A collection system for low boiling point solvents
By using a heat exchanger and a gas-liquid separator in the low-boiling-point solvent collection system, the problem of low cold energy utilization rate is solved, and efficient utilization of cold energy and efficient recovery of solvent are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU HENGMEISHENG BIOTECHNOLOGY CO LTD
- Filing Date
- 2025-07-25
- Publication Date
- 2026-06-26
AI Technical Summary
In existing distillation methods, the utilization rate of cold energy during the condensation process of low-boiling-point solvents is low, resulting in a waste of cold energy.
The reaction vessel, the first heat exchange device, and the second heat exchange device are connected in sequence. The solvent is evaporated into a gaseous state by a temperature control unit and condensed in the first and second heat exchange devices. The cooling capacity of the uncondensed gas is used to further condense the solvent. The gas-liquid separator and the vacuum pump are combined to improve the utilization rate of cooling capacity.
It improves the utilization rate of cold energy and enhances the recovery efficiency of low-boiling-point solvents.
Smart Images
Figure CN224405103U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of chemical equipment, and more specifically, to a collection system for low-boiling-point solvents. Background Technology
[0002] In industries such as pharmaceuticals, chemicals, and food, the processing of low-boiling-point solvents may occur during product preparation, which is a crucial step. Low-boiling-point solvents, such as dichloromethane and diethyl ether, are prone to bumping during distillation. Their low boiling points also make them easily volatile at room temperature, a characteristic that needs to be considered in many applications. Existing collection methods mainly include distillation, adsorption, membrane separation, and chemical conversion.
[0003] Distillation is one of the most traditional and commonly used methods for recovering low-boiling-point solvents. It involves heating the reactants to vaporize the low-boiling-point solvents, followed by condensation and collection, thus separating and purifying the low-boiling-point solvents from other waste gases. This method is simple, inexpensive, and suitable for treating waste liquids with high concentrations of low-boiling-point solvents. However, when using this method for condensation and collection, the waste gas also absorbs cold energy, resulting in a low utilization rate of the cold energy used for condensing the low-boiling-point solvents. Utility Model Content
[0004] The purpose of this application is to provide a collection system for low-boiling-point solvents, which can improve the utilization rate of the cooling capacity used for condensing low-boiling-point solvents.
[0005] The embodiments of this application are implemented as follows:
[0006] In a first aspect, embodiments of this application provide a collection system for low-boiling-point solvents, comprising a reaction vessel, a first heat exchange device, and a second heat exchange device connected in sequence, and also including a collection device.
[0007] The reaction vessel is used to contain solvent, and the reaction vessel is equipped with a temperature control unit configured to allow the solvent in the reaction vessel to evaporate into a gaseous state; the first heat exchange device and the second heat exchange device are used to condense the gaseous solvent, and the collecting device is connected to the first heat exchange device and the second heat exchange device to collect the condensed liquid solvent.
[0008] The first heat exchange device is provided with a first pipe and a second pipe, and the gaseous solvent can be condensed in the first pipe and the second pipe; the inlet end of the first pipe is connected to the reaction tank and the outlet end is connected to the air inlet of the second heat exchange device; the inlet end of the second pipe is connected to the air outlet of the second heat exchange device.
[0009] In the above technical solution, the reaction vessel can be heated by a temperature control unit, causing the low-boiling-point solvent inside the vessel to evaporate into a gaseous state. The reaction vessel, the first heat exchange device, and the second heat exchange device are connected in sequence. The inlet end of the first pipe in the first heat exchange device is connected to the reaction vessel, so the solvent and other gases volatilized in the reaction vessel can enter the first pipe. Some of the solvent condenses in the first pipe, and the uncondensed gaseous solvent continues to enter the second heat exchange device for condensation. The gaseous solvent and other gases also absorb cold energy in the second heat exchange device. Therefore, the gas discharged from the second heat exchange device has cold energy and a low temperature. By connecting the inlet end of the second pipe to the outlet of the second heat exchange device, other gases can return to the first heat exchange device and provide energy to the gaseous solvent in the first pipe through heat exchange. This allows the portion of the cold energy absorbed by other gases in the first and second heat exchange devices to be reused for the condensation of the gaseous solvent. Therefore, the collection system provided by the above technical solution can improve the utilization rate of cold energy.
[0010] In some alternative implementations, a first gas-liquid separator is further connected between the outlet end of the first pipe and the air inlet of the second heat exchange device. The inlet of the first gas-liquid separator is connected to the outlet end of the first pipe, and the outlet of the first gas-liquid separator is connected to the air inlet of the second heat exchange device. The liquid outlet of the first gas-liquid separator is connected to the collecting device.
[0011] In the above technical solution, the first gas-liquid separator can separate the condensed solvent in the first pipeline from the uncondensed gaseous solvent and other gases. The gaseous solvent enters the second heat exchange device from the outlet of the first gas-liquid separator to continue heat exchange; the condensed liquid solvent enters the collection device from the outlet of the first gas-liquid separator and is collected, thus recovering the solvent.
[0012] In some alternative embodiments, the outlet of the second heat exchange device is connected to a second gas-liquid separator, the outlet of the second gas-liquid separator is connected to the inlet end of the second pipe, and the outlet of the second gas-liquid separator is connected to the collecting device.
[0013] In the above technical solution, the solvent condensed in the second heat exchange device can be separated from other gases by the second gas-liquid separator. The condensed liquid solvent enters the collection device from the outlet of the second gas-liquid separator and is collected, thus recovering the solvent.
[0014] In some alternative implementations, a plurality of second heat exchange devices are connected in sequence, with the air inlet of the first second heat exchange device connected to the outlet of the first pipe, and the air outlet of the last second heat exchange device connected to the inlet of the second pipe.
[0015] In the above technical solution, the gaseous solvent is condensed by heat exchange through multiple second heat exchange devices, which enables more gaseous solvent to be absorbed after condensation, thereby improving the solvent recovery rate.
[0016] In some alternative embodiments, a heat exchange medium supply conduit is also included, which is connected to the second heat exchange device to provide a heat exchange medium to the second heat exchange device for condensing the gaseous solvent passing through the second heat exchange device.
[0017] In some alternative implementations, a vacuum pump is also included, which is connected to the outlet end of the second pipe.
[0018] In the above technical solution, by connecting the vacuum pump to the outlet end of the second pipeline, the mixed gas containing gaseous solvent in the reaction vessel can enter the first heat exchange device and the second heat exchange device, providing power for the movement of the mixed gas.
[0019] In some alternative embodiments, a filter device and a vacuum buffer tank are further connected between the vacuum pump and the outlet end of the second pipe; the filter device is connected between the outlet end of the second pipe and the inlet of the vacuum buffer tank, and the vacuum pump is connected to the outlet of the vacuum buffer tank.
[0020] In some alternative implementations, the temperature control unit includes a steam pipe and a cooling water pipe for introducing a heat exchange medium into the reaction vessel.
[0021] In the above technical solution, the steam pipe can provide steam as a heat exchange medium, thereby raising the temperature inside the reaction vessel, and the cooling water pipe can provide cooling water as a heat exchange medium, thereby lowering the temperature inside the reaction vessel. The temperature control unit can regulate the temperature inside the reaction vessel, maintaining it within a range that allows the solvent to evaporate without causing it to react with other substances.
[0022] In some alternative implementations, the steam conduit includes a first steam pipe and a second steam pipe, both of which are equipped with valves.
[0023] In the above technical solution, steam can be supplied to the reaction vessel as a heat exchange medium through the first steam pipe and the second steam pipe. Since both the first steam pipe and the second steam pipe are equipped with valves, the amount of steam supplied to the reaction vessel can be controlled by the valves, thereby controlling the temperature of the reaction vessel more precisely.
[0024] In some optional embodiments, the reaction vessel is provided with a temperature control pipe, the upper inlet of which is connected to the gas supply end of the steam pipe and the water return end of the cooling water pipe; the lower inlet of which is connected to the gas return end of the steam pipe and the water supply end of the cooling water pipe; and valves are provided at the gas supply end and the gas return end of the steam pipe, as well as at the water supply end and the water return end of the cooling water pipe.
[0025] In the above technical solution, the temperature control pipe inside the reaction vessel is used to heat the substances inside the reaction vessel by passing a heat exchange medium. Since the upper inlet of the temperature control pipe is connected to the steam supply end of the steam pipe and the return end of the cooling water pipe, and the lower inlet is connected to the steam return end of the steam pipe and the water supply end of the cooling water pipe, when steam is introduced into the temperature control pipe, the steam enters from the upper end and exits from the lower end, which can better heat the reaction vessel. When cooling water is introduced into the temperature control pipe, the cooling water enters from the lower end and exits from the upper end, which can better cool the reaction vessel. By installing valves at the steam supply and return ends of the steam pipe and the water supply and return ends of the cooling water pipe, it is easy to control whether steam or cooling water is introduced into the temperature control pipe. Attached Figure Description
[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a schematic diagram of the collection system provided in an embodiment of this application.
[0028] Icons: 100 - Reaction vessel; 110 - Cooling water pipe; 121 - First steam pipe; 122 - Second steam pipe; 200 - First heat exchange device; 210 - First pipe; 220 - Second pipe; 300 - Second heat exchange device; 400 - Collection device; 510 - First gas-liquid separator; 520 - Second gas-liquid separator; 600 - Heat exchange medium supply pipe; 700 - Vacuum pump; 800 - Filter device; 900 - Vacuum buffer tank. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0030] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0032] In the description of this application, it should be noted that the terms "center," "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used 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. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0033] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0034] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0035] The inventors of this application have discovered that when existing low-boiling-point solvents are recovered by distillation, other gases are mixed in the evaporated gaseous solvent. Therefore, when the gaseous solvent is condensed, other gases will also absorb the cold energy, resulting in a low utilization rate of the cold energy.
[0036] Based on this, this application provides a collection system for low-boiling-point solvents, which can use the cold energy absorbed by other gases to condense gaseous solvents, thereby improving the utilization rate of cold energy.
[0037] like Figure 1 As shown, the collection system provided in this application includes a reaction vessel 100, a first heat exchange device 200, and a second heat exchange device 300 connected in sequence, and also includes a collection device 400. The reaction vessel 100 is used to contain solvent and is equipped with a temperature control unit. The temperature control unit can cause the solvent in the reaction vessel 100 to evaporate into a gaseous state by heating. The first heat exchange device 200 and the second heat exchange device 300 are used to condense the gaseous solvent. The gaseous solvent then passes through the first heat exchange device 200 and the second heat exchange device 300 in sequence, absorbing cold energy through heat exchange between the first heat exchange device 200 and the second heat exchange device 300 to achieve condensation. The collection device 400 is connected to the first heat exchange device 200 and the second heat exchange device 300 to collect the condensed liquid solvent.
[0038] Furthermore, such as Figure 1 As shown, in some embodiments, the first heat exchange device 200 is provided with a first pipe 210 and a second pipe 220, within which the gaseous solvent can condense. The inlet end of the first pipe 210 is connected to the reaction vessel 100, and the outlet end is connected to the air inlet of the second heat exchange device 300; the inlet end of the second pipe 220 is connected to the air outlet of the second heat exchange device 300. That is, the solvent volatilized in the reaction vessel 100, along with other gases, first passes through the first heat exchange device 200 via the first pipe 210 and absorbs cooling energy. The uncondensed gaseous solvent then passes through the second heat exchange device 300 with other gases and absorbs cooling energy, resulting in a lower temperature gas discharged from the air outlet of the second heat exchange device 300. After other gases that have absorbed cold energy in the first heat exchange device 200 and the second heat exchange device 300 enter the second pipe 220 from the outlet of the second heat exchange device 300, they will exchange heat with the higher-temperature mixed gas in the first pipe 210 in the first heat exchange device 200, providing cold energy to the gas in the first pipe 210. Therefore, more of the cold energy can be used to condense the low-boiling-point solvent that needs to be collected, thus improving the utilization rate of the cold energy.
[0039] In some embodiments, a first gas-liquid separator 510 is further connected between the outlet end of the first pipe 210 and the air inlet of the second heat exchange device 300. The inlet of the first gas-liquid separator 510 is connected to the outlet end of the first pipe 210, and the outlet of the first gas-liquid separator 510 is connected to the air inlet of the second heat exchange device 300; the liquid outlet of the first gas-liquid separator 510 is connected to the collecting device 400. In this embodiment, the liquid discharged from the outlet end of the first pipe 210 includes condensed liquid solvent, uncondensed gaseous solvent, and other gases. By providing a first gas-liquid separator 510 between the outlet end of the first pipe 210 and the air inlet of the second heat exchange device 300, the condensed solvent in the first pipe 210 can be separated from the uncondensed gaseous solvent and other gases. The gaseous solvent enters the second heat exchange device 300 from the outlet of the first gas-liquid separator 510 to continue heat exchange; the condensed liquid solvent enters the collection device 400 from the outlet of the first gas-liquid separator 510 and is collected in time, thus playing the role of solvent recovery.
[0040] The first gas-liquid separator 510 used in the above embodiments can be a conventional gas-liquid separator in the prior art. In other embodiments, a gas-liquid separator may not be provided between the outlet end of the first pipe 210 and the inlet of the second heat exchange device 300. Instead, a receiving cavity may be provided, in which the liquid in the gas-liquid mixture discharged from the outlet end of the first pipe 210 is collected in the receiving cavity, while the gas continues to move towards the inlet of the second heat exchange device 300. The bottom of the receiving cavity is connected to the collecting device 400 through a vertically arranged pipe, so that the liquid solvent in the receiving cavity flows into the collecting device 400 under the action of gravity.
[0041] In some embodiments, a second gas-liquid separator 520 is connected to the outlet of the second heat exchange device 300. The second gas-liquid separator 520 is used to separate the gas mixture discharged from the outlet of the second heat exchange device 300 from the condensed liquid solvent, and then collect the solvent. Further, the outlet of the second gas-liquid separator 520 is connected to the inlet of the second pipe 220, and the outlet of the second gas-liquid separator 520 is connected to the collection device 400. The mixed gas separated by the second gas-liquid separator 520 enters the second pipe 220 through the inlet, and then exchanges heat with the gas in the first pipe 210 within the first heat exchange device 200, providing cooling to the gas in the first pipe 210 to improve the utilization rate of the cooling capacity. The liquid separated by the second gas-liquid separator 520 enters the collection device 400 from the outlet to collect the solvent.
[0042] The second gas-liquid separator 520 used in the above embodiments can be a conventional gas-liquid separator in the prior art. In other embodiments, a gas-liquid separator may not be provided at the outlet of the second heat exchange device 300, but a receiving cavity may be provided instead. The liquid in the gas-liquid mixture discharged from the outlet of the second heat exchange device 300 is collected in the receiving cavity, while the gas continues to move towards the inlet end of the second pipe 220. The bottom of the receiving cavity is connected to the collecting device 400 through a vertically arranged pipe, so that the liquid solvent in the receiving cavity flows into the collecting device 400 under the action of gravity. Furthermore, the structure of the second gas-liquid separator 520 may be the same as or different from that of the first gas-liquid separator 510.
[0043] In some embodiments, a plurality of second heat exchange devices 300 are included, such as Figure 1 In the illustrated embodiment, there are two second heat exchange devices 300. In other embodiments, there may be only one second heat exchange device 300, or three or more second heat exchange devices 300.
[0044] In embodiments having two or more second heat exchange devices 300, the inlet of the first second heat exchange device 300 is connected to the outlet of the first pipe 210, and the outlet of the last second heat exchange device 300 is connected to the inlet of the second pipe 220. The first second heat exchange device 300 refers to the second heat exchange device 300 into which the gas discharged from the outlet of the first pipe 210 first enters; the last second heat exchange device 300 refers to the second heat exchange device 300 through which the gas last passes before entering the second pipe 220.
[0045] Furthermore, the collection system provided in this application also includes a heat exchange medium supply pipeline 600, such as... Figure 1 As shown, the heat exchange medium supply pipe 600 is connected to the second heat exchange device 300 to provide the heat exchange medium to the second heat exchange device 300, so that the second heat exchange device 300 can condense the gaseous solvent passing through the second heat exchange device 300.
[0046] In some embodiments of this application, the second heat exchange device 300 can be an existing tubular heat exchanger. The tubular heat exchanger has internal pipes for the flow of heat exchange components. These pipes within the second heat exchange device 300 are connected to a heat exchange medium supply pipe 600, allowing the heat exchange medium to enter the second heat exchange device 300. As the heat exchange medium passes through the pipes, it can exchange heat with the gaseous solvent passing through the second heat exchange device 300. Furthermore, the first heat exchange device 200 can also be an existing tubular heat exchanger, and cooling capacity can be supplied to the first heat exchange device 200 by connecting it to the heat exchange medium supply pipe 600.
[0047] When using the collection system provided in this application, the heat exchange medium introduced into the first heat exchange device 200 and the second heat exchange device 300 can be cooling water or other heat exchange medium capable of carrying cold energy.
[0048] In some embodiments, the collection system provided in this application further includes a vacuum pump 700, which is connected to the outlet end of the second pipe 220. By connecting the vacuum pump 700 to the outlet end of the second pipe 220, a negative pressure can be provided at the outlet end of the second pipe 220, causing the gas mixture containing gaseous solvent in the reaction vessel 100 to enter the first heat exchange device 200 and the second heat exchange device 300 under the action of negative pressure, thus providing power for the movement of the gas mixture. In other embodiments, other methods can also be used to drive the gas volatilized in the reaction vessel 100 to pass sequentially through the first heat exchange device 200 and the second heat exchange device 300.
[0049] In some embodiments, a filter device 800 and a vacuum buffer tank 900 are also connected between the vacuum pump 700 and the outlet end of the second pipe 220; the filter device 800 is connected between the outlet end of the second pipe 220 and the inlet of the vacuum buffer tank 900, and the vacuum pump 700 is connected to the outlet of the vacuum buffer tank 900. The filter device 800 may be an activated carbon adsorption filter, and the vacuum buffer tank 900 may collect other gases discharged from the reaction vessel 100 along with the gaseous solvent.
[0050] In the embodiments provided in this application, the temperature control unit includes a steam pipe and a cooling water pipe 110, which are used to introduce a heat exchange medium into the reaction vessel 100. Specifically, the steam pipe can introduce steam into the reaction vessel 100 as a heat exchange medium, thereby raising the temperature inside the reaction vessel 100. The cooling water pipe 110 can introduce cooling water into the reaction vessel 100 as a heat exchange medium, thereby lowering the temperature inside the reaction vessel 100. Through the temperature control unit, the temperature inside the reaction vessel 100 can be adjusted to maintain the temperature within a range that allows the solvent to evaporate without causing the solvent to react with other substances. Furthermore, in some embodiments, a temperature control pipe is provided inside the reaction vessel 100, and the steam pipe and cooling water pipe 110 are connected to the temperature control pipe to introduce a heat exchange medium into the temperature control pipe; wherein, the temperature control pipe can be a spiral coil as in the prior art, or other forms of pipe structure.
[0051] Furthermore, the steam pipeline includes a first steam pipe 121 and a second steam pipe 122, both of which are equipped with valves. Steam can be supplied to the reaction vessel 100 as a heat exchange medium via the first steam pipe 121 and the second steam pipe 122. The valves on the first steam pipe 121 and the second steam pipe 122 can control the opening and closing of the two pipes. Therefore, the amount of steam supplied to the reaction vessel 100 can be controlled by the valves, thereby allowing for more precise control of the temperature of the reaction vessel 100.
[0052] In some embodiments, the upper inlet of the temperature control pipe is connected to the steam supply end of the steam pipe and the return end of the cooling water pipe 110; the lower inlet of the temperature control pipe is connected to the steam return end of the steam pipe and the water supply end of the cooling water pipe 110; valves are provided at both the steam supply end and the return end of the steam pipe and the water supply end and the cooling water pipe 110. Because the upper inlet of the temperature control pipe is connected to the steam supply end of the steam pipe and the return end of the cooling water pipe 110, and the lower inlet is connected to the steam return end of the steam pipe and the water supply end of the cooling water pipe 110, when steam is introduced into the temperature control pipe, the steam enters from the upper end and exits from the lower end, which can better heat the reactor 100; when cooling water is introduced into the temperature control pipe, the cooling water enters from the lower end and exits from the upper end, which can better cool the reactor 100. By installing valves at the steam supply and return ends of the steam pipeline and at the water supply and return ends of the cooling water pipeline 110, it is easy to control whether steam or cooling water is introduced into the temperature control pipeline.
[0053] The collection system provided in this application can be used to recover low-boiling-point solvents such as dichloromethane and diethyl ether, as well as other substances that can be recovered by distillation.
[0054] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A collection system for low-boiling-point solvents, characterized in that, It includes a reaction vessel, a first heat exchange device, and a second heat exchange device connected in sequence, and also includes a collection device; The reaction vessel is used to contain solvent. The reaction vessel is equipped with a temperature control unit, which is configured to allow the solvent in the reaction vessel to evaporate into a gaseous state. The first heat exchange device and the second heat exchange device are used to condense the gaseous solvent. The collection device is connected to the first heat exchange device and the second heat exchange device to collect the condensed liquid solvent. The first heat exchange device is provided with a first pipe and a second pipe, and the gaseous solvent can be condensed in the first pipe and the second pipe; the inlet end of the first pipe is connected to the reaction tank and the outlet end is connected to the air inlet of the second heat exchange device; the inlet end of the second pipe is connected to the air outlet of the second heat exchange device.
2. The collection system according to claim 1, characterized in that, A first gas-liquid separator is also connected between the outlet end of the first pipe and the air inlet of the second heat exchange device. The inlet of the first gas-liquid separator is connected to the outlet end of the first pipe, and the outlet of the first gas-liquid separator is connected to the air inlet of the second heat exchange device. The liquid outlet of the first gas-liquid separator is connected to the collecting device.
3. The collection system according to claim 2, characterized in that, The outlet of the second heat exchange device is connected to a second gas-liquid separator, the outlet of the second gas-liquid separator is connected to the inlet of the second pipe, and the outlet of the second gas-liquid separator is connected to the collection device.
4. The collection system according to claim 1, characterized in that, It includes multiple second heat exchange devices connected in sequence. The air inlet of the first second heat exchange device is connected to the outlet end of the first pipe, and the air outlet of the last second heat exchange device is connected to the inlet end of the second pipe.
5. The collection system according to claim 1, characterized in that, It also includes a heat exchange medium supply pipeline, which is connected to the second heat exchange device to provide a heat exchange medium to the second heat exchange device for condensing the gaseous solvent passing through the second heat exchange device.
6. The collection system according to claim 1, characterized in that, It also includes a vacuum pump, which is connected to the outlet end of the second pipe.
7. The collection system according to claim 6, characterized in that, A filter device and a vacuum buffer tank are also connected between the vacuum pump and the outlet end of the second pipe; the filter device is connected between the outlet end of the second pipe and the inlet of the vacuum buffer tank, and the vacuum pump is connected to the outlet of the vacuum buffer tank.
8. The collection system according to claim 1, characterized in that, The temperature control unit includes a steam pipe and a cooling water pipe, which are used to introduce a heat exchange medium into the reaction vessel.
9. The collection system according to claim 8, characterized in that, The steam pipeline includes a first steam pipe and a second steam pipe, both of which are equipped with valves.
10. The collection system according to claim 8, characterized in that, The reaction vessel is equipped with a temperature control pipe. The upper inlet of the temperature control pipe is connected to the gas supply end of the steam pipe and the water return end of the cooling water pipe. The lower inlet of the temperature control pipe is connected to the gas return end of the steam pipe and the water supply end of the cooling water pipe. Valves are provided at the gas supply end and the gas return end of the steam pipe, as well as at the water supply end and the water return end of the cooling water pipe.