Abstract:
Systems for collecting waste water and other fluids are described. The systems are especially useful in connection with showers of decontamination shelters. They permit shelter construction on flat surfaces as well as both positive and negative grades, thereby facilitating use of the shelters in the field.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 61/955,885, filed Mar. 20, 2014, entitled “Grade Variant Sump System,” the entire contents of which are hereby incorporated herein by this reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to sump systems and more particularly, but not necessarily exclusively, to grade-variant sump systems for use in connection with decontamination shelters. 
       BACKGROUND OF THE INVENTION 
       [0003]    Decontamination shelters are increasingly in demand. Portable shelters are especially useful for “first responders” such as mobile medical crew and law enforcement officers as well as for military personnel and others working in the field (i.e. not in permanent institutional settings). Recent outbreaks of the Ebola virus in west Africa, for example, have highlighted need for equipment and structures useful to decontaminate medical workers treating infected populations. 
         [0004]    U.S. Pat. No. 4,800,597 to Healey details a relatively simple decontamination shelter. As shown in the Healey patent, the shelter may include multiple adjacent compartments. One compartment may be designated a shower area and include a shower head. According to the Healey patent, the floor of the shower area “is desirably provided with an opening through which shower water can be drained. A pump, not shown, may be used to evacuate the water.” See Healey, col. 3, 11. 36-28 (numeral omitted). No other description of the water-evacuation system is provided, however, nor does the Healey patent contemplate constructing the shelter other than on flat surfaces. 
         [0005]    U.S. Pat. No. 7,624,543 to Sample, et al., discloses another decontamination shelter which too may contain a shower. Additionally, the shelter includes a fluid delivery system “configured to convey decontamination fluid into the shelter . . . and to distribute decontamination fluid throughout at least a portion of the central space” within the shelter. See Sample, col. 5, 11. 27-30 (numerals omitted); see also id., col. 7, 11. 61-63. Although the Sample patent extensively discusses entry of fluids into the decontamination shelter and contains a single mention of removing conditioned air therefrom, see id., col. 7, 11. 39-40, it neither addresses nor suggests a mechanism for removing any waste water from the shower (or otherwise). 
       SUMMARY OF THE INVENTION 
       [0006]    By contrast, the present invention contemplates systems for collecting waste water and other fluids. Especially useful in connection with showers of decontamination shelters, systems of the present invention permit shelters and their compartments to be constructed on non-flat surfaces. Indeed, the systems allow shelter construction on both positive and negative grades, thereby facilitating their use in the field. 
         [0007]    At least some systems of the invention include generally rigid, hollow tubing bounding a grey-water collection area within a shelter. The tubing may include multiple intake openings in fluid communication with the collection area. Preferably these intake openings are uniformly spaced along the length of the tubing, although uniformity of spacing is not required. Alternatively flexible or semi-rigid tubing may be employed, although in most instances rigid tubing is preferred because it does not collapse under suction. 
         [0008]    Connected directly or indirectly to the tubing may be at least one pump apparatus. This connection may occur at the inlet side of the pump, so that operation of the pump tends to evacuate the tubing. In turn, the outlet of the pump may be connected as desired to convey waste fluid to a sump or other appropriate location for disposal or processing. Any suitable pump may be utilized as part of the present systems, although in some versions diaphragm-containing or gas/liquid mixed-media capable pumps are preferred. 
         [0009]    If a shelter is created with a substantially flat collection area, grey water from the shower (or other fluid-producing means) will accumulate in the collection area until it reaches the level of the intake openings of the tubing. Thereafter it will flow into and collect in the tubing. When the pump is activated, the grey water in the tubing will be evacuated therefrom to the sump. Any further accumulation of water reaching the level of the intake openings likewise will be siphoned by the pump. 
         [0010]    If a collection area has a positive grade, the connection location of the tubing and pump apparatus will be below the remainder of the tubing. In this condition grey water will tend to enter intake openings near the connection location. Activation of the pump will evacuate the tubing, removing the water contained therein in a manner similar to that described in the preceding paragraph. 
         [0011]    If a collection area has a negative grade, the connection location of the tubing and pump apparatus will be above the remainder of the tubing. Hence, gray water will enter intake openings of the tubing remote from the connection location. Pump operation will draw water in the tubing toward the connection location, reducing the water level in the collection area until a sufficient number of intake openings are exposed such that the pressure within the tubing is equalized by impinging air entering the intake openings that are above the water line. This equilibrium point and minimum water level are dependent on the flow rating of the pump and the size and locations of the intake openings and may be designed and optimized as desired for particular constructions. 
         [0012]    It thus is an optional, non-exclusive object of the present invention to provide systems for collecting fluids such as (but not necessarily limited to) grey water. 
         [0013]    It is also an optional, non-exclusive object of the present invention to provide fluid-collection systems for use in connection with decontamination shelters. 
         [0014]    It is another optional, non-exclusive object of the present invention to provide fluid-collection systems facilitating construction of decontamination shelters on non-flat surfaces. 
         [0015]    Other objects, features, and advantages of the present invention will be apparent to those skilled in the relevant art with reference to the remaining text and the drawings of this application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a perspective, partially schematicized view of a portion of a sump system useful in connection with the present invention. 
           [0017]      FIG. 2  is an elevational, partially schematicized view of a portion of the sump system of  FIG. 1  as positioned on a generally flat surface. 
           [0018]      FIG. 3  is an elevational, partially schematicized view of a portion of the sump system of  FIG. 1  as positioned on a positive grade. 
           [0019]      FIG. 4  is an elevational, partially schematicized view of a portion of the sump system of  FIG. 1  as positioned on a negative grade. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Illustrated in  FIGS. 1-4  are portions of sump system  10  consistent with the present invention. Also shown schematically in  FIG. 1  is part of wall  14  of decontamination shelter  18  including sump system  10 . Wall  14  may be formed of any suitable rigid or flexible material and form part of either a permanent or, preferably, temporary chamber or other structure or means for at least partially isolating a human from his or her environment. Together with one or more other walls, optionally a roof, and optionally a floor, wall  14  may form at least part of a chamber of decontamination shelter  18 . 
         [0021]    Sump system  10  is especially useful when decontamination shelter  18  includes a shower assembly. Shelter  18  need not necessarily incorporate such a shower assembly, however, as use of sump system  10  may be advantageous whenever a fluid is preferably collected in controlled manner for transit external to the shelter  18 . 
         [0022]    As depicted especially in  FIG. 1 , sump system  10  may comprise one or more lengths of tubing  22 . Tubing  22  preferably is hollow, so as to readily convey fluid therethrough, as well as rigid so as not to collapse when evacuated in normal use. Tubing  22  conventionally may have circular cross-section, although other cross-sections are acceptable too. 
         [0023]      FIG. 1  illustrates generally linear lengths of tubing  22  connected one to another (using elbow joints or otherwise) so as to form a tubing assembly having a generally rectangular overall shape. Alternatively, connected lengths of tubing  22  may form other, non-rectangular overall shapes. In any event, connected lengths of tubing  22  may be positioned along or adjacent the ground, a floor, or another surface (any of which may be designated “S” on  FIG. 1 ) on which humans may stand and form a boundary B for collection of fluid within at least part of decontamination shelter  18 . 
         [0024]    Additionally shown in  FIG. 1  is connector  26 , which may connect tubing  22  to suction line  30  and, in turn, to an inlet of pump  34 . The outlet of pump  34  may communicate with sump  38 , which may be or include any suitable container for fluid utilized in decontamination shelter  18  and, if desired, may be positioned remote from the fluid-collection area within boundary B. Suction line  30  preferably itself is rigid tubing, so as not to collapse when evacuated. Pump  34  beneficially may be a mixed media pump capable of processing both gases (e.g. air) and liquids (e.g. waste water). 
         [0025]    Illustrated in each of  FIGS. 1-4  is that tubing  22  may include openings  42  along its length. Openings  42  advantageously are uniformly spaced (or generally so) along each length of tubing  22 ; they also may face inward, away from boundary B and toward surface S. Openings  42  may have any desired size and shape. 
         [0026]    The shower assembly within shelter  18  may produce water (or other liquid) for purposes of cleaning a person subject to, or potentially having been subjected to, hazardous material. After contacting the person, the shower water (now typically characterized as waste or “grey water”) begins to accumulate on surface S (as bounded by tubing  22 ). If surface S is flat, or substantially so, relative to the earth, sufficient accumulation of water on surface S causes the water level to reach openings  42  more or less simultaneously. Continued production of grey water causes some of the water to enter openings  42  and accumulate within tubing  22 . Activation of pump  34  will draw grey water within tubing  22  through connector  26  and suction line  30  and out to sump  38 . This evacuation of grey water will continue to occur until tubing  22  is substantially free of water; if the shower assembly thereafter produces more water accumulating on surface S, operation of pump  34  will continue to siphon the water any time levels reach openings  42 . 
         [0027]    Unlike conventional systems, sump system  10  may function well even when surface S is not substantially level relative to the earth. As shown in  FIG. 3 , system  10  slopes at positive inclination, so that connector  26  is in the vicinity of the low point of system  10 . Thus, if surface S itself is generally flat, grey water will collect toward openings  42 A close to connector  26  and away from openings  42 B remote from connector  26 . As grey water accumulates, it will enter tubing  22  via openings  42 A and be drawn by pump  34  eventually for conveyance to sump  38 . 
         [0028]    By contrast, if system  10  slopes at negative inclination, connector  26  will be at or near the high point of system  10 . In such case grey water will collect near openings  42 B remote from connector  26 . Operation of pump  34  will tend to draw the water throughout tubing  22  toward connector  26 , thus reducing the accumulated water level on surface S even if some or most of the water is not drawn out to pump  34  and instead remains within tubing  22 . As the water level decreases, more of openings  42 B are exposed to air such that the pressure within suction line  30  is equalized by virtue of the impinging air. The equilibrium point and minimum water level then depends on the flow rating of pump  34  and the size of openings  42  and can be designed and optimized as desired. 
         [0029]    The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention. Incorporated herein by this reference are the entire contents of the Healey and Sample patents.