Device for recycling solvent of vacuum flash evaporation system

Abstract

The invention provides a solvent recycling device for a vacuum flash evaporation system, which comprises a heatable air exhaust pipeline, the bottom of the heatable air exhaust pipeline is connected with a plurality of groups of solvent recycling assemblies, and each group of solvent recycling assembly comprises a first vacuum pipeline, a second vacuum pipeline, a third vacuum pipeline, a copper pipe cold trap, a solvent recycling tank and a stirring heating base station, one end of the copper pipe cold trap is connected with the bottom of the heatable pumping pipeline through a first vacuum pipeline and a second vacuum pipeline, and the other end of the copper pipe cold trap is connected with the solvent recovery tank through a third vacuum pipeline; the right end of the heatable air exhaust pipeline is connected with a molecular pump, and the bottom of the heatable air exhaust pipeline is connected with a large-pumping-amount mechanical pump through a first auxiliary pipeline; the recycling rate of 99.9% is achieved for the gas solvent generated in the perovskite solar cell flash evaporation technological process, the composition of the recycled solvent can be kept consistent with that of an original solvent, and the method can be used for preparing a fresh solution.

Description

Technical Field

[0001] The invention belongs to the technical field of perovskite photovoltaic cells, and in particular relates to a device for recovering solvents in a vacuum flash evaporation system. Background Art

[0002] Perovskite flash evaporation technology is an advanced preparation process, which is particularly suitable for the preparation of perovskite thin films for solar cells. This technology is green and pollution-free, and can effectively avoid the environmental problems and uneven film formation that may arise during the traditional anti-solvent method. The perovskite film prepared by vacuum flash evaporation technology is uniform and dense, pinhole-free, and has a large grain size. Therefore, the flash evaporation method has great potential in the preparation of high-performance, large-area perovskite solar cells. The solvent recovery step plays a significant role in reducing costs and increasing efficiency.

[0003] In the traditional flash evaporation process, organic solvents such as DMF and DMSO cannot be recycled and reused. On the one hand, it will increase the consumption of solvents and make production costs uncontrollable. On the other hand, the volatile solvents will be discharged into the air through exhaust gas, affecting the environment. Summary of the invention

[0004] The present invention provides a device for solvent recovery and utilization of a vacuum flash evaporation system, which solves the problems of environmental pollution, high cost and low solvent utilization rate caused by the conventional flash evaporation system without a solvent recovery and reuse device. The device can quickly condense the extracted gaseous solvent into a liquid state and collect it, with a recovery rate of up to 99.9%. The recovered solvent can maintain a consistent composition with the original solvent and can be directly used in the preparation of a fresh solution, so as to achieve more efficient, faster and more complete recovery and reuse of the volatile solvent, thereby achieving the purpose of reducing costs and protecting the environment.

[0005] To solve the above problems, the technical solution provided by the present invention is as follows:

[0006] An embodiment of the present invention provides a device for solvent recovery in a vacuum flash evaporation system, comprising a heatable exhaust pipe (7), wherein the heatable exhaust pipe (7) is used to extract gaseous solvent in the flash evaporation process for preparing a perovskite film;

[0007] The heatable exhaust pipe (7) is provided with a plurality of high-pressure nitrogen holes (8) inside, and a plurality of groups of solvent recovery components are connected to the bottom of the heatable exhaust pipe (7); wherein each group of solvent recovery components comprises a first vacuum pipe (12), a second vacuum pipe (13), a third vacuum pipe (14), a copper tube cold trap (1), a solvent recovery tank (5) and a stirring and heating base (6); one end of the copper tube cold trap (1) is connected to the bottom of the heatable exhaust pipe (7) through the first vacuum pipe (12) and the second vacuum pipe (13), and the other end of the copper tube cold trap (1) is connected to the solvent recovery tank (5) through the third vacuum pipe (14); and the stirring and heating base (6) is installed at the bottom of the solvent recovery tank (5);

[0008] The right end of the heatable air extraction pipeline (7) is connected to a molecular pump (10), and the bottom of the heatable air extraction pipeline (7) is also connected to a large-volume mechanical pump (9) via a first auxiliary pipeline (16), and the large-volume mechanical pump (9) is connected to the molecular pump (10) via a second auxiliary pipeline (17).

[0009] According to an optional embodiment of the present invention, a heating constant temperature system is provided in the heatable exhaust pipe (7), so that the temperature of the heatable exhaust pipe (7) is within the range of 25 to 200° C., thereby promoting the extracted gaseous solvent to enter the copper tube cold trap (1) as completely as possible, and preventing the gaseous solvent from condensing and remaining in the heatable exhaust pipe (7), thereby affecting the solvent recovery efficiency and the composition of the recovered solvent.

[0010] According to an optional embodiment of the present invention, a high-pressure nitrogen cleaning device is installed in the heatable exhaust pipe (7), and the nitrogen pressure of the high-pressure nitrogen cleaning device is regulated in the range of 0 to 20 MPa to clean the liquid solvent remaining in the heatable exhaust pipe (7) and promote the solvent to enter the copper tube cold trap (1).

[0011] According to an optional embodiment of the present invention, a sand core filter (3) is arranged at the bottom of the copper tube cold trap (1), and a coil structure (2) is arranged inside the copper tube cold trap (1). The coil structure (2) is filled with chilled water. The coil structure (2) is used to increase the contact area between the chilled water and the gaseous solvent, so as to promote more complete condensation of the gaseous solvent and improve the speed and efficiency of volatile solvent recovery.

[0012] According to an optional embodiment of the present invention, the third vacuum pipe (14) is provided with an automatic switch valve (4), and the automatic switch valve (4) can adjust the solvent recovery amount.

[0013] According to an optional embodiment of the present invention, the heatable exhaust pipe (7), the first vacuum pipe (12), the second vacuum pipe (13), the first auxiliary pipe (16) and the second auxiliary pipe (17) are all provided with solenoid valves (11), and the solenoid valves (11) control the opening or closing of the pipes.

[0014] According to an optional embodiment of the present invention, a drain pipe (18) is provided on the side of the solvent recovery tank (5), and the drain pipe (18) is connected to a side configuration cup (19), and the side configuration cup (19) is used for preparing the solution.

[0015] Compared with the prior art, the embodiment of the present invention provides a device for solvent recovery and utilization in a vacuum flash evaporation system, which has the following beneficial effects: the present invention not only solves the problem of increased solvent cost and environmental pollution caused by the lack of a recovery device in the traditional flash evaporation system, but also can achieve faster, more comprehensive and more efficient recovery of the extracted solvent, improve the recovery and utilization rate of the solvent, which is beneficial to cost saving, and also prevents the solvent from entering the vacuum pump and causing pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of a device for solvent recovery and utilization in a vacuum flash evaporation system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0019] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. It should also be noted that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection: it can be directly connected, it can also be indirectly connected through an intermediate medium, and it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. The following descriptions of the embodiments are with reference to the attached drawings to illustrate specific embodiments in which the present invention can be implemented. The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only used to refer to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, but are not used to limit the present invention. In the drawings, units with similar structures are represented by the same reference numerals.

[0020] The embodiment of the present invention provides a device for solvent recovery and utilization in a vacuum flash evaporation system. The present invention is applied to the flash evaporation process step. By adding a device for solvent recovery and reuse, the recovered solvent can maintain the initial solvent composition, ensure that it is consistent with the original solvent, and can be directly used for fresh solution configuration with a recovery rate of up to 99.9%. This has a significant effect on improving the utilization efficiency of the solvent, saving costs and being environmentally friendly.

[0021] like Figure 1 As shown, a device for solvent recovery and utilization in a vacuum flash evaporation system includes a heatable exhaust pipe 7, which is used to extract gaseous solvents in the flash evaporation process for preparing perovskite thin films. A plurality of high-pressure nitrogen holes 8 are arranged inside the heatable exhaust pipe 7. A plurality of groups of solvent recovery components are connected to the bottom of the heatable exhaust pipe 7; wherein each group of solvent recovery components includes a first vacuum pipe 12, a second vacuum pipe 13, a third vacuum pipe 14, a copper tube cold trap 1, a solvent recovery tank 5 and a stirring and heating base 6, one end of the copper tube cold trap 1 is connected to the bottom of the heatable exhaust pipe 7 through the first vacuum pipe 12 and the second vacuum pipe 13, and the other end of the copper tube cold trap 1 is connected to the solvent recovery tank 5 through the third vacuum pipe 14, and the stirring and heating base 6 is installed at the bottom of the solvent recovery tank 5, and the stirring and heating base 5 prevents the recovered solvent from condensing in the recovery tank, so that the solvent cannot be used for the preparation of fresh solution.

[0022] The right end of the heatable exhaust pipe 7 is connected to a molecular pump 10, and the bottom of the heatable exhaust pipe 7 is connected to a large-volume mechanical pump 9 through a first auxiliary pipe 16, and the large-volume mechanical pump 9 is connected to the molecular pump 10 through a second auxiliary pipe 17. An automatic switch valve 4 is provided on the third vacuum pipe 14. The heatable exhaust pipe 7, the first vacuum pipe 12, the second vacuum pipe 13, the first auxiliary pipe 16 and the second auxiliary pipe 17 are all provided with a solenoid valve 11, and the solenoid valve 11 controls the opening or closing of the pipe. A drain pipe 18 is provided on the side of the solvent recovery tank 5, and the drain pipe 18 is connected to a side configuration cup 19, and the side configuration cup 19 is used for solution preparation. The solvent in the solvent recovery tank 5 in this embodiment is directly used for fresh solution preparation after recovery.

[0023] The heatable exhaust pipe 7 is provided with a heating thermostatic system, so that the temperature of the heatable exhaust pipe 7 is in the range of 25 to 200°C, so as to promote the extracted gaseous solvent to enter the copper tube cold trap 1 as much as possible, and prevent the solvent from condensing and remaining in the heatable exhaust pipe 7, which affects the solvent recovery efficiency and the composition of the recovered solvent. The heatable exhaust pipe in this embodiment has a heating thermostatic system of 25 to 200°C to prevent a large amount of solvent with a low boiling point from condensing and remaining in the vacuum pipe, and ensure that the extracted volatile solvent gas enters the copper tube cold trap and condenses into liquid.

[0024] A high-pressure nitrogen cleaning device is installed in the heatable exhaust pipe 7. The nitrogen pressure of the high-pressure nitrogen cleaning device is regulated in the range of 0 to 20 MPa to clean the residual liquid solvent in the heatable exhaust pipe 7 and promote the gas solvent to enter the copper tube cold trap 1.

[0025] A sand core filter 3 is provided at the bottom of the copper tube cold trap 1, and a coil structure 2 is provided inside the copper tube cold trap 1. The coil structure 2 is filled with chilled water. The coil structure 2 is used to increase the contact area between the chilled water and the gas solvent to promote more complete condensation of the gaseous solvent and improve the speed and efficiency of volatile solvent recovery. The bottom end of the copper tube cold trap 1 in this embodiment is connected to the solvent recovery tank 5 through a 100-160um sand core filter 3 and an automatic switch valve 4 to prevent the recovered solvent from being contaminated and the introduction of impurities such as particles. Cooling water is loaded into the coil structure to promote the rapid condensation of the gaseous solvent into a liquid for collection. The coil design can increase the condensation area of ​​the gas to achieve a rapid and sufficient condensation effect.

[0026] In order to facilitate the recovery of different solvents, multiple sets of solvent recovery components can be set, and the copper tube cold traps 1 of the multiple sets of solvent recovery components recover different solvents, and the solvent recovery tanks 5 of the multiple sets of solvent recovery components store different solvents. Preferably, two or more copper tube cold traps can be designed, which are respectively connected to different solvent recovery tanks, and the electromagnetic valves of the pipelines are used to control the different solvent systems recovered by condensation, so as to facilitate the preparation of perovskite films of different solvent systems.

[0027] The automatic switch valve 4 between the copper tube cold trap 1 and the solvent recovery tank 5 can adjust the solvent recovery amount. The 100-160um sand core filter 3 at the bottom of the copper tube cold trap 1 can prevent the recovered solvent from being contaminated and the introduction of impurities such as particles. The stirring and heating base 6 at the bottom of the solvent recovery tank 5 prevents the recovered solvent from condensing, thereby affecting the use effect of the recovered solvent, ensuring that the solvent is consistent with the initial solvent and can be directly used for the preparation of the next fresh solution.

[0028] A device for solvent recovery and utilization in a vacuum flash evaporation system has the following beneficial effects: it effectively solves the key problems of the traditional flash evaporation vacuum system without solvent recovery devices, the inability to effectively control solvent costs, and environmental unfriendliness. This invention achieves full recovery and reuse of gaseous solvents extracted by the flash evaporation process, with a recovery rate of up to 99.9%, significantly improving the solvent recovery efficiency, and achieving the protection effect of vacuum pipes and vacuum pumps, reducing costs, and optimizing the working environment and efficiency of the flash evaporation process.

[0029] In summary, although the present invention has been disclosed as above in terms of preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A device for solvent recovery in a vacuum flash evaporation system, characterized in that: It comprises a heatable exhaust pipe (7), wherein the heatable exhaust pipe (7) is used to extract the gaseous solvent in the flash evaporation process for preparing the perovskite film; The heatable exhaust pipe (7) is provided with a plurality of high-pressure nitrogen holes (8) inside, and a plurality of groups of solvent recovery components are connected to the bottom of the heatable exhaust pipe (7); wherein each group of solvent recovery components comprises a first vacuum pipe (12), a second vacuum pipe (13), a third vacuum pipe (14), a copper tube cold trap (1), a solvent recovery tank (5) and a stirring and heating base (6); one end of the copper tube cold trap (1) is connected to the bottom of the heatable exhaust pipe (7) through the first vacuum pipe (12) and the second vacuum pipe (13), and the other end of the copper tube cold trap (1) is connected to the solvent recovery tank (5) through the third vacuum pipe (14); and the stirring and heating base (6) is installed at the bottom of the solvent recovery tank (5); The right end of the heatable air extraction pipeline (7) is connected to a molecular pump (10), and the bottom of the heatable air extraction pipeline (7) is also connected to a large-volume mechanical pump (9) via a first auxiliary pipeline (16), and the large-volume mechanical pump (9) is connected to the molecular pump (10) via a second auxiliary pipeline (17).

2. The device for solvent recovery in a vacuum flash evaporation system according to claim 1, characterized in that: The heatable exhaust pipe (7) is provided with a heating constant temperature system, so that the temperature of the heatable exhaust pipe (7) is within the range of 25 to 200° C., thereby promoting the extracted gaseous solvent to enter the copper tube cold trap (1) as completely as possible, and preventing the gaseous solvent from condensing and remaining in the heatable exhaust pipe (7), thereby affecting the solvent recovery efficiency and the composition of the recovered solvent.

3. The device for solvent recovery in a vacuum flash evaporation system according to claim 2, characterized in that: A high-pressure nitrogen cleaning device is installed in the heatable exhaust pipe (7), and the nitrogen pressure of the high-pressure nitrogen cleaning device is regulated in the range of 0 to 20 MPa to clean the liquid solvent remaining in the heatable exhaust pipe (7) and promote the solvent to enter the copper tube cold trap (1).

4. The device for solvent recovery in a vacuum flash evaporation system according to claim 3, characterized in that: A sand core filter (3) is arranged at the bottom of the copper tube cold trap (1), and a coil structure (2) is arranged inside the copper tube cold trap (1). The coil structure (2) is filled with chilled water. The coil structure (2) is used to increase the contact area between the chilled water and the gaseous solvent, so as to promote more complete condensation of the gaseous solvent and improve the speed and efficiency of volatile solvent recovery.

5. The device for solvent recovery in a vacuum flash evaporation system according to claim 1, characterized in that: The third vacuum pipeline (14) is provided with an automatic switch valve (4), and the automatic switch valve (4) can adjust the solvent recovery amount.

6. The device for solvent recovery in a vacuum flash evaporation system according to claim 1, characterized in that: The heatable exhaust pipe (7), the first vacuum pipe (12), the second vacuum pipe (13), the first auxiliary pipe (16) and the second auxiliary pipe (17) are all provided with solenoid valves (11), and the solenoid valves (11) control the opening or closing of the pipes.

7. The device for solvent recovery in a vacuum flash evaporation system according to claim 1, characterized in that: A liquid discharge pipe (18) is arranged on the side of the solvent recovery tank (5), and the liquid discharge pipe (18) is connected to a side configuration cup (19), and the side configuration cup (19) is used for preparing the solution.

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