Abstract:
Embodiments of the present relate generally to devices and methods for separating and removing liquid waste from mixed waste. One embodiment relates to a trash compactor having a suction line for removing collected liquid. A further embodiment relates to a trash compactor having a sloped platen for allowing liquid to collect for subsequent removal or drainage.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/343,246, filed Apr. 26, 2010 titled “Water Extraction for Trash Compactor,” the entire contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    Embodiments of the present invention relate generally to devices and methods for separating and removing liquid waste from mixed waste rubbish, and are particularly useful on-board passenger transport vehicles. 
       BACKGROUND 
       [0003]    The catering process in a passenger transport vehicle, such as an aircraft, train, bus, RV, ship, or other water or air travel vessel often involves collecting mixed waste (i.e., waste that includes solid materials as well as liquid materials). For example, after beverage service, unused items are collected, and it is often the case that ice and other liquids may still be present in cups that are disposed of trash bags. In addition to liquids, solid-like materials are also collected, such as cups, napkins, tea bags, food wrappers, beverage cans, forks, and other packaging or non-consumable items, and food wastes such as leftover sandwiches, fruit cores, or any other type of disposable item that a passenger may consume or bring on-board. Typically, this mixed waste is not separated, but is collected in a single trash bag and disposed of in a single trash compactor. Even if the wastes are coarsely separated during collection (which takes extra time, can be messy, and cannot be completely thorough), it is still often the case that liquids and solids will be mixed together at some level. 
         [0004]    During trash compaction cycle of refuse that contains both a solid waste aspect and a liquid aspect, it has traditionally been the case that the two mediums would simply be mixed, and any leakage that may occur has been dealt with as a necessary consequence. However, this can create a messy workspace, particularly on-board a passenger transport vehicle, where space and materials are at a premium in a galley. 
         [0005]    One attempted solution has been to extract liquid through the bottom of the compacting compartment that contains the solid mixed waste trash. The problem with this attempted solution is that it is difficult to separate the liquid from the solid trash in a harsh environment. For example, the platen exerts a great deal of pressure on the waste, destroying any elastomeric seals below. If a screen, a metallic filter, or drain is used at the base of the compactor, it will be difficult to remove the compacted solid waste without leaking residual liquid. 
         [0006]    Accordingly, it has been the standard to date to simply contain the liquid with the solids in the box or bin containing the trash to be compacted. However, in the event that the box or bin is penetrated or otherwise compromised, liquid can escape and leak onto the floor. Again, this is particularly undesirable in the tight confines of a galley, where safety concerns are heightened. Particularly in today&#39;s competitive airline market, cabin space is a valuable commodity. As the airlines compete to create more passenger space, the storage of trash becomes a critical concern, and new innovations and solutions are continually needed and expected. 
       BRIEF SUMMARY 
       [0007]    Embodiments of the present relate generally to devices and methods for separating and removing liquid waste from mixed waste rubbish. One embodiment relates to a trash compactor having a suction line for removing collected liquid. A further embodiment relates to a trash compactor having a sloped platen for allowing liquid to collect for subsequent removal or drainage. 
         [0008]    One embodiment provides a method for removing liquid from mixed waste collected in a trash compactor, comprising providing a platen for compacting the mixed waste, the platen having an upper surface; and providing a liquid removal system associated with the upper surface of the platen for removing liquid collected near platen edges or on or near the upper surface of the platen during the compacting process. 
         [0009]    A further embodiment provides a trash compactor, comprising a waste receiving container configured to receive mixed waste comprised of solid waste and liquid waste; a platen for applying pressure to and compressing mixed waste contained in the waste receiving container; and a vacuum line associated with the platen, the vacuum line configured to suction liquid waste collected on or through at least a portion of the platen. 
         [0010]    A further embodiment provides a trash compactor, comprising: a waste receiving container configured to receive mixed waste comprised of solid waste and liquid waste; a platen for applying pressure to and compressing waste contained in the waste receiving container, the platen comprising an upper surface having at least a slight downward slope. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  shows a schematic side plan view of one embodiment of a platen having a liquid removal system. 
           [0012]      FIG. 2  shows a side plan view of an alternate embodiment of a platen having a liquid removal system. 
           [0013]      FIG. 3  shows a prior art trash compactor with a platen during use. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    The present inventors have determined that extracting the liquid out of mixed waste can help prevent liquid leakage and spillage that can be messy and unsafe, but also recognize that focusing removal efforts at the bottom of the waste receptacle are not optimal. The general concept developed is to remove excess liquid away from the top of the platen portion of the trash compactor. This may accomplished by either using suction or vacuum to drawn liquid away from areas on or around the platen, or by using a gravity drain path to direct liquid away from the top of the platen. In short, the excess liquid is extracted from the upper portion of the collected mixed waste. 
         [0015]    As background, during a trash compaction cycle, collected waste contained in an appropriate waste receptacle is compressed. An example of compression in process is shown in  FIG. 3 , which illustrates a trash compactor  10  having a traditional platen  12  in its downward movement. To accomplish compression, the platen  12 , which is a flat plate that is configured to be pressed with force against the waste, is lowered against the mixed waste. The force and pressure of the platen  12  compresses the waste into a smaller volume, allowing more waste to be collected and stored in the same waste receptacle, and saving valuable space. However, during the compaction process, liquid waste often bubbles up and through the mixed waste. 
         [0016]    Accordingly, a first embodiment provides an apparatus and method for vacuuming or suctioning the liquid waste that bubbles up during the compaction process.  FIG. 1  shows a schematic view of a suction trash compactor system  14 . The system  14  includes a platen  16  having an lower surface  18  and an upper surface  20 . The lower surface  18  is the portion of the platen that contacts and compresses waste. A liquid removal system, such as vacuum line  22 , is configured to be associated with the upper surface  20 . Vacuum line  22  is generally provided between the upper hydraulic/motor portion of the trash compactor and the platen. In the particular embodiment shown, the vacuum line  22  is a vacuum tube, but it should be understood that any appropriate form of vacuum delivery line may be used and is considered within the scope of this application. The vacuum line  22  may be part of a vacuum system, which includes vacuum line  22  and a vacuum source. (The source of vacuum may be derived from any appropriate vacuum-generating source on-board the vehicle, such as a vacuum pump within the compactor system or a pre-existing vacuum source that already exists on-board the vehicle, such as the on-board toilet system of an aircraft.) 
         [0017]    The vacuum line  22  may have its suction end  24  secured to or otherwise attached to the platen, or suction end  24  may simply be positioned near enough to the platen that suction can be accomplished. For example, the body of the vacuum line may be secured within and extending from an inner surface of the compactor, and have its suction end  24  extending toward and close to the platen, but not necessarily touching the platen. The body  26  of the vacuum line  22  may be flexible, expandable or stretchable so that the suction end  24  can be maneuvered and directed close to the platen for suction when appropriate. Alternatively, the suction end  24  may directly touch the platen or otherwise be secured to the platen so that vacuum line  22  stays in place (i.e., secured to the platen) during movement of the platen. In this embodiment, the body  26  of the vacuum line  22  may be flexible or stretchable so that it moves with the platen  16 , or it may simply be provided at a length such that the tubing can move up and down with the platen, with the excess tubing being maintained above the platen when the platen is at its highest position in the compactor system. 
         [0018]    Optional deflectors  28  may also be associated with or attached to the upper surface  20  of the platen to prevent liquid from splashing above the platen. As shown in  FIG. 1 , deflectors  28  may be positioned at an angle with respect to upper surface  20  such that they create about a 45° angle between the platen and the inner wall  30  of the trash compactor. 
         [0019]    In use, a vacuum source presents vacuum to extract liquid (and any other fluid-like materials, including combinations of liquid and paste-like trash) that surface during and after compression of the mixed waste. The suction end  24  of the vacuum line  22  either scavenges the liquid from the back, edges, or upper surface of the platen. One particularly effective method is to allow the platen to press or compact the mixed waste to a level lower than an original waste level, and when the platen dwells in the lower level position, apply vacuum to remove excess liquid that pools or collects on the sides, edges, or on or near the upper surface of platen. The removed liquid can either be collected in a container and removed between flights or trips, or transferred into the grey or black water systems already present on-board an aircraft or other vehicle. 
         [0020]    In one particular embodiment, the platen may be provided with a screen or other porous medium through which liquid may be suctioned. The screen or porous medium may comprise a substantial part of the platen, a single screen or porous medium, or a plurality of screens or porous mediums selectively positioned throughout the platen surface. 
         [0021]    An alternate embodiment is shown in  FIG. 2 . In this embodiment, the platen  32  is configured so that it allows liquid waste to pool on the upper surface  34  of the platen, then allows the liquid to drain off the platen at the end of the compaction cycle when the platen is in the home (highest) position. More specifically, during the compaction cycle, liquid may bubble up from the mixed waste during compression. That liquid is allowed to collect or pool on the upper surface  34  of the platen  32 . When the platen  32  is lifted up at the end of the compaction cycle, liquid retained on the back of the platen (i.e., the upper surface  34 ) can be dumped or drained into a collection bin or a suction system. 
         [0022]    As shown in  FIG. 2 , one embodiment of platen  32  is designed with an upper surface  34  having at least a slight downward slope  36 . The slope  36  may be directed in any direction, either front-to-back or side-to-side. The purpose of slope  36  is to create a depression on the upper surface  34  of the platen so that any excess liquid is retained during each compaction cycle. In the particular embodiment shown, liquid may be retained between a lowest portion  38  of the slope  36  and a platen side wall  40 . 
         [0023]    Platen side wall  40  forms an edge of the platen  32 . Side wall  40  may be provided with a drain path  42 , which is essentially an opening through a lower portion of the side wall  40  that will allow collected liquid to drain. As shown, drain path  42  may also have a slight downward slope  44 , which will allow pooled liquid to drain away from the platen  32  via gravity. 
         [0024]    Drain path  42  may also be configured with a valve  46  that will operate to open and close in order to control the flow of collected liquid. The valve may be installed at the opening, end, or along any part of the drain path  42  in order to retain the liquid during the return stroke, then discharge the liquid once the platen is at the home (highest) position. Upon retraction (i.e., at the end of a compression cycle) at the home (or uppermost) position of the platen, the valve  46  is opened, which allows the collected liquid to flow by gravity into a drain location. The liquid may drain off directly through and into the grey water system, it may drain into the vacuum system via a grey water interface valve, it may be ejected into a drain mast, it may drain into any appropriate retention tank, or it may be collected in a container for later transfer to the grey or black water systems on-board the aircraft, or for any other type of appropriate disposal. 
         [0025]    The valve  46  at the drain path could be as simple as a flex hose normally pointed at an angle upward that is defected downward at the home position. Alternatively, the valve  46  may be opened mechanically or electrically, as is known in the general valve art. 
         [0026]    Although a single slope is shown in  FIG. 2 , it should be understood that multiple slopes may be provided. For example, all sides of the upper surface of the platen may slope inwardly toward the center, to form a collection pool at the general center of the platen. Instead of allowing the liquid to drain off one side of the plate via gravity, a suction tube may be provided that can suction the pooled liquid form the center of the platen. 
         [0027]    Alternatively, instead of providing a central pooling area, the platen slope may still allow the liquid to pool off to one side, but instead of removing the liquid via a drain path, the liquid may be suctioned from the edges or back surface of the platen, as described in the above vacuum embodiment. 
         [0028]    It is also possible to provide one of the above-described wells or depressions on the top of the platen that collect the liquid at the end of the compression cycle, but the liquid may then be suctioned away when the platen is at its upper position in the unit. For example, liquid pools on the upper surface of the platen, and when the platen is at its highest or an upper position (e.g., the home position) in the cycle, the pooled liquid comes in contact with a suction line. This prevents a suction line from having to extend all the way downward or to follow the platen during the whole cycle. Instead, the suction line can be mounted or otherwise positioned in an upper area of the compactor unit. 
         [0029]    One of the benefits of the sloped platen embodiment is its simplicity. It does not require lines or tubes that could become plugged with debris or congealed liquid. The drain path  42  for the liquid to leave the platen could be designed to be any size, and in some embodiments, can be generally large enough to reduce fouling and offer ease of cleaning. It is also beneficial in that height will not be lost if the hydraulic system can “nest” down into the center rectangular portion of the platen. Moreover, if the drain feature fails for some reason, the unit will still perform exactly the same as a unit without the sloped platen, albeit with some liquid retained on top of the platen. 
         [0030]    Changes and modifications, additions and deletions may be made to the structures and methods recited above and shown in the drawings without departing from the scope or spirit of the invention and the following claims.