Method for using machine oil, machine oil regeneration system, and method for adding machine oil regeneration unit

Abstract

The method for using a machine oil used for at least one of lubrication and power transmission comprises: a first oxidation stability determination step for determining whether the oxidation stability of an in-use or used machine oil is equal to or higher than a first prescribed level; a first continuing use step for continuing to use the in-use or used machine oil when it is determined that the oxidation stability is equal to or higher than the first prescribed level; an addition step for adding an additive for regeneration to the machine oil so that the oxidation stability is equal to or higher than a second prescribed level when it is determined that the oxidation stability is lower than the first prescribed level; and a second continuing use step for continuing to use the machine oil to which the additive has been added.

Description

How to use machine oil, machine oil regeneration system, and how to install a machine oil regeneration unit

[0001] This disclosure relates to a method for using machine oil, a machine oil regeneration system, and a method for installing a machine oil regeneration unit. This application claims priority to Japanese Patent Application No. 2023-107817, filed with the Japan Patent Office on June 30, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 describes a method for regenerating used insulating oil. Specifically, the method involves bringing an adsorbent containing one or more of lime plaster, diatomaceous earth, bentonite, and marine silt into contact with used insulating oil to adsorb degraded components in the insulating oil, removing the adsorbent from the insulating oil, and adding an antioxidant to the insulating oil to obtain regenerated insulating oil.

[0003] WO 2018 / 164188

[0004] According to the method of Patent Document 1, it is possible to regenerate insulating oil, but it is not known whether it is possible to regenerate machine oil used for at least one of lubrication and power transmission.

[0005] The present disclosure provides a method for using machine oil that allows for continuous use of machine oil without disposal, a machine oil regeneration system, and a method for adding a machine oil regeneration unit.

[0006] A method of using machine oil according to at least one embodiment of the present disclosure is a method of using machine oil for at least one of lubrication and power transmission, and comprises: a first oxidation stability determination step of determining whether the oxidation stability of the machine oil in use or that has been used is equal to or greater than a first specified level; a first continued use step of continuing to use the machine oil in use or that has been used if it is determined that the oxidation stability is equal to or greater than the first specified level; an addition step of adding a regeneration additive to the machine oil so that the oxidation stability becomes equal to or greater than a second specified level if it is determined that the oxidation stability is below the first specified level; and a second continued use step of continuing to use the machine oil with the additive added.

[0007] A machine oil regeneration system according to at least one embodiment of the present disclosure includes: a tank for storing in-use or used machine oil for at least one of lubrication and power transmission; an adsorption system including a column filled with an adsorbent; an oil circulation path for circulating the machine oil between the column and the tank; and an oil circulation pump disposed in the oil circulation path, the adsorption system configured to perform an adsorption process in which the machine oil comes into contact with the adsorbent by driving the oil circulation pump; and an additive supply device configured to be able to add a regeneration additive to the machine oil regardless of whether the adsorption process is being performed.

[0008] A method for installing a machine oil recycling unit according to at least one embodiment of the present disclosure is a method for installing a machine oil recycling unit for recycling in-use or used machine oil stored in a tank for at least one of lubrication and power transmission, and includes a column installation step of installing a column filled with an adsorbent, an oil circulation path installation step of installing an oil circulation path for circulating the machine oil between the column and the tank, a pump installation step of installing an oil circulation pump in the oil circulation path, and an additive supply device installation step of installing an additive supply device configured to be able to add a recycling additive to the machine oil.

[0009] According to the present disclosure, it is possible to provide a method for using machine oil that allows machine oil to be used continuously without being discarded, a machine oil recycling system, and a method for adding a machine oil recycling unit.

[0010] FIG. 1 is a schematic diagram showing a schematic configuration of a machine oil regeneration system according to one embodiment; FIG. 2 is a flowchart showing a method of using machine oil according to one embodiment; FIG. 3 is a graph showing a relationship between the RPVOT residual rate and the acid number for machine oil in use or that has been used; FIG. 4 is a flowchart showing a method of using machine oil with additional steps according to one embodiment; FIG. 5 is a schematic diagram showing details of a machine oil regeneration system according to a first embodiment; FIG. 6 is a schematic diagram showing details of a machine oil regeneration system according to a second embodiment; FIG. 7 is a schematic diagram showing details of a machine oil regeneration system according to a third embodiment; FIG. 8 is a schematic diagram showing details of a machine oil regeneration system according to a fourth embodiment; FIG. 9 is a schematic diagram showing details of a machine oil regeneration system according to a fifth embodiment; FIG. 10 is a schematic diagram of a column according to the first embodiment; FIG. 11 is a schematic diagram of a column according to the second embodiment; FIG. 12 is a schematic diagram showing a machine oil regeneration system before modification according to one embodiment; FIG. 13 is a flowchart showing a method of adding a machine oil regeneration unit according to one embodiment.

[0011] Several embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure and are merely illustrative examples. For example, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express relative displacements with a tolerance or angle or distance to the extent that the same function is achieved. For example, expressions expressing the equality of things, such as "same," "equal," and "homogeneous," not only express strict equality, but also express tolerance or differences to the extent that the same function is achieved. For example, expressions expressing shapes such as a square or cylindrical shape not only express shapes such as a square or cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is achieved. On the other hand, the expressions "comprise," "include," or "have" one component are not exclusive expressions that exclude the existence of other components. Note that similar components may be assigned the same reference numerals and descriptions thereof may be omitted.

[0012] <Overview of Machine Oil Regeneration System 1> Figure 1 is a schematic diagram showing the general configuration of a machine oil regeneration system 1 according to one embodiment of the present disclosure. The machine oil regeneration system 1 is configured to perform a regeneration process on machine oil 9 used by a machine oil-using device 100. The machine oil 9 is a lubricating oil used to ensure smooth operation of moving parts that make up the machine oil-using device 100, or a hydraulic oil used in a hydraulic power transmission unit that makes up the machine oil-using device 100.

[0013] As an example, the machine oil-using device 100 is a turbine such as a steam turbine or a gas turbine, and the lubricating oil is mainly turbine oil supplied to the turbine rotor, etc. As another example, the machine oil-using device 100 is a hydraulic cylinder, and hydraulic oil is supplied to the inside of the hydraulic cylinder.

[0014] Note that lubricating oils and hydraulic oils are not limited to the above uses. Lubricating oils may also perform other functions, such as cooling moving parts, in addition to lubricating moving parts. Hydraulic oils may also perform other functions, such as lubricating and cooling moving parts, in addition to transmitting power.

[0015] Machine oil 9 deteriorates with use. For example, the longer turbine oil is used, the more degraded components, such as organic acids such as carboxylic acids, and degraded antioxidants, the more the turbine oil contains, causing its color to turn brown. In this case, the lubricating performance and other oil performance of the turbine oil deteriorates. A similar deterioration phenomenon has also been observed in hydraulic oil. The machine oil regeneration system 1 of this embodiment is configured to regenerate machine oil 9 to prevent partially used or used machine oil 9 from being discarded due to deterioration. The regeneration process includes at least one of adding an additive 6 to the machine oil 9 and bringing the machine oil 9 into contact with an adsorbent 8 (details will be described later).

[0016] Continuing to refer to Figure 1, the configuration of the machine oil recycling system 1 will be outlined. The machine oil recycling system 1 includes a tank 10 for storing machine oil 9 used in a machine oil-using device 100, an adsorption system 3 for performing an adsorption process in which the machine oil 9 is brought into contact with an adsorbent 8, and an additive supply device 50 for adding an additive 6 to the machine oil 9.

[0017] Machine oil 9 flows into the tank 10 from the machine oil-using device 100 via an oil discharge path 101. The machine oil 9 stored in the tank 10 is supplied to the machine oil-using device 100 via an oil supply path 102. In this example, the machine oil 9 is supplied from the tank 10 to the machine oil-using device 100 by operating a supply pump 105 arranged in the oil supply path 102. The number of tanks 10 may be one or more (a single tank 10 is illustrated in FIG. 1 ). The tank 10 may also be provided with an agitator 130 for agitating the machine oil 9.

[0018] The adsorption system 3 includes a column 7 filled with an adsorbent 8, an oil circulation path 40 for circulating machine oil 9 between the column 7 and a tank 10, and an oil circulation pump 48 arranged in the oil circulation path 40. The oil circulation path 40 has a supply path 41 for supplying the machine oil 9 from the tank 10 to the column 7, and a return path 42 for returning the machine oil 9 from the column 7 to the tank 10. The oil circulation pump 48 is arranged in the supply path 41. A filter 4 for collecting the adsorbent 8 flowing out from the column 7 may be arranged in the return path 42.

[0019] The number of columns 7 may be one or more (a single column 7 is illustrated in FIG. 1). The adsorbent 8 packed in the column 7 is silica gel, zeolite, activated alumina, activated clay, kaolin, or any combination thereof. The silica gel may also be spherical silica gel or silica gel modified with an amino group.

[0020] An overview of the adsorption process performed by the adsorption system 3 is as follows: The machine oil 9 stored in the tank 10 flows into the column 7 via the supply path 41 by operation of the oil circulation pump 48. The machine oil 9 flowing through the column 7 is subjected to an adsorption process by coming into contact with the adsorbent 8. More specifically, the deteriorated components contained in the machine oil 9 are adsorbed by the adsorbent 8, and the deteriorated components are removed from the machine oil 9. The machine oil 9 discharged from the column 7 returns to the tank 10 via the return path 42. In this way, the deteriorated components are removed from the machine oil 9 in the tank 10, and the degree of deterioration due to oxidation of the machine oil 9 can be reduced (details of the degree of deterioration will be described later).

[0021] The additive supply device 50 is configured to be able to add a regenerating additive 6 to the machine oil 9. The additive supply device 50 may be configured to directly supply the additive 6 to the machine oil 9 in the tank 10, or may be configured to supply the additive 6 to the machine oil 9 flowing through the return line 42. The additive 6 is an antioxidant, a rust inhibitor, an antifoaming agent, an anti-friction agent, an extreme pressure agent, a metal deactivator, an anti-emulsifier, or any combination thereof. The addition of the additive 6 restores the oxidation stability of the machine oil 9 (oxidation stability will be described in detail later).

[0022] The additive supply device 50 is configured to add the additive 6 to the machine oil 9 regardless of whether the adsorption treatment is being performed or not. That is, the additive supply device 50 can add the additive 6 while the machine oil 9 is passing through the column 7, or can add the additive 6 while the machine oil 9 is not passing through the column 7.

[0023] The inventors discovered that to continuously use the machine oil 9 while avoiding significant oil degradation, it is sufficient to subject the machine oil 9 to adsorption treatment and additive 6 addition treatment from time to time (details of this will be described later with reference to FIG. 3). In this regard, with the above-described configuration, the adsorption system 3 can perform the adsorption treatment, and the additive supply device 50 can add the additive 6. This allows the machine oil 9 to be continuously used without being discarded. Furthermore, the inventors discovered that the period during which the adsorption treatment is required as the degree of deterioration due to oxidation increases can be made longer than the period during which the addition of additive 6 is required as oxidation stability decreases. For example, if the machine oil 9 is turbine oil, the period during which the adsorption treatment is required can be adjusted to between five and six times the period during which additive 6 is required. In this regard, with the above-described configuration, the additive supply device 50 can also perform the process of adding additive 6 without performing the adsorption treatment in the adsorption system 3. This allows the timing of the adsorption treatment and the additive addition treatment to be optimized, thereby realizing a machine oil regeneration system 1 that avoids unnecessary regeneration treatment of the machine oil 9.

[0024] <Outline of Method for Using Machine Oil 9> A method for continuously using machine oil 9 using the machine oil regeneration system 1 will be outlined with reference to Fig. 2. Fig. 2 is a flowchart showing a method for using machine oil 9 according to one embodiment of the present disclosure, and in the example shown in the figure, regeneration processing of machine oil 9 is performed only by adding additives 6, without performing adsorption processing by the adsorption system 3. In the following description, "step" may be abbreviated as "S".

[0025] First, a first oxidation stability determination step (S11) is executed to determine whether the oxidation stability of the partially used or used machine oil 9 is equal to or greater than a first specified level. For example, an operator periodically samples the machine oil 9 from the tank 10 to evaluate the oxidation stability of the machine oil 9. More specifically, the oxidation stability of the machine oil 9 is evaluated based on the RPVOT residual rate of the machine oil 9. Here, the RPVOT residual rate indicates the ratio of the RPVOT value of the used machine oil 9 to the RPVOT value of the unused machine oil 9. The RPVOT value is measured by an operator using various measuring instruments in accordance with the "Rotating Pressure Vessel Oxidation Stability" standard in JIS K 2514-3. The RPVOT residual rate is a value between 0% and 100%. As the degree of deterioration of the machine oil 9 due to oxidation increases, the RPVOT residual rate gradually decreases. In S11, if the RPVOT residual rate is equal to or greater than a first threshold, the oxidation stability is determined to be equal to or greater than a first specified level. The first threshold is determined based on the relationship shown in FIG. 3. For oil types such as those shown in the figure, in which the acid value increases sharply when the RPVOT residual rate falls below 50%, the first threshold is 50% or greater, and more specifically, 70% or greater. In this way, the first threshold is set appropriately depending on the relationship between the RPVOT residual rate and the acid value.

[0026] If it is determined that the oxidation stability is equal to or higher than the first specified level (S11: YES), a first continued use step (S13) is executed to continue using the partially used or used machine oil 9. More specifically, if the supply pump 105 was stopped before the start of this flowchart, the supply pump 105 may resume operation in response to a positive determination in S11. Alternatively, if the supply pump 105 continues to operate after the start of this flowchart, the positive determination in S11 may be used to input a command to the supply pump 105 indicating further continued operation. After S13 is executed, the process returns to S11.

[0027] As the machine oil 9 continues to be used, it is eventually determined that the oxidation stability is below the first specified level (S11: NO). In this case, an addition step is executed to add the additive 6 to the machine oil 9 so that the oxidation stability becomes equal to or higher than the second specified level (S51). In accordance with a command input by the operator or the controller, the machine oil-using device 100 adds the additive 6 to the machine oil 9. This restores the oxidation stability.

[0028] After S51 is performed, it is determined whether the oxidation stability of the machine oil 9 is equal to or greater than a second specified level (S53). More specifically, it is determined whether the RPVOT residual rate is equal to or greater than a second threshold. The second threshold may be any value equal to or greater than the first threshold, and in this example, it is a value greater than the first threshold. That is, in this example, the second specified level is higher than the first specified level. If it is determined that the oxidation stability is less than the second specified level (S53: NO), the process returns to S51. If it is determined that the oxidation stability is equal to or greater than the second specified level (S53: YES), a second continued use step (S55) is performed, in which the machine oil 9 to which the additive 6 has been added is continued to be used. S55 is a step similar to S13, and thereafter, the process returns to S11.

[0029] Here, new additives 6 are sequentially added in S51, and by repeating S51 and S53, the oxidation stability almost certainly returns to the second specified level or higher. Therefore, according to the above-described method of use, the machine oil 9 can be used continuously for a long period of time. For example, it is possible to continue using the machine oil 9 for several years or more.

[0030] The evaluation of oxidation stability performed in S11 and S53 may be performed using a parameter other than the RPVOT residual rate, such as the kinematic viscosity of the machine oil 9. Furthermore, the present disclosure is not limited to directly measuring the RPVOT residual rate, and oxidation stability may be evaluated by sensing a parameter correlated with the RPVOT residual rate. In this case, S11 and S53 may be performed by a controller instead of an operator.

[0031] The inventors have discovered that if additive 6 is added to machine oil 9 from time to time so that the oxidation stability of machine oil 9 is maintained at a certain level or above, machine oil 9 can be used continuously while maintaining its oil performance. Specifically, the inventors have obtained the findings shown in FIG. 3. This figure is a graph showing the relationship between RPVOT residual rate and acid value, obtained by the inventors through testing of used machine oil 9 (more specifically, turbine oil). As can be seen from the graph, when the RPVOT residual rate of machine oil 9 falls below 50%, the acid value of machine oil 9, which is an indicator of the degree of deterioration due to oxidation, increases sharply. In other words, it has been found that if additive 6 is added repeatedly so that the RPVOT residual rate of machine oil 9 does not fall below 50%, machine oil 9 can be used continuously while suppressing the degree of deterioration of machine oil 9.

[0032] 2, even if the oxidation stability of the machine oil 9 falls below the first specified level, the oxidation stability of the machine oil 9 can be restored to the second specified level or higher by performing step (S51) of adding the additive 6. This allows the degree of deterioration of the machine oil 9 due to oxidation to be maintained at the initial level, allowing the machine oil 9 to be used continuously without being discarded.

[0033] <Method of Using Machine Oil 9 Including Additional Steps> Figure 4 is a flowchart showing a method of using machine oil 9 including additional steps according to an embodiment of the present disclosure. In Figure 4, the same steps as in Figure 2 are assigned the same step numbers, and their descriptions will be omitted or simplified below. In Figure 4, in addition to the steps shown in Figure 2, steps S21 to S29 are executed, and these steps are related to the adsorption process.

[0034] S21 is executed when a negative determination is made in S11. In S21, it is determined whether the degree of deterioration due to oxidation of the partially used or used machine oil 9 is below a first degree of deterioration. The degree of deterioration due to oxidation is, for example, the acid value. If the acid value is below the first acid value threshold, it is determined that the degree of deterioration is below the first degree of deterioration. Conversely, if the acid value is equal to or greater than the first acid value threshold, it is determined that the degree of deterioration is equal to or greater than the first degree of deterioration. An example of the first acid value threshold is 0.1 mgKOH / g. The acid value is measured by an operator using various measuring instruments in accordance with JIS K2501:2003.

[0035] If it is determined that the deterioration degree is equal to or greater than the first degree (S21: NO), an adsorption step (S23) is executed to subject the machine oil 9 to an adsorption treatment. More specifically, the oil circulation pump 48 is operated to cause the machine oil 9 to flow into the column 7, and the adsorption treatment is executed.

[0036] After S23 is executed, it is determined whether the deterioration degree of the machine oil 9 falls below the second deterioration degree (S25). More specifically, it is determined whether the acid value falls below the second acid value threshold. The second acid value threshold may be any value equal to or less than the first acid value threshold, and in this example, it is the same value as the first acid value threshold. If it is determined that the deterioration degree falls below the second deterioration degree (S25: YES), the above-mentioned step of adding the additive 6 to the machine oil 9 (S51) is executed.

[0037] If the deterioration level is equal to or higher than the second level (S25: NO), it is determined whether the number of consecutive executions of the adsorption process (N) is equal to or higher than a specified number. If N is less than the specified number (S27: NO), S23 and S25 are executed again in this order. Note that N is the number of consecutive executions of S23 and S25.

[0038] According to the inventor's findings, when the adsorbent 8 is used continuously for a long period of time, deteriorated components accumulate in the adsorbent 8, causing the adsorption capacity of the adsorbent 8 to decrease. In this case, even if the adsorption process (S23) is repeatedly performed, the degree of deterioration does not fall below the second degree of deterioration (S25: NO), and N reaches a predetermined number of times (S27: YES). At this time, the column 7 filled with the adsorbent 8 is replaced with a new column 7 (S29). The process then returns to S23. After the column 7 is replaced, sufficient adsorption capacity is exerted in S23, the degree of deterioration falls below the second degree of deterioration (S25: YES), and the above-mentioned S51 is executed. Note that N is initialized to 0 when S29 is executed.

[0039] The present disclosure is not limited to the evaluation of the degree of deterioration performed in S21 and S25 being performed through the acid value. For example, the degree of deterioration may be evaluated by sensing a parameter correlated with the acid value. In this case, S21 and S25 may be performed by a controller instead of an operator.

[0040] 4 , when it is determined that the deterioration level of the machine oil 9 is below the first deterioration level (S21: YES), a step (S51) of adding the additive 6 is executed. According to the inventor's knowledge, even if the machine oil 9 is continuously used while adding the additive 6, the deterioration level of the machine oil 9 increases due to oxidation. In this regard, according to the above configuration, the addition step (S51) is executed on the machine oil 9 whose deterioration level has been suppressed, so that it is possible to avoid a problem in which the deterioration level due to oxidation does not return to normal even when the addition step is executed.

[0041] 4, even if the degree of deterioration falls below the second degree of deterioration (S25: YES) as a result of the adsorption process (S23), the step (S51) of adding the additive 6 is executed. When the degree of deterioration of the machine oil 9 is high, the adsorption process (S23) is executed before the addition step (S51), so that the degree of deterioration due to oxidation of the machine oil 9 can be reliably maintained at the initial degree.

[0042] 4, if the deterioration level does not fall below the second level (NO in S25, YES in S27) even after repeated adsorption treatment (S23), the column 7 filled with the adsorbent 8 is replaced (S29). If the adsorption capacity of the adsorbent 8 decreases due to continued use, the adsorbent 8 can be replaced, so that effective adsorption treatment can be continuously maintained. This allows the machine oil 9 to be used for a longer period of time.

[0043] <Examples of Specific Configurations of Machine Oil Regeneration System 1> Specific configurations of machine oil regeneration systems 1 according to several embodiments are illustrated with reference to Figures 5A to 5E. Figure 5A schematically illustrates a machine oil regeneration system 1A(1) according to a first embodiment, Figure 5B illustrates a machine oil regeneration system 1B(1) according to a second embodiment, Figure 5C illustrates a machine oil regeneration system 1C(1) according to a third embodiment, Figure 5D illustrates a machine oil regeneration system 1D(1) according to a fourth embodiment, and Figure 5E illustrates a machine oil regeneration system 1E(1) according to a fifth embodiment.

[0044] As shown in Figures 5A to 5D, the machine oil regeneration system 1A to 1D (1) includes a tank 10A to 10D (10), an additive supply device 50A to 50D (50), and an oil circulation path 40A to 40D (40).

[0045] The additive supply devices 50A to 50D (50) are configured to supply the additive 6 to the interiors of the tanks 10A to 10D (10) via an additive supply path 55 that is different from the oil circulation paths 40A to 40D (40). The additive supply path 55 may be a pipe connected to the tanks 10A to 10D, or may be a space (area) through which the additive 6 passes when it falls. The additive 6 flows into the tanks 10A to 10D at a position away from both the connection position C1 between the supply path 41 and the tanks 10A to 10D and the connection position C2 between the return path 42 and the tanks 10A to 10D.

[0046] The process of adding the additive 6 is carried out at a location separate from the oil circulation path 40 where the adsorption process is carried out. This makes it easy to carry out the process of adding the additive 6 separately from the adsorption process.

[0047] 5A to 5C, the tanks 10A to 10C include a first tank 11 and a second tank 12. The first tank 11 is connected to each of the oil discharge passage 101 and the oil supply passage 102. That is, the first tank 11 is configured to store the machine oil 9 discharged from the machine oil using device 100, and is also configured to release the machine oil 9 toward the machine oil using device 100.

[0048] The second tank 12 is disposed separately from the first tank 11. An oil circulation path 40 is connected to the second tank 12. That is, the machine oil 9 stored in the second tank 12 is supplied to the column 7 via a supply path 41, and the machine oil 9 flowing out from the column 7 is returned to the column 7 via a return path 42.

[0049] The machine oil regeneration systems 1A to 1C each include a connection flow path unit 60 that connects a first tank 11 and a second tank 12. The connection flow path unit 60 includes a first oil flow path 61 for guiding the machine oil 9 from the first tank 11 to the second tank 12, a first pump 63 disposed in the first oil flow path 61, a second oil flow path 62 for guiding the machine oil 9 from the second tank 12 to the first tank 11, and a second pump 64 disposed in the second oil flow path 62. When a regeneration process for the machine oil 9 is performed, the first pump 63 is driven, and the machine oil 9 flows from the first tank 11 to the second tank 12. The regenerated machine oil 9 in the second tank 12 is returned to the first tank 11 by driving the second pump 64.

[0050] The additive supplying devices 50A to 50C are configured to supply the additive 6 to at least the second tank 12. More specifically, the additive supplying devices 50A to 50C include a second additive supplying device 52 for supplying the additive 6 to the second tank 12. Furthermore, the agitators 130A to 130C (130) include a second agitator 132 for agitating the machine oil 9 stored in the second tank 12.

[0051] According to the above configuration, the regeneration process of the machine oil 9 is performed in the second tank 12, which is different from the first tank 11 that is required to appropriately release the machine oil 9 toward the machine oil-using device 100. This makes it possible to more easily perform the regeneration process. As a more specific example, in an embodiment in which the machine oil 9 is regenerated in a batch manner during regular inspection of the machine oil-using device 100, it is possible to regenerate the machine oil 9 in the second tank 12, which is different from the first tank 11. As another example, in an embodiment in which the machine oil 9 is regenerated continuously while the machine oil-using device 100 is in operation, the machine oil 9 can be regenerated in the second tank 12, which is different from the first tank 11. This makes it possible to regenerate the machine oil 9 without impeding the flow of the machine oil 9 between the first tank 11 and the machine oil 9.

[0052] 5B and 5C, the additive supplying devices 50B, 50C further include a first additive supplying device 51 for supplying the additive 6 to the first tank 11, in addition to the second additive supplying device 52 described above. Also, the agitators 130B, 130C (130) include a first agitator 131 for agitating the machine oil 9 stored in the first tank 11. With the above configuration, the process of adding the additive 6 can be performed in both the first tank 11 and the second tank 12, so that the oil performance can be maintained more reliably.

[0053] 5C , the second tank 12 of the tank 10C is connected to the first tank 11 via a connection passage unit 60 while mounted on the transport vehicle 5. The connection passage unit 60 is disposed so as to be detachable from the first tank 11 and the second tank 12. The adsorption system 3 may be mounted on the transport vehicle 5 together with the second tank 12, or may be connected to the second tank 12 while installed on land.

[0054] According to the above configuration, only when the regeneration process of the machine oil 9 is required, the transport vehicle 5 carrying the second tank 12 is moved to the vicinity of the first tank 11, and the second tank 12 is connected to the first tank 11 via the connecting flow path unit 60. As a result, when the regeneration process is not required, the second tank 12 and the connecting flow path unit 60 can be used in another machine oil regeneration system 1 or stored in a dedicated area. This allows for more flexible use of the second tank 12 and the connecting flow path unit 60.

[0055] As shown in Figure 5D, tank 10D of machine oil recycling system 1D includes first tank 11 but does not include second tank 12 (see Figures 5A to 5C). In the example shown in Figure 5D, oil circulation path 40D is connected to first tank 11, and additive supply device 50D includes first additive supply device 51 but does not include second additive supply device 52 (see Figures 5A to 5C). With the above configuration, machine oil 9 can be recycled without installing second tank 12 separate from first tank 11, allowing machine oil recycling system 1 to be made more compact.

[0056] As shown in Figure 5E, the tank 10E(10) of the machine oil regeneration system 1E(1) includes the first tank 11 but does not include the second tank 12 (see Figures 5A to 5C). Furthermore, the oil circulation path 40E(40) that constitutes the machine oil regeneration system 1E(1) further includes a bypass path 43 that is connected to the supply path 41 and the return path 42 so as to bypass the column 7.

[0057] A valve 45 is further disposed in the oil circulation path 40E. The valve 45 is configured to selectively allow the machine oil 9 flowing through the supply path 41 to flow to either the column 7 or the bypass path 43. In this example, the valve 45 is a three-way valve disposed at a position where the bypass path 43 and the supply path 41 are connected. The valve 45 may be an on-off valve disposed in at least one of the bypass path 43 and the supply path 41.

[0058] 5E is disposed in the supply line 41 upstream of the valve 45. The present disclosure is not limited thereto, and the oil circulation pump 48 may be composed of a first oil circulation pump disposed between the valve 45 and the column 7 and a second oil circulation pump disposed in the bypass line 43.

[0059] The additive supply device 50E illustrated in FIG. 5E is disposed in the return path 42 downstream of the position where the bypass path 43 and the return path 42 connect. When the process of adding additive 6 is performed, the valve 45 is switched so that machine oil 9 does not flow into the bypass path 43. The oil circulation pump 48 is driven to add additive 6 from the additive supply device 50E to the machine oil 9 flowing through the return path 42 via the bypass path 43. When the adsorption process of column 7 is performed, the valve 45 is switched so that the machine oil 9 flows into column 7. As a result, the machine oil 9 flowing through the supply path 41 flows sequentially through the supply path 41, column 7, and return path 42 as the oil circulation pump 48 is driven. At this time, the additive supply device 50E does not operate.

[0060] According to the above configuration, the additive 6 can be selectively added or adsorbed to the machine oil 9 flowing through the oil circulation path 40 .

[0061] <Example of a specific configuration of column 7> Figure 6A is a schematic diagram of column 7A(7) according to the first embodiment, and Figure 6B is a schematic diagram of column 7B(7) according to the second embodiment. Columns 7A and 7B may be applied to any of the machine oil regeneration systems 1A to 1E(1) shown in Figures 5A to 5E.

[0062] As shown in FIG. 6A , in the first embodiment, a plurality of columns 7A (7) are arranged in parallel to one another on the oil circulation path 40F (40). More specifically, the oil circulation path 40F has a plurality of column connection paths 47 in which a plurality of columns 7A are respectively arranged. Each of the plurality of column connection paths 47 arranged in parallel to one another is connected to a supply path 41 and a return path 42. A plurality of flow adjustment valves 46 may be arranged in each of the plurality of column connection paths 47. Furthermore, a plurality of on-off valves 44 may also be arranged in each of the plurality of column connection paths 47.

[0063] A configuration in which multiple columns 7A are arranged in parallel with one another can suppress a decrease in flow rate due to pressure loss of the machine oil 9 in the oil circulation path 40F, thereby shortening the time required for the adsorption process. Furthermore, a configuration in which multiple flow control valves 95 are arranged in each of the multiple column connection paths 47 can allow the machine oil 9 to flow evenly through the multiple columns 7A, thereby allowing the adsorption process to be carried out evenly in the multiple columns 7A.

[0064] At least one of the multiple columns 7A shown in FIG. 6A is configured to be replaceable with a new column 7A filled with unused adsorbent 8. For example, the on-off valve 44 corresponding to a column 7A that needs to be replaced is closed, and the column 7A is replaced with a new column 7A. During the replacement work, machine oil 9 may be poured into the remaining columns 7A that have not yet needed replacement, and an adsorption process may be performed. With this configuration, the adsorption capacity can be restored by replacing the column 7A, allowing the machine oil 9 to be used continuously for a longer period of time.

[0065] 6A , a heater 77 for adjusting the temperature of the machine oil 9 flowing in the column 7A may be further disposed in the oil circulation path 40F. In the illustrated example, the heater 77 is disposed upstream of the connection position between the supply path 41 and the plurality of column connection paths 47. With this configuration, the temperature of the machine oil 9 can be adjusted to a temperature suitable for the adsorption process, thereby improving the adsorption efficiency in the column 7A.

[0066] 6B , column 7B (7) includes one end 71 where inlet 7a for machine oil 9 is formed, and another end 72 where outlet 7b for machine oil 9 is formed. In the flow direction of machine oil 9 within column 7B (the direction of arrow Z), one end 71 has a shape in which the inner diameter decreases toward the upstream side, while the other end 72 has a shape in which the inner diameter decreases toward the downstream side. This configuration can prevent machine oil 9 from stagnating near inlet 7a or outlet 7b, thereby enabling more effective adsorption of machine oil 9.

[0067] <Machine Oil Regeneration Unit 2> Referring to Figures 7 and 8, a method of adding a machine oil regeneration unit 2 including an adsorption system 3 and an additive supply device 50 to a pre-modification machine oil regeneration system 1F(1) is illustrated. Figure 7 is a schematic diagram showing a machine oil regeneration system 1F before modification according to one embodiment of the present disclosure. Figure 8 is a flowchart showing a method of adding a machine oil regeneration unit 2 according to one embodiment of the present disclosure. The machine oil regeneration unit 2 (see Figure 1) is a unit including an adsorption system 3 and an additive supply device 50.

[0068] As illustrated in Figure 7, the pre-modification machine oil regeneration system 1F includes a tank 10 but does not include a machine oil regeneration unit 2 (see Figure 1). As shown in Figure 8, in the method for adding a machine oil regeneration unit 2, first, a column installation step (S101) is performed in which a column 7 filled with an adsorbent 8 is installed.

[0069] Next, an oil circulation path installation step (S103) is performed to install the oil circulation path 40. In S103, at least the supply path 41 and the return path 42 are installed. In S103, a bypass path 43 may also be installed. In this case, a valve 45 is also installed.

[0070] Next, a pump installation step (S105) of installing the oil circulation pump 48 in the oil circulation path 40, an additive supply device installation step (S107) of installing the additive supply device 50, and an agitator installation step (S109) of installing the agitator 130 in the tank 10 are carried out in this order. This completes the installation of the machine oil regeneration unit 2 and the machine oil regeneration system 1 (see FIG. 1).

[0071] Steps S101 to S109 are performed by an operator, a robot arm operated by the operator, or a combination of these. The order in which steps S101 to S109 are performed may be changed as appropriate. Furthermore, in addition to the steps shown in FIG. 8, a step of installing a heater 77 in the supply path 41 may be additionally performed. Furthermore, if the tank 10 before modification is composed of only the first tank 11, the method for adding the machine oil recycling unit 2 may further include a step of adding a second tank 12 and a step of adding a connection path unit 60.

[0072] <Others> The "controller" in the above description is configured by a computer, and includes a processor, memory (storage medium), and an external communication interface. The processor is a CPU, GPU, MPU, DSP, or a combination thereof. The memory is configured to store various data temporarily or non-temporarily, and is realized by at least one of RAM, ROM, and flash memory, for example. The processor executes various control processes according to the instructions of the program loaded into the memory.

[0073] <Summary> The contents described in the above-described embodiments can be understood, for example, as follows.

[0074] 1) A method of using a machine oil (9) according to one embodiment of the present disclosure is a method of using machine oil for at least one of lubrication and power transmission, comprising: a first oxidation stability determination step (S11) of determining whether the oxidation stability of the machine oil in use or that has been used is equal to or greater than a first specified level; a first continued use step (S13) of continuing to use the machine oil in use or that has been used if it is determined that the oxidation stability is equal to or greater than the first specified level; an addition step (S51) of adding a regeneration additive (6) to the machine oil so that the oxidation stability becomes equal to or greater than a second specified level if it is determined that the oxidation stability is below the first specified level; and a second continued use step (S55) of continuing to use the machine oil to which the additive has been added.

[0075] The inventors discovered that by periodically adding an additive to a machine oil to maintain the oxidation stability of the machine oil above a certain level, the oil's performance can be maintained and the machine oil can be used continuously. According to the above configuration 1), even if the oxidation stability of the machine oil falls below a first specified level, the addition step can restore the oxidation stability of the machine oil to a second specified level or higher. This allows the degree of deterioration of the machine oil due to oxidation to be maintained at its initial level, allowing the machine oil to be used continuously without being discarded.

[0076] 2) In some embodiments, the method of using machine oil described in 1) above further comprises, before the adding step, a first deterioration progress determination step (S21) of determining whether the degree of deterioration due to oxidation of the machine oil in use or after use falls below a first degree of deterioration, and the adding step is executed when it is determined in the first deterioration progress determination step that the degree of deterioration falls below the first degree of deterioration. (According to the inventor's knowledge, even if machine oil is continuously used while adding additives, the degree of deterioration due to oxidation of the machine oil increases. According to the configuration of 2) above, the adding step is executed on machine oil whose degree of deterioration has been suppressed, so it is possible to avoid a problem in which the degree of deterioration due to oxidation does not return to normal even when the adding step is executed.

[0077] 3) In some embodiments, the method of using machine oil described in 2) above further comprises an adsorption step (S23) of carrying out an adsorption treatment of bringing the machine oil into contact with an adsorbent (8) before the adding step when the first deterioration progress determination step determines that the deterioration progress level is equal to or higher than the first progress level, and the adding step adds the additive to the machine oil whose deterioration progress level has fallen below the second progress level as a result of the adsorption treatment.

[0078] According to the above configuration 3), when the deterioration level of the machine oil is high, the adsorption treatment is performed before the addition step, thereby more reliably maintaining the deterioration level of the machine oil due to oxidation at the initial level.

[0079] 4) In some embodiments, the method of using machine oil described in 3) above further comprises an adsorbent replacement step (S29) of replacing the adsorbent used in the adsorption treatment if the degree of deterioration does not fall below the second degree of deterioration even after repeating the adsorption treatment a specified number of times.

[0080] According to the above feature 4), if the adsorbent's adsorption capacity decreases due to continuous use, the adsorbent can be replaced. Since effective adsorption treatment can be continuously maintained, it becomes possible to continue using machine oil for a longer period of time.

[0081] 5) A machine oil regeneration system (1) according to one embodiment of the present disclosure comprises: a tank (10) for storing in-use or used machine oil (9) for at least one of lubrication and power transmission; an adsorption system (3) including a column (7) filled with an adsorbent (8); an oil circulation path (40) for circulating the machine oil between the column and the tank; and an oil circulation pump (48) disposed in the oil circulation path, the adsorption system (3) configured to perform an adsorption process in which the machine oil is brought into contact with the adsorbent by driving the oil circulation pump; and an additive supply device (50) configured to be able to add a regeneration additive to the machine oil regardless of whether the adsorption process is being performed.

[0082] The inventors discovered that to continuously use machine oil while avoiding significant oil degradation, it is sufficient to subject the machine oil to adsorption treatment and additive addition treatment from time to time. According to the configuration of 5) above, the adsorption treatment and additive addition treatment can be performed on the machine oil, allowing the machine oil to be used continuously without being discarded. Furthermore, the inventors discovered that the period during which adsorption treatment is required as the oxidation progresses can be made longer than the period during which additive addition is required as oxidation stability decreases. According to the configuration of 5) above, it is also possible to perform additive addition treatment without performing adsorption treatment. This allows the timing of the adsorption treatment and additive addition treatment to be optimized, resulting in a machine oil regeneration system that avoids unnecessary regeneration treatment of machine oil.

[0083] 6) In some embodiments, in the machine oil regeneration system described in 5) above, the additive supply device is configured to supply the additive to the inside of the tank via an additive supply path (55) that is different from the oil circulation path.

[0084] According to the above-mentioned configuration 6), the process of adding the additive is carried out at a location separate from the oil circulation path where the adsorption process is carried out, which makes it easy to carry out the process of adding the additive separately from the adsorption process.

[0085] 7) In some embodiments, the machine oil regeneration system is as described in 6) above, wherein the tank includes: a first tank (11) for storing the machine oil discharged from an oil-using device (machine oil-using device 100) that uses the machine oil; and a second tank (12) that is arranged separately from the first tank and to which the oil circulation path is connected; the machine oil regeneration system further includes a connection flow path unit (60) that connects the first tank and the second tank and through which the machine oil flows; and the additive supply device is configured to supply the additive to at least the second tank.

[0086] According to the configuration of 7) above, the regeneration process of the machine oil is carried out in a second tank different from the first tank that is required to appropriately release the machine oil toward the oil-using device. This makes it possible to carry out the regeneration process more easily. As a more specific example, in an embodiment in which machine oil is regenerated in a batch manner during periodic inspection of the oil-using device, it is possible to regenerate the machine oil in a second tank different from the first tank. As another example, in an embodiment in which machine oil is regenerated continuously while the oil-using device is in operation, the machine oil can be regenerated in a second tank different from the first tank, so that the machine oil can be regenerated without interrupting the flow of machine oil between the first tank and the machine oil.

[0087] 8) In some embodiments, the machine oil regeneration system described in 7) above, wherein the additive supply device includes a first additive supply device (51) configured to supply the additive to the first tank, and a second additive supply device (52) configured to supply the additive to the second tank.

[0088] According to the above configuration 8), the process of adding the additive can be carried out in both the first tank and the second tank, so that the oil performance can be maintained more reliably.

[0089] 9) In some embodiments, in the machine oil regeneration system described in 7) or 8) above, the second tank is connected to the first tank via the connecting flow path unit while mounted on the transport vehicle (5).

[0090] According to the configuration 9) above, only when the machine oil needs to be recycled, the transport vehicle carrying the second tank is moved to the vicinity of the first tank and the second tank is connected to the first tank via the connecting flow path unit. This allows the second tank and the connecting flow path unit to be used in another machine oil recycling system or stored in a dedicated area when recycling is not required. This allows for more flexible use of the second tank and the connecting flow path unit.

[0091] 10) In some embodiments, the machine oil regeneration system described in 6) above, wherein the tank includes a first tank (11) for storing the machine oil discharged from an oil-using device that uses the machine oil, the additive supply device is configured to supply the additive to the first tank, and the oil circulation path is connected to the first tank.

[0092] According to the configuration of 10) above, the machine oil regeneration process can be carried out without installing a second tank separate from the first tank, so the machine oil regeneration system can be made compact.

[0093] 11) In some embodiments, in the machine oil regeneration system described in 5) above, the oil circulation path has: a supply path (41) for supplying the machine oil from the tank to the column; a return path (42) for returning the machine oil from the column to the tank; and a bypass path (43) connected to the supply path and the return path so as to bypass the column; the adsorption system further includes a valve (45) for allowing the machine oil flowing through the supply path to selectively flow to either the column or the bypass path; and the additive supply device is arranged in the return path downstream of the position where the bypass path and the return path are connected.

[0094] According to the above configuration 11), additive addition processing or adsorption processing can be selectively performed on the machine oil flowing through the oil circulation path.

[0095] 12) In some embodiments, in the machine oil regeneration system according to any one of 5) to 11) above, a plurality of the columns are arranged in parallel on the oil circulation path.

[0096] According to the above configuration 12), a decrease in the flow rate due to pressure loss of the machine oil in the oil circulation path can be suppressed, and therefore the time required for the adsorption process can be shortened.

[0097] 13) In some embodiments, in the machine oil regeneration system described in 12) above, the oil circulation path has a plurality of column connection paths (47) in which a plurality of the columns are arranged and which are arranged in parallel with each other, and the adsorption system further includes a plurality of flow regulating valves (46) respectively arranged in the plurality of column connection paths.

[0098] According to the above configuration 13), the machine oil can be made to flow evenly through the plurality of columns, so that the adsorption process can be performed evenly in the plurality of columns.

[0099] 14) In some embodiments, in the machine oil regeneration system described in 12) or 13) above, at least one of the plurality of columns is configured to be replaceable.

[0100] According to the above configuration 14), the adsorption capacity can be restored by replacing the column, so that the machine oil can be used continuously for a longer period of time.

[0101] 15) In some embodiments, in the machine oil regeneration system described in any one of 5) to 13) above, the column includes one end (71) where the machine oil inlet (7a) is formed, and the other end (72) where the machine oil outlet (7b) is formed, and in the flow direction of the machine oil within the column, the one end has a shape in which the inner diameter becomes smaller toward the upstream, and the other end has a shape in which the inner diameter becomes smaller toward the downstream.

[0102] According to the above configuration 15), it is possible to prevent the machine oil from stagnating near the inlet or outlet, so that a more effective adsorption treatment can be carried out on the machine oil.

[0103] 16) In some embodiments, the machine oil regeneration system described in any one of 5) to 14) above further comprises a heater (77) configured to adjust the temperature of the machine oil flowing within the column.

[0104] According to the above configuration 16), the temperature of the machine oil can be adjusted to a temperature suitable for the adsorption treatment, thereby improving the adsorption efficiency in the column.

[0105] 17) A method for installing a machine oil regeneration unit (2) according to at least one embodiment of the present disclosure is a method for installing a machine oil regeneration unit for regenerating partially used or used machine oil (9) used for at least one of lubrication and power transmission stored in a tank (10), and includes: a column installation step (S101) for installing a column (7) filled with an adsorbent (8); an oil circulation path installation step (S103) for installing an oil circulation path (40) for circulating the machine oil between the column and the tank; a pump installation step (S105) for installing an oil circulation pump (48) in the oil circulation path; and an additive supply device installation step (S107) for installing an additive supply device (50) configured to be able to add a regeneration additive to the machine oil.

[0106] The configuration 17) above provides the same technical advantages as the configuration 5) above.

[0107] DESCRIPTION OF SYMBOLS 1: Machine oil regeneration system 2: Machine oil regeneration unit 3: Adsorption system 4: Filter 5: Transport vehicle 6: Additive 7: Column 7a: Inlet 7b: Outlet 8: Adsorbent 9: Machine oil 10: Tank 11: First tank 12: Second tank 40: Oil circulation path 41: Supply path 42: Return path 43: Bypass path 44: Opening / closing valve 45: Valve 46: Flow regulation valve 47: Column connection path 48: Oil circulation pump 50: Additive supply device 51: First additive supply device 52: Second additive supply device 55: Additive supply path 60: Connection path unit 61: First oil path 62: Second oil path 63: First pump 64: Second pump 71: One end 72 : Other end 77 : Heater 95 : Flow rate adjustment valve 100 : Machine oil using device (oil using device) 101 : Oil discharge path 102 : Oil supply path 105 : Supply pump 130 : Agitator 131 : First agitator 132 : Second agitator C1 : Connection position C2 : Connection position Z : Arrow

Claims

1. A method of using machine oil for at least one of lubrication or power transmission, comprising: a first oxidation stability determination step of determining whether the oxidation stability of the machine oil in use or that has been used is equal to or higher than a first specified level; a first continued use step of continuing to use the machine oil in use or that has been used if it is determined that the oxidation stability is equal to or higher than the first specified level; an addition step of adding a regeneration additive to the machine oil so that the oxidation stability becomes equal to or higher than a second specified level if it is determined that the oxidation stability falls below the first specified level; and a second continued use step of continuing to use the machine oil to which the additive has been added.

2. A method of using machine oil as described in claim 1, further comprising a first deterioration progress determination step of determining whether a degree of deterioration due to oxidation of the machine oil in use or that has been used falls below a first degree of deterioration before the addition step, and the addition step is executed when it is determined in the first deterioration progress determination step that the degree of deterioration falls below the first degree of deterioration.

3. A method of using machine oil as described in claim 2, further comprising an adsorption step of carrying out an adsorption treatment of contacting the machine oil with an adsorbent before the adding step when the first deterioration progress determination step determines that the deterioration progress level is equal to or higher than the first progress level, wherein the adding step adds the additive to the machine oil whose deterioration progress level has fallen below the second progress level as a result of the adsorption treatment.

4. The method of using machine oil as described in claim 3, further comprising an adsorbent replacement step of replacing the adsorbent used in the adsorption process if the degree of deterioration does not fall below the second degree of deterioration even after repeating the adsorption process a specified number of times.

5. A machine oil regeneration system comprising: a tank for storing partially used or used machine oil for at least one of lubrication and power transmission; an adsorption system including a column filled with an adsorbent, an oil circulation path for circulating the machine oil between the column and the tank, and an oil circulation pump disposed in the oil circulation path, the adsorption system configured to perform an adsorption process in which the machine oil is brought into contact with the adsorbent by driving the oil circulation pump; and an additive supply device configured to be able to add an additive for regeneration to the machine oil regardless of whether the adsorption process is being performed.

6. The machine oil regeneration system according to claim 5, wherein the additive supply device is configured to supply the additive to the inside of the tank via an additive supply path different from the oil circulation path.

7. The machine oil regeneration system according to claim 6, wherein the tank includes: a first tank for storing the machine oil discharged from an oil-using device that uses the machine oil; and a second tank that is arranged separately from the first tank and to which the oil circulation path is connected; the machine oil regeneration system further includes a connection flow path unit that connects the first tank and the second tank and through which the machine oil flows; and the additive supply device is configured to supply the additive to at least the second tank.

8. The machine oil regeneration system according to claim 7, wherein the additive supplying device includes: a first additive supplying device configured to supply the additive to the first tank; and a second additive supplying device configured to supply the additive to the second tank.

9. A machine oil regeneration system as described in claim 7 or 8, wherein the second tank is connected to the first tank via the connection passage unit while mounted on a transport vehicle.

10. The machine oil regeneration system of claim 6, wherein the tank includes a first tank for storing the machine oil discharged from an oil-using device that uses the machine oil, the additive supply device is configured to supply the additive to the first tank, and the oil circulation path is connected to the first tank.

11. The machine oil regeneration system according to claim 5, wherein the oil circulation path has: a supply path for supplying the machine oil from the tank to the column; a return path for returning the machine oil from the column to the tank; and a bypass path connected to the supply path and the return path so as to bypass the column; the adsorption system further includes a valve for allowing the machine oil flowing through the supply path to selectively flow to either the column or the bypass path; and the additive supply device is arranged in the return path downstream of a position where the bypass path and the return path are connected.

12. A machine oil regeneration system according to any one of claims 5 to 7, wherein a plurality of the columns are arranged in parallel on the oil circulation path.

13. The machine oil regeneration system according to claim 12, wherein the oil circulation path has a plurality of the columns arranged therein and a plurality of column connection paths arranged in parallel with each other, and the adsorption system further includes a plurality of flow regulating valves respectively arranged in the plurality of column connection paths.

14. The machine oil regeneration system according to claim 12, wherein at least one of the plurality of columns is configured to be replaceable.

15. A machine oil recycling system as claimed in any one of claims 5 to 7, wherein the column includes one end where the machine oil inlet is formed and the other end where the machine oil outlet is formed, and in the flow direction of the machine oil within the column, the one end has a shape in which the inner diameter becomes smaller as it moves upstream, and the other end has a shape in which the inner diameter becomes smaller as it moves downstream.

16. The machine oil regeneration system according to any one of claims 5 to 7, further comprising a heater configured to adjust the temperature of the machine oil flowing through the column.

17. A method for installing a machine oil regeneration unit for regenerating partially used or used machine oil stored in a tank for at least one of lubrication and power transmission, comprising: a column installation step of installing a column filled with an adsorbent; an oil circulation path installation step of installing an oil circulation path for circulating the machine oil between the column and the tank; a pump installation step of installing an oil circulation pump in the oil circulation path; and an additive supply device installation step of installing an additive supply device configured to be able to add an additive for regeneration to the machine oil.

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