Abstract:
A flexible bag for receiving flowable material is suspended, as from a gantry, and is tethered transversely and yet has substantially free movement along three sides for complete filling. The length of the tethers may be selected to prevent complete collapse of the bag when empty, and tubular perforated members having an “H” configuration within the bag may be provided for this purpose. Auxiliary structures provide for cooling of materials provided to the bag, their diffusion on inlet to the bag, their recirculation in the bag, and their removal from the bag. Accessories for use with wet gas provide for separation of inlet liquid and drainage of condensate within the bag.

Description:
BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The present invention relates to dispensing, to receptacles, and to flowable material separation using a supported flexible bag. 
   (2) Description of the Related Art 
   The following ten United States patents show prior art related to the present invention: 
   U.S. Pat. No. 3,391,409, which issued 9 Jul. 1968 to Gatley, and U.S. Pat. No. 4,699,613, which issued 13 Oct. 1987 to Donawick et al., show relatively small, suspended, untethered flexible bags with drains centrally of their lower sides for dispensing liquids. 
   U.S. Pat. No. 5,638,989 issued 17 Jun. 1997 to Ophardt et al., and discloses a box-like dispenser having a collapsible bag, the bag having a central, downward outlet secured to the dispenser and an upper end tensioned or otherwise supported above the outlet. 
   U.S. Pat. No. 4,902,304, which issued 20 Feb. 1990 to Hallen, and U.S. Pat. No. 4,986,446, which issued 22 Jan. 1991 to Montgomery et al., disclose flexible bladder receptacles, each receptacle being supported by resting on a surface below the receptacle. The bottom of the bladder of U.S. Pat. No. 4,902,304 is flatly disposed on a concrete “anchor ring” and the bladder is secured by “restraining cables” which pass over the top of the bladder to relieve stress in the bladder material. The bladder of U.S. Pat. No. 4,986,446 is, in accordance with its claim 1, in nonattached disposition within an open top containment vessel which is installed in an elevated position. 
   U.S. Pat. No. 1,288,241 issued 17 Dec. 1918 to Smyth and shows an unsuspended, downwardly tethered, inflatable flexible bag for aeronautics. 
   U.S. Pat. No. 6,497,156 issued 24 Dec. 2002 to Dageforde and discloses bags for exhaust and dilution gases collected by pumps, no arrangements being disclosed for supporting or otherwise restraining the bags. 
   U.S. Pat. No. 5,038,960 issued 13 Aug. 1991 to Seery and shows a flexible bladder disposed within a storage compartment and provided with a pipe extending into the bladder for conducting flowable material. 
   U.S. Pat. No. 4,177,844 issued to Kuss et al. on 11 Dec. 1979 and shows a silo breather bag which communicates with the atmosphere through a flexible conduit and which is suspended by a continuous hanger strap engaged by a plurality of hooks. 
   U.S. Pat. No. 6,251,171 issued 18 Feb. 2003 to Tateishi et al. and discloses cooling exhaust gas before the gas enters a bag filter. 
   SUMMARY OF THE INVENTION 
   The present invention involves a flexible bag or bladder receptacle for receiving, storing, and dispensing flowable materials including gases, liquids, and particulates. 
   The bag, typically, has rectangular opposite sides joined in sealed relation along their edges. The bag is suspended, as from a gantry, by an upper edge, the other three edges being unrestrained to the extent that the bag can expand to the fullest possible extent when filled. 
   Since the bag is substantially unrestrained, except at the above-mentioned upper edge, inlet or outlet flow connections to the bag are made through this upper edge. These flow connections may be made through flexible conduits disposed at this upper edge and extended inwardly thereof to piping structure described below. 
   The present invention includes tethers connected to each of the opposite bag sides and extending downwardly and generally normally therefrom. The length of the tethers may be selected to provide wind stability when the bag is located outdoors. Also, the length of the tethers may be selected so that, when the bag is substantially empty, the tethers limit the minimum volume of the bag to prevent the formation of isolated pockets of material remaining in the bag when it is effectively emptied. The length of the tethers may be selected to provide both wind stability and such limitation of the minimum bag volume. 
   The bag may be suspended so that a lower edge of the bag slopes downwardly to a corner of the bag for drainage of material, such as condensate, from the bag through a flexible connection which does not restrain expansion of the bag. 
   For fluid materials which may be provided at a high rate, filling piping structure is extended within the bag and provided with openings disposed to diffuse the inlet flow for mixing, to minimize material fatigue causing movement of the bag material, and to minimize jet reactions which flex the above-mentioned conduits and cause piping strains. 
   As another way to limit the minimum volume of the bag and prevent the formation of isolated pockets of material remaining in the bag when it is effectively emptied, the present invention includes piping structure within the bag, typically for inlet and having an “H” configuration with side conduits disposed toward the bag sides and extending diagonally of the bag sides so that the bag sides remain somewhat spaced when the bag is substantially emptied. Openings are provided on the facing regions of the side conduits for outlet of material from the bag when the bag is at its minimum volume with the bag sides against the side conduits. 
   A receptacle arrangement of the present invention may include cooling spray apparatus and a separator for liquids provided to the bag, the separator having a sump for the separated liquids and recovered spray liquid. The cooling spray may be taken from the sump liquid and an inlet conduit opening thereunder may be provided to prevent reverse flow of gas supplied to the bag. 
   It is an object of the present invention to provide, for flowable materials, a receptacle that is economical in construction, requires a small area, and is convenient to set up and to remove. 
   Another object is to provide such a receptacle adapted to receive and to dispense materials that are, variously, hot, wet, and corrosive. 
   A further object is to provide such a receptacle which fully utilizes the available space when filled and yet retains a minimal amount of material when effectively emptied and in which any such retained material is not disposed in isolated regions. 
   A particular object is to provide such a receptacle which is adapted to receive such materials at a high flow rate and to then dispense the materials at a lower, controlled flow rate for processing. 
   Still another object is to provide such a receptacle meeting the above and other objects with a flexible bag which may be adapted for mixing of the contents, may be effectively drained, may be exposed to the weather, and in which fatigue of the bag material is minimized. 
   Additional objects include providing such a flexible bag receptacle adaptable for use with a variety of inlet and outlet arrangements including arrangements for diffusing inlet flow, structures to prevent complete collapse of the bag and isolated pockets of material therein on emptying, and fluid flow structures causing minimal stress to themselves and supporting structures from fluid flow reactions. 
   Other objects include providing such a flexible bag receptacle adaptable for use with auxiliary apparatus to control the temperature and liquid content of inlet fluids, to provide interior access for inspection and maintenance, to protect the receptacle from excessive internal pressure and vacuum, and to prevent undesired reverse flows. 
   Still other objects include providing receptacles which meet the above objects and which may be fully sealed from the environment and are fully effective for their intended purposes. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects, advantages, and novel features of the present invention will be apparent from the following detailed description when considered with the accompanying drawings wherein: 
       FIG. 1  is an elevation of a holder for flowable material which embodies the principles of the present invention in having a tethered, inflatable flexible bag which is shown in a filled configuration in solid lines and is shown in an empty configuration in dot-dash lines, the holder being shown with auxiliary structures for support and for use of the holder to receive hot, wet gas; 
       FIG. 2  is a plan view of the bag from the position of line  2 - 2  in  FIG. 1 , the bag being shown in the filled configuration and with certain of the auxiliary structures; 
       FIG. 3  is an end elevation of the bag and certain of the auxiliary structures from the position of line  3 - 3  in  FIG. 1 , the bag being shown in a filled configuration in solid lines and in an empty configuration in dot-dash lines; and 
       FIG. 4  is a view, from the position of line  4 - 4  in  FIG. 1  and at an enlarged scale, of members further embodying principles of the present invention and disposed within the bag to prevent its complete collapse when empty, the members being fragmentarily and somewhat schematically represented for illustrative convenience. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring more particularly to the drawings,  FIGS. 1 through 3  show a tethered, flexible bag and associated apparatus embodying the principles of the present invention. The depicted elements, considered generally, are those elements directly connected with the bag, which is indicated generally by the numeral  10 , elements forming a gantry  11  for supporting the bag, and flow elements indicated generally by numeral  12  for providing flowable material to the bag and for circulating and removing such material from the bag. 
   The bag and associated apparatus are adapted to receive hot, wet, corrosive gas, as is emitted during destruction by burning of materials for rocket propulsion, explosives, and explosive devices, where such gas is generated at a rapid rate and stored in the bag for removal at a lower rate for processing. The depicted bag has a capacity of about 2000 cubic feet (56.6 cubic meters) when fully inflated and may be constructed in any suitable manner from any suitable flexible material, such as that used for military fuel storage bladders, for use with gas at temperatures ranging from ambient to about 180° F. (82° C.). Pressures in the burn chamber will range from about 3 psi (20.7 kpascals) to about 10 psi (68.9 kpascals) and will manifest in the gasholder at pressures of about 0 to about 5 inches H 2 O gage. 
   However, it will be apparent to one skilled in the art of flexible bag receptacles that, in view of the present disclosure, the principles of the present invention may be applied to receptacles of a wide range of capacities and for a variety of received materials, including but not limited to, gases and liquids of all kinds and flowable particulate solids such as those transportable by entrainment in air or other gases. It will also be apparent that, while the described embodiment of the present invention is associated with a separate inlet and outlet for the above-identified gas and with a drain for liquids associated with such gas, other embodiments of the invention may use other inlet and outlet arrangements including a single combined inlet/outlet as well as a large number of openings for different materials and their separation. These arrangements may include a variety of piping, valving, and pumping devices disposed both inside and outside of a flexible bag receptacle embodying the principles of the present invention. 
   Gantry  11  is a representative example of suitable structures for supporting bag  10 . Such structures may be of conventional construction and may be readily assembled and erected on and removed from any suitable surface  15 , such as the earth surface, where the bag is to be used. Each end of the gantry has an A-frame  16 , typically provided with casters, and these frames are connected by an I-beam  17  which is provided with any suitable bag hangers  18  spaced along the I-beam. 
   Bag  10  has a filled configuration, which is shown in  FIGS. 1 through 3  and indicated by numeral  20 , and has a substantially emptied configuration which is indicated by numeral  21  and shown in  FIGS. 1 and 3 . It can be seen from  FIG. 3  that, in end view, the bag is flattened in configuration  21  and can expand therefrom into the pillow-like form of configuration  20 . As a result and in accordance with the principles of the present invention, the bag fully utilizes the available space on surface  15  on which the bag and the gantry are disposed and yet retains a minimal amount of flowable material when effectively emptied 
   Bag  10  has opposite side panels or sides  25  which are sheet-like and generally rectangular, particularly when the bag is in its configuration  21  where sides  25  are disposed in a predetermined spaced relation for a purpose subsequently described. These sides are joined in sealed relation along their edges so that the bag, as shown in  FIG. 1 , has an upward edge  26  toward beam  17 , an opposite lower edge  27  toward surface  15  and opposite end edges  28  and  29  toward frames  16 . For purposes of exposition, edge  28  is at the left of  FIG. 1  and edge  29  at the right. 
   Bag  10  includes a broad strap or band  35  fitted over and extending along upward bag edge  26 . This band is of inverted V-shape as seen in  FIG. 3 . The open edges of the band are individually attached to the bag sides  25  and the closed edge of the band is connected to the hangers  18  which support the bag at its upward edge when the bag is supported from gantry  11 . Centrally of its length, the band has an opening  36  for certain of the flow elements  12  which are subsequently described in detail. 
   It is apparent from  FIGS. 1 through 3 , that bag  10  is suspended from gantry  11  at the upward edge  26  of the bag and that the other three bag edges,  27  through  29  are unrestrained so that the bag can expand to the fullest possible extent when filled into its configuration  20 . It is also apparent that bag lower edge  27  is relatively near surface  15  when the bag is in its emptied configuration and that this edge is raised substantially above surface  15  when the bag is in its filled configuration. It is further apparent that gantry  11  and band  35  are connected to the bag only at its upward edge. 
   When a bag incorporating the principles of the present invention is utilized with flowable particulates, liquids or, as with bag  10 , gases which may contain liquids as droplets or condensate, band  35  may be configured, as shown in  FIG. 1 , so that the bag is suspended with lower edge  27  of the bag sloping downwardly for drainage toward a corner  40  of the bag. 
   The present invention includes a plurality of tethers  45  individually connected by loops at one end to each of the opposite bag sides  25  by triangular attachment pieces of flexible material spaced generally horizontally along the bag sides and secured thereto, the positions of these pieces in filled configuration  20  being indicated by numeral  47  and their positions in substantially emptied configuration  21  being indicated by numeral  48 . From these pieces, the tethers extend downwardly in a catenary-like configuration as seen in  FIG. 3 ; and, as seen in plan view in  FIG. 2 , the tethers extend transversely of the bag and generally normally from its sides  25  to any suitable anchors  49 , shown in  FIG. 3 , which fix the opposite tether ends to surface  15 . In  FIG. 1 , the lengths of the tethers corresponding to the positions  47  are represented fragmentarily for illustrative convenience. 
   In accordance with the present invention, the length of tethers  45  may be selected so that, as bag  10  empties, the tethers restrain the sides  25  so as to limit the minimum volume of the bag to that of its configuration  21  and thus prevent the formation of isolated pockets of flowable material remaining in the bag when it is effectively emptied. The lengths of the tethers  45  may also be selected to provide wind stability when the bag is located outdoors. 
   It will be apparent to one skilled in the art, particularly when  FIG. 3  is considered, that the lengths of tethers  45  can be selected so that the tethers  45  provide both wind stability and minimum volume control. For this purpose, the anchor point  49  at surface  15  for each tether  45  is positioned so that the anchor point is the same vector distance from the corresponding filled bag tether attachment position  47  as the anchor point is from the corresponding emptied bag tether attachment position  48 . Further, the anchor point positions are selected so that, during transitions of bag  10  between its filled configuration  20  and its emptied configuration  21 , the tethers slacken only minimally as necessary to prevent bag damage and to allow minimal bag shifting from any winds present. When the anchor positions are so selected, the exact curvature of the tethers varies with the materials and dimensions involved, but is, typically, less downwardly than depicted in  FIG. 3 . 
   The tether  45  material may be selected by one skilled in the art. This material may be elastic, akin to bungie materials or inelastic materials, such as strap materials or cables. 
   Typically, a bag such as bag  10  is fitted, as at a side  25 , with a removable panel  50  for access to the bag interior for inspection and maintenance and is fitted with a combined vacuum and pressure relief valve  51 . Such features are well-known and are indicated in  FIG. 1  in their positions occupied when the bag is in its emptied configuration  21 . 
   The depicted flow elements  12  associated with bag  10  will now be described beginning with rigid, tubular conduits within the bag and attached directly to it at its upward edge below opening  36  in support band  35 . These conduits are best shown in  FIG. 1 , and consist of an interior inlet structure of T-configuration, indicated generally by numeral  55 , and an interior outlet structure which is indicated generally by numeral  56  and has an H-configuration shown in  FIG. 4 . 
   T-shaped inlet structure  55  has a stem  60  extending downwardly from bag upper edge  26  and transversely centrally through bag  10  to a cross arm  61  disposed at a position which is somewhat above and parallel to lower bag edge  27 . This cross arm is provided with outlet openings  63  disposed for mixing of material in the bag as additional material is supplied thereto. Since, as before mentioned, the inlet flow to bag  10  is at a rapid rate, openings  63  are also disposed to diffuse the inlet flow to minimize “flapping” of the bag and resulting fatigue of its material. Openings  63  are also disposed oppositely of cross arm  61  to minimize jet reactions on structure  55  which would strain this structure and the bag at edge  26  thereof. 
   The depicted structure  56  is constructed in accordance with the present invention so as to determine the emptied configuration  21  and corresponding volume of bag  10  and so prevent the formation of isolated pockets of material remaining in the bag when it is effectively emptied. This structure may be used in place of or together with the above-described arrangement and disposition of tethers  45  for the same purpose. Neither of these arrangements may be utilized with a bag, corresponding to bag  10  and embodying the principles of the present invention, for purposes wherein the retention of some material in the bag when it is substantially emptied is not objectionable. 
   As shown in  FIG. 1 , structure  56  has a first conduit or stem  65  extending downwardly from bag upper edge  26  and transversely centrally through bag  10  beside stem  61  of structure  55  to the center of a relatively short cross conduit  66  shown in  FIG. 4 . This cross conduit extends transversely between bag sides  25  to a pair of second or side conduits  67  which extend diagonally within the bag, as seen in  FIG. 1 , and extend oppositely of inlet structure stem  60  as seen in  FIG. 4 . The stem and cross conduit retain the side conduits in their disposition between the bag sides and provide flow communication between the side conduits and the exterior of the bag. 
   As seen in  FIG. 1 , conduits  67  extend generally between an upper and a lower corner of the bag when in its filled configuration  20 . Conduits  67  are thus disposed between bag sides  25  so that, as may be envisioned from  FIG. 3 , these conduits are engaged by bag sides  25  when the bag is emptied and the bag sides remain somewhat spaced and define the substantially emptied configuration  21  of the bag. 
   It is apparent that structure  56  thus restrains sides  25  so as to limit the minimum volume of the bag to that of its configuration  21 , and that conduits  67  are a pair of rigid members fixedly connected in a disposition wherein these conduits are between the sides  25 , extend generally parallel to these sides, and are spaced transversely of the sides a distance such that engagement of the sides with said conduits maintains a portion of each side in a position corresponding to the above-mentioned and predetermined spaced relation of the sides when the bag is in the flattened configuration. 
   Conduits  67  are provided with a plurality of inlet openings  68  best shown in  FIG. 4  and positioned along and around these conduits. As a result, such openings are provided on the facing regions of the side conduits for outlet of material from the bag when the bag is at its minimum volume and flattened configuration with the bag sides against the side conduits. 
   Flow connections from outside bag  10  to structures  55  and  56  are preferably made through flexible conduits  70  connected to stems  60  and  65  at bag upper edge  26  and extending upwardly therefrom through opening  36 . Also, a flexible hose  72  is connected at one end thereof to bag corner  40  for a purpose subsequently described. Hose  72  is shown in  FIG. 1  in its disposition corresponding to emptied bag configuration  21 , it being apparent that the hose end at corner  40  will be drawn upward with flexing of the hose as the bag expands toward its filled configuration  20 . It is thus apparent that, due to flexible elements  70  and  72 , expansion and contraction of bag  10  is not affected by flow connections to its interior. 
   The depicted flow elements  12  associated with bag  10  and external thereto will now be described with reference to  FIG. 1 . These elements include a separation and collection tower  75  which is represented as a cylinder extending upwardly from surface  15  to a conduit  77  which connects to the one of the flexible conduits  70  associated with inlet structure  85 . The lower portion of the tower is used as a liquid-containing sump  78 . This sump is connected by hose  72  to bag corner  40  for drainage of any condensate or other liquid in bag  10  to the sump. 
   Fluids for processing by the elements shown in the Figures are provided through a main supply conduit  80  which enters tower  75  above the liquid in sump  78  and turns downwardly to an opening  82  disposed a short distance, typically a few inches, below the level of this liquid. This arrangement prevents reverse flow into conduit  80 , since as before stated, the operating pressure of the depicted bag  10  is a few inches of H 2 O gage pressure. A plurality, not shown, of such inlet conduits may be provided for a corresponding plurality of sources of fluids for bag  10 . 
   Tower  75  and conduit  80  are provided with a representative spray cooling or quench system  85  for hot gas and other fluids which enter the tower through this conduit. System  85  draws liquid from sump  78  by a pump  86  and discharges the liquid into conduit  80  through a spray nozzle  87 . Any suitable valves and automatic controls may be used to control the flow of liquid and thus the temperature of fluids entering bag  10 . 
   Tower  75  allows entrained droplets of liquid from system  85  to separate by gravity and not enter bag  10 . These droplets thus cannot be drawn into outlet structure  86  to undesirably affect subsequent processing of gas from the bag. 
   Bag  10  is provided with a withdrawal and recirculation system indicated generally by numeral  90 . This system is only representative of arrangements for withdrawing flowable material from a bag which corresponds to bag  10  and embodies the principles of the present invention. In other arrangements, there may only be a fluid outlet corresponding to hose  72  for dispensing of liquids from the bag. In still other arrangements, as for processing of environmentally hazardous gases, flow from the bag may be provided by processing apparatus which is directly connected to the one of the flexible conduits  70  corresponding to outlet structure  56  and which applies a vacuum to this structure. 
   The depicted system  90  includes a blower  92  which may be of any suitable type and have any suitable disposition, such as that shown in  FIG. 1  on surface  15 . A bag withdrawal conduit  93  connects the one of the flexible conduits  70  corresponding to outlet structure  56  to the blower. Fluid output from the blower goes to a three-way valve  94  which selectively provides this output to an exit conduit  95  for removal from the depicted elements or to a recirculation conduit  96 . Conduit  96  conducts material from bag  10  back to tower  75 . This recirculation may be to obtain additional separation of liquids in gas from the bag or may be to mix the contents of the bag for analysis or in preparation for processing when the contents are finally withdrawn via exit conduit  95 . 
   Although the present invention has been herein shown and described in connection with what is conceived as a preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not limited to the illustrative details disclosed and which may be practiced within the scope of the following claims by using certain features of the invention to the exclusion of others.