# US 8,769,731 B2 · Flushing device and flushing method for a vacuum toilet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,769,731 B2 - Document ID: US8769731B2 - Status: Granted - Kind: B2 - Application number: 12/077,593 - Filed: 2008-03-20 - Published: 2008-10-02 - Granted: 2014-07-08 - Earliest claimed: 2007-03-23 - Assignees: Airbus Operations GmbH - Applicants: Christian Seibt - Inventors: Christian Seibt - Web page: https://patentgrep.com/patent/US8769731B2 ## CPC - E03F 1/006: {Pneumatic sewage disposal systems; accessories specially adapted therefore} - B64D 11/02: Toilet fittings - E03D 11/08: Bowls with means producing a flushing water swirl - E03D 2201/40: Devices for distribution of flush water inside the bowl - Y02T 50/40: Weight reduction - E03F: SEWERS; CESSPOOLS - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - E03D: WATER-CLOSETS OR URINALS WITH FLUSHING DEVICES; FLUSHING VALVES THEREFOR - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A vacuum toilet and a method for operating a vacuum toilet, wherein generating negative pressure to remove solids by suction is also used for generating a desired flushing medium flow. To this effect, if necessary, guiding devices are used which influence a flow upstream of a nozzle outlet and downstream of a nozzle outlet such that flow optimization of the flushing medium can be carried out. ## Claims ### Claim 1 A vacuum toilet comprising a first volume; a second volume; and a nozzle arrangement; wherein the first volume comprises a first opening for supplying a medium to be disposed of, wherein the first opening can be closed off in a negative-pressure-proof manner, and a drain, to which a negative-pressure-generating device can be connected, for removing the medium to be disposed of; wherein the second volume comprises a reservoir for a flushing medium; wherein the nozzle arrangement includes a nozzle that comprises a nozzle outlet, wherein the nozzle arrangement connects the second volume to the first volume such that the nozzle outlet is directed to the first volume, and the flushing medium, by a pressure differential between the first volume and the second volume, through the nozzle reaches the first volume from the second volume in a directional manner, wherein the pressure differential is caused by negative pressure generated in the first volume; and wherein the first volume comprises an interior wall with a curvature that is at least in part concave, and the nozzle outlet is aligned such that the flow of the flushing medium travels laminarly along the concave curvature, and wherein the geometry of the nozzle arrangement is configured such that the hydrodynamic boundary layer on the toilet bowl is coverable by a laminar flow up to the drain. ### Claim 2 (depends on 1) The vacuum toilet of claim 1, further comprising a guiding device for guiding the flushing medium, wherein the guiding device is arranged such that the guiding device displaces the turbulence of a flow of the flushing medium away from the nozzle outlet. ### Claim 3 (depends on 1) The vacuum toilet of claim 1, wherein the second volume comprises a reservoir for a gaseous flushing medium and a reservoir for a liquid flushing medium. ### Claim 4 (depends on 2) The vacuum toilet of claim 2, wherein the guiding device is configured to guide a gaseous flushing medium around the reservoir for a liquid flushing medium. ### Claim 5 (depends on 3) The vacuum toilet of claim 3, further comprising a separation device configured to separate a gaseous flushing medium supplied from the reservoir for a gaseous medium, into a first partial quantity and a second partial quantity, wherein the liquid flushing medium is added to the first partial quantity. ### Claim 6 (depends on 5) The vacuum toilet of claim 5, wherein the first partial quantity leaves the nozzle arrangement closer to the interior wall of the first volume than does the second partial quantity. ### Claim 7 (depends on 2) The vacuum toilet of claim 2, wherein the guiding device is configured to guide the second partial quantity of a gaseous flushing medium. ### Claim 8 (depends on 1) The vacuum toilet of claim 1, wherein the second volume comprises an opening to the surroundings of the vacuum toilet. ### Claim 9 (depends on 1) The vacuum toilet of claim 1, wherein an interior wall of the first volume comprises an anti-adhesive or hydrophobic surface. ### Claim 10 (depends on 1) The vacuum toilet of claim 1, further comprising a lid movable between a first position and a second position, wherein the lid in the first position is configured to seal off the first volume in a negative-pressure-proof manner and in the second position is configured to release the first volume in order to feed in a medium to be disposed of. ### Claim 11 (depends on 1) The vacuum toilet of claim 1, wherein the nozzle is a slit nozzle that at least in part extends so as to be essentially parallel to the first opening. ### Claim 12 (depends on 1) The vacuum toilet of claim 1, further comprising a first valve configured to release the second opening to a device that generates negative pressure, a second valve configured to release a liquid flushing medium, and a control device configured to control a time sequence of controlling the first valve and the second valve. ### Claim 13 (depends on 1) A method for operating a vacuum toilet of claim 1, comprising: Negative-pressure-proof sealing of a first volume after feeding-in a medium to be disposed of; generating negative pressure in the first volume to remove, by suction, the medium to be disposed of, and to generate a pressure differential between the first volume and a second volume; placing a flushing medium from the second volume, by the negative pressure generated in the first volume, into the first volume by a nozzle that connects the second volume to the first volume, with a nozzle outlet that is directed into the first volume, wherein the first volume comprises an interior wall with a curvature that is at least in part concave, and the nozzle outlet is aligned such that the flow of the flushing medium travels laminarly along the concave curvature; and removing, by suction, the medium to be disposed of; wherein the geometry of the nozzle arrangement is configured such that the hydrodynamic boundary layer on the toilet bowl is covered by a laminar flow up to the drain. ### Claim 14 An aircraft comprising a vacuum toilet, the vacuum toilet comprising: a first volume; a second volume; and a nozzle arrangement; wherein the first volume comprises a first opening for supplying a medium to be disposed of, wherein the first opening can be closed off in a negative-pressure-proof manner, and a drain, to which a negative-pressure-generating device can be connected, for removing the medium to be disposed of; wherein the second volume comprises a reservoir for a flushing medium; wherein the nozzle arrangement includes a nozzle that comprises a nozzle outlet, wherein the nozzle arrangement connects the second volume to the first volume such that the nozzle outlet is directed to the first volume, and the flushing medium, by a pressure differential between the first volume and the second volume, through the nozzle reaches the first volume from the second volume in a directional manner, wherein the pressure differential is caused by negative pressure generated in the first volume; and wherein the first volume comprises an interior wall with a curvature that is at least in part concave, and the nozzle outlet is aligned such that the flow of the flushing medium travels laminarly along the concave curvature, and wherein the geometry of the nozzle arrangement is configured such that the hydrodynamic boundary layer on the toilet bowl is coverable by a laminar flow up to the drain.