Target liquid recovery system

Abstract

We provide a liquid recovery system for liquids with high concentration. [Solution] The adsorption device 30 includes a vaporization tank 32 for vaporizing a mixed liquid ML and an adsorption tank 33 in which an adsorbent 36 for adsorbing the water RL vaporized in the vaporization tank 32 is placed; a vapor discharge unit 40 for discharging the vapor from the adsorption tank 33; a recovery tank 50 for recovering the isopropyl alcohol CL vaporized in the vaporization tank 32; a passage thermometer T1 for measuring the passage temperature of the vapor passing through the vapor discharge unit 40; and a control unit 90 for executing a recovery process that controls the vapor discharge unit 40 so as to recover the vapor in the recovery tank 50 when the passage temperature is below a predetermined first threshold temperature (85°C) which is higher than the boiling point of isopropyl alcohol CL and lower than the boiling point of water RL, and not recover the vapor in the recovery tank 50 when the passage temperature is 85°C or higher.

Description

Technical Field

[0001] The present invention relates to a target liquid recovery system for recovering a target liquid to be recovered from a mixed liquid in which a liquid to be recovered and a liquid to be removed having a boiling point higher than the boiling point of the liquid to be recovered are mixed.

Background Art

[0002] In a semiconductor manufacturing factory, after a semiconductor wafer is washed with a cleaning liquid such as hydrogen fluoride or pure water rinse liquid by a cleaning device, it is dried by a drying device.

[0003] Such a drying device includes a drying chamber into which a semiconductor wafer can be inserted and removed, and a storage tank provided below the drying chamber for storing isopropyl alcohol as a treatment liquid.

[0004] The drying device is configured to carry a plurality of semiconductor wafers into the drying chamber in a substantially vertical posture, and to heat and evaporate the isopropyl alcohol stored in the lower part of the processing chamber to bring the vapor of isopropyl alcohol into contact with the surface of the semiconductor wafer.

[0005] When the liquid droplets generated by the condensation of the vapor on the surface of the semiconductor wafer fall from the semiconductor wafer while taking in the cleaning liquid adhering to the semiconductor wafer, the cleaning liquid is removed from the surface of the semiconductor wafer.

[0006] In this way, the semiconductor wafer is washed. When the temperature of the semiconductor wafer becomes equal to the temperature of the vapor of isopropyl alcohol, the condensation ends, and the surface of the semiconductor wafer becomes dry. Then, the semiconductor wafer is carried out of the drying device.

[0007] The vapor of isopropyl alcohol in the drying chamber is cooled and liquefied in a cooling chamber and recovered.

[0008] With repeated use, the water content of recovered isopropyl alcohol increases, gradually reducing its cleaning power. Isopropyl alcohol that has lost its cleaning power becomes industrial waste.

[0009] Patent Document 1 discloses a configuration for separating isopropyl alcohol and water. However, in recent years, there has been a growing need for a liquid recovery system that can regenerate isopropyl alcohol to a higher purity, due to the need to reduce environmental impact, processing costs, and rising prices of isopropyl alcohol. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 3010463 [Overview of the project] [Problems that the invention aims to solve]

[0011] This invention has been made in view of the above-mentioned problems, and aims to provide a target liquid recovery system in which the liquid concentration of the target liquid is high. [Means for solving the problem]

[0012] To achieve the above-mentioned objective, the present invention provides a target liquid recovery system for recovering a target liquid from a mixed liquid obtained by mixing a target liquid to be recovered with a target liquid to be removed having a boiling point higher than the boiling point of the target liquid to be recovered, the system comprising: an adsorption device provided with a vaporization tank for vaporizing the mixed liquid and an adsorption tank in which an adsorbent is disposed for adsorbing the target liquid to be removed vaporized in the vaporization tank; a vapor discharge unit for discharging the vapor from the adsorption tank; a recovery tank for recovering the target liquid to be recovered vaporized in the vaporization tank; a passage thermometer for measuring the passage temperature of the vapor passing through the vapor discharge unit; and a control unit that executes a recovery process, which controls the vapor discharge unit to recover the vapor in the recovery tank when the passage temperature is below a predetermined first threshold temperature that is higher than the boiling point of the target liquid to be recovered and lower than the boiling point of the target liquid to be removed, and does not recover the vapor in the recovery tank when the passage temperature is equal to or higher than the first threshold temperature.

[0013] The mixed liquid is composed of a liquid to be recovered and a liquid to be removed, which has a boiling point higher than the boiling point of the liquid to be recovered. Therefore, when the passing temperature is below a predetermined first threshold temperature, which is in the range of higher than the boiling point of the liquid to be recovered and lower than the boiling point of the liquid to be removed, the vapor is assumed to originate from the liquid to be recovered and is recovered in the recovery tank. The liquid to be recovered may be discharged into the recovery tank as vapor or after being liquefied.

[0014] When the passing temperature is above the first threshold temperature, it is assumed that the vapor contains not only vapor from the liquid to be recovered but also vapor from the liquid to be removed, and therefore it is not recovered by the recovery tank. In this way, the target liquid recovery system focuses on the temperature of the vapor resulting from the difference between the boiling point of the liquid to be recovered and the boiling point of the liquid to be removed, and can efficiently recover only the liquid to be recovered, resulting in a high concentration of the liquid to be recovered.

[0015] In the target liquid recovery system according to the present invention, a mixed liquid tank capable of storing the mixed liquid is provided, the vapor discharge unit is configured to selectively discharge the vapor discharged from the adsorption tank to the recovery tank or the mixed liquid tank, and the control unit controls the vapor discharge unit in the recovery process such that, when the passing temperature is equal to or greater than the first threshold temperature, the vapor is recovered by the mixed liquid tank.

[0016] When the passing temperature is above the first threshold temperature, the vapor is assumed to originate not only from the liquid to be recovered but also from the liquid to be removed, and is therefore discharged to the mixed liquid tank instead of the recovery tank. The liquid to be recovered and the liquid to be removed may be discharged to the mixed liquid tank as vapor or after liquefaction. The mixed liquid discharged to the mixed liquid tank is then supplied back to the adsorption device.

[0017] In the present invention, the steam discharge section may be characterized by having a condensation mechanism for condensing the steam, and the steam, in a liquefied state by the condensation mechanism, is selectively discharged to the recovery tank or the mixed liquid tank.

[0018] If the steam is discharged directly into a recovery tank or mixed liquid tank, a blower is required to pump the steam. In contrast, with the above-described configuration, the steam can be liquefied by a condensation mechanism, allowing it to flow into the recovery tank or mixed liquid tank by gravity simply by creating a gradient in the piping.

[0019] The target liquid recovery system according to the present invention is characterized in that it includes a mixed liquid tank capable of storing the mixed liquid, a mixed liquid supply unit capable of supplying the mixed liquid stored in the mixed liquid tank to the adsorption device, and a tank thermometer for measuring the temperature inside the vaporization tank, and the control unit controls the mixed liquid supply unit so that, in the recovery process, when the temperature inside the tank is below a predetermined second threshold temperature which is higher than the boiling point of the liquid to be removed, the mixed liquid is not supplied to the adsorption device, and when the temperature inside the tank is equal to or higher than the second threshold temperature, the mixed liquid is supplied to the adsorption device.

[0020] When there is a sufficient amount of the mixture in the vaporization tank, the tank temperature will not exceed the boiling point of the liquid to be removed. Therefore, when the tank temperature is below the predetermined second threshold temperature, there is no need to supply the mixture to the adsorption device yet.

[0021] On the other hand, when the mixture runs out in the vaporization tank, the tank temperature rises above the second threshold temperature, which is higher than the boiling point of the liquid to be removed. Therefore, when the tank temperature in the vaporization tank is above the second threshold temperature, the mixture is supplied to the adsorption device. In this way, the mixture can be supplied at the appropriate timing based on the tank temperature.

[0022] In the target liquid recovery system according to the present invention, the system is equipped with a heating unit for heating the vaporization tank and a heating thermometer for measuring the heating temperature of the heating unit, and the control unit controls the mixed liquid supply unit so that, in the recovery process, when the heating temperature is below a predetermined third threshold temperature, the mixed liquid is not supplied to the adsorption device, and when the heating temperature is equal to or greater than the third threshold temperature, the mixed liquid is supplied to the adsorption device.

[0023] When the heating temperature of the heating unit that heats the vaporization tank is less than a predetermined third threshold temperature, there is a risk that the liquid mixture cannot be sufficiently vaporized in the vaporization tank. In such a case, even if the liquid mixture is supplied to the adsorption device, it may cause the temperature inside the vaporization tank to decrease, resulting in an increase in the time of the vaporization process in the vaporization tank. Therefore, when the heating temperature of the heating unit is less than the third threshold, the liquid mixture is not supplied to the adsorption device, and when the temperature reaches or exceeds the third threshold temperature, the liquid mixture is supplied to the adsorption device, enabling the liquid mixture to be efficiently vaporized in the vaporization tank in a short time.

[0024] In the target liquid recovery system according to the present invention, a heat generation thermometer for measuring the heat generation temperature of the adsorbent disposed in the adsorption tank is provided, and in the recovery process, when the heat generation temperature becomes equal to or higher than a predetermined fourth threshold temperature, the control unit controls the liquid mixture supply unit so as not to supply the liquid mixture to the adsorption device, and ends the recovery process.

[0025] The adsorbent generates heat by adsorbing the target liquid to be removed. When the heat generation temperature becomes equal to or higher than a predetermined fourth threshold temperature, the adsorbent has sufficiently adsorbed the target liquid to be removed, and further adsorption is unlikely. According to the above configuration, the supply of the liquid mixture is stopped in such a case. Thus, the recovery process can be ended at an appropriate timing based on the heat generation temperature.

[0026] In the target liquid recovery system according to the present invention, a supply device for supplying dry air to the adsorption device is provided, and when the recovery process ends, the control unit executes a blowing process of controlling the supply device to supply the dry air to the adsorption device.

[0027] When the adsorbent has sufficiently adsorbed the target liquid to be removed and further adsorption is unlikely, it is necessary to remove the target liquid adsorbed on the adsorbent. As will be described later, in the process of drying the adsorbent (drying process), high-temperature dry air is supplied to the adsorption device, and the target liquid adsorbed on the adsorbent is removed by this high-temperature dry air.

[0028] However, vapors originating from the liquid to be recovered still exist in the adsorption device. Therefore, before performing the drying process, a blowing process is carried out to supply dry air to the adsorption device, pushing out the vapors originating from the liquid to be recovered that remain in the adsorption device and allowing them to be recovered in the recovery tank.

[0029] In the target liquid recovery system according to the present invention, the control unit may terminate the blow-out process by controlling the supply device such that, in the blow-out process, the supply of dry air to the adsorption device is stopped when the passing temperature falls below a predetermined fifth threshold temperature which is below the boiling point of the target liquid to be recovered, or when a predetermined first threshold time has elapsed since the start of supplying dry air to the adsorption device.

[0030] When the temperature of the dry air supplied to the adsorption device falls below a predetermined fifth threshold temperature, or when a predetermined first threshold time has elapsed, it is assumed that the vapors originating from the liquid to be recovered in the adsorption device have been sufficiently pushed out and recovered, and therefore the supply of dry air is stopped. In this way, the blowing process can be terminated at an appropriate timing based on the passing temperature.

[0031] In the target liquid recovery system according to the present invention, a drying device is provided that supplies high-temperature dry air to the adsorption device, and the control unit may perform a drying process in which, after the blowing process is completed, the drying device controls the device to supply the high-temperature dry air to the adsorption device.

[0032] According to the above configuration, once the recovery of vapors from the target liquid from the adsorption device is complete, high-temperature dry air can then be supplied to the adsorption device to dry the adsorbent.

[0033] In the target liquid recovery system according to the present invention, the control unit may be characterized in that, in the drying process, when the temperature inside the tank reaches a predetermined sixth threshold temperature or above, or when a predetermined second threshold time has elapsed since the supply of the high-temperature dry air to the adsorption device began, the control unit controls the drying device to stop supplying the high-temperature dry air to the adsorption device and terminate the drying process.

[0034] When the temperature inside the vaporization tank of the adsorption device reaches or exceeds the sixth threshold temperature, or when the second threshold time has elapsed since the start of supplying high-temperature dry air to the adsorption device, it is assumed that the removal of the target liquid from the adsorbent is complete and that it has dried sufficiently to be suitable for the next use. In this way, the supply of high-temperature dry air is stopped at an appropriate time. In this manner, the drying process can be terminated at an appropriate time based on the tank temperature and elapsed time.

[0035] In the target liquid recovery system according to the present invention, a heating unit for heating the mixed liquid tank and an exhaust device capable of exhausting the high-temperature dry air supplied from the drying device to the adsorption device to the heating unit are provided, wherein the exhaust device is configured to selectively exhaust the high-temperature dry air supplied from the drying device to the adsorption device to the heating unit or outside the system, and the control unit controls the exhaust device such that, in the drying process, when the temperature inside the tank is above a predetermined seventh threshold temperature, the high-temperature dry air supplied from the drying device to the adsorption device is exhausted to the heating unit, and when the temperature inside the tank is below the seventh threshold temperature, the high-temperature dry air supplied from the drying device to the adsorption device is exhausted outside the system.

[0036] Since the high-temperature dry air used to dry the adsorbent still contains a considerable amount of heat, it is not economical to exhaust this high-temperature dry air directly to the outside of the system. When the temperature inside the tank is above the seventh threshold temperature, the high-temperature dry air still has sufficient heat, so it can be supplied to the heating section of the mixed liquid tank by the exhaust device and used to heat the mixed liquid stored in the tank. On the other hand, when the temperature inside the tank is below the seventh threshold temperature, it is exhausted to the outside of the system.

[0037] In the target liquid recovery system according to the present invention, the control unit is configured to perform a cooling process in which it controls the supply device to supply the dried air to the adsorption device when the drying process is completed, and the control unit may be configured to perform a cooling process in which it controls the supply device to stop supplying the dried air to the adsorption device when the temperature inside the tank falls below a predetermined eighth threshold temperature, or when a predetermined third threshold time has elapsed since the start of supplying the dried air to the adsorption device, thereby terminating the cooling process.

[0038] When the temperature inside the tank falls below a predetermined eighth threshold temperature, or when a predetermined third threshold time has elapsed since the start of supplying dry air to the adsorption device, it is assumed that the adsorbent has been sufficiently cooled. With the above configuration, the cooling process can be terminated at an appropriate timing based on the temperature inside the tank and the elapsed time.

[0039] In the target liquid recovery system according to the present invention, a heater is provided for heating the bottom of the vaporization tank, a plurality of heat transfer fins are provided at the bottom of the vaporization tank, and the plurality of heat transfer fins are arranged such that they are denser at the periphery than at the center of the bottom.

[0040] The mixture is heated and vaporized by a heater that heats the bottom of the vaporization tank. However, the mixture in the peripheral areas of the vaporization tank absorbs heat from the side walls of the tank and is therefore less heated than in the center. Consequently, it is more difficult to vaporize the mixture in the peripheral areas of the vaporization tank than in the center.

[0041] Because the vaporization of the mixed liquid occurs unevenly within the plane of the vaporization tank, the steam may be supplied to the adsorption tank unevenly. In other words, a large amount of steam is supplied to the center of the adsorption tank, while less is supplied to the periphery. The more contact the steam has with the adsorbent, the more easily the steam originating from the liquid to be removed is adsorbed by the adsorbent. Therefore, adsorption of steam from the liquid to be removed progresses in the adsorbent located in the center, while adsorption does not progress as much in the adsorbent located in the periphery.

[0042] As the adsorbent absorbs vapors from the target liquid, it generates more heat. Therefore, the adsorbent in the center generates more heat than the adsorbent in the surrounding area, resulting in uneven heating temperatures within the surface of the adsorbent.

[0043] Since the start of the drying process is controlled according to the exothermic temperature of the adsorbent, if the adsorbent in the central part, which has sufficiently adsorbed steam, is used as the reference point, the next process is executed even though there is still adsorbent in the peripheral part that can adsorb steam, and therefore the adsorption tank's capacity cannot be fully utilized.

[0044] Therefore, in order to ensure that the liquid to be removed is evenly adsorbed onto the adsorbent regardless of its position within the adsorption tank, it is desirable that vapor be supplied uniformly across the surface of the adsorption tank.

[0045] As described above, when equipping the bottom of a vaporization tank with multiple heat transfer fins, arranging the fins so that they are denser at the periphery than in the center increases the heat transfer area at the periphery compared to the center, thereby transferring more heat to the mixed liquid in the vaporization tank. By compensating for the heat absorbed by the side walls of the vaporization tank, vaporization can be promoted at the periphery to the same extent as in the center, making the amount of steam in the vaporization tank more uniform across the surface.

[0046] Furthermore, when arranging the heat transfer fins so that they are denser at the periphery than in the center of the bottom, when viewed from above, the bottom can be arranged in a way that promotes active convection in the mixture heated in the vaporization tank, thereby equalizing the temperature of the mixture within the vaporization tank. This allows for uniform vaporization within the plane of the vaporization tank.

[0047] Furthermore, if there is a large difference in the degree of absorption of the liquid to be removed at different locations within the plane of the adsorption tank, a difference will occur in the exothermic temperature of the adsorbent in the central part and the exothermic temperature of the adsorbent in the peripheral part. Therefore, in order to accurately understand the state of the adsorption tank for proper control, it is necessary to install exothermic thermometers at multiple locations in the central and peripheral parts.

[0048] In contrast, as described above, if the amount of steam generated in the vaporization tank can be made nearly uniform across the surface, the adsorbent will adsorb the steam originating from the liquid to be removed almost uniformly regardless of its position within the adsorption tank, and generate heat. Therefore, even with a single heat thermometer, the heat temperature measured by that single heat thermometer can be considered the representative temperature.

[0049] In the target liquid recovery system according to the present invention, the adsorption tank is provided directly above the vaporization tank, the inside of the adsorption tank is partitioned vertically by a plurality of perforated metal sheets on which the adsorbent is arranged, and the plurality of holes provided in each of the perforated metal sheets are arranged such that the amount of airflow is greater in the peripheral areas than in the central areas.

[0050] The mixed liquid is vaporized by heat from a heater that heats the bottom of the vaporization tank, and rises through the adsorption device. As the vapor rises, it passes through the holes in the perforated metal and through the gaps in the adsorbent placed on the perforated metal, during which time the vapor originating from the liquid to be removed is adsorbed.

[0051] Within the adsorption device, the peripheral areas have higher pressure loss than the central areas due to their proximity to the sides. The vapor flow rate is higher in the central area of ​​the adsorption device than in the peripheral areas. Therefore, in the adsorption tank, vapor from the liquid to be removed is more easily absorbed by the adsorbent in the central area, while vapor is less easily adsorbed by the adsorbent in the peripheral areas. The adsorbent in the central area generates heat faster than the adsorbent in the peripheral areas.

[0052] However, if the central adsorbent, which has sufficiently adsorbed the vapor, is used as a reference, the drying process will be carried out as described above, even though there is still adsorbent in the surrounding area that can adsorb vapor. In order to evenly adsorb the liquid to be removed within the plane of the adsorption tank, it is desirable to allow the vapor to pass uniformly within the plane of the adsorption tank.

[0053] As described above, by arranging the holes in the perforated metal so that the airflow is greater at the periphery than at the center, the pressure loss at the periphery is relatively reduced, and the steam from the central area with high airflow is diverted to the periphery, making the steam flow rate in the adsorption tank more uniform across the surface. As a result, the liquid to be removed can be adsorbed evenly across the surface of the adsorption tank.

[0054] The adsorption tank may be partitioned by a single sheet of perforated metal, or by multiple sheets.

[0055] In the target liquid recovery system according to the present invention, the adsorption tank is provided directly above the vaporization tank, and a perforated metal on which the adsorbent is placed is provided inside the adsorption tank, and the adsorbent is arranged such that the thickness of the layer in the center of the perforated metal is greater than that of the peripheral part.

[0056] The mixed liquid is vaporized by heat from a heater that heats the bottom of the vaporization tank and rises through the adsorption device. As it passes through the holes in the perforated metal and through the gaps in the adsorbent placed on the perforated metal, the vapor originating from the liquid to be removed is adsorbed.

[0057] The adsorbent is placed in perforated metal that partitions the adsorption tank, and the steam generated in the vaporization tank rises through the holes in the perforated metal.

[0058] Within the adsorption device, the peripheral areas have higher pressure loss than the central areas due to their proximity to the sides. The vapor flow rate is higher in the central area of ​​the adsorption device than in the peripheral areas. Therefore, in the adsorption tank, vapor from the liquid to be removed is more easily absorbed by the adsorbent in the central area, while vapor is less easily adsorbed by the adsorbent in the peripheral areas. The adsorbent in the central area generates heat faster than the adsorbent in the peripheral areas.

[0059] However, if the central adsorbent, which has sufficiently adsorbed the vapor, is used as a reference, the drying process will be carried out as described above, even though there is still adsorbent in the surrounding area that can adsorb vapor. In order to evenly adsorb the liquid to be removed within the plane of the adsorption tank, it is desirable to allow the vapor to pass uniformly within the plane of the adsorption tank.

[0060] As described above, by arranging the adsorbent on the perforated metal so that the layer thickness is greater in the center than in the periphery, the pressure loss in the periphery can be relatively reduced and brought closer to the pressure loss in the center, thereby making the vapor flow rate in the adsorption tank more uniform across the surface. As a result, the liquid to be removed can be adsorbed evenly across the surface of the adsorption tank. [Brief explanation of the drawing]

[0061] [Figure 1] Figure 1 is an explanatory diagram showing the recovery process of the target liquid recovery system according to the present invention. [Figure 2] Figure 2 is an explanatory diagram showing the blow-by process of the target liquid recovery system according to the present invention. [Figure 3] Figure 3 is an explanatory diagram showing the drying process of the target liquid recovery system according to the present invention. [Figure 4] Figure 4 is an explanatory diagram showing the cooling process of the target liquid recovery system according to the present invention. [Figure 5] Figure 5 is a plan view of the perforated metal provided in the target liquid recovery system according to the present invention. [Modes for carrying out the invention]

[0062] Based on Figures 1 to 4, an example of recovering isopropyl alcohol CL by removing water RL from a mixture ML of isopropyl alcohol CL and water RL using the target liquid recovery system 100 according to the present invention will be described. Isopropyl alcohol CL is an example of the "liquid to be recovered" in the claim, and water RL is an example of the "liquid to be removed" in the claim.

[0063] Isopropyl alcohol (Cl) has a boiling point of 82.4°C at standard pressure and is a colorless, transparent liquid at room temperature. Water (RL) has a boiling point of 100°C at standard pressure and is a colorless, transparent liquid at room temperature.

[0064] The target liquid recovery system 100 comprises a mixed liquid tank 10, a mixed liquid supply unit 20, an adsorption device 30, a vapor discharge unit 40, a recovery tank 50, a supply device 60, a drying device 70, an exhaust device 80, and a control unit 90. All parts of the target liquid recovery system 100, except for the mixed liquid tank 10 and the recovery tank 50, are housed in a chamber 101. A gas detector 102 is provided near the bottom of the chamber 101, and the signal from the gas detector 102 is input to the control unit 90. This allows for the detection of isopropyl alcohol CL leakage within the chamber 101. When the control unit 90 detects leakage of isopropyl alcohol or the like into the chamber 101 using the gas detector 102, it supplies an inert gas into the chamber 101. The control unit 90 may be located inside or outside the chamber 101.

[0065] In order for the target liquid recovery system 100 to function properly, safety valves, check valves, etc., are appropriately provided in each pipe. However, for the purposes of explaining the present invention, the explanation of such components and their depiction in Figures 1 to 4 will be omitted.

[0066] (Mixed liquid tank) The mixed liquid tank 10 is provided for storing a mixed liquid ML, which is a mixture of isopropyl alcohol CL and water RL. Below the mixed liquid tank 10, a heating unit 11 is provided for heating the mixed liquid tank 10.

[0067] (Mixed liquid supply section) The mixed liquid supply unit 20 supplies the mixed liquid ML stored in the mixed liquid tank 10 to the adsorption device 30, and is equipped with a pump P and a valve 22 in the piping 21. The pump P is driven and stopped by the control unit 90. The valve 22 is an air-driven valve and is opened and closed by the control unit 90.

[0068] (Adsorption device) The adsorption device 30 comprises a heating unit 31, a vaporization tank 32, and an adsorption tank 33. The housing of the adsorption device 30 is manufactured by bending and welding stainless steel.

[0069] (heating part) The heating unit 31 heats the bottom of the vaporization tank 32 and is equipped with a heating thermometer T3 that measures the heating temperature of the heating unit 31. The heating unit 31 consists of a heater (for example, a plate heater) and is controlled by the control unit 90. The heating temperature of the heating unit 31 measured by the heating thermometer T3 is input to the control unit 90.

[0070] (Steam tank) The vaporization tank 32 is a tank heated by the heating unit 31, and the mixed liquid ML supplied from the mixed liquid tank 10 is vaporized in the vaporization tank 32. The vaporization tank 32 is equipped with a tank thermometer T4 for measuring the temperature inside the tank. The temperature inside the vaporization tank 32 measured by the tank thermometer T4 is input to the control unit 90.

[0071] The bottom of the steam tank 32 is equipped with multiple heat transfer fins 34. The multiple heat transfer fins 34 are arranged such that they are denser around the periphery than in the center of the bottom.

[0072] The heat transfer fins 34 are made of the same stainless steel as the housing of the adsorption device 30 and are welded to the bottom of the vaporization tank 32. When the bottom of the vaporization tank 32 is heated by the heating unit 31, the heat is also transferred to the heat transfer fins 34. The heat from the heating unit 31 is transferred from the bottom of the vaporization tank 32 and the heat transfer fins 34 to the mixed liquid ML inside the vaporization tank 32.

[0073] When arranging the heat transfer fins 34 such that they are denser at the periphery than in the center of the bottom, and when viewed from above, the bottom can be arranged, for example, in an intermittent radial or spiral pattern, to generate active convection in the mixed liquid ML heated in the vaporization tank 32, thereby homogenizing the temperature of the mixed liquid ML in the vaporization tank 32. This enables uniform vaporization within the plane of the vaporization tank 32.

[0074] (Adsorption tank) The adsorption tank 33 is located directly above the vaporization tank 32. The interior of the adsorption tank 33 is divided vertically by two perforated metal plates 35. Adsorbent 36 is placed in each perforated metal plate 35. The adsorption tank 33 is equipped with a heat-generating thermometer T2 for measuring the heat-generating temperature of the adsorbent 36. The temperature of the adsorbent 36 inside the tank, as measured by the heat-generating thermometer T2, is input to the control unit 90.

[0075] As shown in Figure 5, the perforated metal 35 is a stainless steel plate approximately 580 mm long, 280 mm wide, and 3 mm thick, with multiple holes 35H provided in it. The holes 35H are arranged so that the airflow is greater in the peripheral area 35P (approximately outside the dashed ellipse in Figure 5) than in the central area 35C (approximately inside the dashed ellipse in Figure 5, however, the dashed ellipse is a line illustrated for illustrative purposes and does not represent the structure of the perforated metal 35). In this embodiment, the diameter of the holes 35HB in the peripheral area 35P (for example, about φ30 mm) is larger than the diameter of the holes 35HS in the central area 35C (for example, about φ10 mm). Furthermore, smaller diameter holes 35HS are also arranged between the holes 35HB. In this way, the pressure loss in the peripheral area 35P is relatively reduced, and the steam from the central area 35C, which has a high airflow rate, is diverted to the peripheral area 35P, making the steam flow rate in the adsorption tank 33 more uniform across the plane. This allows the water RL, which is the liquid to be removed, to be adsorbed evenly within the plane of the adsorption tank 33. Note that the above dimensions of the perforated metal 35, the holes 35HB and 35HS are examples and are not limited to these dimensions.

[0076] According to the inventors' experiments, when the holes 35H of the perforated metal 35 were all the same diameter (for example, about φ10 mm) (comparative example), the steam airflow per unit area in the central part 35C was 2.48 times greater than in the peripheral part 35P. In contrast, as described above, when the holes 35H were arranged so that the airflow was greater in the peripheral part 35P than in the central part 35C (experimental example), the steam airflow per unit area in the central part 35C was approximately uniform, at 1.05 times greater than in the peripheral part 35P. Consequently, the amount of water RL adsorbed in the experimental example was 1.3 times greater than in the comparative example.

[0077] In this embodiment, molecular sieves are used as the adsorbent 36. The diameter of the micropores of the adsorbent 36 is larger than the particle size of water RL molecules and smaller than the particle size of isopropyl alcohol CL molecules, which is the liquid to be recovered. Therefore, only water RL is adsorbed into the micropores of the adsorbent 36. The adsorbent 36 is arranged such that the layer thickness is greater in the central part 35C than in the peripheral part 35P of the perforated metal 35. The water RL vaporized in the vaporization tank 32 is adsorbed by the adsorbent 36. A mesh (not shown) with a mesh size smaller than the particle size of the adsorbent 36 is laid on top of the perforated metal 35, and the adsorbent 36 is layered on top of the mesh.

[0078] (Steam discharge section) The steam discharge section 40 is capable of selectively discharging steam discharged from the adsorption tank 33 to either the recovery tank 50 or the mixed liquid tank 10. The piping 41 is equipped with valves 42, 43, and 44, a condensation mechanism 45, and a passage thermometer T1 that measures the passage temperature of steam passing through the piping 41. The passage temperature measured by the passage thermometer T1 is input to the control unit 90. Valves 42, 43, and 44 are air-driven valves, and their opening and closing are controlled by the control unit 90.

[0079] When valve 43 is open and valve 44 is closed, the steam discharged from the adsorption tank 33 is discharged to the recovery tank 50. When valve 43 is closed and valve 44 is open, the steam discharged from the adsorption tank 33 is discharged to the mixed liquid tank 10.

[0080] The condensation mechanism 45 is installed in the middle of the piping 41 and is configured to liquefy the steam passing through the piping 41 by exchanging heat with cooling water supplied from outside the system. Therefore, the steam discharged from the adsorption tank 33 is condensed by the condensation mechanism 45 and discharged downstream in a liquefied state.

[0081] (Recovery tank) The recovery tank 50 is a tank for recovering isopropyl alcohol CL that is discharged by the steam discharge unit 40 and liquefied by the condensation mechanism 45. The recovery tank 50 is equipped with a liquid level meter, and the liquid level of isopropyl alcohol CL measured by the liquid level meter is input to the control unit 90. When the control unit 90 determines that the liquid level in the recovery tank 50 is full, it issues an alarm or otherwise prompts the worker to replace the recovery tank 50 or recover the liquid.

[0082] (Feeding device) The supply device 60 supplies dry air DA to the adsorption device 30, and the duct 61 is equipped with an air dryer 62, a valve 63, and a valve 64. The air dryer 62 is configured to remove dust and other particles from the atmosphere, then compress the air to remove water, and supply dry air DA to the adsorption device 30. The valves 63 and 64 are air-driven valves, and their opening and closing are controlled by the control unit 90.

[0083] (drying equipment) The drying device 70 supplies high-temperature dry air HA to the adsorption tank 33 of the adsorption device 30, and a blower B, a heater 72, and a valve 73 are provided in the duct 71. The blower B and heater 72 are controlled to be driven and stopped by the control unit 90. The valve 73 is an air-driven valve and is controlled to be opened and closed by the control unit 90.

[0084] (Exhaust system) The exhaust system 80 selectively exhausts the high-temperature dry air HA supplied from the drying device 70 to the adsorption device 30 to the heating unit 11 or outside the system, and is equipped with valves 82 and 83 in the piping 81. Valves 82 and 83 are air-driven valves and their opening and closing are controlled by the control unit 90.

[0085] (Control Unit) The control unit 90 includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and receives measurement signals from each thermometer and sensor, and outputs control signals to each valve, etc. The CPU reads the control program stored in the ROM, and predetermined controls are executed on the mixed liquid supply unit 20, adsorption device 30, steam discharge unit 40, supply device 60, drying device 70, and exhaust device 80, so that the target liquid recovery system 100 repeatedly executes the recovery process, blowdown process, drying process, and cooling process in order at appropriate timings.

[0086] The recovery process, blowing process, drying process, and cooling process performed by the control unit 90 will be described below.

[0087] (Recovery process) As shown in Figure 1, the control unit 90 controls the mixed liquid supply unit 20, the adsorption device 30, and the steam discharge unit 40 in the recovery process as follows. Note that the supply device 60, the drying device 70, and the exhaust device 80 are stopped during the recovery process.

[0088] First, the control unit 90 drives the heating unit 31, and when the temperature inside the tank reaches the second threshold temperature (102°C) or higher, and the heating temperature reaches the third threshold temperature (180°C) or higher, it drives the pump P and opens the valve 22. As a result, the mixed liquid ML is supplied to the adsorption device 30, and the vaporization of the mixed liquid ML begins.

[0089] When the passage temperature measured by the passage thermometer T1 is below a predetermined first threshold temperature (85°C) which is higher than the boiling point of isopropyl alcohol CL (82.4°C) and lower than the boiling point of water RL (100°C), the control unit 90 opens valve 43 in addition to valve 42 and closes valve 44. As a result, the vapor is recovered by the recovery tank 50. When the passage temperature is 85°C or higher, the control unit 90 opens valve 44 in addition to valve 42 and closes valve 43. As a result, the vapor is not recovered by the recovery tank 50 but is recovered by the mixed liquid tank 10.

[0090] Furthermore, if the temperature inside the tank measured by the tank thermometer T4 is below a predetermined second threshold temperature (102°C) which is higher than the boiling point of water RL, the control unit 90 stops the pump P and closes the valve 22. As a result, the mixed liquid ML is not supplied to the adsorption device 30.

[0091] Furthermore, the control unit 90 stops the pump P and closes the valve 22 when the heating temperature measured by the heating thermometer T3 is below a predetermined third threshold temperature (180°C). As a result, the mixed liquid ML is not supplied to the adsorption device 30.

[0092] Furthermore, when the heat generation temperature exceeds a predetermined fourth threshold temperature (120°C), the control unit 90 stops the pump P and closes the valve 22. As a result, the mixed liquid ML is not supplied to the adsorption device 30. In this way, the recovery process is completed.

[0093] (Blow-drying process) As shown in Figure 2, the control unit 90 controls the steam discharge unit 40 and the supply device 60 during the blowdown process as follows. During the blowdown process, the mixed liquid supply unit 20, the adsorption device 30, the drying device 70, and the exhaust device 80 are stopped.

[0094] When the heat generation temperature exceeds the fourth threshold temperature (120°C), the control unit 90 opens valve 64 and closes valve 63. This supplies dry air DA to the adsorption device 30.

[0095] In addition, in the blowdown process, similar to the recovery process, the control unit 90 selectively recovers the steam in the recovery tank 50 or the mixed liquid tank 10 based on the passage temperature measured by the passage thermometer T1.

[0096] The control unit 90 closes the valve 64 when the passing temperature falls below a predetermined fifth threshold temperature (60°C), which is below the boiling point of isopropyl alcohol Cl, or when a predetermined first threshold time (25 minutes) has elapsed since the start of supplying dry air DA to the adsorption device 30. This stops the supply of dry air DA to the adsorption device 30 and ends the blowing process.

[0097] (drying process) As shown in Figure 3, the control unit 90 controls the drying apparatus 70 and the exhaust apparatus 80 in the drying process as follows. Note that the mixed liquid supply unit 20, the adsorption device 30, the steam discharge unit 40, and the supply device 60 are stopped during the drying process.

[0098] As described above, the control unit 90 closes valves 63 and 64, thereby stopping the supply of dry air DA to the adsorption device 30. Then, it drives the blower B and heater 72 to open valve 73. This allows high-temperature dry air HA to be supplied to the adsorption device 30, drying the adsorbent 36.

[0099] The control unit 90 opens valve 82 and closes valve 83 to control the exhaust device 80 so that the high-temperature dry air HA is exhausted to the heating unit 11 of the mixed liquid tank 10. As a result, the mixed liquid ML in the mixed liquid tank 10 is heated before being supplied to the adsorption device 30, and the amount of heat required for the heating unit 31 to vaporize the mixed liquid ML is reduced, so that power consumption in the recovery process can be reduced by 10% or more (when the mixed liquid ML has a water content of 30 wt%).

[0100] When the temperature inside the tank reaches or exceeds the sixth threshold temperature (120°C), or when a predetermined second threshold time (100 minutes) has elapsed since the supply of high-temperature dry air HA to the adsorption device 30 began, the control unit 90 stops the blower B and heater 72 and closes the valve 73. This stops the supply of high-temperature dry air HA to the adsorption device 30, and the drying process ends.

[0101] (cooling process) As shown in Figure 4, the control unit 90 controls the supply device 60 and the exhaust device 80 during the cooling process as follows. During the cooling process, the mixed liquid supply unit 20, the adsorption device 30, the steam discharge unit 40, and the drying device 70 are stopped.

[0102] When the temperature inside the tank is above a predetermined seventh threshold temperature (50°C), the control unit 90 opens valves 63 and 82 and closes valves 64 and 83. This supplies dry air DA to the adsorption device 30. As a result, the dry air DA supplied from the supply device 60 to the adsorption device 30 is exhausted to the heating unit 11.

[0103] When the temperature inside the tank is below the seventh threshold temperature (50°C), the control unit 90 opens valves 63 and 83 and closes valves 64 and 82. As a result, the dry air DA supplied from the supply device 60 to the adsorption device 30 is exhausted out of the system.

[0104] When the temperature inside the tank falls below a predetermined eighth threshold temperature (31°C), or when a predetermined third threshold time (100 minutes) has elapsed since the start of supplying dry air DA to the adsorption device 30, the control unit 90 closes valves 63, 64, 82, and 83. This ends the cooling process, which stops the supply of dry air DA to the adsorption device 30.

[0105] As described above, the control unit 90 of the target liquid recovery system 100 operates continuously, with the recovery process, blowing process, drying process, and cooling process forming one cycle.

[0106] Specifically, the mixed liquid ML in the mixed liquid tank 10 is supplied to the adsorption device 30 by the pump P and heated in the vaporization tank 32. The vaporized mixed liquid ML rises inside the adsorption device 30, and the vapor derived from water RL is absorbed by the adsorbent 36 in the adsorption tank 33. The vapor from which water RL has been removed is derived from isopropyl alcohol CL and is therefore discharged from the adsorption device 30, condensed in the condensation mechanism 45, and recovered in the recovery tank 50. If the temperature of the vapor discharged from the adsorption device 30 is above the first threshold temperature, it is presumed that vapor derived from water RL is present, and the recovery process is terminated. This vapor is condensed and supplied to the mixed liquid tank 10 without being recovered in the recovery tank 50. Subsequently, dry air DA is supplied to the adsorption device 30, thereby discharging any remaining vapor inside the adsorption device 30. This vapor is condensed in the condensation mechanism 45 and supplied to the recovery tank 50 or the mixed liquid tank 10. Subsequently, high-temperature dry air HA is supplied to the adsorption device 30, thereby drying the adsorbent 36. Then, dry air DA is supplied to the adsorption device 30, thereby cooling the adsorbent 36. According to this target liquid recovery system 100, the liquid concentration of the recovered isopropyl alcohol CL can be increased to 99.9 wt% or higher.

[0107] In the embodiments described above, an example was given in which isopropyl alcohol CL is recovered by removing water RL from a mixture ML of isopropyl alcohol CL and water RL, but this is not limited to this example. The liquid to be recovered may be other liquids instead of isopropyl alcohol CL, as long as the boiling point of the liquid to be removed is higher than the boiling point of the liquid to be recovered.

[0108] In the embodiment described above, the adsorbent 36 was arranged such that the layer thickness in the central part 35C was greater than that in the peripheral part 35P of the perforated metal 35, but this is not limited to this. The adsorbent 36 may be arranged to have a uniform layer thickness on the perforated metal 35.

[0109] In the embodiment described above, the adsorbent 36 was a molecular sieve, but this is not limited to that. Any adsorbent that functions similarly to a molecular sieve with respect to the liquid to be removed in the target liquid recovery system 100 is acceptable.

[0110] In the embodiment described above, the multiple holes 35H provided in each of the two perforated metals 35 were arranged such that the amount of airflow was greater in the peripheral portion 35P than in the central portion 35C, but this is not limited to this configuration.

[0111] Preferably, the multiple holes 35H provided in any of the perforated metal 35 are arranged such that the amount of airflow is greater in the peripheral portion 35P than in the central portion 35C. The multiple holes 35H provided in the other perforated metal 35 may be arranged so that the amount of airflow is equal in the central portion 35C and the peripheral portion 35P, or they may be arranged so that the amount of airflow is greater in the central portion 35C than in the peripheral portion 35P.

[0112] In the embodiment described above, a configuration was described in which the inside of the adsorption tank 33 is partitioned by two perforated metal sheets 35, but this is not limited to this configuration. There may be one perforated metal sheet 35, or there may be three or more sheets.

[0113] In the embodiment described above, a heating unit 11 for heating the mixed liquid tank 10 was provided below the mixed liquid tank 10, but the invention is not limited to this. For example, the piping 21 connecting the mixed liquid tank 10 and the adsorption device 30 may be configured as a double pipe, with high-temperature dry air HA flowing through the outer pipe to heat the mixed liquid ML flowing through the inner pipe.

[0114] The isopropyl alcohol (CL) used as the recovery liquid and water (RL) used as the removal liquid, as mentioned above, are examples. The removal liquid only needs to have a boiling point higher than that of the recovery liquid. The first threshold temperature (85°C), second threshold temperature (102°C), third threshold temperature (180°C), fourth threshold temperature (120°C), fifth threshold temperature (60°C), sixth threshold temperature (120°C), seventh threshold temperature (50°C), and eighth threshold temperature (31°C) are values ​​set according to the boiling point of isopropyl alcohol (CL), the recovery liquid, being 82.4°C, and the boiling point of water (RL), the removal liquid, being 100°C. For example, if the recovery liquid is ethanol, its boiling point under standard atmospheric pressure is 78.37°C, so the temperatures are set accordingly.

[0115] The temperatures mentioned above—first threshold temperature (85°C), second threshold temperature (102°C), third threshold temperature (180°C), fourth threshold temperature (120°C), fifth threshold temperature (60°C), sixth threshold temperature (120°C), seventh threshold temperature (50°C), and eighth threshold temperature (31°C)—and the times—first threshold time (25 minutes), second threshold time (100 minutes), and third threshold time (100 minutes)—are examples. These temperatures and times should be set to appropriate values ​​depending on the boiling point of the liquid to be recovered, the boiling point of the liquid to be removed, the dimensions of the adsorption device 30, the type of adsorbent 36, the amount of adsorbent 36 to be placed, etc.

[0116] In the embodiment described above, the control unit 90 controlled the steam discharge unit 40 so that when the passing temperature is above the first threshold temperature (85°C), the steam is not recovered by the recovery tank 50 but recovered by the mixed liquid tank 10. However, this is not limited to this configuration. The control unit 90 may also exhaust the steam outside the system without recovering it by the recovery tank 50 when the passing temperature is above the first threshold temperature (85°C).

[0117] The configurations disclosed in any of the above-described embodiments can be applied in combination with configurations disclosed in other embodiments, provided that they do not conflict with each other. Furthermore, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto and can be modified as appropriate without departing from the purpose of the present invention. [Explanation of symbols]

[0118] 10: Mixed liquid tank 11:Heating section 20: Mixed liquid supply section 21: Piping 22: Valve 30: Adsorption device 31: Heating part 32: Steam tank 33: Adsorption tank 34: Heat transfer fins 35: Perforated Metal 35C: Central part 35P: Peripheral area 35H: Hole 35HB: Hole 35HS: Hole 36: Adsorbent 40: Steam discharge section 41: Piping 42: Valve 43: Valve 44: Valve 45: Condensation mechanism 50: Recovery Tank 60: Feeding device 61: Duct 62: Air dryer 63: Valve 70:Drying equipment 71: Duct 72: Heater 73: Valve 80: Exhaust system 81: Piping 82: Valve 83: Valve 90: Control Unit 100: Target liquid recovery system 101: Chamber 102: Gas detector ML: Mixed liquid CL: Isopropyl alcohol (liquid to be recovered) RL: Water (liquid to be removed) P: Pump B: Blower DA: Dry air HA: High-temperature dry air T1: Passage thermometer T2: Fever thermometer T3: Heating thermometer T4: In-tank thermometer

Claims

1. A target liquid recovery system for recovering a target liquid from a mixture obtained by mixing the target liquid with a target liquid having a boiling point higher than the boiling point of the target liquid, An adsorption apparatus comprising a vaporization tank for vaporizing the mixed liquid and an adsorption tank in which an adsorbent is placed for adsorbing the liquid to be removed vaporized in the vaporization tank, A steam discharge section for discharging steam from the adsorption tank, A recovery tank for recovering the liquid to be recovered, which has been vaporized in the aforementioned vaporization tank, A passage thermometer for measuring the passage temperature of the steam passing through the steam discharge section, When the passing temperature is below a predetermined first threshold temperature that is higher than the boiling point of the liquid to be recovered and lower than the boiling point of the liquid to be removed, the vapor is recovered by the recovery tank. A target liquid recovery system characterized by comprising: a control unit that performs a recovery process to control the steam discharge unit so as not to recover the steam by the recovery tank when the passing temperature is equal to or greater than the first threshold temperature.

2. A mixed liquid tank capable of storing the aforementioned mixed liquid is provided. The steam discharge unit is configured to selectively discharge the steam discharged from the adsorption tank to the recovery tank or the mixed liquid tank. The control unit, The target liquid recovery system according to claim 1, characterized in that, in the recovery step, when the passing temperature is equal to or greater than the first threshold temperature, the steam discharge unit is controlled to recover the steam using the mixed liquid tank.

3. The steam discharge section has a condensation mechanism for condensing the steam, The target liquid recovery system according to claim 2, characterized in that the steam is configured to be selectively discharged to the recovery tank or the mixed liquid tank in a liquefied state by the condensation mechanism.

4. A mixed liquid tank capable of storing the aforementioned mixed liquid, A mixed liquid supply unit capable of supplying the mixed liquid stored in the mixed liquid tank to the adsorption device, The steaming tank is equipped with a tank thermometer for measuring the temperature inside the tank, The control unit, In the recovery process, if the temperature inside the tank is below a predetermined second threshold temperature that is higher than the boiling point of the liquid to be removed, the mixed liquid is not supplied to the adsorption device. The target liquid recovery system according to claim 1, characterized in that when the temperature inside the tank is equal to or greater than the second threshold temperature, the mixed liquid supply unit is controlled to supply the mixed liquid to the adsorption device.

5. A heating section for heating the aforementioned steaming tank, The heating section is equipped with a heating thermometer for measuring the heating temperature, The control unit, In the recovery process, if the heating temperature is below a predetermined third threshold temperature, the mixed liquid is not supplied to the adsorption device. The target liquid recovery system according to claim 4, characterized in that when the heating temperature is equal to or greater than the third threshold temperature, the mixed liquid supply unit is controlled to supply the mixed liquid to the adsorption device.

6. The adsorption tank is equipped with a thermometer for measuring the exothermic temperature of the adsorbent placed in the adsorption tank. The control unit, The target liquid recovery system according to claim 5, characterized in that, in the recovery step, when the heat generation temperature exceeds a predetermined fourth threshold temperature, the mixed liquid supply unit is controlled so as not to supply the mixed liquid to the adsorption device, thereby terminating the recovery step.

7. A supply device is provided for supplying dry air to the adsorption device. The control unit, The target liquid recovery system according to claim 6, characterized in that, after the recovery process is completed, a blowing process is performed to control the supply device so that the dry air is supplied to the adsorption device.

8. The control unit, The target liquid recovery system according to claim 7, characterized in that, in the blowing step, the supply device is controlled to terminate the blowing step by stopping the supply of dry air to the adsorption device when the passing temperature falls below a predetermined fifth threshold temperature which is below the boiling point of the liquid to be recovered, or when a predetermined first threshold time has elapsed since the start of supplying the dry air to the adsorption device.

9. A drying device is provided that supplies high-temperature dry air to the adsorption device. The control unit, The target liquid recovery system according to claim 8, characterized in that, after the blowing process is completed, a drying process is performed in which the drying device is controlled to supply the high-temperature dry air to the adsorption device.

10. The control unit, The target liquid recovery system according to claim 9, characterized in that, in the drying step, the drying device is controlled to stop supplying the high-temperature dry air to the adsorption device when the temperature inside the tank reaches or exceeds a predetermined sixth threshold temperature, or when a predetermined second threshold time has elapsed since the supply of the high-temperature dry air to the adsorption device began, thereby ending the drying step.

11. A heating unit for heating the aforementioned mixed liquid tank, The system is equipped with an exhaust device capable of exhausting the high-temperature dry air supplied from the drying device to the adsorption device to the heating unit, The exhaust device is configured to selectively exhaust the high-temperature dry air supplied from the drying device to the adsorption device to the heating unit or outside the system. The control unit, In the drying process, when the temperature inside the tank is above a predetermined seventh threshold temperature, the high-temperature drying air supplied from the drying apparatus to the adsorption apparatus is exhausted to the heating section. The target liquid recovery system according to claim 10, characterized in that when the temperature inside the tank is below the seventh threshold temperature, the exhaust device is controlled to exhaust the high-temperature dry air supplied from the drying device to the adsorption device to the outside of the system.

12. The control unit, When the drying process is completed, the system is configured to execute a cooling process that controls the supply device to supply the dried air to the adsorption device. The target liquid recovery system according to claim 11, characterized in that the supply device is controlled to stop supplying the dry air to the adsorption device when the temperature inside the tank falls below a predetermined eighth threshold temperature, or when a predetermined third threshold time has elapsed since the start of supplying the dry air to the adsorption device, thereby ending the cooling process.

13. The steam tank is equipped with a heater to heat the bottom of the tank. The bottom of the steam tank is provided with a plurality of heat transfer fins, The target liquid recovery system according to any one of claims 1 to 12, characterized in that the plurality of heat transfer fins are arranged such that the periphery is denser than the central part at the bottom.

14. The adsorption tank is provided directly above the vaporization tank. The interior of the adsorption tank is divided vertically by multiple perforated metal plates, each on which the adsorbent is placed. The target liquid recovery system according to any one of claims 1 to 12, characterized in that the multiple holes provided in each of the perforated metals are arranged such that the amount of airflow is greater in the peripheral areas than in the central areas.

15. The adsorption tank is provided directly above the vaporization tank. The adsorption tank is equipped with perforated metal on which the adsorbent is placed. The target liquid recovery system according to any one of claims 1 to 12, characterized in that the adsorbent is arranged such that the layer thickness is greater in the central part than in the peripheral part of the perforated metal.

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