JP2003088701A - Solvent recovering apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solvent recovering apparatus and method capable of efficiently distilling and recovering even a solvent containing a pollutant changed by heat such as thermosetting resins or the like, a highly viscous pollutant or the like without bringing about the lowering of efficiency or closure of a heat exchanger. SOLUTION: The solvent is put in a distiller 10 and supplied to the heat exchanger 16 arranged lower than the distiller 10 to be heated and the heated solvent is again introduced into the distiller 10 in a liquid phase state to generate the vapor of the solvent in the distiller 10. The vapor of the solvent generated in the distiller 10 is cooled by a condenser 12 to obtain the regenerated solvent in a liquid phase state from which the pollutant is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solvent regeneration apparatus and method for distilling and regenerating a contaminated hydrocarbon solvent used for cleaning or the like.

[0002]

2. Description of the Related Art Conventionally, a vacuum distillation disclosed in Japanese Patent Laid-Open No. 2000-345375 is known as a technique for distilling and regenerating a contaminated solvent such as a hydrocarbon solvent to make it reusable. Reproducing device and Japanese Patent Laid-Open No. 7-13640
The vacuum distillation regeneration device disclosed in Japanese Patent No. 2 is known.

A conventional vacuum distillation regenerator will be described with reference to FIG. FIG. 2 is a schematic diagram showing an example of the configuration of a conventional vacuum distillation regeneration device.

As shown in FIG. 2, an evaporation heat exchanger 100 for evaporating a contaminated solvent, and a solvent vapor evaporated by the evaporation heat exchanger 100 for cooling to be a liquid-phase solvent again for condensation. And a heat exchanger 102. A heating coil 104 in which steam or heat transfer oil circulates is provided in the evaporation heat exchanger 100. Inside the heat exchanger 102 for condensation, a cooling coil 106 through which cooling water circulates is provided. An upper outlet of the heat exchanger 100 for evaporation,
The upper inlet of the condensing heat exchanger 102 has an inverted U-shaped pipe 1
It is connected by 08.

A pipe 110 for introducing a contaminated solvent is connected to the lower inlet of the heat exchanger 100 for evaporation. A pipe 112 for introducing a contaminated solvent is provided with a valve 112 for solvent supply and a flow meter 1
14, a flow rate adjusting valve 116, a filter 118, and a filter maintenance valve 120 are provided.

A pipe 122 is branched from between a connection portion of the pollutant solvent introduction pipe 110 to the evaporation heat exchanger 100 and the solvent supply valve 112. A valve 124 is provided in the pipe 122, and a pollution recovery tank 126 for recovering the contaminant liquid accumulated in the evaporation heat exchanger 100 is connected to the valve 122. In addition, the pollution recovery tank 126 is the pipe 1
It is connected to the inverted U-shaped pipe 108 via 28. A valve 130 is provided in the pipe 128.

A pressure reducing mechanism 132 for reducing the pressure inside the condensation heat exchanger 102 and the evaporation heat exchanger 100 is connected to the bottom outlet of the condensation heat exchanger 102. Pressure reducing mechanism 132
Is an ejector 136 connected to the bottom outlet of the condensing heat exchanger 102 via a check valve 134, a solvent tank 138,
And a solvent pump 140. Then, a solvent circulation system is constructed in which the solvent is sucked from the solvent tank 138 into the solvent pump 140 and returned to the solvent tank 138 again via the ejector 136. Thus, the decompression mechanism 132 by the ejector effect is constructed.

Next, the regeneration of the solvent by the conventional vacuum distillation regeneration device will be described.

In advance, the decompression mechanism 132 decompresses the evaporation heat exchanger 100 and the condensation heat exchanger 102 to a predetermined pressure. Then, a predetermined amount of contaminated solvent is transferred from the contaminated solvent introduction pipe 110 to the evaporation heat exchanger 100.
Then, the solvent supply valve 112 is closed.

Next, steam or heat transfer oil is circulated in the heating coil 104 in the evaporation heat exchanger 100 to heat the solvent in the evaporation heat exchanger 100. The solvent vapor generated by this heating is introduced into the condensing heat exchanger 102 through the inverted U-shaped pipe 108.

The solvent vapor introduced into the condenser heat exchanger 102 is cooled and liquefied by a cooling coil in which the cooling water of the condenser heat exchanger 102 circulates. By cooling in this way, the solvent vapor is again collected in the solvent tank 138 of the decompression mechanism 132 as a liquid phase solvent.

By heating and evaporating the contaminated solvent in this way, the solvent contaminants are concentrated in the evaporation heat exchanger 100. The polluted liquid containing the pollutants concentrated in the heat exchanger 100 for evaporation is periodically collected in the pollution collection tank 126 via the pipe 122. When collecting the contaminated liquid, the valve 130 of the pipe 128 is opened by opening the valve 130 of the pipe 128 to make the pressure inside the evaporation heat exchanger 100 and the inside of the pollution recovery tank 126 the same.

[0013]

As described above, in the conventional vacuum distillation regenerator, solvent vapor is generated in the evaporation heat exchanger 100, and contaminating solvent contaminants are generated in the evaporation heat exchanger 100. Was to be concentrated. Therefore, depending on the type of contaminants contained in the contaminated solvent, they will stick to the inside of the evaporation heat exchanger 100. Therefore, the evaporation heat exchanger 100 may need to be frequently cleaned, and further, the safe operation of the evaporation heat exchanger 100 may be hindered.

For example, the solvent used for washing a paint containing a thermosetting component such as unsaturated polyester contains not only pigments but also fine particles of the thermosetting component as contaminants. When the solvent is vaporized in the evaporation heat exchanger 100, the particles of the thermosetting component are converted into the evaporation heat exchanger 100.
Sticks to the inner surface. Therefore, the evaporation heat exchanger 100
However, the efficiency of the heat treatment may be reduced, and the evaporative heat exchanger 100 may become clogged with contaminants, resulting in an inoperable closed state.

It is an object of the present invention to efficiently use a solvent containing contaminants such as thermosetting which changes with heat and contaminants of high viscosity, without causing a decrease in efficiency or blockage of the heat exchanger. It is an object of the present invention to provide an apparatus and method for regenerating a solvent that can be regenerated by distillation.

[0016]

[Means for Solving the Problems] The above-mentioned object is to arrange a distillation can for storing a solvent and a position below the distillation can.
A heat exchanger that heats the solvent supplied from the distillation can and re-introduces it to the distillation can in the liquid state, and regenerates the liquid state by cooling the vapor of the solvent generated in the distillation can. And a condenser for obtaining a solvent.

Further, the above-mentioned solvent regenerator may further include a decompression means for decompressing the inside of the distillation can.

Further, the above-mentioned solvent regenerator further comprises a recovery means for recovering the regenerated solvent obtained in the condenser, and the recovery means is connected to the outlet of the regenerated solvent of the condenser. The upper vessel and the lower vessel connected to the lower portion of the upper vessel via a pipe having a valve may be provided.

Further, the above-mentioned solvent regenerator further comprises recovery means for recovering the regenerated solvent obtained in the condenser, and the recovery means is connected to an outlet of the regenerated solvent of the condenser. The upper vessel and the lower portion of the upper vessel, has a lower vessel connected via a pipe having a valve, the decompression means, so as to decompress the inside of the upper vessel and / or the lower vessel as well. Good.

Further, the above-mentioned purpose is to put a solvent in a distillation can,
The solvent in the distillation can is supplied below the distillation can and heated, and the heated solvent is reintroduced into the distillation can in a liquid phase state, and vapor of the solvent is generated in the distillation can. ,
It is achieved by a solvent regeneration method, characterized in that the solvent vapor generated in the distillation can is cooled to obtain a regenerated solvent in a liquid phase in which contaminants are removed.

Further, in the above solvent regeneration method, in order to recover the regenerated solvent obtained by cooling the vapor of the solvent generated in the distillation still, an upper vessel and a valve at the bottom of the upper vessel are provided. Provided with a lower vessel connected via a pipe having, when the regenerated solvent in the lower vessel is less than a predetermined liquid volume, the valve is opened to the lower vessel via the upper vessel. When the regenerated solvent is recovered and the regenerated solvent in the lower vessel exceeds a predetermined liquid amount, the valve is closed to separate the upper vessel and the lower vessel and the regenerated solvent is added to the upper vessel. May be recovered and the regenerated solvent in the lower vessel may be discharged.

Further, in the above-mentioned solvent regeneration method, vapor of the solvent may be generated in the distillation can while the pressure inside the distillation can is reduced.

[0023]

DETAILED DESCRIPTION OF THE INVENTION A solvent recycling apparatus and method according to an embodiment of the present invention will be described with reference to FIG. Figure 1
FIG. 3 is a diagram showing a configuration of a solvent regeneration device according to the present embodiment.

[1] Solvent Regenerating Device First, the solvent regenerating device according to the present embodiment will be explained with reference to FIG.

The solvent regenerator according to the present embodiment is provided with a distillation can 10 in which the solvent is distilled, and is filled with a contaminated solvent to be regenerated. A condenser 12 for condensing the solvent vapor generated in the distillation can 10 is connected to the tower of the distillation can 10 via a pipe 14. A feed pipe 11 for supplying a contaminated solvent is connected to the distillation can 10.

A heat exchanger 16 for heating the solvent supplied from the distillation can 10 is provided below the distillation can 10. The distillation can 10 and the heat exchanger 16 are the distillation can 1
Pipe 20 for supplying the solvent from 0 to the heat exchanger 16
And the solvent heated by the heat exchanger 16 is used again for the distillation can 1
It is connected by a pipe 18 for returning to zero. The connection positions of the pipes 18 and 20 to the distillation can 10 are positions where the solvent in the distillation can 10 is filled. The pipe 20 is provided with a circulation pump 22 for sending the solvent heated by the heat exchanger 16 to the distillation can 10.

A recovery unit 24 for recovering the solvent condensed by the condenser 12 is connected to the condenser 12. The recovery unit 24 has an upper vessel 26 and a lower vessel 28 for taking out the solvent from the condenser 12. The upper vessel 26 is connected to the solvent outlet of the condenser 12 via a pipe 30. The lower vessel 26 is connected to a position below the upper vessel 26 via a pipe 32. A valve 34 is provided in the pipe 32.
The pipe 32 is connected to the bottom of the upper vessel 26, but may be at the bottom.

A vacuum pump 38 is connected to the upper vessel 26 via a pipe 36. A vacuum pump 38 is connected to the lower vessel 28 via a pipe 40 branched from the pipe 36. The pipes 36 and 40 are provided with valves 42 and 44, respectively.

A pipe 46 for discharging the solvent collected in the lower vessel 28 is provided at the bottom of the lower vessel 28.
Are connected. A valve 48 is provided in the pipe 46. A pipe 50 for introducing compressed air into the lower vessel 28 is connected to the upper portion of the lower vessel 28. A valve 52 is provided in the pipe 50.
Note that compressed nitrogen may be used instead of compressed air.

A contaminated liquid reservoir 54 is connected to the bottom of the distillation can 10 via a pipe 56 for discharging a contaminated liquid in which the contaminants collected in the bottom of the distillation can 10 are concentrated. Piping 5
6 is provided with a valve 58.

A vacuum pump 38 is connected to the contaminated liquid reservoir 54 via a pipe 60 branched from the pipe 36.
A valve 62 is provided in the pipe 60. A pipe 64 for introducing compressed air into the contaminated liquid reservoir 54 is connected to the contaminated liquid reservoir 54. A valve 66 is connected to the pipe 64. A pipe 68 for discharging the contaminated liquid is provided at the bottom of the contaminated liquid reservoir 54. A valve 70 is provided in the pipe 68.

As described above, the solvent regenerator according to the present embodiment is characterized mainly in that the heat exchanger 16 for heating the solvent stored in the distillation can 10 is located below the distillation can 10. . Heat exchanger 16 below the distillation can 10
Due to the liquid pressure in the pipes 18 and 20 due to the arrangement, it is possible to suppress vaporization of the solvent in the heat exchanger 16 and the pipes 18 and 20. Moreover, since the solvent in the liquid phase is circulated between the distillation can 10 and the heat exchanger 16 by the circulation pump 22, the speed of the solvent passing through the heat exchanger 16 is high, and the temperature of the heat exchanger 16 is high. Even if the difference is small,
The amount of heat required to vaporize the solvent can be supplied. In this way, between the distillation can 10 and the heat exchanger 16,
Since the solvent always circulates in the liquid phase, the heat exchanger 1
It is possible to prevent the contaminants from adhering to the inside of 6.

The components of the solvent regenerator according to the present embodiment will be described in detail below.

(A) Distillation can 10 The distillation can 10 stores the contaminated solvent to be regenerated,
The solvent is vaporized. Examples of the regenerable solvent include hydrocarbon solvents such as xylene, cyclohexane, and Solvesso (trade name).

The distilling can 10 is provided with a liquid amount monitor mechanism (not shown) for monitoring the liquid amount of the stored solvent. As a result, the solvent regenerator can be controlled according to the amount of the solvent in the distillation can 10 to be monitored.

At the height of the connection between the pipe 20 for supplying the solvent to the heat exchanger 16 of the distillation can 10 and the pipe 18 for reintroducing the solvent heated by the heat exchanger 16, It is always filled with liquid phase solvent during operation of the regenerator. The contaminated solvent can be supplied into the distillation can 10 via the feed pipe 11.

The distillation can 10 itself is not heated and the solvent is vaporized in the distillation can 10 by the heat given to the solvent by the heat exchanger 16 described below. Further, when the solvent is vaporized, the inside of the distillation can 10 is depressurized by a vacuum pump 38 described later. Thereby, the solvent can be vaporized at a lower temperature.

(B) Heat Exchanger 16 and Circulation Pump 22 The heat exchanger 16 is arranged below the distillation can 10 and heats the solvent supplied from the distillation can 10 through the pipe 18 and filling the inside thereof. It is a thing. In the heat exchanger 16,
For example, a heating coil (not shown) in which steam or heat transfer oil is circulated is provided, and the solvent is heated by bringing the heating coil and the solvent into contact with each other.

The circulation pump 22 is for circulating the liquid phase solvent introduced from the pipe 20 back to the distillation can 10 after being heated by the heat exchanger 16. Distillation can 10
Depending on the state of the solvent in the distillation can 10 and the heat exchanger 16
The circulation speed of the solvent circulated between and can be adjusted by the valve 23.

The solvent regenerator according to this embodiment is characterized mainly in that the heat exchanger 16 is arranged at a position lower than the distillation can 10 by at least 2 m or more. In particular,
The upper end of the heat exchanger 16 filled with the solvent in the liquid phase is positioned at least 2 m or more below the gas-liquid interface of the solvent in the distillation can 10 so as to be located below. By disposing the distillation can 10 and the heat exchanger 16 in this manner, the pipes 18, 20
The vapor pressure of the solvent is suppressed by the liquid pressure inside. That is, the solvent circulating between the distillation can 10 and the heat exchanger 16 can always remain in the liquid phase. Therefore, contaminants in the solvent do not stick to the inside of the heat exchanger 16, and labor required for maintenance such as cleaning of the heat exchanger 16 is reduced. Further, the heat exchanger 16 will not be clogged with contaminants and will not be in a closed state in which it cannot operate.

When the solvent is circulated by the circulation pump 22 while being heated by the heat exchanger 16, the temperature of the solvent in the distillation can 10 rises and vaporization of the solvent occurs in the distillation can 10. As will be described later, since the pressure inside the distillation can 10 is reduced, the solvent vaporizes at a lower temperature.

(C) Condenser 12 The condenser 12 cools and liquefies the solvent vapor introduced from the distillation can 10 through the pipe 14. Condenser 1
For example, a cooling coil (not shown) in which cooling water circulates is provided in 2, and the solvent vapor is cooled and liquefied by bringing this cooling coil into contact with the solvent vapor.

(D) Recovery Section 24 (Upper Vessel 26, Lower Vessel 28) The recovery section 24 is for recovering the solvent liquefied by being cooled by the condenser 12, and the upper vessel 26 in which the solvent is stored, It has a lower vessel 28.

The upper vessel 26 directly receives the solvent in the liquid phase accumulated at the bottom of the condenser 12.
The lower vessel 28 stores the solvent from the upper vessel 26,
It is received through the pipe 34. Lower vessel 28
When the amount of the solvent accumulated in the lower vessel 28 exceeds a predetermined amount, the solvent in the lower vessel 28 can be recovered from the pipe 46 connected to the bottom of the lower vessel 28.

During the distillation regeneration of the solvent, the upper vessel 26
The inside of the lower vessel 28 is depressurized by the vacuum pump 38. When recovering the solvent from the lower vessel 28 via the pipe 46, first, the valve 34 of the pipe 32 is closed to separate the upper vessel 26 from the lower vessel 28. Next, the valve 44 of the pipe 40 is closed and the lower vessel 28 is closed.
Stop depressurizing. Next, the valve 52 of the pipe 50 is opened and compressed air is introduced into the lower vessel 28 to pressurize the lower vessel 28. And the piping 46
The valve 48 is opened to collect the solvent from the lower vessel 28. While the solvent is being collected from the lower vessel 28, the solvent cooled and liquefied by the condenser 12 can be stored in the upper vessel 26. Lower vessel 2
The procedure for recovering the solvent from No. 8 will be described in detail in the explanation of the solvent regeneration method.

(E) Vacuum Pump 38 The vacuum pump 38 is, as described above, the upper vessel 26.
The inside, the inside of the lower vessel 28, the inside of the condenser 12, and the inside of the distillation can 10 are decompressed, respectively. By depressurizing the distillation can 10 and the like with the vacuum pump 38, the solvent in the distillation can 10 can be vaporized at a lower temperature than when the solvent is vaporized under normal pressure. Thereby, in the solvent regenerator according to the present embodiment, the solvent heated by the heat exchanger 16 can be vaporized in the distillation can 10 without directly vaporizing the solvent in the heat exchanger 16.

Further, the vacuum pump 38 depressurizes the inside of the contaminated liquid reservoir 54 in order to discharge the contaminated liquid from the depressurized bottom of the distillation can 10 to the contaminated liquid reservoir 54.

The pressure reduction by the vacuum pump 38 is preferably adjusted appropriately according to the type of solvent to be regenerated.
For example, in the case of a hardly volatile solvent, it is necessary to reduce the pressure inside the distillation can 10 to a lower pressure.

A mist recovery tank 39 is connected to the vacuum pump 38, and solvent vapor contained in the exhaust gas can be recovered.

(F) Contaminated Liquid Reservoir 54 The contaminated liquid reservoir 54 is for collecting the contaminated liquid containing concentrated contaminants at the bottom of the distillation can 10. By opening the valve 58 of the pipe 56, the contaminated liquid stored in the bottom of the distillation can 10 in the contaminated liquid reservoir 54 is collected in the contaminated liquid reservoir 54.

[2] Solvent Regeneration Method Next, the solvent regeneration method according to the present embodiment will be explained with reference to FIG. In the solvent regeneration device before the start of solvent regeneration, all valves except the valve 23 are closed.

First, the contaminated solvent to be regenerated is put in the distillation can 10. Next, the operation of the vacuum pump 38 is started, the valves 44 and 34 are opened, and the inside of the lower vessel 28, the upper vessel 26, the condenser 12, and the distillation can 10 are depressurized to a predetermined pressure. At this time, the degree of vacuum is controlled by opening and closing the valve 44.

Further, the valve 62 of the pipe 60 is opened to depressurize the inside of the contaminated liquid reservoir 54 to a predetermined pressure. This is because the contaminated liquid reservoir 54 cannot be drained unless the pressure in the distillation can 10 is the same. That is, by reducing the pressure in the contamination reservoir 54, it is possible to prevent the liquid from flowing back in the pipe 56 when the valve 58 is opened.

Next, the solvent in the distillation can 10 is removed from the pipe 20.
And is introduced into the heat exchanger 16 via the circulation pump 22 to heat it, and the heated solvent is returned to the distillation can 10 via the pipe 18. Thus, the solvent in the liquid phase is circulated between the distillation can 10 and the heat exchanger 16 while heating the solvent by the heat exchanger 16. The heating temperature of the solvent by the heat exchanger 16 is appropriately adjusted according to the type of solvent, the pressure inside the distillation can 10, and the like.

As described above, the distillation can 10 and the heat exchanger 16 are
By circulating the solvent in the liquid phase between and, the temperature of the solvent in the distillation can 10 rises and gradually evaporates. Here, since the inside of the distillation can 10 is depressurized, the solvent evaporates at a temperature lower than that under normal pressure. The solvent vapor thus generated in the distillation can 10 is introduced into the condenser 12 via the pipe 14. After the evaporation is stabilized, the contaminated solvent is introduced through the feed pipe 11.

The solvent vapor introduced into the condenser 12 is cooled and liquefied in the condenser 12. The solvent in a liquid phase obtained by cooling the condenser 12 flows to the upper vessel 26 of the recovery unit 24 via the pipe 30 and further accumulates in the lower vessel 28 via the pipe 32. In this way, the solvent that has been distilled and regenerated to remove contaminants is accumulated in the lower vessel 28. Regarding the condenser 12, cooling water is made to flow through an internal cooling coil in advance, and the conditions are set so that the solvent that becomes vapor is condensed.

On the other hand, the contaminants of the solvent are concentrated on the bottom of the distillation can 10. Therefore, the valve 5 of the pipe 56 is regularly
8 is opened, and the contaminated liquid containing the contaminant at the bottom of the distillation can 10 is discharged to the contaminated liquid reservoir 54.

When the amount of the contaminated liquid in the contaminated liquid reservoir 54 exceeds a predetermined amount, the contaminated liquid is discharged from the contaminated liquid reservoir 54 by the following procedure. First, the valve 62 of the pipe 60 is closed to stop the pressure reduction in the contaminated liquid reservoir 54. Next, the valve 66 of the pipe 64 is opened to introduce compressed air into the contaminated liquid reservoir 54 to pressurize it. Then, the valve 70 of the pipe 68 provided at the bottom of the contaminated liquid reservoir 54 is opened to discharge the contaminated liquid to the outside of the contaminated liquid reservoir 54.

As described above, in the present embodiment, since the contaminants of the solvent are concentrated in the distillation can 10, even if the solvent contains the contaminants of the thermosetting component, the contaminants are contaminated in the heat exchanger 16. Nothing sticks.

Now, the procedure for recovering the solvent that has been distilled and regenerated from the lower vessel 28 will be described.

First, the upper vessel 26 and the vacuum pump 38.
The valve 42 of the pipe 36 for connecting to and is opened. Next, the valve 34 of the pipe 32 that connects the upper vessel 26 and the lower vessel 28 is closed, and the upper vessel 26 and the lower vessel 28 are separated.

Then, the valve 44 of the pipe 40 is closed to stop the pressure reduction in the lower vessel 28 by the vacuum pump 38. Thus, while recovering the solvent from the lower vessel 28, the distillation regeneration of the solvent is continued while reducing the pressure in the condenser 12 and the distillation can 10 via the upper vessel 26. Then, the solvent from the condenser 12 is stored in the upper vessel 26. In addition, the condenser 1 in the upper vessel 26 in the meantime
The vacuum pump 38 is used for reducing the pressure inside the distillation tank 2 and inside the distillation can 10.
42 of the pipe 36 for connecting the upper vessel 26 and the upper vessel 26
Adjust by opening and closing.

Next, the valve 52 of the pipe 50 is opened to pressurize the inside of the lower vessel 28. Then, the valve 48 is opened to collect the solvent from the pipe 46.

As described above, in this embodiment, since the solvent that has been distilled and regenerated can be recovered intermittently, it is not necessary to interrupt the distillation and regeneration of the solvent, and the solvent can be regenerated efficiently. . Further, since the depressurized state in the distillation can 10 can be stably maintained, the solvent can be distilled and regenerated with high purity.

As described above, the regenerated solvent is collected from the lower vessel 28 and the contaminated liquid containing the contaminants at the bottom of the distillation can 10 is appropriately discharged to regenerate the solvent in the distillation can 10 by distillation.

As described above, according to the present embodiment, the heat exchanger 16 for heating the solvent is arranged below the distillation can 10, so that the evaporation of the solvent in the heat exchanger 16 is suppressed and the distillation is performed. Since the solvent evaporates in the can 10, the heat exchanger 10
It is possible to prevent the contaminants therein from sticking, to reduce the labor required for cleaning the inside of the heat exchanger 10, and to prevent the heat exchanger 10 from being blocked.

[Modified Embodiments] Various modifications are possible without being limited to the above-described embodiments of the present invention.

For example, the control of the solvent regenerator such as the opening and closing of the valve in the above-described embodiment is performed according to the height of the liquid level in the distillation can 10, the height of the liquid level in the upper vessel 26 and the lower vessel 28, and the like. It may be automatically controlled.

Further, the heat exchanger 16 in the above embodiment.
Although various types of heat exchangers such as plate type and spiral type can be applied, a shell-and-tube type heat exchanger is preferable because the internal flow velocity is constant.

In the above embodiment, the solvent to be regenerated is supplied in accordance with the amount of the solvent in the distillation can 10 and the like, and the solvent is continuously regenerated by distillation. Alternatively, it may be carried out in a batch manner.

Further, in the above embodiment, the vacuum pump 38 is used as a means for reducing the pressure inside the distillation can 10, but instead of the vacuum pump 38, a means for reducing the pressure inside the distillation can 10 such as by an ejector is used. You may comprise.

[0072]

As described above, according to the present invention, a solvent is placed in a distillation can, the solvent in the distillation can is supplied below the distillation can and heated, and the heated solvent is distilled in a liquid phase state. It is re-introduced into the can, generates solvent vapor in the distillation can, and cools the solvent vapor generated in the distillation can to obtain a recycled solvent in a liquid phase from which contaminants have been removed. Even if the solvent contains a pollutant that changes due to the heat, a highly viscous pollutant, and the like, the distillation can be efficiently regenerated without causing a decrease in efficiency or clogging of the heat exchanger.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a solvent recycling apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of the configuration of a conventional vacuum distillation regeneration device.

[Explanation of symbols]

10 ... Distillation can 11 ... Feed piping 12 ... condenser 14 ... Piping 16 ... Heat exchanger 18 ... Piping 20 ... Piping 22 ... Circulation pump 23 ... Valve 24 ... Collection Department 26 ... Upper vessel 28 ... Lower vessel 30 ... Piping 32 ... Piping 34 ... Valve 36 ... Piping 38 ... Vacuum pump 39 ... Mist collection tank 40 ... Piping 42 ... Valve 44 ... Valve 46 ... Piping 48 ... Valve 50 ... Piping 52 ... Valve 54 ... Contaminated liquid reservoir 56 ... Piping 58 ... Valve 60 ... Piping 62 ... Valve 64 ... Piping 66 ... Valve 68 ... Piping 70 ... Valve 100 ... Heat exchanger for evaporation 102 ... Condensing heat exchanger 102 104 ... heating coil 106 ... Cooling coil 108 ... Inverted U-shaped piping 110 ... Piping for supplying contaminated solvent 112 ... Supply valve 114 ... Flowmeter 116 ... Flow control valve 118 ... Filter 120 ... Filter maintenance valve 122 ... Piping 124 ... Valve 126 ... Pollution recovery tank 128 ... Piping 130 ... Valve 132 ... Decompression mechanism 134 ... Check valve 136 ... Ejector 138 ... Solvent tank 140 ... Solvent pump

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Claims (7)

[Claims] 1. A distillation can for storing a solvent, and a heat arranged below the distillation can for heating the solvent supplied from the distillation can and re-introducing the solvent in a liquid state into the distillation can. A solvent regenerator comprising: an exchanger and a condenser for cooling the vapor of the solvent generated in the distillation can to obtain a regenerated solvent in a liquid phase. 2. The solvent regenerator according to claim 1, further comprising decompression means for decompressing the inside of the distillation can. 3. The solvent regenerator according to claim 1, further comprising a recovery means for recovering the regenerated solvent obtained in the condenser, wherein the recovery means is for regenerating the regenerated solvent in the condenser. An upper vessel connected to the outlet and a lower portion of the upper vessel,
And a lower vessel connected via a pipe having a valve. 4. The solvent regenerator according to claim 2, further comprising a recovery means for recovering the regenerated solvent obtained in the condenser, wherein the recovery means is provided at an outlet of the regenerated solvent of the condenser. At the lower stage of the connected upper vessel and the upper vessel,
A lower stage vessel connected via a pipe having a valve, wherein the decompression unit also decompresses the inside of the upper stage vessel and / or the lower stage vessel. 5. A solvent is placed in a distillation can, the solvent in the distillation can is supplied below the distillation can and heated, and the heated solvent is reintroduced into the distillation can in a liquid state,
A method of regenerating a solvent, wherein vapor of the solvent is generated in the distillation can, and the vapor of the solvent generated in the distillation can is cooled to obtain a regenerated solvent in a liquid phase in which contaminants are removed. . 6. The method for regenerating a solvent according to claim 5, wherein an upper vessel is provided to recover the regenerated solvent obtained by cooling the vapor of the solvent generated in the distillation can.
A lower vessel is provided below the upper vessel via a pipe having a valve, and when the regenerated solvent in the lower vessel is less than a predetermined liquid volume, the valve is opened to open the upper vessel. The regenerated solvent is recovered in the lower vessel via, and when the regenerated solvent in the lower vessel exceeds a predetermined liquid amount, the valve is closed to separate the upper vessel and the lower vessel. The regenerated solvent is recovered in the upper vessel, and the regenerated solvent in the lower vessel is discharged. 7. The method of regenerating a solvent according to claim 5 or 6, wherein vapor of the solvent is generated in the distillation can while the pressure inside the distillation can is reduced.