Patent ID: 12203249

DETAILED DESCRIPTION

Throughout the figures like elements are designated with like reference numerals.

FIG.1shows an example embodiment of a buffer1for providing a liquid in the form of water at a consumer pressure to a consumer equipment. The consumer equipment itself is not shown inFIG.1. However, a consumer supply line2connecting the buffer1to the consumer equipment is shown. The buffer1comprises a housing3defining a storage volume4for holding a liquid and a gas. In the example embodiment, the storage volume4is separated by a partition element5into a liquid compartment6which holds the water in the storage volume4and a gas compartment7for holding the air in the storage volume4.

The partition element5seals the liquid compartment6from the gas compartment7thereby forming a barrier preventing water from entering the gas compartment7. Likewise, gas is prevented from flowing from the gas compartment7to the liquid compartment6. The partition element is further configured so that the volume of the liquid compartment6can be increased by reducing the volume of the gas compartment7and vice versa. Further, the pressure of the air in the gas compartment7and the pressure of the water in the liquid compartment6are positively correlated. Hence, when the pressure of the air in the gas compartment7rises, the pressure of the water in the liquid compartment6also rises. Since the pressure of the water in the liquid compartment6is positively correlated with the pressure of the air in the gas compartment7, the air is held at an operating pressure in the gas compartment7when the water is held at the consumer pressure in the liquid compartment6. The partition element5is formed from a flexible membrane so that the pressure of the gas along the membrane and the pressure of the water along the membrane are about equal.

Water shall be supplied from the buffer1at a consumer pressure which exceeds the environmental pressure. In case the buffer1is used onboard an aircraft, the environmental pressure corresponds to the cabin pressure. When the aircraft is on the ground and the cabin is vented, the cabin pressure corresponds to the atmospheric pressure. However, when the aircraft is in flight and the cabin is pressurized, the cabin pressure and, thus, the environmental pressure may be above the atmospheric pressure.

The buffer1further comprises a pressurizer8in form of a diaphragm pump9. The pressurizer8is connected to the gas compartment7of the storage volume4via a gas opening10and can be operated to supply air to the gas compartment7. In the example embodiment shown inFIG.1, the diaphragm pump9can supply air at a flow rate of 1.7 l/min at a pressure of 2.8 bar to the storage volume4. The power consumption of the diaphragm pump9is less than 30 W and it weighs less than 250 g. Using a diaphragm pump9as a pressurizer8has the advantage that it intrinsically prevents backflow of air from the gas compartment7. The pressurizer8is used to supply air to the gas compartment7when water has been drained from the liquid compartment6to bring the pressure in the gas compartment7back to the operating pressure.

To this end, a gas pressure sensor11is part of the buffer1which measures the pressure of the air in the gas compartment7of the storage volume4. The pressure sensor11is communicatively connected to a controller12which controls amongst others the operation of the pressurizer8via a control line13. In the example embodiment shown inFIG.1, the controller12is a microcontroller which is configured to read the values form the pressure sensor11and control the operation of the diaphragm pump9. The controller12turns the diaphragm pump9on when the pressure in the gas compartment7as sensed by the pressure sensor11reaches a filling threshold which may, for example, be 0.3 bar below the operating pressure, i.e., when the operating pressure is at 2.8 bar, the filling threshold would be 2.5 bar. Hence, the diaphragm pump9is turned on by the controller12when the pressure measured by the pressure sensor11drops below 2.5 bar.

The controller12also turns the diaphragm pump9off when the pressure measured by the pressure sensor11in the gas compartment7of the buffer1reaches the operating pressure. Thus, in the embodiment shown inFIG.1, the diaphragm pump9is turned off, when the pressure in the gas compartment7reaches 2.8 bar.

In order to release air from the gas compartment7of the buffer1, a ventilator14in form of a relief valve15is provided. The relief valve15is also connected to the gas opening10of the storage volume4so that the buffer1in the example shown inFIG.1comprises only one opening for filling the gas compartment7with gas and removing gas therefrom. The relief valve15is configured to automatically open when the pressure in the gas compartment7exceeds the operating pressure of, for example, 2.8 bar. In the embodiment inFIG.1the relieve valve15is a passive device which opens automatically when the pressure in the gas compartment7exceeds the operating pressure and closes automatically when the pressure in the gas compartment7is at or below the operating pressure.

The buffer1further comprises a liquid opening16which is provided for supplying water to the liquid compartment6of the storage volume4and for removing water from the liquid compartment6. Water is supplied to the liquid compartment6and, thus, to the storage volume from a central water tank which is not shown inFIG.1. However, a line17connecting the buffer1to the central water tank is shown inFIG.1. The line17is connected to the liquid opening16of the buffer1and comprises a fill valve18for controlling the supply of water from the central water tank.

Opening and closing of the fill valve18is also controlled by the controller12. The controller12opens the fill valve18, when water has been removed from the storage volume4for supplying water to a consumer equipment and closes the fill valve18when the liquid compartment6has been filled with water, for example, up to a maximum fill level. In the example embodiment shown inFIG.1, two fill level sensors20,21are provided. Both fill level sensors20,21are communicatively connected to the controller12. The latter is configured, for example, to close the fill valve18when the water level in the liquid compartment reaches the upper fill level sensor21. The fill valve18may open when level is lower than the lower fill level sensor20. A redundancy check included in the controller12verifies, for example, whether the lower level sensor20was also activated while the higher level sensor21gets active.

Finally, a protective release valve22is provided in the consumer supply line2. The protective release valve22is configured such that it opens when a maximum operating pressure is exceeded. Thereby, the equipment is protected from damage caused by high water pressure which is in particularly useful if a high-pressure water supply system is used to supply water from the central water tank to the buffer1.

The buffer1shown inFIG.1is operated as follows: when water is requested from a consumer equipment connected to the consumer supply line2, for example, by opening a valve at the consumer equipment, water is pushed out of the storage volume4due to the pressurized gas in the gas compartment7of the storage volume4and thus supplied to the consumer equipment. When the water level in the storage volume4drops, the volume of the gas compartment7and, thus, the storage volume increases and the gas pressure drops. Once the pressure sensed by the pressure sensor11drops below the filling threshold, the controller12activates the pressurizer8which supplies air to the gas compartment to increase the gas pressure. When the pressure in the gas compartment reaches the operating pressure, the pressurizer8is shut off by the controller12.

In case the consumer equipment is, for example, a toilet in an aircraft lavatory, the water flow to be provided by the buffer1is pulsed. For example, a state of the art toilet rising takes up water at a flow rate of approximately 9 l/min for about 1.2 s. Subsequent toilet flushes are separated by at least 8 s. Thus, the flow that needs to be provided by the buffer1is highly pulsed. Since the residual gas pressure in the gas compartment7of the buffer1is preferably sufficient to provide water for several toilet flushes, the pressurizer8does not have to supply the gas with the same flow at which water is removed from the buffer1. Hence, as compared to a pump provided in a buffer which provides water from the buffer1, the pressurizer8takes up less power and weighs less.

FIG.2shows a schematic drawing of an example embodiment of a water supply system23for an aircraft. The water supply system23comprises a central water tank24which is connected via low-pressure plumbing25to a high-pressure water pump26which provides water from the central water tank24to various pieces of consumer equipment27ato27dvia a high-pressure conduit system28. The pieces of consumer equipment27ato27dare collectively referred to as consumer equipment27. Each consumer equipment27ato27dis associated with a buffer1ato1cas shown inFIG.1. The buffers1ato1care collectively identified using the reference numeral1. The consumer equipment27ais a toilet rinsing which is arranged in the same lavatory (not shown) as a sink forming the consumer equipment27b. The two pieces of consumer equipment27a,27barranged in the same lavatory are supplied by the same buffer1a. The other two pieces of consumer equipment27c,27d, a sink in a galley and steam oven, are supplied from individual buffers1band1c. With regard to the details of the buffers1ato1creference is made toFIG.1and the corresponding description.

The high-pressure water supply conduit system28is made-up from flexible conduits29made from a plastic material with an internal diameter of, for example, 4-6 mm. The buffers1ato1cstore the water at a consumer pressure of, for example, 2.8 bar at which the water can be directly supplied to the consumer equipment27ato27d.

Finally,FIG.3shows an example embodiment of an aircraft30with an example embodiment of a water supply system23as shown inFIG.2. With regard to the details of the water supply system23, reference is made toFIG.2and the corresponding parts of the description.

While at least one example embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the example embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a”, “an” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.