacuum assembly 500 is quickly activated to reduce the air pressure inside the drying chamber 220 to a set vacuum level (e.g., -0.09 MPa), lowering the boiling point of moisture in the material and creating conditions for low-temperature drying. Subsequently, the hot air system is introduced into the drying chamber 220 at a lower temperature (e.g., 50°C) and a larger flow rate to quickly replenish the heat required for moisture vaporization and carry the water vapor to the vacuum pipe 520 for discharge. As drying progresses, when the moisture content of the material decreases to a certain level, the hot air temperature and flow rate are gradually reduced based on sensor feedback, while the vacuuming frequency is decreased to maintain a stable vacuum environment and avoid over-drying and energy waste. In the later stages of drying, low-frequency vacuuming and intermittent hot air circulation are maintained to utilize residual heat to evaporate residual moisture, ensuring uniform drying of the material and optimal energy consumption.

[0034] Furthermore, the initial stage of materials with high moisture content (such as wet granules) requires high-frequency vacuuming (rapid pressure reduction) + high-frequency hot air (continuous heating) to accelerate the evaporation of free water.

[0035] Furthermore, for materials containing bound water (such as crystals), low-frequency vacuuming (to maintain vacuum level) and medium-frequency hot air are required in the later stages (to avoid overheating and damage to the structure).

[0036] Generally, during the initial constant-speed drying stage, a large amount of moisture evaporates, requiring high-frequency vacuuming (5-10 minutes / time) and continuous high-frequency hot air to quickly remove the moisture.

[0037] In the later stage of slow-down drying, the rate of moisture vaporization decreases, requiring low-frequency vacuuming (15-30 minutes / time) + intermittent operation of medium-frequency hot air to avoid over-drying of materials or waste of energy.

[0038] Furthermore, the control logic in this embodiment is as follows: when the humidity sensor detects an increase in water vapor concentration, the vacuum pump 510 is started, and the hot air system is heated to compensate for the heat loss caused by vacuuming. After the humidity drops below the threshold, the vacuuming is paused, and the hot air returns to normal temperature.

[0039] Furthermore, after the drying chamber 220 is evacuated, the internal air pressure decreases, and the boiling point of water decreases as the air pressure decreases. At this time, hot air is introduced, and the moisture in the material can be quickly removed in the form of "vaporization" rather than "slow evaporation," which significantly improves the moisture removal efficiency compared to traditional atmospheric pressure drying (which relies solely on hot air heating to evaporate moisture).

[0040] Vacuuming creates a uniform low-pressure environment within the drying chamber 220. When hot air is introduced, the hot airflow diffuses more evenly under low pressure, preventing localized high or low temperature zones. Simultaneously, under vacuum, moisture inside the material migrates more easily to the surface due to the pressure difference. Combined with the heat transfer of the hot air and the rotating mechanism 300, uniform drying from the inside out is achieved, reducing surface crusting and residual moisture inside the material. Together with the rotating mechanism 300, it solves the problems of uneven drying and unstable material quality.

[0041] Further, please see Figure 4 The rotating mechanism 300 includes a rotating motor 310 disposed on the top of the machine compartment and a driven wheel 320 driven by the rotating motor 310; the driven wheel 320 is connected to a connecting shaft 330 disposed on the drying chamber 220; the other end of the drying chamber 220 is connected to the heat preservation chamber 210 via a bearing. The connecting shaft 330 is connected to the drying chamber 220 via a fixing frame 340; the fixing frame 340 includes a plurality of fixing plates 341 arranged at intervals in the circumferential direction, and the plurality of fixing rods form an installation space for the drying chamber 220.

[0042] In use, the drying chamber 220 is installed inside the machine compartment and installation space, and is tightly engaged with the driven wheel 320 via the connecting shaft 330 to ensure smooth rotation of the drying chamber 220 when driven by the rotating motor 310. The structural design of the fixing frame 340 not only enhances the stability of the drying chamber 220 but also facilitates installation and disassembly, improving equipment maintenance efficiency. The spacing between the fixing plates 341 ensures that the drying chamber 220 is heated evenly during rotation, further enhancing the drying effect. In addition, the use of bearings effectively reduces friction between the drying chamber 220 and the insulation chamber 210, extending the service life of the equipment while ensuring the sealing of the vacuum environment. This design is particularly suitable for temperature-sensitive materials or materials requiring uniform drying, fully demonstrating the high efficiency and reliability of the equipment.

[0043] Furthermore, the drying chamber 220 is also equipped with a guide plate. During the drying process, the guide plate effectively guides the movement of the material within the drying chamber 220, allowing the material to tumble between its inner and outer layers as it is driven by the rotating mechanism 300. This prevents material accumulation or uneven distribution during drying. By designing the angle and shape of the guide plate, the tumbling frequency of the material can be further increased, resulting in more uniform heating during the drying process. In addition, the guide plate accelerates the drying speed, shortens the operation time, and thus improves overall work efficiency. The guide plate is made of high-temperature and corrosion-resistant materials, ensuring long-term stable operation under high-temperature and vacuum environments.

[0044] Further, please see Figure 2 A spacer is provided between the insulated chamber 210 and the drying chamber 220 to form an insulation layer 230, which is filled with insulation material. The insulation material can be fiberglass, rock wool, or polyurethane foam, etc., which have excellent thermal insulation properties and can effectively reduce heat loss, thereby reducing energy consumption. The thickness of the insulation material is generally adjusted according to actual needs and equipment specifications, typically between 50 mm and 150 mm. The design of the insulation layer 230 not only improves the thermal efficiency of the equipment but also further enhances the temperature stability within the drying chamber 220, providing a more ideal drying environment for the materials. Simultaneously, this structure effectively isolates the internal effects of external temperature changes on the equipment, ensuring that the equipment maintains high efficiency even under harsh working conditions.

[0045] Further, please see Figure 3 The heating assembly 400 includes a blower 410 and a heating chamber 420 connected to the blower 410; multiple sets of heating elements 421 are spaced apart inside the heating chamber 420; the heating pipe 430 is connected to the heating chamber 420 and delivers hot air to the interior of the drying chamber 220.

[0046] Furthermore, both sides of the nacelle are connected to the top of the frame via shock-absorbing springs.

[0047] Furthermore, the vacuum assembly 500 includes a vacuum pump 510 connected to the vacuum pipe 520, which intermittently evacuates the interior of the drying chamber 220. The heating assembly 400 and the vacuum assembly 500 perform heating or vacuuming operations, respectively.

[0048] This solution, through a synergistic mechanism of "vacuum depressurization + hot air synergy," essentially solves the problem of "how to achieve rapid and uniform drying of chemically synthesized raw materials under the premise of high efficiency, low energy consumption, and no pollution," and is particularly suitable for pharmaceutical raw material processing scenarios that are sensitive to drying temperature and require high purity.

[0049] In this embodiment, the drying equipment is based on the principle of "vacuum depressurization-hot air synergy," achieving efficient drying through structural design and process coordination. Under low pressure, the boiling point of water decreases significantly, allowing the moisture in the material to vaporize rapidly without high temperatures, avoiding the damage to heat-sensitive chemically synthesized raw materials and their intermediates (such as ferrous succinate and sertraline hydrochloride) caused by high temperatures in traditional atmospheric pressure drying. The heating component 400 sends air into the heating chamber 420 via a blower 410. After being heated by the heating element 421, the air is introduced into the drying chamber 220 through the heating pipe 430. The hot air provides the necessary heat for moisture vaporization and simultaneously drives the vaporized water vapor to flow, accelerating its discharge outside the chamber. The drying chamber 220 is connected to the rotating mechanism 300. The rotating motor 310 drives the driven wheel 320 to rotate the drying chamber 220, ensuring full contact between the material and the hot air during the tumbling process. The insulation layer 230 between the insulation chamber 210 and the drying chamber 220 reduces heat loss and maintains a stable drying temperature.

[0050] 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 vacuum dryer for chemical synthesis of bulk drug, characterized in that, include: Rack (100); The machine compartment includes an insulated compartment (210) and a drying compartment (220) disposed within the insulated compartment (210); the drying compartment (220) is connected to a rotating mechanism (300) disposed on one side of the frame (100) and can rotate based on the rotating mechanism (300) and the insulated compartment (210); A heating assembly (400) is disposed at the bottom of the frame (100) and is connected to the interior of the drying chamber (220) via a heating pipe (430); A vacuum assembly is located at the bottom of the frame (100) and is connected to the interior of the drying chamber (220) via a vacuum pipe (520); The drying chamber (220) is open at one end, and a chamber door (110) for sealing the opening is provided on the frame (100); the vacuum pipe (520) and the heating pipe (430) both extend into the interior of the drying chamber (220) through the chamber door (110).

2. The vacuum drying machine for chemical synthesis of bulk drug substances as claimed in claim 1 wherein, The rotating mechanism (300) includes a rotating motor (310) disposed on the top of the cabin, and a driven wheel (320) driven by the rotating motor (310); The driven wheel (320) is connected to the connecting shaft (330) provided on the drying chamber (220); The other end of the drying chamber (220) is connected to the heat preservation chamber (210) via a bearing.

3. The vacuum drying machine for chemical synthesis of bulk drug substances according to claim 2, characterized in that, The connecting shaft (330) is connected to the drying chamber (220) via a fixing frame (340); The fixing frame (340) includes a plurality of fixing plates (341) spaced apart in the circumferential direction, and the fixing plates (341) form an installation space for the drying chamber (220).

4. The vacuum drying machine for chemical synthesis of bulk drug substances as claimed in claim 1 wherein, A gap is provided between the heat preservation chamber (210) and the drying chamber (220) to form a heat preservation layer (230), and the heat preservation layer (230) is filled with heat preservation material.

5. The vacuum drying machine for chemical synthesis of bulk drug substances as claimed in claim 1 wherein, The heating assembly (400) includes a blower (410) and a heating chamber (420) connected to the blower (410); multiple sets of heating elements (421) are spaced apart inside the heating chamber (420); the heating pipe (430) is connected to the heating chamber (420) and delivers hot air to the interior of the drying chamber (220).

6. A vacuum dryer for chemically synthesized pharmaceutical raw materials according to claim 1, characterized in that, The two sides of the door (110) are connected to the top of the frame (100) by shock-absorbing springs (111).

7. A vacuum dryer for chemically synthesized pharmaceutical raw materials according to claim 1, characterized in that, The vacuum assembly includes a vacuum pump (510) connected to the vacuum pipe (520), which performs vacuuming operations on the interior of the drying chamber (220) intermittently.

8. A vacuum dryer for chemically synthesized pharmaceutical raw materials according to claim 1, characterized in that, The heating component (400) and the vacuuming component perform heating or vacuuming operations respectively.

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