Cleaning device and cleaning method

Abstract

This cleaning device (100) comprises: an additive transport unit (8) for transporting an additive in a non-supercritical state between a heating unit (4) and a cleaning tank (1) in a supercritical fluid flow path (2a) through which a supercritical fluid flows; and a control unit (6) for controlling the additive transport unit (8) so that the supercritical fluid transport unit (3) transports the additive when transporting the supercritical fluid. Accordingly, since it is not necessary to heat the additive together with a supercritical fluid raw material, energy efficiency during heating is improved. In addition, when using an additive that is deactivated by heating, the deactivation of the additive by heating can be prevented. Thus, contaminants in a body to be cleaned can be efficiently removed.

Description

Cleaning device and cleaning method

[0001] The present disclosure relates to a cleaning device and a cleaning method.

[0002] Supercritical fluids have intermediate viscosities, diffusion coefficients, densities, and dissolving powers between those of gases and liquids, and are characterized by their ability to easily penetrate micromechanical structures and their high solubility for hydrophobic substances. Because of these advantages, supercritical fluids are used as solvents in cleaning equipment. Furthermore, single-component supercritical fluids cannot completely remove hydrophilic contaminants and proteinaceous contaminants. Therefore, when the object to be cleaned contains a large amount of either hydrophilic contaminants or proteinaceous contaminants, it is necessary to use additives appropriate for each contaminant.

[0003] Therefore, for example, Patent Document 1 describes a cleaning device that cleans an object to be cleaned with carbon dioxide in a supercritical state or a liquid state. It also describes a configuration in which, when an additive is used to remove at least one of water-soluble contaminants and proteinaceous contaminants, a pump or the like is added to the cleaning system for mixing the additive into a carbon dioxide supply pipe.

[0004] JP 2010-136860 A

[0005] However, the invention described in Patent Document 1 does not take into consideration heating of the additive when using the additive, and may result in inefficient removal of contaminants. In the invention described in Patent Document 1, the pressure and temperature of the cleaning tank are adjusted by a supply pump and a cleaning tank temperature regulator so that the supplied liquid carbon dioxide becomes supercritical carbon dioxide at a pressure and temperature suitable for cleaning the object to be cleaned. In this case, for example, if a proteolytic enzyme is used as an additive to remove proteinaceous contaminants, the temperature in the cleaning tank may exceed the enzyme deactivation temperature, resulting in the deactivation of the enzyme. Furthermore, for example, if water is used as an additive to remove water-soluble contaminants, the specific heat of water is greater than that of carbon dioxide, resulting in reduced energy efficiency when heating the cleaning tank.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a cleaning device and a cleaning method that can efficiently remove contaminants from an object to be cleaned by preventing the additive from being heated by the heating unit.

[0007] a supercritical fluid transport unit that pressurizes the supercritical fluid raw material within the supercritical fluid flow path and transports the supercritical fluid raw material to the cleaning tank; a heating unit that is disposed between the supercritical fluid raw material supply unit and the cleaning tank and heats the supercritical fluid raw material to form a supercritical fluid; an additive supply unit that supplies an additive that is composed of at least one component and is in a non-supercritical state, not in a supercritical state; an additive flow path that connects the heating unit and the cleaning tank within the supercritical fluid flow path with the additive supply unit and through which the additive flows; an additive transport unit that is disposed in the additive flow path and transports the additive in a non-supercritical state between the heating unit and the cleaning tank within the supercritical fluid flow path;

[0008] The cleaning method according to the present disclosure is characterized by comprising the steps of: supplying a supercritical fluid raw material from a supercritical fluid raw material supply unit to a cleaning tank containing an object to be cleaned; heating the supercritical fluid raw material to form a supercritical fluid by a heating unit disposed between the supercritical fluid raw material supply unit and the cleaning tank; and transporting an additive in a non-supercritical state between the heating unit and the cleaning tank while the supercritical fluid is being transported in a supercritical fluid flow path connecting the supercritical fluid raw material supply unit and the cleaning tank.

[0009] According to the present disclosure, a cleaning apparatus includes an additive transport unit that transports an additive in a non-supercritical state between a heating unit and a cleaning tank within a supercritical fluid flow path through which a supercritical fluid flows, thereby providing a cleaning apparatus and a cleaning method that can efficiently remove contaminants from an object to be cleaned.

[0010] FIG. 1 is a schematic diagram of a cleaning apparatus according to a first embodiment. FIG. 2 is a schematic phase diagram of carbon dioxide, showing its solid, liquid, gas, and supercritical states. FIG. 3 summarizes the critical temperatures and critical pressures of representative substances that reach a supercritical state. FIG. 4 summarizes the enzyme deactivation temperatures of representative protease enzymes. FIG. 5 is a schematic diagram of a cleaning apparatus equipped with a disinfectant supply unit according to a first embodiment. FIG. 6 is a flowchart showing a cleaning method using the cleaning apparatus according to a first embodiment. FIG. 7 is a flowchart showing a cleaning method using the cleaning apparatus according to a first embodiment when carbon dioxide is used as the supercritical fluid and a protease is used as the additive. FIG. 8 is a flowchart showing a cleaning method using the cleaning apparatus according to a first embodiment, when a step of supplying a disinfectant to disinfect the object to be cleaned is added.

[0011] A cleaning device 100 and a cleaning method according to an embodiment will be described below with reference to the drawings. The following embodiment is merely an example, and the embodiment can be modified as appropriate. In the drawings, similar components are designated by the same reference numerals.

[0012] Embodiment 1. A cleaning apparatus 100 in embodiment 1 will be described with reference to Fig. 1. Fig. 1 is a schematic diagram of the cleaning apparatus 100 in embodiment 1. The cleaning apparatus 100 includes a cleaning tank 1, a supercritical fluid raw material supply unit 2, a supercritical fluid flow path 2a through which the supercritical fluid raw material flows, a supercritical fluid transport unit 3, a heating unit 4, a discharge unit 5, a control unit 6, an additive supply unit 7, an additive transport unit 8, a pressure measurement unit 9, a temperature measurement unit 10, and a separation unit 11.

[0013] The cleaning tank 1 includes a storage chamber, which is an internal space for storing an object to be cleaned. The cleaning tank 1 also includes a cleaning tank body 1a, the upper opening of which corresponds to the opening of the storage chamber, and a lid member 1b, which is attached to the upper opening in a liquid-tight and airtight manner. The cleaning tank 1 is designed to have sufficient pressure resistance to allow a supercritical fluid to be injected into it at a predetermined pressure.

[0014] The object to be cleaned is, for example, a medical device such as a catheter, a dialyzer, a plasma filter, a test tube for blood testing, a blood tube, a part of a large medical device, a small medical device, or a small medical device. When reusing a medical device, it is necessary to thoroughly remove any adhering body fluids, etc. Therefore, a supercritical fluid, which easily penetrates into micromechanisms and has a high solubility of hydrophobic substances, is suitable as a solvent for cleaning medical devices. Furthermore, the object to be cleaned is not limited to a medical device, and may also be, for example, a fibrous structure made of fibers, such as clothing or a futon.

[0015] The cleaning device 100 may also be provided with a lid member restricting portion that restricts the lid member 1b when pressurized, thereby preventing the lid member 1b from slipping out of the upper opening of the cleaning tank body 1a due to the pressure of the supercritical fluid injected into the cleaning tank 1.

[0016] The lid member restricting portion includes a member that restricts the movement of the bottom surface of the cleaning tank 1 and the top surface of the lid member 1b. The lid member restricting portion is, for example, a yoke. The lid member restricting portion includes a horizontal support member that supports the bottom surface of the cleaning tank 1 so that it cannot move, an upper horizontal member that restricts the lid member 1b of the cleaning tank 1 from protruding upward, and a vertical member that connects the horizontal support member and the upper horizontal member to each other.

[0017] The lid member restricting portion is provided in a position retracted from the cleaning tank 1 except during pressure treatment so that the lid member 1b can be removed from the cleaning tank body 1a. The lid member restricting portion may be provided on a rail so that it can be moved to a position where it restricts the lid member 1b and the cleaning tank body 1a when pressure treatment is performed.

[0018] The control unit 6 controls the heating unit 4, the exhaust unit 5, the pressure measuring unit 9, the temperature measuring unit 10, and various valves in the system. A personal computer or the like programmed with the process operations can be used as the control unit 6. The control method by the control unit 6 will be explained in the cleaning method described below.

[0019] Here, a supercritical fluid refers to a fluid in a region exceeding the critical temperature and critical pressure specific to the substance. Substances that can form supercritical fluids include, for example, carbon dioxide, nitrous oxide, ethane, and propane. FIG. 2 is a schematic phase diagram of carbon dioxide, showing the solid, liquid, gas, and supercritical states. In region A in FIG. 2, carbon dioxide is a solid. In region B in FIG. 2, carbon dioxide is a liquid. In region C in FIG. 2, carbon dioxide is a gas. In region D in FIG. 2, carbon dioxide is in a supercritical state. As shown in FIG. 2, carbon dioxide enters a supercritical state at a temperature higher than the critical temperature of 31° C. and at a pressure higher than the critical pressure of 7.4 MPa.

[0020] Figure 3 shows the critical temperatures and critical pressures of typical substances that reach a supercritical state. The supercritical fluid to be used is determined appropriately depending on the level and type of contaminants on the object to be cleaned. Carbon dioxide is often the preferred supercritical fluid because it has a relatively low critical temperature and has little impact on the environment when discharged as a gas.

[0021] Supercritical fluids have a viscosity, diffusion coefficient, density, and dissolving power intermediate between those of gases and liquids, allowing them to easily penetrate micromechanical structures and have high solubility for hydrophobic substances. This allows them to dissolve contaminants on the object being cleaned. Furthermore, supercritical fluids do not oxidize, hydrolyze, deteriorate, or alter plastics. Furthermore, supercritical fluids extract only a small amount of additives, such as plasticizers, in plastics, and can dissolve or decompose residual blood and proteins at low temperatures for removal. Furthermore, supercritical fluids of the above-listed substances are not harmful to workers. Furthermore, because they are originally compressed gases, supercritical fluids return to gas form when the pressure is returned to normal.

[0022] The supercritical fluid raw material supply unit 2 is a cylinder for the supercritical fluid raw material filled with a gas or liquid that will become a supercritical fluid. A supercritical fluid flow path 2a through which the supercritical fluid raw material flows connects the cleaning tank 1 and the supercritical fluid raw material supply unit 2. The supercritical fluid transport unit 3 is a pressure pump for pressurizing the supercritical fluid raw material into the cleaning tank 1. The supercritical fluid transport unit 3 pressurizes the supercritical fluid raw material to a pressure higher than the critical pressure of the supercritical fluid raw material. For example, when the supercritical fluid raw material is carbon dioxide, the supercritical fluid transport unit 3 pressurizes the supercritical fluid raw material to a pressure higher than 7.4 MPa, which is the critical pressure of carbon dioxide. The supercritical fluid transport unit 3 transports the supercritical fluid raw material supplied from the supercritical fluid raw material supply unit 2 to the cleaning tank 1 within the supercritical fluid flow path 2a. The supercritical fluid raw material supply unit 2 includes a supercritical fluid supply valve 2b in a supercritical fluid flow path 2a, and is capable of adjusting the supply amount of the supercritical fluid raw material.

[0023] The heating unit 4 is disposed between the supercritical fluid raw material supply unit 2 and the cleaning tank 1. The heating unit 4 includes a heating unit temperature measuring unit that measures the temperature of the heating unit 4. The control unit 6 receives a temperature detection signal output by the heating unit temperature measuring unit provided in the heating unit 4. The heating unit 4 heats the supercritical fluid raw material so that the temperature becomes higher than the critical temperature of the supercritical fluid raw material. For example, when the supercritical fluid raw material is carbon dioxide, the heating unit 4 heats the supercritical fluid raw material so that the temperature becomes higher than 31°C, which is the critical temperature of carbon dioxide. The heating unit 4 is formed, for example, by an electric heater or a hot water flow pipe. In many cases, an electric heater is used for the heating unit 4.

[0024] The additive supply unit 7 supplies an additive consisting of at least one component to the cleaning tank 1. An additive flow path 7a through which the additive flows connects the additive supply unit 7 with the section between the heating unit 4 and the cleaning tank 1 in the supercritical fluid flow path 2a. The additive supply unit 7 is provided with an additive supply valve 7b in the additive flow path 7a, and is capable of adjusting the amount of additive supplied. The additive is dissolved in the supercritical fluid and supplied to the cleaning tank 1. The additive is dissolved in the supercritical fluid in a non-supercritical state, i.e., not in a supercritical state.

[0025] Here, the additives in the first embodiment will be described. A single-component supercritical fluid cannot completely remove hydrophilic contaminants and proteinaceous contaminants. For example, when the object to be cleaned is a medical device, body fluids often adhere to the object. Therefore, it is necessary to remove the body fluids adhered to the object to be cleaned and reuse the object. However, a single-component supercritical fluid cannot completely remove hydrophilic contaminants and proteinaceous contaminants derived from body fluids. Therefore, when the object to be cleaned contains a large amount of hydrophilic contaminants or proteinaceous contaminants, it is necessary to use an additive appropriate for each contaminant. For example, polar substances, proteolytic enzymes, etc. are used as additives.

[0026] Examples of polar substances include water and alcohol. Examples of alcohol include methanol, ethanol, propanol, n-propanol, and isopropanol. Polar substances have polarity within their molecules. Hydrophilic contaminants generally have high solubility in polar substances, so polar substances dissolve the hydrophilic contaminants. This makes it possible to remove the hydrophilic contaminants from the object to be cleaned. The polar substances are transported to the cleaning tank 1 by dissolving in the supercritical fluid. At this time, the polar substances are supplied within a range that does not exceed their solubility in the supercritical fluid. This makes it possible to prevent the polar substances that have dissolved the contaminants from remaining in the cleaning tank 1.

[0027] Examples of protease include protease, amylase, lipase, and cellulase. Proteases are often preferred. When proteases are used as additives, they may be added together with water. Proteases act as catalysts, hydrolyzing proteins into smaller polypeptides or amino acids. This removes proteinaceous contaminants from the object being cleaned. Proteases are transported to the cleaning tank 1 by dissolving them in a supercritical fluid. The proteases are supplied within a range that does not exceed their solubility in the supercritical fluid. This prevents the proteases from remaining in the cleaning tank 1. Figure 4 also summarizes the enzyme deactivation temperatures of representative proteases. The enzyme deactivation temperature is the temperature at which the proteases are irreversibly thermally denatured and inactivated. When proteases are used as additives, the control unit 6 controls the heating unit 4 so that the temperature is lower than the enzyme deactivation temperature of the proteases.

[0028] The additive transport unit 8 is a pressure pump provided in the additive flow path 7a for pressurizing the additive. The additive transport unit 8 transports the additive between the heating unit 4 and the cleaning tank 1 within the supercritical fluid flow path 2a. When the heating unit 4 heats the supercritical fluid raw material to a target temperature equal to the critical temperature of the target supercritical fluid raw material, the temperature of the portion of the supercritical fluid flow path 2a where the heating unit 4 is located is higher than the target temperature. When the additive is transported, the additive dissolves in the supercritical fluid because the supercritical fluid flows within the supercritical fluid flow path 2a. At this time, the supercritical fluid flows within the supercritical fluid flow path 2a from the heating unit 4 toward the cleaning tank 1, so the additive is transported to the cleaning tank 1 without flowing through the portion of the supercritical fluid flow path 2a where the heating unit 4 is located.

[0029] The pressure measuring unit 9 employs a known means or device capable of measuring the pressure inside the cleaning tank 1 and outputting a pressure detection signal corresponding to the pressure inside the cleaning tank 1. The control unit 6 receives the pressure detection signal output by the pressure measuring unit 9, determines the amount of supercritical fluid to be injected into the cleaning tank 1, and controls the supply amount of the supercritical fluid raw material.

[0030] The temperature measuring unit 10 employs a known means or device capable of measuring the temperature inside the cleaning tank 1 and outputting a temperature detection signal corresponding to the temperature inside the cleaning tank 1. The control unit 6 inputs the temperature detection signal output from the temperature measuring unit 10.

[0031] The discharge unit 5 discharges the supercritical fluid in which contaminants on the object to be cleaned have been dissolved from the cleaning tank 1. This allows the contaminants on the object to be removed. The discharge unit 5 is formed, for example, with a discharge flow path 5a of the discharge unit that communicates from the cleaning tank 1 to the outside, and a discharge valve 5b arranged midway along the discharge flow path 5a. Furthermore, the control unit 6 controls the discharge unit 5 based on the pressure and temperature within the cleaning tank 1 so as to discharge the supercritical fluid while maintaining the supercritical state of the supercritical fluid.

[0032] The separation unit 11 receives the supercritical fluid discharged from the cleaning tank 1 by the discharge unit 5. The separation unit 11 can depressurize the supercritical fluid until it becomes a gaseous state. At this time, the supercritical fluid separates from the contaminants dissolved in the supercritical fluid. The contaminants separated from the supercritical fluid and turned into a solid or liquid are discharged from a separation unit discharge flow path 11a that communicates with the outside from the separation unit 11. A separation unit discharge valve 11b is disposed in the separation unit discharge flow path 11a, and the opening and closing of the separation unit discharge valve 11b is controlled by the control unit 6. The supercritical fluid separated from the contaminants is exhausted from a separation unit exhaust flow path 11c that communicates with the outside from the separation unit 11. A separation unit exhaust valve 11d is disposed in the separation unit exhaust flow path 11c, and the opening and closing of the separation unit exhaust valve 11d is controlled by the control unit 6.

[0033] The cleaning apparatus 100 may further include a sterilant supply unit 12 that supplies a sterilant to the cleaning tank 1 for sterilizing the object to be cleaned. FIG. 5 is a schematic diagram of the cleaning apparatus 100 including the sterilant supply unit 12 of the first embodiment. The sterilant may be, for example, water vapor, ethylene gas, or ethanol. A sterilant flow path 12a through which the sterilant flows connects the cleaning tank 1 and the sterilant supply unit 12. The sterilant is transported by a sterilant transport unit 13. The sterilant transport unit 13 is a pressure pump provided in the sterilant flow path 12a for pressurizing the sterilant into the cleaning tank 1. The sterilant transport unit 13 supplies the sterilant to the cleaning tank 1 when the supercritical fluid in which contaminants are dissolved is discharged from the cleaning tank 1 by the discharge unit 5. The sterilant supply unit 12 includes a sterilant supply valve 12b in the sterilant flow path 12a, which can adjust the amount of sterilant supplied.

[0034] Next, a cleaning method using the cleaning apparatus 100 according to the first embodiment will be described. FIG. 6 is a flowchart illustrating a cleaning method using the cleaning apparatus 100 according to the first embodiment. In step S101, the control unit 6 controls the supercritical fluid source supply unit 2 to supply a supercritical fluid source to the cleaning tank 1 containing the object to be cleaned. When supplying the supercritical fluid source, the control unit 6 controls the supercritical fluid supply valve 2b to adjust the supply amount of the supercritical fluid source. The control unit 6 also controls the supercritical fluid transport unit 3 to transport the supercritical fluid source supplied from the supercritical fluid source supply unit 2 to the cleaning tank 1 through the supercritical fluid flow path 2a. In step S102, the control unit 6 controls the heating unit 4 disposed between the cleaning tank 1 and the supercritical fluid source supply unit 2 to heat the supercritical fluid source to form a supercritical fluid. In step S103, the control unit 6 controls the additive supply unit 7 to supply an additive to the cleaning tank 1. When supplying the additive, the control unit 6 controls the additive supply valve 7b to adjust the supply amount of the additive. The control unit 6 also controls the additive transport unit 8 to transport the additive in a non-supercritical state between the heating unit 4 and the cleaning tank 1 through the additive flow path 7a while the supercritical fluid is being transported in the supercritical fluid flow path 2a connecting the cleaning tank 1 and the supercritical fluid supply unit. In step S104, the control unit 6 controls the discharge unit 5 to discharge the supercritical fluid from the cleaning tank 1. Based on the pressure detection signal output by the pressure measurement unit 9 and the temperature detection signal output by the temperature measurement unit 10, the control unit 6 controls the discharge unit 5 to discharge the supercritical fluid from the cleaning tank 1 while maintaining the supercritical state of the supercritical fluid.

[0035] 7 is a flowchart showing a cleaning method using the cleaning apparatus 100 of embodiment 1 when carbon dioxide is used as the supercritical fluid and a protease is used as the additive. In step S111, the control unit 6 controls the supercritical fluid raw material supply unit 2 to supply gaseous or liquid carbon dioxide to the cleaning tank 1 containing the object to be cleaned. In step S112, the control unit 6 controls the heating unit 4, which is disposed between the cleaning tank 1 and the supercritical fluid raw material supply unit 2, to heat the gaseous or liquid carbon dioxide to form a supercritical fluid. In step S113, the control unit 6 controls the additive transport unit 8 to transport a non-supercritical protease between the heating unit 4 and the cleaning tank 1 while supercritical carbon dioxide is being transported through the supercritical fluid flow path 2a connecting the cleaning tank 1 and the supercritical fluid supply unit. In step S114, the control unit 6 controls the heating unit 4 so that the temperature of the carbon dioxide transported to the cleaning tank 1 is higher than the critical temperature of carbon dioxide but lower than the enzyme deactivation temperature, at which the protease is deactivated. In step S115 , the control unit 6 controls the discharge unit 5 to discharge the carbon dioxide in a supercritical fluid state from the cleaning tank 1 .

[0036] 8 is a flowchart showing a cleaning method using the cleaning apparatus 100 of the first embodiment, when a step of supplying a sterilizing agent to sterilize the object to be cleaned is added. Steps S121 to S124 are the same as steps S101 to S104, respectively. In step S125, the control unit 6 controls the sterilizing agent supply unit 12 to supply the sterilizing agent to the cleaning tank 1 for sterilizing the object to be cleaned. When supplying the sterilizing agent, the control unit 6 controls the sterilizing agent supply valve 12b to adjust the amount of sterilizing agent supplied. The control unit 6 also controls the sterilizing agent transport unit 13 to transport the sterilizing agent supplied from the sterilizing agent supply unit 12 to the cleaning tank 1 through the sterilizing agent flow path 12a.

[0037] As described above, the cleaning apparatus 100 of the first embodiment includes an additive transporter 8 that transports a non-supercritical additive between the heating unit 4 and the cleaning tank 1 within the supercritical fluid flow path 2a through which the supercritical fluid flows, and a control unit 6 that controls the additive transporter 8 to transport the additive while the supercritical fluid transporter 3 transports the supercritical fluid. With the above configuration, the additive is transported to the cleaning tank 1 without flowing through the portion of the supercritical fluid flow path 2a where the heating unit 4 is located, and therefore the additive is not heated by the heating unit 4. This eliminates the need to heat the additive together with the supercritical fluid raw material, thereby improving energy efficiency during heating. Furthermore, when an additive that is deactivated by heat is used, the additive can be prevented from being deactivated by heating. Therefore, contaminants on the object to be cleaned can be efficiently removed.

[0038] Furthermore, the control unit 6 controls the discharge unit 5 to discharge the supercritical fluid while maintaining the supercritical state of the supercritical fluid, based on the pressure and temperature in the cleaning tank 1. With the above configuration, the supercritical fluid and the contaminants dissolved in the supercritical fluid are not separated from each other in the cleaning tank 1, and therefore, it is possible to prevent the contaminants from re-adhering to the object to be cleaned.

[0039] Furthermore, the separation unit 11 separates the supercritical fluid discharged from the cleaning tank 1 by the discharge unit 5 from the contaminants dissolved in the supercritical fluid. With the above configuration, the contaminants separated from the supercritical fluid and turned into a solid or liquid are discharged from the separation unit discharge flow path 11a communicating with the outside from the separation unit 11, thereby preventing the contaminants from reattaching to the object to be cleaned and the equipment piping.

[0040] The additive may also be a protease. The above-described configuration makes it possible to remove proteinaceous contaminants from the object to be cleaned that cannot be completely removed by a single-component supercritical fluid. This allows for efficient removal of contaminants from the object to be cleaned. When a protease is used as an additive, it may be added together with water. This can promote hydrolysis of proteinaceous contaminants by the protease.

[0041] Alternatively, the additive may be a protease, and carbon dioxide, which has a relatively low critical temperature, may be used as the supercritical fluid raw material. In this case, the control unit 6 controls the heating unit 4 so that the temperature of the carbon dioxide transported to the cleaning tank 1 is higher than the critical temperature of carbon dioxide but lower than the enzyme deactivation temperature. This configuration allows the carbon dioxide to be brought to a supercritical state, and the protease can be dissolved in the supercritical carbon dioxide without being deactivated. This allows for efficient removal of contaminants from the object to be cleaned.

[0042] The additive may also be a polar substance. By adopting the above configuration, it is possible to remove hydrophilic contaminants from the object to be cleaned that cannot be completely removed by a single-component supercritical fluid. This allows for efficient removal of contaminants from the object to be cleaned.

[0043] Furthermore, the sterilizing agent supply unit 12 supplies the sterilizing agent to the cleaning tank 1 when the discharge unit 5 discharges the supercritical fluid from the cleaning tank 1. With the above configuration, the object to be cleaned can be sterilized after the contaminants on the object to be cleaned are removed by the supercritical fluid, thereby improving the cleaning performance of the cleaning device 100.

[0044] The cleaning method using the cleaning apparatus 100 of the first embodiment includes the steps of: supplying a supercritical fluid raw material by the supercritical fluid raw material supply unit 2; heating the supercritical fluid raw material to form a supercritical fluid by the heating unit 4 disposed between the cleaning tank 1 containing the object to be cleaned and the supercritical fluid raw material supply unit 2; transporting an additive in a non-supercritical state between the heating unit 4 and the cleaning tank 1 by the additive transport unit 8 within the supercritical fluid flow path 2a connecting the cleaning tank 1 and the supercritical fluid supply unit and through which the supercritical fluid flows; and discharging the supercritical fluid from the cleaning tank 1 by the discharge unit 5. This prevents the additive from being heated by the heating unit 4, allowing efficient removal of contaminants from the object to be cleaned.

[0045] Although the description has been given assuming that the supercritical fluid separated from the contaminants is exhausted from the separation unit exhaust passage 11c communicating with the outside from the separation unit 11, this is not limiting. That is, the supercritical fluid may be circulated without being exhausted. When circulating the supercritical fluid without being exhausted, the separation unit exhaust passage 11c may be arranged so as to communicate between the supercritical fluid raw material supply unit 2 and the heating unit 4. Even in this case, the additive is not heated by the heating unit 4, and therefore the same effect of efficiently removing contaminants from the object to be cleaned can be achieved.

[0046] 1 Cleaning tank, 1a Cleaning tank body, 1b Lid member, 2 Supercritical fluid raw material supply unit, 2a Supercritical fluid flow path, 2b Supercritical fluid supply valve, 3 Supercritical fluid transport unit, 4 Heating unit, 5 Discharge unit, 5a Discharge unit discharge flow path, 5b Discharge unit discharge valve, 6 Control unit, 7 Additive supply unit, 7a Additive flow path, 7b Additive supply valve, 8 Additive transport unit, 9 Pressure measurement unit, 10 Temperature measurement unit, 11 Separation unit, 11a Separation unit discharge flow path, 11b Separation unit discharge valve, 11c Separation unit exhaust flow path, 11d Separation unit exhaust valve, 12 Sterilant supply unit, 12a Sterilant flow path, 12b Sterilant supply valve, 13 Sterilant transport unit

Claims

1. A pressure-resistant cleaning tank for accommodating an object to be cleaned, a supercritical fluid raw material supply unit for supplying a supercritical fluid raw material, a supercritical fluid flow path connecting the cleaning tank and the supercritical fluid raw material supply unit through which the supercritical fluid raw material flows, a supercritical fluid transport unit in the supercritical fluid flow path for pressurizing the supercritical fluid raw material and transporting the supercritical fluid raw material to the cleaning tank, a heating unit arranged between the supercritical fluid raw material supply unit and the cleaning tank for heating the supercritical fluid raw material into a supercritical fluid, an additive supply unit for supplying an additive composed of at least one component and being in a non-supercritical state that is not in a supercritical state, an additive flow path connecting between the heating unit and the cleaning tank in the supercritical fluid flow path and the additive supply unit through which the additive flows, an additive transport unit provided in the additive flow path for transporting the non-supercritical additive between the heating unit and the cleaning tank in the supercritical fluid flow path, and a control unit for controlling the additive transport unit to transport the additive when the supercritical fluid transport unit is transporting the supercritical fluid. A cleaning device characterized by comprising the above components.

2. The cleaning device according to claim 1, wherein the additive is a proteolytic enzyme.

3. The supercritical fluid raw material is carbon dioxide, and the control unit controls the heating unit so that the temperature of the carbon dioxide transported to the cleaning tank is higher than the critical temperature of the carbon dioxide and lower than the enzyme inactivation temperature at which the proteolytic enzyme is inactivated. The cleaning device according to claim 2, characterized by the above.

4. The cleaning device according to claim 1, wherein the additive is a polar substance.

5. Further comprising a pressure measurement unit for measuring the pressure in the cleaning tank, a temperature measurement unit for measuring the temperature in the cleaning tank, and a discharge unit for discharging the supercritical fluid from the cleaning tank, and the control unit controls the discharge unit to discharge the supercritical fluid while maintaining the supercritical state of the supercritical fluid based on the pressure and temperature in the cleaning tank. The cleaning device according to any one of claims 1 to 4, characterized by the above.

6. The cleaning apparatus according to any one of claims 1 to 5, further comprising a discharge unit that discharges the supercritical fluid from the cleaning tank, and a separation unit that separates the supercritical fluid discharged from the cleaning tank by the discharge unit and contaminants dissolved in the supercritical fluid.

7. The cleaning apparatus according to any one of claims 1 to 6, further comprising a discharge unit that discharges the supercritical fluid from the cleaning tank, and a disinfectant supply unit that supplies a disinfectant for sterilizing the object to be cleaned to the cleaning tank when the discharge unit discharges the supercritical fluid from the cleaning tank.

8. A cleaning method comprising: a step of supplying a supercritical fluid raw material from a supercritical fluid raw material supply unit to a cleaning tank in which an object to be cleaned is accommodated; a step of heating the supercritical fluid raw material by a heating unit disposed between the supercritical fluid raw material supply unit and the cleaning tank to obtain a supercritical fluid; and a step of transporting an additive in a non-supercritical state between the heating unit and the cleaning tank when the supercritical fluid is being transported in a supercritical fluid flow path connecting the supercritical fluid raw material supply unit and the cleaning tank.

9. The cleaning method according to claim 8, comprising a step of controlling the heating unit such that the temperature of the carbon dioxide transported to the cleaning tank is higher than the critical temperature of the carbon dioxide and lower than the enzyme inactivation temperature at which the proteolytic enzyme is inactivated, wherein the supercritical fluid raw material is carbon dioxide and the additive is a proteolytic enzyme.

10. The cleaning method according to claim 8 or 9, comprising a step of supplying a disinfectant for sterilizing the object to be cleaned to the cleaning tank when the supercritical fluid is discharged from the cleaning tank.

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