Cleaning device for microgravity environment

Abstract

To achieve efficient cleaning under a microgravity environment.SOLUTION: A cleaning device cleans an object to be cleaned by discharging cleaning water stored in a tank 20 through a hose 21 out of pipes 11, 12 provided in a discharge section 10. In order to prevent the discharged water from dispersing in a zero-gravity environment, the surroundings of the object are covered with a cover 40, and the discharged water is sucked with a suction device 32 and collected in a collection tank 30 through a hose 31. The discharge section 10 includes two pipes 11, 12 arranged in parallel for discharging water and has a swirl flow generation mechanism that imparts a circumferential velocity component to the main water flow so that the water can be discharged as a swirl flow and that rotates the pipes 11, 12 around their axes to generate the swirl flow. This enables the generation of swirl flow even under a microgravity environment, thereby improving cleaning efficiency.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for cleaning an object in a microgravity environment. [Background technology]

[0002] Various technologies have been proposed to improve cleaning efficiency when cleaning an object with a liquid such as water. For example, Patent Document 1 discloses a technology for improving cleaning efficiency in a human body cleaning device by discharging water from a second flow path connected eccentrically to the water discharged from a first flow path, thereby generating a swirling flow. Patent Document 2 discloses a technology for improving cleaning efficiency by discharging water from a flow path formed with a spiral groove at the tip of an endoscope, thereby generating a swirling flow. These prior art techniques were useful for discharging water at a relatively high flow rate under gravity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-232401 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-137349 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, space development has been attracting attention, and the possibility of people staying in space for long periods of time is now well within reach. It is also quite conceivable that people staying in space may be injured for some reason, or may need to undergo surgery by a doctor, resulting in bleeding. In such cases, it may be necessary to clean the bleeding area.

[0005] However, in the microgravity or zero-gravity conditions of outer space, the water sprayed for cleaning can disperse and cause damage to the equipment. In addition, water is a limited resource in outer space, and cannot be used like hot water.

[0006] Thus, in space, even greater improvements in cleaning efficiency are required compared to on Earth. However, the prior art described above is useful when discharging water at a relatively high flow rate under gravity, but it is unable to generate a good swirling flow when discharging at a reduced flow rate under zero gravity. Furthermore, the prior art also had the problem of the discharged water scattering because the velocity component in the swirling direction was too strong.

[0007] This problem is not limited to cleaning bleeding sites or cleaning the human body, but is a common problem when cleaning various objects in a microgravity environment. In view of this problem, the present invention aims to provide a technology that achieves efficient cleaning in a microgravity environment. [Means for solving the problem]

[0008] The present invention provides A cleaning device for cleaning an object in a microgravity environment, a pipe for discharging the liquid; The cleaning device can be provided with a swirling flow generating mechanism that generates a swirling flow by imparting a velocity component to the liquid in a swirling direction relative to the discharge direction, without using a method for making the liquid flow spiral, in a microgravity environment where the effect of gravity on the liquid flow can be ignored.

[0009] According to the present invention, a swirling flow generating mechanism can discharge liquid in a swirling flow state. Unlike the methods introduced in the prior art, i.e., a method of discharging liquid in a spiral shape from a second flow path connected eccentrically to a first flow path (see Patent Document 1) or a method of discharging water from a flow path with a spiral groove formed at the tip (see Patent Document 2), this swirling flow generating mechanism does not use a method of making the liquid flow spiral, thereby avoiding excessive velocity components in the swirling direction and suppressing the dispersion of the discharged liquid under microgravity. However, because the fluid is swirling, cleaning efficiency can be improved compared to discharging without swirling.

[0010] Here, we will explain the cleaning method assumed in this invention. Since the purpose of this invention is to increase cleaning efficiency while preventing the liquid used for cleaning from spreading, we do not assume that the liquid will be ejected in the normal direction to the object to be cleaned. This is because if the liquid were ejected in this way, it would spread after hitting the object. In this invention, it is assumed that the liquid is discharged in a direction parallel to the surface of the object to be cleaned, because discharging in this manner can prevent the liquid from spreading and, in some cases, can even be recovered downstream. When the liquid is discharged in this manner, the velocity component in the swirling direction of the liquid acts on the object, thereby improving the cleaning efficiency.

[0011] In this specification, microgravity refers to gravity that is small enough that the effect of gravity on the flow of liquid can be ignored. Whether the effect of gravity can be ignored can be evaluated by examining the area where the liquid discharged from the cleaning device reaches the target object.

[0012] In the present invention, a swirling flow refers to a flow that has a velocity component in a swirling direction relative to the direction of discharge. A swirling flow in this sense can also be generated by flowing the liquid in a spiral, as in the methods described in Patent Documents 1 and 2. However, as explained above, in the present invention, a method of flowing the liquid in a spiral is not used, but rather a swirling flow is generated by applying a force to the liquid that generates a velocity component in the swirling direction, as will be described below. In the present invention, the swirl flow generating mechanism can be various methods, such as forming a spiral groove on the inside of a straight pipe, or providing a mechanism for rotating the liquid, such as a screw, inside the pipe, etc. In the present invention, any mechanism can be used as long as it can provide a relatively weak swirl that does not cause the discharged swirl flow to diffuse.

[0013] In the present invention, as an example, The swirl flow generating mechanism may be a mechanism that rotates the pipe around an axis.

[0014] In this embodiment, by rotating the pipe, the viscosity of the liquid is used to impart a velocity component in the swirling direction, generating a swirling flow. This mechanism has the advantage of being able to generate a swirling flow with a relatively simple configuration. Another advantage is that the strength of the swirling flow can be easily controlled by controlling the rotation speed.

[0015] In the above embodiment, the inside of the pipe may be treated to increase viscosity in order to efficiently generate swirl. For example, coating the inside of the pipe with a material to increase viscosity, roughening the inside surface, or forming grooves or protrusions may be used.

[0016] In the present invention, the number and arrangement of pipes to be used can be determined arbitrarily. for example, The pipes are arranged in parallel, The swirling flow generating mechanism may be a mechanism that generates the swirling flow in each of the pipes.

[0017] According to the above aspect, a swirling flow can be discharged from each of the two pipes arranged in parallel, so that the cleaning efficiency can be further improved. The swirl flow generating mechanism may be provided individually for each pipe, or may be a single mechanism common to both pipes. As long as the fluids ejected from the two pipes can interact near the object, the pipes do not necessarily need to be parallel. They can be arranged at any angle between them, ranging from a widening angle of approximately 30 degrees in the direction of ejection to a narrowing angle of approximately 30 degrees in the direction of ejection. A narrowing arrangement offers the advantage that the distance between the ejected fluids and the interaction changes depending on the distance from the pipe tips to the object, allowing the pipes to be moved closer or farther away from the object during cleaning to achieve the most effective cleaning. On the other hand, a parallel arrangement offers the advantage that the interaction between the two fluids is less dependent on the distance from the pipe tips to the object, resulting in a generally consistent cleaning effect. The pipe arrangement can be determined by taking these various factors into consideration.

[0018] When two pipes are provided in this way, the distance between them can be determined arbitrarily, It is desirable that the width of the gap between the liquids discharged from the two pipes be smaller than half the radius of either of the pipes.

[0019] When the gap between the two pipes is relatively narrow, the interaction between the two streams of liquid discharged from the pipes can further improve the cleaning efficiency. The liquid gap does not refer to the distance between the centers of the two liquid streams discharged from the two pipes, but rather refers to the narrowest gap between the liquid streams. As an example, it may be determined by adding the distance between the narrowest parts of the two pipes to the wall thickness of the two pipes. In the above embodiment, it is of course possible for there to be no gap, i.e., for the liquid streams to be in contact with each other.

[0020] When two pipes are arranged, the direction of the swirl of the swirling flow generated in each pipe can also be determined arbitrarily. As an example, the swirl flow generating mechanism may generate a clockwise swirl flow in one of the pipes and a counterclockwise swirl flow in the other pipe.

[0021] Numerical simulation results confirmed that cleaning efficiency is improved when the two swirls are facing each other in this way.

[0022] When two streams of liquid with opposing swirling directions are sprayed along the surface of the object to be cleaned, two possible swirling patterns are possible when viewed along the direction of spraying: (1) a first swirling pattern in which the right side is clockwise and the left side is counterclockwise, and (2) a second swirling pattern in which the right side is counterclockwise and the left side is clockwise. In the first swirling pattern, the liquid flows away from the surface of the object between the two streams, while in the second swirling pattern, the liquid flows toward the surface of the object. Either of these two swirling patterns can be used, but numerical simulations have confirmed that the second swirling pattern provides higher cleaning efficiency.

[0023] In the cleaning device described in the present invention, whether or not it has two pipes, The ink jet head may include a recovery mechanism for recovering the ejected liquid.

[0024] By doing so, it is possible to recover the ejected liquid, and to prevent problems caused by the liquid spreading.

[0025] The recovery mechanism can employ various configurations, such as a configuration including a cover that covers the cleaning portion and a suction portion that sucks the liquid downstream.

[0026] The various features of the present invention described above do not necessarily have to be provided in their entirety, and some of them may be omitted or combined as appropriate. In addition to the above-described embodiment as a cleaning device, the present invention may also be configured as a cleaning method using such a cleaning device or a swirling flow. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 2 is an explanatory diagram showing the configuration of a cleaning device. [Figure 2] FIG. 1 is an explanatory diagram showing the influence of the Reynolds number. [Figure 3] FIG. 10 is an explanatory diagram showing the influence of the swirl number. [Figure 4] FIG. 10 is an explanatory diagram showing the influence of the presence or absence of a swirling flow. [Figure 5] FIG. 10 is an explanatory diagram showing the influence of two-line discharge. [Figure 6] FIG. 10 is an explanatory diagram showing the influence of the swirl direction in the case of two-line discharge. [Figure 7] FIG. 10 is an explanatory diagram showing the influence of the flow rate in the case of two-way discharge. [Figure 8] FIG. 10 is an explanatory diagram showing the influence of the size of the gap in the case of two-line discharge. DETAILED DESCRIPTION OF THE INVENTION

[0028] Examples of the present invention will be described below. Figure 1 is an explanatory diagram showing the configuration of a cleaning device, which is a device for cleaning bleeding areas of the human body by discharging water in a zero-gravity environment. The overall configuration is shown in Figure 1(a). The cleaning device of this embodiment cleans the object to be cleaned, which in this embodiment is a bleeding site, by discharging cleaning water stored in a tank 20 through a hose 21 from pipes 11 and 12 provided in a discharge unit 10. In a zero-gravity environment, the ejected water easily disperses, potentially damaging equipment. Therefore, in this embodiment, the object is covered with a cover 40. The cover 40 can be, for example, a transparent vinyl sheet. To prevent water from dispersing, the water ejected from the cleaning device is ejected in a direction generally parallel to the surface to which the object is attached, as shown in FIG. 1(a), rather than in a direction directly hitting the object. While FIG. 1(a) shows the water and the object at a large distance to avoid cluttering the illustration, this distance can be adjusted as desired. From the perspective of enhancing the cleaning effect, it is preferable to eject the water closer to the surface to which the object is attached. The cleaning device includes a suction device 32 for sucking and recovering the discharged water. The sucked water is collected in a recovery tank 30 via a hose 31.

[0029] 1(a) is merely an example. For example, the cover 40 may be omitted if it can effectively suppress the diffusion of water and sufficiently recover the water. Also, when cleaning a covered space, such as in laparoscopic surgery, the cover 40 may not be necessary. Furthermore, various modifications can be made with regard to the necessity and configuration of the tanks 20 and 30.

[0030] Figure 1(b) shows the structure of the discharge part 10. The discharge part 10 is equipped with two pipes 11 and 12 for discharging water. The length of the pipes 11 and 12 is 50 mm, the inner diameter is 5 mm, and the wall thickness is 1 mm, but these dimensions can be determined arbitrarily. Also, both pipes have the same radius R, but this does not exclude the use of pipes with different diameters. The two pipes 11 and 12 are arranged in parallel. The gap between them at their narrowest point can be determined arbitrarily. The length g obtained by adding the thickness of the two pipes 11 and 12 to this gap is the gap between the two water streams discharged from the pipes 11 and 12, i.e., the distance between the narrowest points, and can be one of the parameters that affect the cleaning effect.

[0031] The two pipes 11 and 12 are each equipped with a swirling flow generating mechanism that gives the water not only a velocity component in the direction of discharge, i.e., a velocity component in the main flow, but also a velocity component in the swirling direction relative to the main flow, so that the water can be discharged as a swirling flow. In this embodiment, the swirl flow generating mechanism generates a swirl flow by rotating the pipes 11 and 12 around their axes. For this purpose, the ends of the pipes 11 and 12 are rotatably attached to fixed portions 11f and 12f connected to the hose 21. Drive rings 13 and 14 are fixed to the outside of the pipes 11 and 12. The drive rings 13 and 14 have a rough outer surface with a high friction coefficient, and by applying a rotational torque to this surface using frictional force, the pipes 11 and 12 can be rotated. The drive rings 13 and 14 are in contact with each other, so that rotating one rotates the other.

[0032] 1(b), the drive rings 13, 14 are shown as members having a larger diameter than the pipes 11, 12, but the drive rings 13, 14 may be made to have approximately the same diameter as the pipes 11, 12. Also, the drive rings 13, 14 may be configured by making part of the surface of the pipes 11, 12 a rough outer surface.

[0033] In this embodiment, drive ring 15, which is fixed to rotation shaft 15a of motor 16 (see FIG. 1(a)) provided in discharge unit 10, is rotated by contacting drive ring 14 of pipe 12. For example, when drive ring 15 is rotated in the direction of arrow a, pipe 12 rotates in the direction of arrow b, and pipe 11 rotates in the direction of arrow c. When water is discharged while the pipes 11 and 12 are rotating in this manner, a swirling flow can be generated in the water due to the friction between the inner surfaces of the pipes 11 and 12 and the water.

[0034] The swirl flow generating mechanism is not limited to the above example and can have various configurations. Also, in Fig. 1(b), a single motor 16 is used to rotate both pipes 11 and 12, but pipes 11 and 12 may each be provided with a separate motor. The rotation direction of pipes 11 and 12 may also be switchable.

[0035] 1 shows an example in which the cleaning device is equipped with two pipes 11 and 12, but the number of pipes is arbitrary, and it may be configured with one pipe, or three or more pipes. Furthermore, the cleaning device in FIG. 1 may be configured to be switchable between discharging water from both pipes 11 and 12, and discharging water from only one of them.

[0036] When cleaning is performed using such a cleaning device, the cleaning efficiency varies depending on various parameters, such as the water flow rate and the strength of the swirling flow. These parameters can be determined arbitrarily depending on the object to be cleaned, the type of fluid used for cleaning, the diameter of the pipe, etc. Below, we will explain the effects of these parameters on cleaning efficiency based on the results of a numerical simulation.

[0037] The Reynolds number Re and swirl number Sw are used as parameters to describe the swirling flow. They are defined by the following equations. The Reynolds number Re is a parameter related to the flow rate, and the swirl number Sw is a parameter related to the flow in the swirling direction. In the case of water, if Re=380, the flow rate is approximately 90 ml / min.

[0038]

number

[0039] Figure 2 shows the effect of the Reynolds number. Each figure shows the results of a numerical simulation. The flow discharged from a single pipe was analyzed. Figure 2(a) shows the cross section of the discharged water (the area shown in light gray in the figure) for three Reynolds numbers: Re = 190, 380, and 760, with a swirl number of 0.11, in the range of distance x from the pipe outlet / radius R = 0 to 6. For the Reynolds number Re = 190, the cross section is nearly circular immediately after discharge (x / R = 0), and no significant collapse, i.e., no diffusion of the water, is observed until around x / R = 5. Figure 2(b) shows the flow when the Reynolds number Re = 190. The gray area on the right represents the ejected water. It can be visually confirmed that there is no significant diffusion of the water in the area enclosed by the dashed line in the figure.

[0040] Returning to Figure 2(a), the results for other Reynolds numbers, Re = 380 and 760, show that no significant diffusion is observed up to around x / R = 3. Figures 2(c) and 2(d) show the flow conditions at Reynolds numbers Re = 380 and 760, respectively. Within the area enclosed by the dashed line in the figure, it can be visually confirmed that there is no significant diffusion in the water. From the above results, it can be considered that as long as cleaning is performed near the pipe outlet, the effect of the Reynolds number Re on the water diffusion state is relatively small.

[0041] Figure 3 shows the effect of swirl number. Each figure shows the results of a numerical simulation. The flow discharged from a single pipe was analyzed. Figure 3(a) shows the cross section of the discharged water (the area shown in light gray in the figure) for four swirl numbers: Sw = 0, 0.11, 0.27, and 0.40, with the Reynolds number Re = 380, in the range of distance x from the pipe outlet / radius R = 0 to 6. When the swirl number Sw = 0 (no swirling flow), it can be seen that no diffusion of water is observed until around x / R = 4. Figure 3(b) shows the flow when the swirl number Sw = 0. It can be visually confirmed that there is no significant diffusion of the water overall.

[0042] Returning to Figure 3(a), the results for swirl number = 0.11 show that no significant diffusion is observed up to around x / R = 4, but diffusion can be seen further downstream. Figure 3(c) shows the flow when swirl number = 0.11. As it reaches downstream, it can be seen that the water flow breaks down from its cylindrical shape.

[0043] Returning to Figure 3(a), the results for swirl number = 0.27 show that diffusion can already be seen around x / R = 1. Figure 3(d) shows the flow when swirl number = 0.27. It can be seen that diffusion occurs shortly after discharge.

[0044] Returning to Figure 3(a), the results for swirl number = 0.40 show that diffusion can already be seen around x / R = 1. Figure 3(e) shows the flow when swirl number = 0.40. Immediately after discharge, it can be seen that the diffusion is greater than when swirl number = 0.27. From the above results, it can be seen that the swirl number has a large effect on the water diffusion. From the viewpoint of suppressing diffusion, it is preferable that the swirl number is less than 0.27, and more preferably around 0.11.

[0045] Figure 4 is an explanatory diagram showing the effects of the presence or absence of swirling flow. Each diagram shows the results of a numerical simulation. The flow discharged from a single pipe was analyzed. Figure 4(a) shows the state when the swirl number is 0, i.e., when no swirling flow occurs. The object to be cleaned was a liquid that was discharged at a constant flow rate to model bleeding. As shown in Figure 4(a), when no swirling flow occurs, the object is not sufficiently cleaned. Figure 4(b) shows the shear force acting on the floor surface due to the flow in Figure 4(a). The water is flowing from left to right. The whitish areas, such as area b1, are areas where significant shear force is obtained. The dark areas, such as area b2 in the center of the flow, are areas where shear force is small. From these results, it can be seen that the cleaning efficiency of the target object is low when the swirl number is 0.

[0046] Figure 4(c) shows the state when the swirl number is 0.11, i.e., when a swirling flow is occurring. As shown in the figure, when a swirling flow is occurring, the object cannot be identified, but is washed away and carried downstream with the water. Figure 4(d) shows the shear force acting on the floor surface due to the flow in Figure 4(c). The water is flowing from left to right. The whitish area c1 is the area where significant shear force is obtained. Unlike Figure 4(b), no dark areas with weak shear force are observed. However, because a swirling flow is occurring, it can be seen that the shear force acts biased towards the upper side in Figure 4(d), that is, towards one side of the main flow. From the above results, it is confirmed that the cleaning efficiency is improved by generating a swirling flow.

[0047] Figure 5 is an explanatory diagram showing the effect of two outlets. Each shows the results of a numerical simulation. The flow discharged from two pipes was analyzed. The Reynolds number Re=637. Figure 5(a) shows a state where the swirl number is 0, i.e., no swirling flow is occurring. Since the object to be cleaned is not visible, it can be confirmed that cleaning is being performed relatively well. However, it can be confirmed that the object is scattered in the area downstream, enclosed by the dashed line. The cause of this phenomenon has not been fully elucidated, but it is thought that the absence of swirling flow weakens the effect of holding the object within the water flow. Figure 5(b) shows a state where the swirl number is 0.11, i.e., a swirling flow is occurring. The left side of Figure 5(b) shows a schematic of the swirling direction of the two streams of water. This shows the state as seen from the downstream side. In this example, as seen from the downstream side, the right side is counterclockwise and the left side is clockwise, generating swirling flows in opposite directions. In the central area where the two streams of water approach each other (the area surrounded by the dashed line in the figure), both swirling flows have a velocity component directed toward the floor. In this state, no objects are visible, indicating that cleaning is occurring satisfactorily. It can also be confirmed that no objects are scattered downstream. Figure 5(c) shows the results for a comparative example where water at the same flow rate as the two water streams was discharged from a single thick pipe. The swirl number was set to 0. In this case, the object was clearly visible, indicating that cleaning was not performed well. These results show that using two water flows is more effective than simply increasing the flow rate. Also, by creating a swirling flow in the opposite direction to the two water flows, cleaning becomes even more efficient.

[0048] Figure 6 is an explanatory diagram showing the effect of the swirl direction in the case of two outlets. Each shows the results of a numerical simulation. The flow discharged from two pipes was analyzed. The Reynolds number Re = 637 and the swirl number = 0.11. Figure 6(a) is the same as Figure 5(b), in that the swirling flows swirl in opposite directions, and in the central area where the two streams of water approach each other (the area surrounded by the dashed line in the figure), both swirling flows are directed toward the floor (hereafter referred to as "downward opposing swirling" for convenience). Since the object being cleaned is not visible, it can be confirmed that cleaning is being carried out relatively well. Figure 6(b) shows swirling flows swirling in opposite directions, but in the central area where the two streams of water approach (the area surrounded by the dashed line in the figure), both swirling flows are directed upward. Although the object being cleaned does not remain on the floor, it can be seen that the object and water are spreading upward, as indicated by the arrows in the figure. Figure 6(c) shows a swirling flow that swirls in the same direction. This shows an example where both streams swirl clockwise when viewed from downstream. Although the object being cleaned does not remain on the floor, as shown by the arrow in the figure, it can be seen that the object and water are being dispersed diagonally upward to the right. Similarly, when swirling counterclockwise, the object and water are likely to be dispersed diagonally upward to the left. From the above results, when creating a swirling flow in two streams of water, it is considered that either direction does not matter from the viewpoint of cleaning efficiency, but from the viewpoint of suppressing the diffusion of the target object and water, it is considered preferable to use a downward opposing swirling flow.

[0049] Figure 7 is an explanatory diagram showing the effect of flow rate in the case of two discharges. Each shows the results of a numerical simulation. The flow discharged from two pipes was analyzed. Figure 7(a) is the same as Figure 5(b), with a Reynolds number Re = 637 and a swirl number = 0.11, showing downward counter-swirling. As already explained, it can be confirmed that cleaning is being performed well. Figure 7(b) shows the results when the flow rate in Figure 7(a) is increased by 10 times. The condition for swirl is that the angular velocity of the swirling flow is the same as in Figure 7(a). By increasing the flow rate, the Reynolds number Re becomes 10 times larger, but the swirl number becomes smaller than in Figure 7(a). From the above results, it can be seen that the swirl number for ensuring cleaning efficiency can be relatively lowered as the Reynolds number Re increases. It is also confirmed that the swirl angular velocity can be one of the parameters that influences cleaning efficiency.

[0050] Figure 8 is an explanatory diagram showing the effect of the gap size in the case of two-pipe discharge. Each shows the results of a numerical simulation. The flow discharged from two pipes was analyzed. Figure 8(a) is the same as Figure 5(b), with a Reynolds number Re = 637 and a swirl number = 0.11, showing downward opposing swirling. The gap between the two water streams is set to 1 mm. Since the pipe diameter is 5 mm (radius 2.5 mm), the gap is smaller than half the radius. As already explained, it can be confirmed that cleaning is being carried out satisfactorily. Figure 8(b) shows the downward counter-swirling flow with the same Reynolds number Re and swirl number as Figure 8(a), but with the gap between the two water streams widened to 2 mm. The gap is now larger than half the radius. Since the objects to be cleaned do not spread across the floor surface, it can be seen that cleaning is being carried out well. However, as indicated by the arrows in the figure, it can be seen that the objects are being scattered upward (area indicated by the dashed line). The example shown in Figure 8 is merely one example, and the scattering situation is thought to differ depending on the viscosity and other properties of the object, the surface area to which the object is attached, etc., but in any case, it is thought that narrower gaps in the water flow are preferable. Considering the results in Figure 8 in terms of the relative relationship between the gap and the thickness of the water flow (diameter of the pipe), one guideline would be to make the gap between the two water flows smaller than half the radius.

[0051] The cleaning device of the embodiment described above can achieve efficient cleaning by generating a swirling flow in the discharged water flow under a microgravity environment. Furthermore, by adjusting various parameters related to the swirling flow, such as the swirl number and swirl direction, it is possible to further improve cleaning efficiency.

[0052] The various features described in the embodiments do not necessarily have to be provided in their entirety, and some of them may be omitted or combined as appropriate. Furthermore, the present invention is not limited to the embodiments, and can be configured in various forms. In the examples, a bleeding site is assumed as the object to be cleaned, but the cleaning device of the present invention can be used to clean various objects, such as oil stains adhering to devices. In addition, although the embodiment assumes the use of water, it is also applicable to various other fluids. [Industrial Applicability]

[0053] The present invention can be used for cleaning in a microgravity environment. [Explanation of symbols]

[0054] 10 Discharge part 11, 12 pipes 11f, 12f fixed part 13, 14, 15 Drive ring 15a Rotation axis 16 motors 20 Tank 21 Hose 30 Tank 31 Hose 32 Aspirator 40 Cover

Claims

1. A cleaning device for cleaning an object in a microgravity environment, a pipe for discharging the liquid; A cleaning device comprising: a swirling flow generating mechanism that generates a swirling flow by applying a velocity component to the liquid in a direction that swirls relative to the direction of discharge, without using a method for making the liquid flow spiral, in a microgravity environment where the effect of gravity on the liquid flow can be ignored.

2. 2. The cleaning device according to claim 1, The cleaning device, wherein the swirling flow generating mechanism is a mechanism that rotates the pipe around its axis.

3. 2. The cleaning device according to claim 1, The pipes are arranged in parallel, The swirling flow generating mechanism is a mechanism that generates the swirling flow in each of the pipes.

4. 4. The cleaning device according to claim 3, A cleaning device in which the width of the gap between the liquids discharged from the two pipes is smaller than half the radius of either of the pipes.

5. 4. The cleaning device according to claim 3, The swirling flow generating mechanism generates a clockwise swirling flow in one of the pipes and a counterclockwise swirling flow in the other pipe.

6. The cleaning device according to claim 1, further comprising: The cleaning device includes a recovery mechanism for recovering the discharged liquid.

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