Vacuum drying oven capable of recycling solvent

Abstract

The utility model provides a vacuum drying oven capable of recovering a solvent, which is used for effectively recovering the evaporated solvent in the vacuum drying oven and comprises a vacuum drying oven body, a vacuum box cover, a vacuum box cover and a vacuum box cover, an air inlet and an air outlet of the condenser are formed in the lower end and the upper end respectively, and the air inlet is connected with the extraction opening of the vacuum drying box body; an air inlet of the vacuum pump is connected with an air outlet of the condenser; according to the vacuum drying box, the solvent outlet is formed in the bottom of the vacuum drying box body, so that the situation that solvent steam flows back to the bottom of the box body to be accumulated in the rising process after being evaporated out of materials can be avoided; the solvent evaporated in the vacuum drying box body is effectively recycled, waste of the solvent and corrosion of equipment are avoided, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a vacuum drying oven with recyclable solvent. Background Technology

[0002] In the production of raw materials and excipients in the pharmaceutical industry, vacuum drying ovens are widely used for drying intermediates and finished products. However, when drying drugs containing solvents, traditional vacuum drying ovens often directly release the evaporated solvents into the atmosphere. This not only wastes resources but may also pollute the environment. Some solvents can also corrode pipes and vacuum pumps. In addition, most organic solvents are flammable and explosive, posing certain safety hazards during vacuum pipeline transportation and discharge.

[0003] Most vacuum drying ovens have their air outlets located at the top of the chamber, which can lead to solvent vapors evaporating from the material and then flowing back to the bottom of the chamber during their ascent, resulting in low sample drying efficiency. Therefore, developing a vacuum drying oven that can effectively evaporate and recover solvents is of great significance for the sustainable development of the pharmaceutical industry. Utility Model Content

[0004] This invention provides a vacuum drying oven with recyclable solvent to effectively recover the solvent evaporated inside the vacuum drying oven. To achieve the above objective, the technical solution adopted is as follows:

[0005] A vacuum drying oven for recyclable solvents, characterized in that it comprises:

[0006] The vacuum drying oven body has an air extraction port at the bottom.

[0007] The condenser has an air inlet and an air outlet located at the lower and upper ends, respectively, and the air inlet is connected to the air extraction port of the vacuum drying oven body.

[0008] A vacuum pump, wherein the inlet of the vacuum pump is connected to the outlet of the condenser;

[0009] The solvent recovery tank is located below the air inlet of the condenser, and the inlet of the solvent recovery tank is connected to the air inlet of the condenser.

[0010] Furthermore, it also includes a filter, the inlet and outlet of which are connected to the air extraction port of the vacuum drying oven body and the air inlet of the condenser, respectively.

[0011] Furthermore, a first switching valve and a second switching valve are respectively installed at the air inlet of the condenser and the inlet of the solvent recovery tank.

[0012] Furthermore, a drain pipe is provided at the bottom of the solvent recovery tank, and a third switch valve is provided on the drain pipe.

[0013] Furthermore, a sight glass is provided on the side wall of the air inlet of the condenser.

[0014] Furthermore, the temperature of the cooling medium inside the condenser is 10-20°C lower than the boiling point of the recovered solvent.

[0015] The beneficial effects of this utility model are as follows:

[0016] 1. Setting the outlet of the solvent to be recovered at the bottom of the vacuum drying chamber facilitates the drainage of the solvent and avoids the situation where the steam condenses and accumulates at the bottom of the chamber, which is not easy to drain. This facilitates the outflow of the solvent and improves the drying efficiency of the material. Moreover, compared with the existing technology where the outlet is located at the top, the evaporated solvent will be drawn out from the bottom more quickly, reducing the situation where the solvent adheres to the inner wall of the vacuum chamber.

[0017] 2. The air inlet and outlet of the condenser are respectively located at the lower and upper ends of the condenser body. Moreover, the air extraction port of the vacuum drying oven body and the inlet of the solvent recovery tank are both connected to the air inlet of the condenser. The air inlet of the condenser can simultaneously serve as the inlet for recovering solvent vapor and the outlet for the condensed solvent, which not only simplifies the structure of the condenser but also simplifies the connection with other structures.

[0018] 3. A filter is installed at the air extraction port of the vacuum drying oven body to effectively prevent the dust of the extracted material from entering the recovery solvent.

[0019] 4. The first and second switching valves installed at the condenser inlet and solvent recovery tank inlet can control the opening and closing of each pipeline. When the residual solvent in the dried material is mainly water, the condenser can be shut off and the second switching valve can be shut off at the same time.

[0020] 5. A sight glass is installed at the air inlet at the lower end of the condenser to observe the amount of recovered solvent produced during drying. When the amount of recovered solvent produced during drying is small, the condenser can be turned off and a vacuum can be drawn directly.

[0021] 6. The solvent recovery tank is equipped with a drain pipe and a third switch valve at the bottom. When there is too much solvent recovered inside or when different solvents need to be recovered, the third switch valve can be opened to drain the solvent through the drain pipe and collect other types of solvents. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present utility model.

[0023] in:

[0024] 1-Vacuum drying oven body, 2-Filter, 3-Condenser, 4-Vacuum pump, 5-Solvent recovery tank, 6-Extraction port, 7-First switch valve, 8-Second switch valve, 9-Drain pipe, 10-Third switch valve, 11-Sight glass. Detailed Implementation

[0025] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0026] In the description of the utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the view direction or positional relationship, and are only for the convenience of describing the utility model, 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 on the utility model.

[0027] like Figure 1 The vacuum drying oven shown includes a vacuum drying oven body 1, a filter 2, a condenser 3, a vacuum pump 4, and a solvent recovery tank 5.

[0028] Specifically, the lower end of the vacuum drying oven body 1 is provided with an air extraction port 6, the air inlet and outlet of the condenser 3 are located at the lower end and the upper end respectively, and the air extraction port 6 is connected to the air inlet of the condenser 3, the air outlet of the condenser 3 is connected to the air inlet of the vacuum pump 4, and the solvent recovery tank 5 is located directly below the air inlet of the condenser 3, and the inlet of the solvent recovery tank 5 is connected to the air inlet of the condenser 3.

[0029] By setting an extraction port 6 at the bottom of the vacuum drying oven body 1 as a solvent recovery outlet, compared with the existing technology that sets the solvent outlet at the top of the drying oven, the problem of vapor condensation flowing back to the bottom of the drying oven and accumulating is avoided. This facilitates the drainage of solvent and improves the material drying efficiency. Moreover, the molecular weight of the evaporated solvent gas is generally greater than that of air and water vapor. Therefore, if the outlet is set at the top of the vacuum drying oven, air or water vapor will be extracted first, which will make it easier for solvent vapor to adhere to the inner side wall of the drying oven and condense. However, this solution sets the extraction port 6 at the bottom of the vacuum drying oven 1, so the solvent vapor with a larger molecular weight is extracted from the bottom more quickly, reducing the possibility of solvent vapor contacting the side wall of the drying oven, thereby reducing the solvent condensation backflow. In addition, the air inlet of the condenser 3 serves as both the solvent recovery air inlet and the liquid outlet after condensation, simplifying the structure of the condenser and the connection method of the overall structure.

[0030] To further improve the solvent recovery effect, a filter 2 is connected between the vacuum drying oven body 1 and the condenser 3. The inlet and outlet of the filter 2 are connected to the air extraction port 6 and the air inlet of the condenser 3, respectively. The filter 2 can effectively prevent dust in the extracted material from entering the recovered solvent.

[0031] In this embodiment, the condenser 3 is a coil-type or array-type condenser. The temperature of the internal cooling medium is set according to the boiling point of the solvent to be condensed. In this embodiment, the temperature of the cooling medium is 10-20°C lower than the boiling point of the solvent to be recovered. Furthermore, a sight glass 11 is provided on the side wall at the lower air inlet of the condenser 3. The amount of recovered solvent generated during the drying process of the vacuum drying oven body 1 can be observed through the sight glass 11.

[0032] Furthermore, a first switching valve 7 is installed at the air inlet of the condenser 3, which is located above the sight glass 11. A second switching valve 8 is installed at the upper inlet of the solvent recovery tank 5, and a drain pipe 9 is installed at the lower end of the solvent recovery tank 5. A third switching valve 10 is installed on the drain pipe 9.

[0033] When using this device to recover solvents, a suitable coolant should be selected based on the boiling point of the solvent to be recovered. It should also be noted that when recovering mixed solvents, the boiling point difference of the multiple components should be considered, and the cooling temperature of the condenser 3 should be reasonably determined. In this embodiment, the temperature of the coolant in the condenser 3 is adjusted to be 10-20°C lower than the boiling point of the solvent to be recovered. After the vacuum drying chamber body 1 starts working, the first switch valve 7 and the second switch valve 8 are opened. After the recovered solvent vapor passes through the filter 2, it enters the condenser 3. After being condensed by the condenser 3, the recovered solvent vapor flows downward through the air inlet of the condenser 3 under the influence of gravitational potential energy into the solvent recovery tank 5, thus completing the recovery of the solvent. When there is a lot of solvent in the solvent recovery tank 5 or different solvents need to be recovered, the second switch valve 8 can be closed first and the third switch valve 10 can be opened to transfer the solvent in the solvent recovery tank 5 before material drying and solvent recovery. After the material drying is completed, the first switch valve 7 and the second switch valve 8 are closed before depressurizing and collecting the material in the vacuum drying chamber body 1.

[0034] In addition, when the residual solvent in the material drying is mainly water, the condenser 3 and the second switch valve 8 can be closed, and vacuum can be directly performed by the vacuum pump 4. The water will evaporate and not be recovered. Alternatively, the lower part of the condenser 3 can be observed through the sight glass 11. When the amount of recovered solvent is small, the condenser 3 can be closed and vacuum can be directly performed.

[0035] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present utility model, and these improvements should also be considered within the protection scope of the present utility model.

Claims

1. A vacuum drying oven with recyclable solvent, characterized in that, include: The vacuum drying oven body has an air extraction port at the bottom. The condenser has an air inlet and an air outlet located at the lower and upper ends, respectively, and the air inlet is connected to the air extraction port of the vacuum drying oven body. A vacuum pump, wherein the inlet of the vacuum pump is connected to the outlet of the condenser; The solvent recovery tank is located below the air inlet of the condenser, and the inlet of the solvent recovery tank is connected to the air inlet of the condenser.

2. The vacuum drying oven for recyclable solvents according to claim 1, characterized in that, It also includes a filter, the inlet and outlet of which are connected to the air extraction port of the vacuum drying oven body and the air inlet of the condenser, respectively.

3. The vacuum drying oven for recyclable solvents according to claim 1, characterized in that, The condenser inlet and the solvent recovery tank inlet are respectively equipped with a first switching valve and a second switching valve.

4. The vacuum drying oven for recyclable solvents according to claim 1, characterized in that, The solvent recovery tank is equipped with a drain pipe at the bottom, and a third switch valve is installed on the drain pipe.

5. The vacuum drying oven for recyclable solvents according to claim 1, characterized in that, A sight glass is provided on the side wall of the air inlet of the condenser.

6. The vacuum drying oven for recyclable solvent according to claim 1, characterized in that, The temperature of the cooling medium inside the condenser is 10-20°C lower than the boiling point of the recovered solvent.

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