Microgravity dry cleaning systems

Abstract

Microgravity dry-cleaning systems and rotary drums thereof are described. The microgravity dry-cleaning systems include a drum assembly having an inner drum and an outer drum and a cleaning solvent dispenser arranged within the inner drum and a drive assembly. The drive assembly is configured to rotationally drive the inner drum and the outer drum relative to the cleaning solvent dispenser and direct a cleaning solvent into the cleaning solvent dispenser for dispensing the cleaning solvent toward an interior surface of the inner drum.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States Application 63 / 777,983, filed Mar. 26, 2025, the disclosure of which is incorporated herein by reference in its entirety.BACKGROUND

[0002] The subject matter disclosed herein generally relates to soft goods cleaning systems and, more particularly, to dry cleaning systems for use in low-, micro-, and zero-gravity environments.

[0003] In current space exploration and travel, supplying clean clothing and cleaning of dirty clothing (soft goods) provides logistical and financial challenges. Currently, there is no way to clean dirty laundry in space. As such, clothing is a consumable that must be brought up to a space station or vehicle, or must be carried onboard. Once the clothing has been used and worn out, the clothing is discarded, and new clothing must be provided. For example, clothing on the International Space Station is supplied to the Station about once a year, with about 68 kg of clothing being launched for each astronaut on the Station. With very high launch costs based on weight (e.g., $10,000 / kg), and multiple astronauts, the cost of providing clean clothing can be very expensive, and requires space both on the launch vehicle each time plus storage space onboard the Station for new and old clothing. Additional cloth-based items can significantly increase the costs of supply, resupply, and waste disposal, such as for clothing, sanitary / disposable wipes, and the like. As such, the clothing and hygiene needs of a crew of a space mission can exceed millions of dollars per year.

[0004] Additionally, as human space exploration expands, such as by way of deep space missions, extended missions on the Moon, to asteroids, Mars, and the like, resupply and replacement clothing cannot be easily or feasibly provided. On such missions, all clothing to be used for the duration of the mission must be launched and then carried by the crew and craft / station. Conventional cleaning systems require water and are designed to operate on Earth, having gravity at play along with access to resources, such as water. In view of this, it may be beneficial to develop systems for cleaning clothing in low-, micro-, and zero-gravity environments without water.SUMMARY

[0005] According to some embodiments, microgravity dry-cleaning systems are provided. The microgravity dry-cleaning systems include a drum assembly having an inner drum and an outer drum and a cleaning solvent dispenser arranged within the inner drum and a drive assembly. The drive assembly is configured to rotationally drive the inner drum and the outer drum relative to the cleaning solvent dispenser and direct a cleaning solvent into the cleaning solvent dispenser for dispensing the cleaning solvent toward an interior surface of the inner drum.

[0006] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the inner drum defines a permeable wall.

[0007] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the permeable wall is defined by perforations, holes, or apertures in the material of the inner drum.

[0008] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the inner drum comprises one or more agitation features on an interior surface thereof and configured to interact with and agitate and / or tumble a soft good disposed within the inner drum.

[0009] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the outer drum comprises a plurality of flow directors arranged on an interior surface of the outer drum, the plurality of flow directors configured to direct a capillary-driven flow of cleaning solvent toward an outlet end of the drum assembly.

[0010] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the cleaning solvent dispenser includes a helical path extending about a periphery of the cleaning solvent dispenser and a plurality of jet nozzles arranged about the exterior of the cleaning solvent dispenser and oriented to direct a jet of cleaning solvent to impinge upon an inner surface of the inner drum and any soft goods within the inner drum.

[0011] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the plurality of jet nozzles are configured to direct the jet of cleaning solvent in a direction counter to a rotation direction of the inner drum and outer drum to cause tumbling and agitation of a soft good within the inner drum.

[0012] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the plurality of jet nozzles are configured to direct a jet of cleaning solvent with a force defining a breakup distance of the jet of cleaning solvent and a maximum radius of the inner drum is less than the breakup distance.

[0013] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the cleaning solvent dispenser comprises an input bore for receiving a cleaning solvent and a transition bore that fluidly connects the input bore to the helical path.

[0014] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the cleaning solvent dispenser defines a fluid interface end comprising at least the input bore. The cleaning solvent dispenser further includes one or more exit conduits fluidly coupled to an interior of the outer drum and configured to receive used cleaning solvent to direct the used cleaning solvent out of the outer drum.

[0015] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include a cleaning solvent source containing a cleaning solvent to be supplied into the drum assembly.

[0016] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the drive assembly includes a motor and a pump. The motor is configured to rotationally drive the inner drum and the outer drum about the cleaning fluid dispenser and to operably drive the pump.

[0017] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the motor is rotationally connected to the outer drum via a belt.

[0018] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the inner drum, the outer drum, and the cleaning solvent dispenser define a drum assembly. The drum assembly includes a door configured to selectively sealingly engage with the outer drum.

[0019] In addition to one or more of the features described herein, or as an alternative, further embodiments of the microgravity dry-cleaning systems may include that the cleaning solvent is sourced from one of a carbon dioxide removal system or an external ambient atmosphere.

[0020] According to some embodiments, drum assemblies for microgravity dry-cleaning systems are provided. The drum assemblies include an outer drum having a plurality of axially extending flow directors on an interior surface of the outer drum, an inner drum arranged within the outer drum, the inner drum defining a permeable wall, and a cleaning solvent dispenser arranged within the inner drum and configured to direct a jet of cleaning solvent toward the inner drum from a plurality of jet nozzles, the cleaning solvent dispenser having a helical path defining a flow path for cleaning solvent to be supplied to the jet nozzles.

[0021] In addition to one or more of the features described herein, or as an alternative, further embodiments of the drum assemblies may include that the outer drum and the inner drum are configured to be rotationally driven about the cleaning solvent dispenser in a rotation direction. The plurality of jet nozzles are configured to direct the jet of cleaning solvent in a direction counter to the rotation direction of the inner drum and outer drum to cause tumbling and agitation of a soft good within the inner drum.

[0022] In addition to one or more of the features described herein, or as an alternative, further embodiments of the drum assemblies may include that the plurality of jet nozzles are configured to direct a jet of cleaning solvent with a force defining a breakup distance of the jet of cleaning solvent and a maximum radius of the inner drum is less than the breakup distance.

[0023] In addition to one or more of the features described herein, or as an alternative, further embodiments of the drum assemblies may include that the cleaning solvent dispenser comprises an input bore for receiving a cleaning solvent and a transition bore that fluidly connects the input bore to the helical path.

[0024] In addition to one or more of the features described herein, or as an alternative, further embodiments of the drum assemblies may include that the cleaning solvent dispenser defines a fluid interface end comprising at least the input bore. The cleaning solvent dispenser further includes one or more exit conduits fluidly coupled to an interior of the outer drum and configured to receive used cleaning solvent to direct the used cleaning solvent out of the outer drum.

[0025] The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and non-limiting.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The subject matter is particularly pointed out and distinctly claimed at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

[0027] FIG. 1 is a schematic diagram of a closed-loop microgravity dry cleaning system for use in low-, micro-, and zero-gravity environments, that may incorporate embodiments of the present disclosure;

[0028] FIG. 2 is a schematic diagram of a microgravity dry cleaning system in accordance with an embodiment of the present disclosure;

[0029] FIG. 3A is a schematic illustration of a rotary cleaner of a microgravity dry cleaning system in accordance with an embodiment of the present disclosure;

[0030] FIG. 3B is an enlarged illustration of a drum assembly of the rotary cleaner of FIG. 3A;

[0031] FIG. 4A is a schematic diagram of operation of a rotary cleaner in accordance with an embodiment of the present disclosure;

[0032] FIG. 4B is an enlarged detailed schematic diagram of a region 4B of the rotary cleaner shown in FIG. 4A;

[0033] FIG. 4C is a cross-sectional view of the rotary cleaner of FIG. 4A as viewed along the line 4C-4C shown in FIG. 4A;

[0034] FIG. 5A is a schematic illustration of a portion of a rotary cleaner in accordance with an embodiment of the present disclosure;

[0035] FIG. 5B is a schematic illustration of a cleaning solvent dispenser of the rotary cleaner of FIG. 5A;

[0036] FIG. 5C is an enlarged detailed illustration of a portion of cleaning solvent dispenser of the rotary cleaner of FIG. 5A;

[0037] FIG. 5D is a cross-sectional view of a portion of the cleaning solvent dispenser of FIG. 5B as viewed along the line 5D-5D;

[0038] FIG. 5E is an enlarged illustration of an outlet end of a drum assembly of the rotary cleaner of FIG. 5A;

[0039] FIG. 5F is an enlarged illustration of details of the cleaning solvent dispenser of the embodiment of FIG. 5A;

[0040] FIG. 6A is a schematic illustration of a portion of an interior surface of an inner drum of a rotary cleaner in accordance with an embodiment of the present disclosure;

[0041] FIG. 6B is a side view of the portion of the inner drum of a rotary cleaner of FIG. 6A;

[0042] FIG. 7A is a partial view of a portion of an outer drum of a rotary cleaner in accordance with an embodiment of the present disclosure; and

[0043] FIG. 7B is an elevation view of the portion shown in FIG. 7A illustrating the action of flow directors in accordance with embodiments of the present disclosure.DETAILED DESCRIPTION

[0044] As shown and described herein, various features of the disclosure will be presented. Various embodiments may have the same or similar features and thus the same or similar features may be labeled with similar reference numerals and / or description thereof may be omitted in certain later described embodiments for conciseness. Various embodiments will be described and various features may include changes, alterations, modifications, etc. as will be appreciated by those of skill in the art, whether explicitly described or otherwise would be appreciated by those of skill in the art. Further, it will be appreciated that, unless otherwise stated, features from the various separately described embodiments may be combined in various combinations and each embodiment is not intended to be mutually exclusive from features of other embodiments described herein and / or mutually exclusive from other features and components not explicitly described.

[0045] As human space exploration continues and the time and distance of the duration in space continues, clean clothing supply will become an issue that must be addressed. Currently, there is no way to clean dirty laundry in space, and as a result, worn out and used clothing is discarded with trash and other waste. Such a solution has been feasible for low Earth orbit stations (e.g., International Space Station), as the Station is relatively close to Earth, resupply missions happen regularly, and the Station is generally government supported, resulting in a relatively high budget that can absorb the cost of regular clothing replacement and resupply. For example, 150 pounds or 68 kg of fresh clothes must be replenished on crewed missions to the International Space Station. Assuming a cost of about $10,000 / kg, this results in a cost of about $680,000 of launch cost per crew member per year. Additional costs may come from sanitary and hygiene goods and associated waste. As such, supply, resupply, and waste disposal can be a very costly activity for a human space presence.

[0046] It is likely that future deep space crewed missions will not be able to throw anything away, and so a solution for cleaning dirty clothes is needed. Moreover, as more commercial space exploration expands, reducing the costs of launch and resupply (e.g., by reducing the amount of clothing launched) can provide significant benefits. Conventional clothing cleaning relies upon the use of water. However, water is a scarce and very limited resource when in space, whether on a spacecraft, a station, or a base / station that is on a celestial body (e.g., the Moon, Mars, asteroid, etc.). Additionally, because such space-based cleaning operations must necessarily take place in non-Earth-based gravity environments (e.g., low-, micro-, or zero-gravity environments), cleaning systems must be configured to operate in such space environments, without the assistance of gravity. For example, conventional, Earth-based cleaning floods a drum with a cleaning solvent and relies on gravity to tumble and agitate the clothing. Microgravity dry cleaning systems will not flood a drum and do not rely on gravity. Instead, as described herein, such systems rely on centrifugal forces and fluid jet forces to tumble and agitate soft goods. As used herein, the term “microgravity” will be used to encompass low-gravity, micro-gravity, and zero-gravity environments. Microgravity environments, as intended herein, includes environments including, but not limited to, orbits about a celestial body, open space travel or transit between celestial bodies, and / or surface environments on celestial bodies having gravity lower than that of Earth (e.g., the Moon, Mars, asteroids, moons, planetesimal, etc.).

[0047] In view of the above and other considerations, embodiments of the present disclosure are directed to space-based clothing and garment cleaning systems. In accordance with some embodiments of the present disclosure, cleaning solvents are used as cleaning fluid and replaces the need for water to be used for cleaning of clothing. Such cleaning solvents can include, for example and without limitation, subcritical carbon dioxide, supercritical carbon dioxide, perchloroethylene, modified alcohols, siloxanes, hydrocarbons, glycol ethers, halogenated solvents, and the like. Use of such cleaning solvents results in a waterless, dry-cleaning solution for both low Earth orbit and deep space missions where water may be scarce. At a minimum, such systems may enable reduced launch and resupply costs by enabling cleaning of clothing and thus reuse thereof, avoiding the need for resupply. Furthermore, such systems may reduce the total waste generation of a space mission, such as by allowing for recycling of materials (e.g., portions of cleaning solvent) and reducing disposal waste. Further advantages and benefits of embodiments of the present disclosure will be apparent in view of the following discussion and description of various non-limiting embodiments of the present disclosure. Although a number of different embodiments will be described herein, it will be appreciated that features of the various embodiments may be interchanged and / or exchanged to result in one or more embodiments not expressly described but rather are encompassed by the spirit and scope of the disclosure. Further, additional features and structures may be incorporated into embodiments without departing from the scope of the present disclosure.

[0048] In accordance with embodiments of the present disclosure, non-water based solvent dry-cleaning systems for cleaning clothes are provided. The cleaning systems described herein may use various cleaning solvents, although the use of carbon dioxide will be described it will be appreciated that the use of other cleaning solvents may be implemented without departing from the scope of the present disclosure. In operation, embodiments of the present disclosure are directed to a cleaning system where contaminants from dirty clothes are removed by low viscosity and surface tension of the cleaning solvent (e.g., liquid CO2). Further, a jet force of application of the cleaning solvent can cause tumbling of the articles to be cleaned, thereby increasing the cleaning efficiency and functionality. In some embodiments, once the liquid cleaning process is completed, a pressure of a cleaning cavity (e.g., drum, container, etc.) may be reduced and the liquid cleaning solvent may be converted to a gas state, which can allow for scrubbing and removal of dirt, debris, and waste that is removed from the clothing during the cleaning process.

[0049] In some configurations, once the cleaning process is complete, the used solvent may be removed from the rotary cleaner and directed to a separate distillation tank where it can be converted to a gas state. The cleaning solvent may be reclaimed, as a liquid or gas, and the waste separated therefrom. The cleaning solvent may be recaptured, treated and / or processed, and may be reused for subsequent cleaning cycles. Embodiments of the present disclosure provide for a waterless, dry-cleaning solution for cleaning clothes in space and microgravity environments and applications. Further, in accordance with some embodiments, the cleaning process may occur at ambient (e.g., room) temperatures within an occupied space (e.g., cabin, crew quarters, etc. that are part of a vehicle, station, etc.). Soft goods may be dried rapidly after a cleaning cycle because CO2is a gas at ambient pressure and room temperature, therefor an energy intensive drying cycle is not required. The use of such cleaning solvents (e.g., liquid CO2) can result in cleaning of clothes that is more gentle than conventional water-based washing, which can result in increased life / longevity of clothing. This can result in extending the usable life of clothing, which in turn can reduce the total amount of clothing that is launched and carried aboard spacecraft and / or space-based stations and the like.

[0050] As noted, embodiments of the present disclosure are directed to microgravity dry cleaning systems. Such systems may be closed-loop systems, where the cleaning solvent is recaptured, reclaimed, or otherwise recycled within the system. In other embodiments, the systems may be open-loop, where the cleaning solvent and waste are disposed of directly, without reclamation thereof. Further, some combination of closed- and open-loop may be employed, where a system typically operates as a closed-loop system, but may be converted to open-loop to dispose of used cleaning solvent and then a new supply of cleaning solvent may be provided, and then the system converted back to a closed-loop system. In some such open-loop or closed-loop systems, a supplemental supply of cleaning solvent, such as CO2, may be provided to ensure that necessary levels of cleaning solvent are maintained within the system and to provide a replenishment of the cleaning solvent if losses occur, such as through evaporation, capture, and disposal with waste removed from soft goods, or the like. In some such open-loop or closed-loop systems, CO2 can be supplied from in-situ or crew-generated CO2 sources, such as from a CO2 removal system, or from a planetary atmosphere (e.g., Mars). In some embodiments, additional co-solvents, detergents, additives, chemicals and / or cleaning agents may be used to provide additional cleaning and / or deodorizing to clothes and / or of the system itself. In some embodiments, optional distillers and / or slug tanks may be employed to improve removal of residues, dirt, debris, and waste. In some embodiments, filters (e.g., adsorption filters or activated carbon filters) may be utilized to aid in purifying the cleaning solvent in a recirculation loop. In some embodiments, optional desiccants or water separators may be utilized to aid in the removal of residual water in the cleaning solvent recirculation loop. In some embodiments, heating elements may be utilized to aid in regenerating carbon dioxide adsorbing textiles.

[0051] Referring to FIG. 1, illustrated is a schematic diagram of a microgravity dry-cleaning system 100 that may incorporate cleaning devices in accordance with embodiments of the present disclosure. The microgravity dry-cleaning system 100 may be used onboard a spacecraft, space station, non-Earth station or base, or the like, which is subject to a microgravity environment. The microgravity dry-cleaning system 100 of FIG. 1 is a closed-loop configuration that uses a cleaning solvent (e.g., subcritical carbon dioxide (CO2), supercritical CO2, perchloroethylene, modified alcohols, siloxanes, hydrocarbons, glycol ethers, halogenated solvents, etc.) for cleaning of clothing. FIG. 1 is illustrated using liquid subcritical CO2 as the cleaning solvent, but other cleaning solvents may be employed without departing from the scope of the present disclosure.

[0052] The microgravity dry-cleaning system 100 includes a holding tank 102 which is configured to contain a cleaning solvent (e.g., liquid CO2). The holding tank 102 may be a pressure tank, a bellows tank, a variable volume container, or the like, as will be appreciated by those of skill in the art. The holding tank 102 may be configured to ensure a high pressure is maintained such that CO2 that is within the holding tank 102 is maintained in liquid form. In a flow direction along a flow path 104 from the holding tank 102 is a first pump 106 and a rotary cleaner 108 for receiving both laundry through a door 110 and liquid CO2 from the primary flow path 104. The rotary cleaner 108 includes an internal drum 109 that is arranged within the rotary cleaner 108 and provides a mechanism to allow for separation of the liquid CO2 from clothes during a cleaning operation of the microgravity dry-cleaning system 100. Output from the rotary cleaner 108 may be liquid and / or gaseous CO2. Downstream from the rotary cleaner 108, along the flow path 104, may be an optional first filter 112 and optional second pump 114, and then a distillation tank 116. Continuing along the flow path 104 may be an optional second filter 118, a compressor 120, and a condenser 122, before returning to the holding tank 102.

[0053] The microgravity dry-cleaning system 100 may include additional components, which may be optional in this configuration. For example, as shown, a fluid connection from the rotary cleaner 108 may be provided to fluidly connect to an occupied space 124 (e.g., a cabin or crew quarters) and / or fluidly connect to an air outlet 126 which may include a third pump 128. Additionally, an auxiliary supply 130 may be provided to add additional CO2into the microgravity dry-cleaning system 100. Furthermore, the condenser 112 may be arranged along the flow path 104, with the flow path 104 providing the CO2 as a first working fluid within the condenser 122 and a coolant loop 132 providing a second working fluid within the condenser 122, and thus remove heat from the CO2 as it passes through the condenser 122, as described herein. As shown and in this non-limiting configuration, the flow of CO2, whether liquid or gas, through the microgravity dry-cleaning system 100 may be controlled by a set of valves V1-V9. The valves V1-V9 may be passive (e.g., one-way valves, check valves, or the like) or may be active valves (e.g., solenoid valves, electronic valves, or the like), and each of the valves V1-V9 may be configured for manual or automated operation, depending on the specific configuration of the microgravity dry-cleaning system 100. In some embodiments, a controller 134 may be provided for control and operation of the microgravity dry-cleaning system 100, with the controller 134 operably connected to some or all of the valves V1-V9.

[0054] Embodiments of the present disclosure are directed to rotary cleaners, such as rotary cleaner 108 shown in FIG. 1. It will be appreciated that the rotary cleaners described herein may be implemented in other cleaning systems and / or arrangements thereof, and the microgravity dry-cleaning system 100 is merely an example of such cleaning systems that may be used in microgravity environments. Embodiments of the present disclosure provide various mechanisms for cleaning clothing in microgravity environments and additional capabilities, including but not limited to, agitation of garments with phase changing solvent fluid, filtering and reclamation of contaminated cleaning solvent(s), separation of liquid and gas phases of cleaning solvent(s) during cleaning and post-cleaning processes, and capability to withstand high pressures and RPMs during operation.

[0055] Embodiments of the present disclosure include a rotary cleaning machine that uses a cleaning solvent to clean garments, clothing, and / or soft goods (collectively “soft goods”). Contaminants from soft goods are removed by the low viscosity and surface tension of a liquefied solvent that is directed to impinge upon and pass through the soft goods. In accordance with embodiments of the present disclosure, a dual-drum configuration is provided such that garments and liquid / gas phases are separated with inner and outer drums in a rotary phase separator. In some embodiments, the cleaning solvent, when in liquid phase, may be filtered and distilled, then converted back to gas, reclaimed, and then may be reused for a subsequent cleaning cycle. The microgravity dry cleaning systems described herein can provide one or more of the following benefits: reducing resupply payloads for fresh clothes or other soft goods; enabling reduction of disposable wipes for crew personal hygiene; and the like. Further, such system may offer increases to crew comfort and morale by enabling the ability to frequently refresh clothing and other soft goods.

[0056] Although various different types of cleaning solvents may be used with embodiments described herein, it has been realized that CO2 is an underutilized, renewable resource in crewed space vehicles and habitats. On the ISS, for example, CO2 is currently vented to space or may be used for water / oxygen reclamation via a Sabatier system and Oxygen Generator Assembly. However, the CO2 may be used for other purposes, as described herein, such as cleaning soft goods. For example, and without limitation, CO2-based dry-cleaning systems in accordance with the present disclosure can improve the efficiency of a closed-loop environmental control and life support systems (“ECLSS”) by utilizing the CO2 that would otherwise be vented as waste and using such CO2as a cleaning solvent. The microgravity dry-cleaning systems of the present disclosure may be integrated into ECLSS systems. For example, a microgravity dry-cleaning system of the present disclosure may be arranged downstream of a CO2 removal system, rather than a venting port, waste disposal, or the like. Further, the microgravity dry-cleaning systems of the present disclosure may provide purified CO2upstream of a Sabatier reactor to be converted into oxygen / water. Integration with existing CO2 handling and recycling systems can minimize the additional system mass, conserve water, and can avoid complex water recycling. For example, recycling metabolic waste CO2for use in the cleaning cycles of the microgravity dry-cleaning systems described herein can reduce a reliance upon resupplied consumables, reduce payload costs, and can allow for more sustainable systems for long duration missions.

[0057] Referring now to FIG. 2, a schematic diagram of a microgravity dry-cleaning system 200 in accordance with an embodiment of the present disclosure is shown. The microgravity dry-cleaning system 200 includes a rotary cleaner 202. The rotary cleaner 202 includes a cover, lid, or door 204, an outer drum 206, and an inner drum 208, defining an annular cavity 210 between the inner drum 208 and the outer drum 206. The inner drum 208 includes perforations that allow a cleaning solvent to pass through to the annular cavity 210. For example, the cleaning solvent may be subcritical CO2, supercritical CO2, perchloroethylene, modified alcohols, siloxanes, hydrocarbons, glycol ethers, halogenated solvents, and the like. In accordance with some embodiments, the interior of the rotary cleaner 202 may be maintained at a constant pressure when the door 204 is closed and sealed to the outer drum 206.

[0058] The inner drum 208 is configured to receive soft goods. The inner drum 208 and the outer drum 206 are configured to be rotationally driven, as described herein. The rotary cleaning 202 includes a cleaning solvent dispenser 212, which is configured to dispense cleaning solvent toward the inner drum 208. The cleaning solvent dispenser 212 may be configured as a shaft or rod with a plurality of dispensing apertures arranged about the circumference thereof, and may include an internal fluid path for supplying cleaning solvent to be dispensed toward the inner drum 208. The dispensing of cleaning solvent, in combination with rotation of the inner drum 208, may cause agitation and tumbling of the soft goods within the inner drum 208, thereby providing efficient cleaning functionality.

[0059] As illustrated, the rotary cleaner 202 is configured to be rotationally driven by a motor 214 via a first drive belt 216. Although a belt-based system is described herein, it will be appreciated that other rotational driving mechanisms, such as gears, magnets, electromagnets, or the like, may be used without departing from the scope of the present disclosure. A pump 218 is configured to pump a cleaning solvent 220 into the rotary cleaner 202 from a cleaning solvent source 221 (e.g., storage tank, container, etc.). The pump 218 may also be driven by the motor 214 via a second drive belt 222. Because the rotational speeds of the rotary cleaner 202 and the pump 218 may be different, a gearbox 224 may be provided to control rotational speeds. Although shown with the gearbox 224 associated with the pump 218, it will be appreciated that one or both of the pump 218 and the rotary cleaner 202 may have an associated gearbox, depending on the specific implemented configuration.

[0060] In this illustrative configuration, a four-way valve assembly 226 is provided to control various fluid operations of the microgravity dry-cleaning system 200. The microgravity dry-cleaning system 200 is configured to evacuate air to space (e.g., vacuum), such as when evacuating the interior of the rotary cleaner 202 of gases. The system is further configured to pressurize the interior of the rotary cleaner 202 with ambient air 228 via the four-way valve assembly 226. In some configurations, and as shown, the four-way valve assembly 226 is configured to supply a cleaning solvent (e.g., gas phase 230) at a start of a cleaning cycle and evacuate cleaning solvent (e.g., gas phase 230) at an end of the cleaning cycle. In some configurations, the four-way 226 may be configured to receive CO2 (e.g., gas phase 230) form a CO2 removal system of a habitat or spacecraft, or from a local external environment (e.g., Martian atmosphere). The pump 218 may also be configured to recirculate the cleaning solvent (e.g., liquid phase 232). A bearing and seal assembly 234 may be provided at a base of the rotary cleaner 202 to support rotation of the rotary cleaner 202. In some configurations, the cleaning solvent dispenser 212 may be stationary (i.e., not rotationally driven), and the drums 206, 208 are rotationally driven around the cleaning solvent dispenser 212. The bearing and seal assembly 234 is arranged to support such operation.

[0061] The microgravity dry-cleaning system 200 includes a solvent outlet flow of output solvent 236 which may be directed to a solvent processing device 238, such as a filter. The output solvent 236 may be directed to a three-way valve assembly 240 after processing in the solvent processing device 238. At the three-way valve assembly 240, the processed used solvent may be recycled back through the pump 218 for a subsequent cleaning cycle or may be directed to a storage or distillation tank 242.

[0062] In accordance with some embodiments, and as described herein, the outer drum 206 may include vanes or other guiding structures and features that are configured to utilize capillary-driven flow (e.g., surface tension and wetting) to guide the cleaning solvent (liquid phase) along the interior of the outer drum 206 to be removed by suction generated by the pump 218. In some embodiments, the outer drum 208 may include radially spaced suction ports or the like that are plumbed into the structure of the outer drum 208. Such radially spaced suction ports may fluidly connect to an outlet port to direct the output solvent 236 to the solvent processing device 238.

[0063] As noted above, the motor 214 is configured to drive operation of both the rotary cleaner 202 and the pump 218. In various embodiments, the motor 214 may be configured as an electric motor, a turbomachine, or other type of drive mechanism or motor, as will be appreciated by those of skill in the art. Various gearing systems, such as gearbox 224, may be provided to enable engagement and disengagement from the pump 218 and / or the rotary cleaner 202. In some embodiments, all rotating parts (e.g., drums 206, 208, pump 218) may be driven by the same motor 214. In such single-motor configurations, the proper speeds for driving the respective components may be achieved with gear ratios and belt drives. In some configurations, the pump 218 can be disengaged while the rotary cleaner 202 is continued to be rotationally driven by the motor 214.

[0064] With continued reference to FIG. 2, an example operation of the microgravity dry-cleaning system 200 is provided. First, the door 204 is opened and soft goods are placed within the inner drum 208. The door 204 is closed and sealingly engaged with the outer drum 206 or other sealing structure. The four-way valve assembly 226 is opened and a pressure delta evacuates air from the rotary cleaner 202 (e.g., to the vacuum of space), and then the vacuum connection is closed. In accordance with some embodiments, the air side (e.g., 228) of the four-way valve assembly 226 is connected to both the vacuum of space and to a cabin environment of a spacecraft or habitation structure. The four-way valve assembly 226 opens and a pressure delta charges the rotary cleaner 202 with cleaning solvent (gas phase 230). The four-way valve assembly 226 then operates with the pump 218 to fill the rotary cleaner 202 with clean solvent (e.g., liquid phase 232). Excess liquid cleaning solvent may be removed via the three-way valve assembly 240 to allow solvent (liquid phase) to be recirculated back into rotary cleaner 202, as schematically shown.

[0065] The motor 214 is then operated to rotationally drive both the rotary cleaner 202 (rotationally drive the drums 206, 208) and the pump 218. The rotary cleaner 202 will spin and the pump 218 is operated to cycle cleaning solvent (liquid phase 232) through the cleaning solvent dispenser 212, which is directed at the soft goods and the inner drum 208. During such operation, the cleaning solvent may be cycled via an output solvent 236 loop, via the three-way valve assembly 240. In this operation, the output solvent 236 may be filtered or otherwise processed within the solvent processing device 238. In some operations, the pump 218 may be disengaged from the motor 214, allowing for a spin cycle where no additional cleaning solvent is injected into the rotary cleaner 202. In some configurations, the motor 214 may be configured to reverse rotational direction, thus driving the rotary cleaner 202 in reverse which may provide for additional agitation and cleaning and / or tumbling of the soft goods within the rotary cleaner 202.

[0066] At the end of a cleaning cycle, the two-way valve 240 may be opened and used cleaning solvent (e.g., liquid phase) is directed to the distillation tank 242. The operational and / or cleaning cycle can be repeated to dilute with clean solvent (liquid phase) as needed. Once the cleaning solvent has been evacuated from the rotary cleaner 202, the three-way valve assembly 240 is closed and the pump 218 is disengaged from the motor 214. The four-way valve assembly 226 may then be opened and a pressure delta evacuates any remaining cleaning (e.g., gas phase) solvent from the rotary cleaner 202. Next, the four-way valve assembly 226 is operated to generate a pressure delta to repressurize the rotary cleaner 202 with ambient air (228). The rotary cleaner 202 may then disengage from the motor 214 and stop spinning and / or the motor 214 may be stopped. The door 204 can now be opened and clean soft goods can be removed from the rotary cleaner 202.

[0067] Referring now to FIGS. 3A-3B, schematic illustrations of a rotary cleaner 300 in accordance with an embodiment of the present disclosure is shown. The rotary cleaner 300 may be arranged as part of a microgravity cleaning system (e.g., microgravity dry-cleaning system 200 of FIG. 2) or a cleaning system for use in microgravity (e.g., microgravity dry-cleaning system 100 of FIG. 1), or other systems configured for cleaning soft goods in microgravity environments.

[0068] The rotary cleaner 300 includes a drum assembly 302 and a drive assembly 304. The drum assembly 302 is configured to be operably mounted or otherwise attached to the drive assembly 304. In accordance with some embodiments, the drive assembly 304 is configured to rotationally drive portions of the drum assembly 302.

[0069] The drum assembly 302 includes a cover, lid, or door 306, an outer drum 308, and an inner drum 310. The drum assembly 302 has a first end 312 that is configured to operably engage with the drive assembly 304 and a second end 314 that includes the door 306. A cross-sectional interior view of the drum assembly 302 is shown in FIG. 3B. The drum assembly 302 defines a cleaning cavity 316 within the inner drum 310 and an annular cavity 318 is defined between the inner drum 306 and the outer drum 304. The door 306 is configured to be opened to allow access to the cleaning cavity 316 to enable depositing and removal of soft goods into and out of the cleaning cavity 316. In this illustrative embodiment, the door 306 is configured with a hinge 320 and a locking mechanism 322. The door 306 or a surface of the outer drum 308 may be provided with a seal 324, such as a gasket or the like. It will be appreciated that other mechanisms of operation of the door 306 may be employed without departing from the scope of the present disclosure.

[0070] The inner drum 310 defines a permeable wall 326, which may include as illustrated, perforations, holes, apertures, as well as various agitation features, such as, but not limited to, raised ridges, bumps, protrusions, vanes, dimples, patterned textures, or any other feature(s) and combinations thereof that may aid in agitation of the soft goods. The permeable wall 326 may take other form or structure, which may be dependent upon the specific cleaning solvent used. or other permeability features, allow for cleaning solvent to pass through the inner drum 310 to the annular cavity 318 and to impinge upon a surface of the outer drum 308. The outer drum 308 includes flow directors 328 on the interior surface thereof. The flow directors 328 may be vanes or other structures that are arranged to direct a capillary-driven flow of cleaning solvent toward the first end 312 of the drum assembly 302. The flow directors 328 may be provided on and extend along (e.g., axially) the interior surface of the outer drum 308 from the first end 312 to the second end 314.

[0071] In accordance with some embodiments, the flow directors 328 may define tapering flow passages along the interior surface of the outer drum 308. Such tapering may result in narrowing passages extending from widest at the second end 314 and narrowing toward the first end 312. Additionally, as illustratively shown, the geometry of the outer drum 308 may taper or narrow from the second end 314 (largest radius) toward the first end 312 (smallest radius). During operation, the rotation of the rotary cleaner 300 will centrifugally force the cleaning solvent radially outward to the flow directors 328. The collected cleaning solvent will then be driven by capillary action (surface tension and wetting) toward the first end 312. Such capillary action provides a collection mechanism when operated in microgravity environments. The cleaning solvent may then be recaptured or recirculated by means of a suction operation or the like, as described herein.

[0072] Arranged within the drum assembly 302 and extending from the first end 312 to the second end 314 is a cleaning solvent dispenser 330. The cleaning solvent dispenser 330 extends axially through the interior of the drum assembly 302. The cleaning solvent dispenser 330 is configured to operably connect to a portion of the drive assembly 304, such as to receive a supply of cleaning solvent therefrom. The cleaning solvent dispenser 330, in this illustrative configuration, is a shaft or rod having an input bore 332 that fluidly connects to a source of cleaning solvent. The input bore 332 transitions into a helical path 334 which directs fluid to a plurality of jet nozzles 336 or other fluid dispenser structures / elements. The jet nozzles 336 are distributed axially along the cleaning solvent dispenser 330 in a helical pattern based on the helical path 334. The jet nozzles 336 may be arranged to direct a jet of cleaning solvent in a substantially radial direction toward the inner drum 310, and may include a tangential component, as described herein.

[0073] As noted above, the drum assembly 302 is configured to be operably connected to the drive assembly 304. In accordance with some embodiments of the present disclosure, the drums 308, 310 are arranged to be rotationally driven by the drive assembly 304, and the cleaning solvent dispenser 330 may be stationary or non-rotating relative to the drums 308, 310. Accordingly, one or more bearings 338 may provide an interface between the stationary cleaning solvent dispenser 330 and the rotating drums 308, 310. In some embodiments, the inner drum 310 may be fixedly attached to the outer drum 308, such as by fasteners, welding, adhesives, or the like, or a portion of the inner drum 310 may be seated within a slot or the like of the outer drum 308, such that relatively motion between the two drums 308, 310 is prevented.

[0074] At the first end 312 of the drum assembly 302, the outer drum 308 includes an assembly aperture 342. The assembly aperture 342 may be sized to receive a bearing 338, a portion of the cleaning solvent dispenser 330, and various flow or fluid pathways, as described herein. The flow and fluid pathways may be arranged to enable pressurization of the internal cavities of the drum assembly 302 and extract or direct a flow of used or excess cleaning solvent out of the internal cavities of the drum assembly. The exterior surface of the outer drum 308 may include a drive element 344, such as a channel or slot for engaging with a first drive belt 346 of the drive assembly 304. It will be appreciated that the drive element 344 of the drum assembly 302 may take other forms, such as a magnet or electromagnet configuration, a geared or toothed configuration, or the like, as will be appreciated by those of skill in the art.

[0075] Referring again to FIG. 3A, the drive assembly 304 includes a motor 348 and a pump 350. The motor 348 is configured to drive operation of the pump 350 and the rotating portions of the drum assembly 302. In this illustrative configuration, the pump 350 is operably mounted and coupled to the motor 348, providing for a relatively small profile / volume of the components. It will be appreciated that in other configurations, a pump may be operably coupled to and driven by the motor using other connection and drive mechanisms, without departing from the scope of the present disclosure.

[0076] The motor 348 is also operably coupled to the drive element 344 of the drum assembly 302 via a drive shaft 352. In this configuration, the motor 348 connects to the drive shaft 352 via a second drive belt 354. Although illustrated as a direct connection drive shaft, the drive shaft of various embodiments may include gearing, multiple shafts, direct connects, or other types of drive mechanisms, including but not limited to magnetic and electromagnetic.

[0077] The pump 350 is configured to receive a cleaning solvent, such as a liquid or gas, via a cleaning solvent inlet 356. The pump 350 is configured to pump the cleaning solvent into the interior of the drum assembly 302 for cleaning soft goods deposited therein. The pump 350 also includes a cleaning solvent outlet 358. The cleaning solvent outlet 358 may be arranged to direct used cleaning solvent from the drum assembly 302 during a cleaning operation. Further, in some embodiments, the cleaning solvent outlet 358 may be used for gaseous charging (e.g., gaseous inlet operation) of the interior of the drum assembly 302, such as during a pre-cleaning cycle of the rotary cleaner 300.

[0078] Referring now to FIGS. 4A-4C, schematic illustrations of portions of a drum assembly 400 in accordance with an embodiment of the present disclosure are shown. FIG. 4A illustrates a side view of an inner drum 402 of the drum assembly 400. FIG. 4B is an enlarged illustration of the 4B labeled in FIG. 4A. FIG. 4C is a top-down view along the line 4C-4C shown in FIG. 4A. The drum assembly 400 may be similar to that shown and described above, although the outer drum is omitted for illustrative purposes. As such, the drum assembly 400 may be part of a rotary cleaner in accordance with embodiments of the present disclosure. The schematic illustrations of FIGS. 4A-4C demonstrate the agitation physics of microgravity dry-cleaning systems in accordance with the present disclosure.

[0079] The drum assembly 400 includes the inner drum 402 with a cleaning solvent dispenser 404 arranged therein. The inner drum 402 is configured to be rotationally driven about an axis of rotation 403 and about the cleaning solvent dispenser 404. In some embodiments, the cleaning solvent dispenser 404 is configured to be retained in a stationary, non-rotating position / orientation. The cleaning solvent dispenser 404 includes a plurality of jet nozzles 406 configured to direct jets of cleaning solvent 408 toward the inner drum 402 and any soft goods 410 deposited within the drum assembly 400.

[0080] In an example operation, the inner drum 402 is rotationally driven about the rotation axis 403, such as by a motor or the like, as described above. As the inner drum 402 is rotated relative to the cleaning solvent dispenser 404, a cleaning solvent may be dispensed from the jet nozzles 406 of the cleaning solvent dispenser 404 as jets of cleaning solvent 408. The jet nozzles 406 are configured, in combination with pressurized cleaning solvent (e.g., pressurized by a pump), to direct a forceful stream of cleaning solvent at the soft goods 410. The cleaning solvent may be absorbed into the soft goods 410 to pick up particulate matter (e.g., dirt, sweat, debris, etc.) and remove it from the soft goods 410. Additionally, the jets of cleaning solvent 408 may have a radial force sufficient to cause tumbling or agitation of the soft goods 410. For example, as shown, the jets of cleaning solvent 408 may include a radial force Fjet-radial and a tangential force Fjet-tangent. As the jets of cleaning solvent 408 impinge on the soft goods 410, and the inner drum 402 is rotated, tumbling and agitation may be provided simultaneously, thereby increasing the cleaning efficiency. The component of force of the jets of cleaning solvent 408 (Fjet-tangent) may overcome the force of friction (Ffriction) of the soft goods 410 against the wall or surface of the inner drum 402, thereby causing rolling, tumbling, or other agitation of the soft goods 410 within the inner drum 402.

[0081] In the illustrative configuration of FIGS. 4A-4C, the inner drum 402 is rotationally driven in a clockwise direction, and the jet nozzles 406 are oriented to direct the jets of cleaning solvent 408 with a force component opposite or against the direction of rotation of the inner drum 402. As shown in FIG. 4B, the jets of cleaning solvent 408 may experience jet breakup as the stream of fluid travels from the jet nozzles 406 toward the soft goods 410 and inner surface of the inner drum 402. At each axial position along the rotation axis 403 of the jet nozzles 406, the radial distance Rdrum of the inner surface of the inner drum 402 from a respective jet nozzle 406 is selected or set to be less than a jet breakup distance xbreak-up. That is, the maximum radial dimension Rdrum_max of the inner drum 402 is set to be less than the jet breakup distance xbreak-up. The jet breakup distance x break-up is based on the diameters or opening size of the jet nozzles 406 and the velocity of the cleaning solvent as it is ejected from the jet nozzles 406, which may be controlled by the pumping from the pump of the system. By ensuring that the maximum radial dimension Rdrum_max of the inner drum 402 is less than the jet breakup distance xbreak-up at all axial positions, the system may be configured to ensure tumbling or rolling of the soft goods 410 is achieved during operation.

[0082] Referring now to FIGS. 5A-5F, schematic illustrations of portions of a rotary cleaner 500 in accordance with an embodiment of the present disclosure are shown. FIG. 5A is a schematic illustration of a drum assembly 502 of the rotary cleaner 500, which is operably attached to a drive assembly 504. FIG. 5B is an illustration of a cleaning solvent dispenser 506 of the drum assembly 502. FIG. 5C is an enlarged detail illustration of a fluid interface end 508 of the cleaning solvent dispenser 506. FIG. 5D is a cross-sectional view of the cleaning solvent dispenser 506 viewed along the line 5D-5D shown in FIG. 5B. FIG. 5E is an enlarged detailed view of fluid interface end 508 of the cleaning solvent dispenser 506 within the drum assembly 502 and coupling to the drive assembly 504. FIG. 5D is an enlarged detailed illustration of flow paths within the fluid interface end 508 of the cleaning solvent dispenser 506. The rotary cleaner 500 may be configured similarly to that shown and described above, and thus similar features may not be described again.

[0083] The drum assembly 502 includes an outer drum 510 and an inner drum 512. The drums 510, 512 are configured to be rotationally driven by the drive assembly 504 (or other drive mechanism). The inner drum 512 defines a permeable wall 514, which may be defined by perforations or apertures formed in the structure of the inner drum 512. The outer drum 510 defines a solid wall or surface that includes flow directors 516 on the interior surface thereof. The flow directors 516 are configured to direct a flow of fluid that impinges upon the interior surface of the outer drum 510 toward an outlet end 518 (e.g., first end 312 of FIG. 3B) of the drum assembly 502.

[0084] The cleaning solvent dispenser 506 is arranged within the drum assembly 502 and is configured to dispense jets of cleaning solvent toward the inner surface of the inner drum 512 and any soft goods contained within the drum assembly 502. The cleaning solvent dispenser 506 includes an input bore 520 for receiving a cleaning solvent. The input bore 520 transitions into a helical path 522 via a transition bore 524. The helical path 522 is defined about a periphery of the structure of the cleaning solvent dispenser 506 and fluidly couples to a plurality of jet nozzles 526 arranged about the exterior of the cleaning solvent dispenser 506 (e.g., FIG. 5D). As shown in FIG. 5D, the jet nozzles 526 are arranged to dispense jets of cleaning solvent 528 which are directed to impinge upon soft goods and the inner surface of the inner drum 512.

[0085] After the cleaning solvent impinges upon soft goods and the inner drum 512, the cleaning solvent will pass through the permeable wall 514 and collect on the inner surface of the outer drum 510 between the flow directors 516. The flow directors 516 will cause the collected cleaning solvent to be directed toward the outlet end 518 of the drum assembly 502. The cleaning solvent may then collect or pool at the outlet end 518 and may flow into or be siphoned into exit conduits 530. The exit conduits 530 are fluidly coupled to a cleaning solvent outlet 532 that is part of the drive assembly 504, such as part of a pump 534. As shown in FIG. 5F, an input cleaning solvent 536 may be directed through the input bore 520 via the pump 534 or the like, as described above. The input cleaning solvent 536 is then directed through the cleaning solvent dispenser 506 and dispensed via the jet nozzles 526. After interacting with soft goods within the drum assembly 502, the used cleaning solvent is collected and directed to the outlet end 518 of the drum assembly 502 by the flow directors 516. The used cleaning solvent 538, as shown in FIG. 5F, is then directed into the exit conduits 530 and removed from the drum assembly 502. As shown in FIG. 5F, the input bore 520 and the exit conduits 530 may be formed or defined within the structure of the cleaning solvent dispenser 506. In other configurations, the two flow paths may be formed or defined within separate physical structures. However, it will be appreciated that the illustrative configurations provide for a compact solution.

[0086] Referring now to FIGS. 6A-6B, schematic illustrations of a portion of an inner drum 600 in accordance with an embodiment of the present disclosure are shown. FIG. 6A is a view of an interior surface 602 of the inner drum 600, and FIG. 6B is a side view thereof. The inner drum 602 defines the interior surface 602 and an exterior surface 604. When installed in a rotary cleaner of the present disclosure, the interior surface 602 will face and define the interior chamber for receiving soft goods and the exterior surface 604 will face an interior surface of an outer drum, as shown and described above. As discussed above, the interior drum 600 defines a permeable structure to allow for fluids to pass from the interior surface 602, through the material or body of the inner drum 600, and exit from the exterior surface 604.

[0087] The permeability of the inner drum 600 is illustrated as a set of apertures, holes, or perforations 606 defined through the material of the inner drum 600. It will be appreciate that other types of permeability may be employed without departing from the scope of the present disclosure. The inner drum 600 may also include various agitation features to increase the ability of the system to agitate and tumble soft goods during a cleaning operation. Various examples of such agitation features are shown in FIGS. 6A-6B. A first agitation feature 608 is arranged as a set or pattern of bumps or dimples that extend from the interior surface 602 of the inner drum 600. The first agitation feature 608 is arranged between rows of the perforations 606. A second agitation feature 610 is arranged to span multiple rows of the perforations 606. The second agitation feature 610 is a blade or vane extending from the interior surface 602. The length and angle of orientation, and curvature thereof, may be set to achieve a desired agitation and tumbling functionality. A third agitation feature 612 is illustrated as a set of small blades, vanes, or protrusions. A third agitation feature 614 is arranged as pyramidal shapes.

[0088] Although FIGS. 6A-6B illustrate a limited number of options for the agitation features, it will be appreciated that the shape, geometry, number, and orientation may all be varied to achieve a desired agitation and / or tumbling of soft goods that are contained within the inner drum and subject to a cleaning cycle using a rotary cleaner as shown and described herein. Alternatively, or in combination with the positive structured agitation features 608, 610, 612, 614, in some embodiments, the interior surface 602 may have an undulating or wavy surface pattern / texture that may be used to cause agitation and / or tumbling of soft goods. Further, although shown as discrete or discontinuous feature, it will be appreciated that blades, vanes, ridges, or the like may be continuous from top to bottom (second end to first end) of the interior surface 602 of the inner drum 600. Accordingly, the examples of FIGS. 6A-6B are merely for illustrative and explanatory purposes and are not intended to be limiting.

[0089] Referring now to FIGS. 7A-7B, schematic illustrations of a portion of a rotary cleaner 700 in accordance with an embodiment of the present disclosure are shown. The rotary cleaner 700 includes an outer drum 702 having a set of flow directors 704 extending from an interior surface 706 thereof. The flow directors 704 define open channels 708 that extend from a first end 710 (e.g., outlet / suction end of rotary cleaner to a second end 712 (e.g., lid end of rotary cleaner). The open channels 708 are configured to narrow toward the first end 710.

[0090] FIGS. 7A-7B illustrate the flow directors 704 and relationship to a cleaning solvent 708 that is collected thereon during a cleaning operation, as described above. The cleaning solvent 714 is ejected from a cleaning solvent dispenser, interacts with soft goods, and passes through a permeable wall of an inner drum, as described above. The cleaning solvent 708 (which may be used and may include picked up dirt, debris, sweat, and other waste) is forced radially outward via centrifugal force Fcent. The centrifugal force Fcent urges or pushes the cleaning solvent 708 to the interior surface 706 of the outer drum 702. Surface tension at the corners defined at the intersection or base of the flow directors 704 of the open channels 708 restrains the cleaning solvent 714 and the contracting angle of the flow directors 704 drives a capillary force Fcap in the flow toward the first end 710 of the outer drum 702 to be collected by suction or other mechanism.

[0091] In accordance with some embodiments, the interior of the rotary cleaner (i.e., the drum assembly) may be maintained at a constant pressure when the door is closed and sealed to the outer drum. The pressurization of the interior of rotary cleaner may be achieved via a pump and valve system, such as described above. That is, the same pump system that pumps the cleaning solvent into and through the rotary cleaner may also be used to pump pressurizing fluids (e.g., ambient air) into the interior of the sealed drum assembly. By controlling the interior pressure, for example, the phase state of the cleaning solvent may be controlled. The pressure control may be selected based on the specific cleaning solvent employed. For example, the cleaning solvent may be subcritical carbon dioxide, supercritical carbon dioxide, perchloroethylene, modified alcohols, siloxanes, hydrocarbons, glycol ethers, halogenated solvents, and the like. In some operations or steps of operations, the cleaning solvent may be in liquid form.

[0092] Advantageously, embodiments of the present disclosure provide a mechanical system concept that utilizes waterless, dry-cleaning solvent(s) and provides a physical means to clean soft goods and clothing articles in microgravity environments. Embodiments of the present disclosure can enable reductions in or minimized weight, volume, and power consumption for soft good cleaning systems used in microgravity environments. A rotary drum is configured to rotates about a stationary shaft which houses a helical flow passage for fluid to enter and spray out tangentially therefrom. The jets of cleaning solvent may be arranged to agitate the soft goods and saturate the soft goods to perform a cleaning operation. The cleaning solvent will then pass through a permeable wall of an inner drum and be collected and directed by capillary-driven flow directors or guide vanes arranged on an interior surface of an outer drum. Centrifugal force pulls the used cleaning solvent to an outlet end of the drum assembly where integral ports or exit conduits pull the used cleaning solvent out of the drum assembly. The removal of the used cleaning solvent may be aided by the generation of suction from an external source (e.g., pump). The pump and rotation of the drum assembly may optionally be driven from the same power train or motor. Such dual driving operation may be accomplished by externally driven pulleys, cables, belts, or the like. In some embodiments, gear ratios can be optimized for proper pump speed-to-drum speed ratios.

[0093] Advantageously, embodiments of the present disclosure provide for improved cleaning systems for laundry and the like that may be used in microgravity environments. Benefits of the embodiments described herein include, for example and without limitation, elimination of the use of water for laundry and cleaning operations onboard space stations or space craft where water is a limited and valuable resource. Accordingly, water consumption for sanitation may be reduced by use of cleaning systems as described herein. Furthermore, advantageously, because of the manipulation of pressure to ensure the phase state of cleaning solvents, the systems described herein may be wholly or primarily operated at room temperature, and no cooling is required to maintain the cleaning solvent in a liquid state.

[0094] Advantageously, embodiments of the present disclosure provide for highly efficient soft goods cleaning by inducing tumbling of the soft goods, even in microgravity environments. For example, a jet of cleaning solvent may be directed at a rotating drum surface, which may have soft goods thereon. The impinging jets of cleaning solvent may be of sufficient force to overcome the frictional engagement between the soft goods and the wall of the drum. This high force impingement can cause the soft goods to tumble or agitate the soft goods, increasing the cleaning efficiency of a rotary cleaner. These and other benefits will be appreciated by those of skill in the art in view of the teachings herein.

[0095] The use of the terms "a", "an", "the", and similar references in the context of description (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or specifically contradicted by context. The modifier "about" used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. As used herein, the terms “about” and “substantially” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, the terms may include a range of ± 8% of a given value or other percentage change as will be appreciated by those of skill in the art for the particular measurement and / or dimensions referred to herein.

[0096] While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions, combinations, sub-combinations, or equivalent arrangements not heretofore described, but which are commensurate with the scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description but is only limited by the scope of the appended claims.

Claims

1. A microgravity dry-cleaning system comprising:a drum assembly having an inner drum and an outer drum and a cleaning solvent dispenser arranged within the inner drum; anda drive assembly configured to:rotationally drive the inner drum and the outer drum relative to the cleaning solvent dispenser; anddirect a cleaning solvent into the cleaning solvent dispenser for dispensing the cleaning solvent toward an interior surface of the inner drum.

2. The microgravity dry-cleaning system of claim 1, wherein the inner drum defines a permeable wall.

3. The microgravity dry-cleaning system of claim 2, wherein the permeable wall is defined by perforations, holes, or apertures in the material of the inner drum.

4. The microgravity dry-cleaning system of claim 1, wherein the inner drum comprises one or more agitation features on an interior surface thereof and configured to interact with and agitate and / or tumble a soft good disposed within the inner drum.

5. The microgravity dry-cleaning system of claim 1, wherein the outer drum comprises a plurality of flow directors arranged on an interior surface of the outer drum, the plurality of flow directors configured to direct a capillary-driven flow of cleaning solvent toward an outlet end of the drum assembly.

6. The microgravity dry-cleaning system of claim 1, wherein the cleaning solvent dispenser comprises:a helical path extending about a periphery of the cleaning solvent dispenser; anda plurality of jet nozzles arranged about the exterior of the cleaning solvent dispenser and oriented to direct a jet of cleaning solvent to impinge upon an inner surface of the inner drum and any soft goods within the inner drum.

7. The microgravity dry-cleaning system of claim 6, wherein the plurality of jet nozzles are configured to direct the jet of cleaning solvent in a direction counter to a rotation direction of the inner drum and outer drum to cause tumbling and agitation of a soft good within the inner drum.

8. The microgravity dry-cleaning system of claim 7, wherein the plurality of jet nozzles are configured to direct a jet of cleaning solvent with a force defining a breakup distance of the jet of cleaning solvent and a maximum radius of the inner drum is less than the breakup distance.

9. The microgravity dry-cleaning system of claim 6, wherein the cleaning solvent dispenser comprises an input bore for receiving a cleaning solvent and a transition bore that fluidly connects the input bore to the helical path.

10. The microgravity dry-cleaning system of claim 9, wherein the cleaning solvent dispenser defines a fluid interface end comprising at least the input bore, the cleaning solvent dispenser further comprising:one or more exit conduits fluidly coupled to an interior of the outer drum and configured to receive used cleaning solvent to direct the used cleaning solvent out of the outer drum.

11. The microgravity dry-cleaning system of claim 1, further comprising a cleaning solvent source containing a cleaning solvent to be supplied into the drum assembly.

12. The microgravity dry-cleaning system of claim 1, wherein the drive assembly comprises:a motor; anda pump,wherein the motor is configured to rotationally drive the inner drum and the outer drum about the cleaning fluid dispenser and to operably drive the pump.

13. The microgravity dry-cleaning system of claim 12, wherein the motor is rotationally connected to the outer drum via a belt.

14. The microgravity dry-cleaning system of claim 1, wherein the inner drum, the outer drum, and the cleaning solvent dispenser define a drum assembly, the drum assembly further comprising:a door configured to selectively sealingly engage with the outer drum.

15. The microgravity dry-cleaning system of claim 1, wherein the cleaning solvent is sourced from one of a carbon dioxide removal system or an external ambient atmosphere.

16. A drum assembly for a microgravity dry-cleaning system, the drum assembly comprising:an outer drum having a plurality of axially extending flow directors on an interior surface of the outer drum;an inner drum arranged within the outer drum, the inner drum defining a permeable wall; anda cleaning solvent dispenser arranged within the inner drum and configured to direct a jet of cleaning solvent toward the inner drum from a plurality of jet nozzles, the cleaning solvent dispenser having a helical path defining a flow path for cleaning solvent to be supplied to the jet nozzles.

17. The drum assembly of claim 16, wherein:the outer drum and the inner drum are configured to be rotationally driven about the cleaning solvent dispenser in a rotation direction, andthe plurality of jet nozzles are configured to direct the jet of cleaning solvent in a direction counter to the rotation direction of the inner drum and outer drum to cause tumbling and agitation of a soft good within the inner drum.

18. The drum assembly of claim 17, wherein the plurality of jet nozzles are configured to direct a jet of cleaning solvent with a force defining a breakup distance of the jet of cleaning solvent and a maximum radius of the inner drum is less than the breakup distance.

19. The drum assembly of claim 16, wherein the cleaning solvent dispenser comprises an input bore for receiving a cleaning solvent and a transition bore that fluidly connects the input bore to the helical path.

20. The drum assembly of claim 19, wherein the cleaning solvent dispenser defines a fluid interface end comprising at least the input bore, the cleaning solvent dispenser further comprising:one or more exit conduits fluidly coupled to an interior of the outer drum and configured to receive used cleaning solvent to direct the used cleaning solvent out of the outer drum.

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