Carbon dioxide-based cleaning systems
Carbon dioxide-based cleaning systems include a holding tank containing a supply of liquid carbon dioxide (CO 2 ), a rotary cleaner having an internal drum arranged therein, the rotary cleaner fluidly coupled to the holding tank to receive liquid CO 2 therefrom, the rotary cleaner configured to output CO 2 with contaminants after a cleaning cycle, a compressor arranged to receive gaseous CO 2 and increase a pressure of the gaseous CO 2 , and a condenser arranged to receive the increased pressure gaseous CO 2 from the compressor and convert the gaseous CO 2 into liquid CO 2 and direct the liquid CO 2 into the holding tank.
1 . A carbon dioxide-based cleaning system for a low-gravity human occupancy environment, the carbon dioxide-based cleaning system comprising:
a holding tank containing a supply of liquid carbon dioxide (CO 2 );
a rotary cleaner having an internal drum arranged therein and defining a cleaning cavity, the rotary cleaner fluidly coupled to the holding tank to receive liquid CO 2 therefrom, the rotary cleaner configured to output CO 2 with contaminants after a cleaning cycle;
a compressor arranged to receive gaseous CO 2 and increase a pressure of the gaseous CO 2 ;
a condenser arranged to receive the increased pressure gaseous CO 2 from the compressor and convert the gaseous CO 2 into liquid CO 2 and direct the liquid CO 2 into the holding tank, and
a first valve configured to selectively fluidly couple the cleaning cavity of the rotary cleaner with the low-gravity human occupancy environment, wherein the low-gravity human occupancy environment is one of a spacecraft, a space station, or a station on a non-Earth celestial object, wherein the valve is configured to be opened to pressurize the cleaning cavity with air from the low-gravity human occupancy environment, and
a second valve configured to selectively operate to cause evacuation of gas from the cleaning cavity of the rotary cleaner;
wherein the rotary cleaner is configured as a rotating centrifuge or rotary phase separator configured to perform an operation for cleaning clothes in the absence of gravity, wherein the rotary cleaner is configured to separate liquids and gases within the rotary cleaner and wherein the internal drum and the rotary cleaner are configured to rotate in tandem resulting in liquid CO 2 being forced radially outward through the clothes, through holes of the internal drum, and collect on an internal surface of the rotary cleaner that is external to the internal drum.
2 . The cleaning system of claim 1 , wherein the output CO 2 with contaminants is directed from the rotary cleaner to the compressor after the cleaning cycle.
3 . The cleaning system of claim 2 , further comprising a distillation tank arranged between the rotary cleaner and the compressor, the distillation tank configured to receive at least one of gaseous and liquid CO 2 from the rotary cleaner and separate contaminants from the CO 2 and supply clean gaseous CO 2 to the compressor.
4 . The cleaning system of claim 3 , wherein the distillation tank is coaxially arranged within the rotary cleaner.
5 . The cleaning system of claim 4 , wherein the distillation tank comprises a third valve configured to selective fluidly couple a distillation cavity defined within the distillation tank with a cleaning cavity defined within the rotary cleaner and external to the distillation tank.
6 . The cleaning system of claim 3 , further comprising a heating element arranged to provide heat to the distillation tank.
7 . The cleaning system of claim 3 , further comprising a slug tank arranged to receive CO 2 and contaminants captured by the CO 2 from the distillation tank.
8 . The cleaning system of claim 1 , wherein the internal drum is porous to liquid CO 2 and contaminants carried by the liquid CO 2 but prevents clothing from passing out of the internal drum.
9 . The cleaning system of claim 1 , wherein the rotary cleaner comprises a cleaning cavity defined within the internal drum and an annular cavity is defined radially between an external surface of the internal drum and an internal surface of an outer housing of the rotary cleaner.
10 . The cleaning system of claim 1 , further comprising a pump associated with the second valve, the pump configured to provide a motive force to draw the gas from the cleaning cavity of the rotary cleaner.
11 . The cleaning system of claim 1 , further comprising a filter and pump connected to the rotary cleaner, wherein the pump is configured to pull liquid CO 2 from the rotary cleaner and pass it through the filter and then redirect the liquid CO 2 back into the rotary cleaner.
12 . The cleaning system of claim 11 , further comprising a dispenser arranged along a flow path through the pump and the filter, wherein the dispenser is configured to apply at least one of a deodorizer and a detergent to the liquid CO 2 prior to being redirected back into the rotary cleaner.
13 . The cleaning system of claim 1 , further comprising an auxiliary supply of CO 2 arranged upstream from the compressor, the auxiliary supply of CO 2 configured to provide additional CO 2 into the system to replenish losses from the holding tank.
14 . The cleaning system of claim 1 , further comprising a slug tank arranged to receive CO 2 and contaminants captured by the CO 2 from the rotary cleaner.
15 . The cleaning system of claim 1 , wherein the holding tank is a bellows tank arranged to maintain the liquid CO 2 under pressure and in a liquid state in the low-gravity human occupancy environment.
16 . The cleaning system of claim 1 , wherein the second valve is configured to selectively fluidly couple the cleaning cavity with the vacuum of space outside the low-gravity human occupancy environment.
17 . The cleaning system of claim 1 , wherein the condenser is configured as part of a coolant loop having a second working fluid, wherein the second working fluid is configured as a heat sink.
18 . The cleaning system of claim 17 , wherein the coolant loop is a dedicated coolant loop associated with the cleaning system.
19 . The cleaning system of claim 17 , wherein the coolant loop is configured as part of other systems of the spacecraft, the space station, or the station on the non-Earth celestial object.