Abstract:
Apparatus useful for feeding a particulate starter material comprising nutrient and bacteria to a mixing tank, for solubilizing the starter material inside the mixing tank, for promoting growth of the bacteria and for discharging an aqueous slurry comprising the bacteria from the mixing tank. The apparatus preferably has a gravity-flow feeder and discharge port, does not require a pump, and comprises disposable parts.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    This invention relates to a system and apparatus for feeding and solubilizing a solid biological starter material, and for aerating, growing and dispensing aqueous mixtures of select vegetative bacterial strains for various end use applications. Such end use applications can include, for example, digestion and removal of grease from food processing or restaurant drains, grease traps, grease interceptors and sewers, and bio-remediation of other amenable wastes and waste streams. The system and apparatus of the invention preferably comprise some disposable components, principally for convenience and to reduce the time required to clean and maintain the device. 
         [0003]    2. Related Art 
         [0004]    Biological growth and dispensing systems with various feeder devices have previously been disclosed, for example, in U.S. Pat Nos. 7,081,361 and 6,335,191, and in the prior art referenced in those patents, and in pending published United States Patent Application No. 20090130740. 
         [0005]    Some devices previously disclosed for use in feeding tableted, prilled, pelletized, granular or powdered bacterial starter materials have encountered difficulties with bridging or jamming. Similarly, some devices previously disclosed for use in solubilizing solid starter materials in an aqueous or other liquid medium have required the use of a pump driven by an electric motor for mixing, transferring or dispensing the liquid medium. Other previously disclosed devices have required time-consuming and costly periodic cleaning to alleviate flow path blockages attributable to bacterial growth inside flow lines. 
         [0006]    A need therefore exists for a compact and relatively inexpensive system and apparatus that can reliably feed, solubilize, transfer and dispense functionally effective amounts of solubilized and/or slurried vegetative biological material for smaller volume applications by gravity flow without requiring a pump. Such system and apparatus will desirably comprise some disposable components and will reduce or eliminate the need for periodic manual cleaning and associated downtime and expense associated with time-consuming maintenance intervals. 
       SUMMARY OF THE INVENTION 
       [0007]    The system and apparatus of the invention desirably comprise a compact, wall-mounted housing with a frame and cover that support and conceal a feeder unit containing a solid starter material, a feeder drive assembly disposed beneath the feeder unit, a mixing tank that also serves as a bacteria growth vessel in which the solid starter material is solubilized, circulated and aerated to increase the bacteria population during a predetermined cycle of operation (such as 24 hours), a water supply at standard line pressure to fill, circulate and aerate the bacteria inside the mixing tank, a control system that comprises liquid flow lines, timing circuitry and solenoid valves operated by motors powered by direct current, and a direct current power supply such as a battery. 
         [0008]    According to one preferred embodiment of the invention, the feeder unit further comprises a feed canister or hopper and a feeder base and lid assembly that includes a rotatable feeder cup. Particulate solid starter material, preferably comprising a bacterial component and a nutrient component, is desirably provided in the form of pellets, grills, tablets or granules. A plastic container in which the solid starter material is shipped can also serve as the feed canister or hopper, and becomes an integral part of the feeder unit when attached to the feeder base and lid assembly. The rotatable feeder cup can optionally further comprise anti-bridging surface enhancements and can be used in combination with an overlying pellet dam having an upwardly directed surface configured to help orient the solid feed particles so as to reduce the likelihood of bridging or jamming. In either case, the rotatable feeder cup will desirably comprise a feed chamber having an open top and bottom through which a predetermined measure of the solid feed material can fall by gravity flow as the opening passes over aligned feed ports disposed above the mixing tank. The feeder drive assembly that rotates the rotatable feeder cup preferably comprises a drive shaft and gear assembly powered by a small DC motor. 
         [0009]    The mixing tank is preferably disposed beneath the feeder unit and is generally cylindrical with a lower section that is preferably frusta-conical and comprises a bottom drain. A rigid overflow drain tube is preferably disposed in sealing engagement with the drain and has an upwardly extending free end. The drain tube is optionally releasably engageable with the bottom wall of the mixing tank, provided that a liquid seal is provided in the area of the releasable engagement to prevent leakage. The free end of the overflow drain tube is adapted to receive and drain liquid from the vessel so as to prevent the liquid level inside the vessel from exceeding a desired maximum level that is at least one inch lower than the closest water inlet to establish the air gap required by most building codes to avoid possible contamination of potable water supplies. Water is desirably introduced into the growth vessel at the beginning of each cycle of operation, after which solid starter material is introduced into the mixing tank from the feeder unit. Throughout the cycle of operation, smaller quantities of water are again introduced into the mixing tank periodically to mix and aerate the aqueous bacterial slurry inside the tank. This is most preferably achieved by directing at least two diametrically opposed jets of the incoming water in either a clockwise or counter-clockwise direction that is substantially tangential to the outside wall of the tank. 
         [0010]    As the cumulative liquid fill level inside the mixing tank approaches the drain level of the rigid overflow drain tube, bacteria floating at or near the top surface of The liquid are carried by the liquid into the rigid overflow drain tube and out the drain by gravity flow, preferably to intermediate storage or to a desired end-use application. Inlet scuppers are desirably provided near the top of the rigid overflow drain tube to facilitate the flow of bacterial slurry into the rigid overflow drain tube. At the end of each cycle operation and commencement of the next cycle of operation, most of the bacteria present in the mixing tank and floating near the surface is discharged through the rigid overflow drain tube by introducing a sufficient volume of new water to displace the water already present in the tank. 
         [0011]    The control system preferably comprises a microprocessor that operates solenoid valves to control water flow to the apparatus at designated times for predetermined and preset intervals, and also activates the feeder drive assembly beneath the feeder unit at desired times and for a preset interval, thereby facilitating charging, solubilization and mixing of the solid feed material, periodic mixing and aeration of the beneficial aqueous vegetative bacterial slurry thus created, and harvesting of the bacteria during and at the end of each cycle of operation. 
         [0012]    The particulate starter material comprising bacteria and nutrient is desirably discharged downwardly through the apparatus of the invention by gravity flow, relying only on a small direct current motor rotating the drive shaft of the feeder drive assembly to sweep a desired quantity of starter material into the mixing tank. The quantity of starter material introduced into the mixing tank is determined by the size of the feed chamber and/or the number of complete (360°) rotations of the rotatable feeder cup. 
         [0013]    Similarly, the aqueous bacterial slurry that is produced in the subject apparatus is preferably discharged from the unit by gravity flow. Normal municipal water pressure is typically relied upon for operation of the invention, and no pump is required to circulate the water or to pump out the aqueous bacterial slurry at the conclusion of each cycle of operation. The normal line pressure is typically sufficient to introduce water into the mixing tank and to periodically pulse water through jets disposed above the liquid level in the mixing tank with sufficient force to cause the water to swirl inside the tank, thereby solubilizing the particulate starter material, aerating the water and enhancing bacterial growth. 
         [0014]    According to another embodiment of the invention, a feeder unit for particulate solids is disclosed that comprises a feed canister, a dam disposed below the feed canister, a rotatable feeder cup disposed below the dam, and a receptacle disclosed below the rotatable feeder cup. The dam and rotatable feeder cup preferably each comprise an arcuate section having an opening through which particulate solids can flow gravitationally. The rotatable feeder cup is preferably rotatable relative to the dam. At least one, and preferably both, of the dam and the rotatable feeder cup desirably comprises upwardly facing surface enhancements that help reduce the likelihood of bridging or jamming of the particulate solids. According to a particularly preferred embodiment of the invention, the entire particulate solids feeder unit is disposable and recyclable, and is changed out during periodic servicing following use of substantially all the particulate starter material in the feed canister. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    For a more complete understanding of the present invention and for further advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which: 
           [0016]      FIG. 1  is a bottom front perspective view of a preferred embodiment of an apparatus for feeding and solubilizing a solid biological starter material, and for aerating, growing and discharging aqueous slurries of select vegetative bacterial strains for various end use applications, with the housing cover in place; 
           [0017]      FIG. 2  is a front elevation view of the apparatus of  FIG. 1 ; 
           [0018]      FIG. 3  is a right side elevation view of the apparatus of  FIG. 1 ; 
           [0019]      FIG. 4  is a bottom plan view of the apparatus of  FIG. 1 ; 
           [0020]      FIG. 5  is a rear elevation view of the apparatus of  FIG. 1 ; 
           [0021]      FIG. 6  is a top plan view of a preferred housing frame for use in the apparatus of  FIG. 1 , rotated 90 degrees in a clockwise direction from the front elevation position as shown in  FIG. 7  to a position corresponding to the top plan view of the right side elevation view of the frame as shown in  FIG. 8 ; 
           [0022]      FIG. 7  is a front elevation view of the frame of the  FIG. 6 ; 
           [0023]      FIG. 8  is a right side elevation view of the frame of  FIG. 6 ; 
           [0024]      FIG. 9  is a top plan view of a preferred mixing tank and bacteria growth vessel (“mixing tank”) for use in the apparatus of  FIG. 1 ; 
           [0025]      FIG. 10  is a front elevation view, partially broken away and partially in section, of the mixing tank of  FIG. 9 ; 
           [0026]      FIG. 11  is a right side elevation view of the mixing tank of  FIG. 9 ; 
           [0027]      FIG. 12  is a bottom perspective view of a preferred feeder unit for use in the apparatus of  FIG. 1 ; 
           [0028]      FIG. 13  is an exploded bottom perspective view of the feeder unit of  FIG. 12  in combination with a preferred feeder drive assembly that activates the rotatable feeder cup; 
           [0029]      FIG. 14  is a top perspective view of a preferred embodiment of a pellet dam for use in the feeder unit of  FIG. 12 ; 
           [0030]      FIG. 15  is a top perspective view of a preferred embodiment of a rotatable feeder cup for use in the feeder unit of  FIG. 12 ; 
           [0031]      FIG. 16  is a top plan view of the apparatus of  FIG. 1  with the cover removed; 
           [0032]      FIG. 17  is a front elevation view of the apparatus of  FIG. 1  with the cover removed; and 
           [0033]      FIG. 18  is a right side elevation view of the apparatus of  FIG. 1  with the cover removed. 
       
    
    
       [0034]    Like reference numerals are used to indicate like parts in all figures of the drawings. 
       DESCRIPTION OF PREFERRED EMBODIMENT 
       [0035]    Referring to  FIGS. 1-8 , a preferred apparatus  20  of the invention preferably includes a housing having a removable cover  30  and a frame  24 . Cover  30  desirably has a modern styled highly finished look and is attachable to frame  24  by frictional engagement and is preferably completely removable to facilitate access to the interior of apparatus  20 . It will be understood and appreciated, however, that cover  30  can likewise be connected to frame  24  by other similarly effective means such as hinges, for example, provided that access to the interior of apparatus  20  can still be achieved. Cover  30  can also snap on or screw on and, if desired, a lock (not shown) can also be provided to control access to the interior of the housing. Cover  30  includes front, top and bottom wall sections  22 ,  24 ,  28 , respectively. Extending from or through bottom  28  of cover  30  is an outlet port  34  for use in discharging aqueous bacterial slurries produced in apparatus  20 . Either or both of cover  30  and frame  24  are preferably made of a suitable metal or plastic, although frame  24 , if made of plastic, should be made of durable plastic that is resistant to fading, cracking, creep or other structural failure when used over prolonged periods. 
         [0036]    Frame  24  of apparatus  20  preferably includes mounting plate  65  having apertures  32  ( FIGS. 5 and 7 ) for insertion of mounting screws or other conventional fasteners (not shown) for mounting frame  24  and apparatus  20  to a support structure such as, for example, a wall. Frame  24  desirably further comprises upper support plate  66  and lower support plate  64 , each of which is either made integrally with or connected to mounting plate  65  and bracket members  62 ,  63 , respectively, that are preferably disposed at each side of the respective base plates and also project forwardly from mounting plate  65 . Upper support plate  66  desirably includes aperture  68  for receiving a drive shaft for feeder unit  70 , described in greater detail below, and apertures  69  for use in installing circulating jets  116 ,  118  as described below in relation to  FIGS. 17-18 . Top bracket  46  is provided for use in releasably attaching cover  22  ( FIG. 1 ) to frame  24  if desired. 
         [0037]    Referring to  FIGS. 16, 17 and 18 , mounting plate  65  and upper and lower support plates  66 ,  64  facilitate attachment of, and provide mounting sites for, microprocessor  49 , battery  42  or, alternatively, an alternating current power adapter (not shown), water flow lines  110 ,  112 ,  114 , liquid flow control system  48 , feeder unit  70 , feeder drive assembly  50  and mixing tank  56 . Mixing tank  56  preferably has top flanges that slide into engagement with a cooperating flange of upper support plate  66 . Lower support plate  64  comprising drain port  34  desirably mates with an effluent outlet lip on the bottom side of mixing tank  56 . 
         [0038]    Referring to  FIGS. 9-11 , mixing tank  56  can be made of a disposable and recyclable material, and preferably comprises a top flange  130  defining a substantially circular top opening, a substantially cylindrical upper wall section  124 , a frusto-conical lower sidewall section  126 , and bottom  128  having a centrally disposed drain port  57 . Overflow drain tube  120 , preferably comprising inlet scuppers  122 , is provided for use in harvesting the aqueous bacterial slurry produced in the invention. The liquid capacity of mixing tank  56 , which is determined by the height of overflow drain tube  120 , is desirably about 750 ml in a preferred embodiment of the invention, but can vary according to other design parameters and the intended application for a particular apparatus. Bacteria slurry periodically overflow via gravity at preset timed intervals triggered by additions of cold water to the mixing tank. The liquid capacity of the mixing tank can also vary depending on the specific design of a particular apparatus intended for a particular end use application. 
         [0039]    Referring to  FIGS. 12-15 , particulate matter feeder unit  70  preferably comprises inverted feed canister  44  having a solid end wall  47  and an opposed open end surrounded by threads  45 . The volume of feed canister  44  is preferably sufficient to contain enough particulate feed material to last through a targeted number of operational cycles during a desired service interval. Feed canister  44  is preferably designed so that threads  45  are cooperatively engageable with threads  53  of feeder base and lid assembly  52 . Pellet dam  78  and rotatable feeder cup  74  are preferably disposed inside feeder base and lid assembly  52  prior to attachment of feed canister  74  to feeder base and lid assembly  52 . When constructed in this or a similarly effective configuration, feed canister  44  can be shipped preloaded with the particulate starter material, pellet dam  78  and rotatable feeder cup  74  in place and oriented so that feeder base and lid assembly  52  is attached and ready for insertion into feeder drive base  72  of feeder drive assembly  50  at the time of use. Following use for predetermined service intervals, the entire feeder unit can be disposed of for subsequent recycling, and a new feeder unit can be installed. If desired, mixing tank  56  can likewise be disposed of and another installed together with the feeder unit. 
         [0040]    Feeder base and lid assembly  52  preferably further comprises side wall  148  having circumferentially spaced keyways  152  that receive keys  78   a  (shown as  140  in  FIG. 14 ) of pellet dam  78  to prevent pellet dam from rotating relative to feeder base and lid assembly  52 . Referring to  FIG. 14 , pellet dam  78  preferably further comprises a raised, wedge-shaped section  138  comprising surface enhancements  142  intended to help prevent the particulate feed material flowing downwardly out of feed canister  44  ( FIG. 13 ) from bridging or jamming prior to flowing further downward by gravity flow through opening  80  inside bottom rim  144  of pellet dam  78  and through feed chamber  76  of rotatable feeder cup  74  ( FIG. 15 ), downwardly projecting discharge port  54  of feeder base and lid assembly  52  ( FIG. 13 ), and aperture  160  of feeder drive base  72  into mixing tank  56  ( FIG. 17 ). Feed chamber  76  of rotatable feeder cup  74  has no top or bottom, but is disposed over a solid surface of bottom  154  of feeder base and lid assembly  52  at the time it receives particulate feed material flowing downwardly through opening  80  in pellet dam  78 . As rotatable feeder cup  74  rotates between pellet dam  78  and bottom  154  of feeder base and lid assembly  52 , feed chamber  76  sweeps under opening  80  and receives particulate feed sufficient to substantially fill the cup, then rotates over aperture  68  ( FIG. 16 ) in projecting discharge port  54  in bottom  154  of feeder base and lid assembly  52  to discharge the particulate feed into mixing tank  56   
         [0041]    The preferred rectangular shape of downwardly projecting discharge port  54  of feeder base and lid assembly  52  ( FIG. 13 ) desirably releasably engages aperture  160  in bottom  158  of feeder drive base  72  and prevents feeder base and lid assembly  52  from rotating relative to feeder drive base  72 . Drive shaft  96  is preferably square and cooperatively sized to fit snugly inside aperture  79  of rotatable feeder cup  74  to insure that rotatable feeder cup  74  rotates with drive shaft  96 . Conversely, apertures  86  of feeder drive base  72  and aperture  146  in bottom  154  of feeder base and lid assembly  52  are desirably large enough to permit drive shaft  96  to rotate freely inside them. Ribs  150  in outside wall  148  of feeder lid and base assembly  52  are sized and configured to cooperatively engage ribs  162  inside wall  156  of feeder drive base  72  to snugly hold feed canister  44  in place during use of apparatus  20  ( FIG. 1 ). 
         [0042]    Referring to  FIGS. 13 and 15-18 , feeder drive assembly  50  preferably further comprises gear assembly  90 ,  92 ,  94  driven by shaft  84  of small direct current motor  82  that is mounted through aperture  88  in bottom  158  of feeder drive base  72 . This is preferably a center axle multiple gear drive with an offset motor. Rotatable feeder cup  74  preferably comprises a substantially cylindrical disk having a centrally disposed aperture  79  adapted to receive drive shaft  96  ( FIG. 13 ) extending upwardly through coaxially aligned apertures  86  and  146  in feeder drive base  72 . When motor  82  powered by battery  42  is actuated by a signal received from microprocessor  49 , gear assembly  90 ,  92 ,  94  causes drive shaft  96  to rotate, thereby causing rotatable feeder cup  74  to rotate and feed particulate starter material into mixing tank  65 . 
         [0043]    Battery  42 , which is most preferably a rechargeable battery pack and/or a 110v a/c to d/c converter, supplies power to liquid flow control unit  48 , die motor  82  for gear for feeder drive assembly  50 , and microprocessor  49 . Liquid flow control unit  48  desirably comprises at least one solenoid valve, and microprocessor  49  controls the cold tap water inlet solenoid cycles at designated times, thereby facilitating dissolution and mixing of the solid product in the initial operational cycle, and for mixing addition of dissolved oxygen and final dispensing of vegetative bacteria to the desired application near and at the end of the operational cycle. Microprocessor  49  also actuates motor  82  of feeder drive assembly  50  to cause feeder unit  70  to discharge particulate feed material into the water contained in mixing tank  56 . 
         [0044]    An example of microprocessor pre-set times for addition of the particulate starter material comprising bacterial and nutrient components and for water injection according to a preferred 24-hour operational cycle are as follows: 
         [0045]    Beginning of cycle @ 0 hours,≧run cold tap water for 5 min. 
         [0046]    After this cycle, feeder unit  70  activates and discharges a predetermined weight or volume of particulate feed material to the water in the growth vessel. 
         [0047]    Mix and aerate cycle # 1 @ 6 hours—run cold tap water for 3 seconds. 
         [0048]    Mix and aerate cycle # 2 @ 12 hours—run cold tap water for 3 seconds. 
         [0049]    Mix and aerate cycle # 3 @ 16 hours—run cold tap water for 3 seconds. 
         [0050]    Mix and aerate cycle # 4 @ 19 hours—run cold tap water for 3 seconds. 
         [0051]    Mix and aerate cycle # 5 @ 22 hours—run cold tap water for 3 seconds 
         [0052]    Return to step # 1 @ 24 hours. 
         [0000]    It should be understood that these water injection times can vary based on requirements for specific bacteria, ambient temperatures or other conditions affecting dissolved oxygen requirements. 
         [0053]    Flow control system  48 , which comprises at least one solenoid valve, controls the mix/aeration cycle as well as the ‘run tap water for 5 minutes’ beginning of cycle which results in the dispensing of the live vegetative bacteria into the desired application. This ‘run tap water for 5 minutes’ cycle also replenishes the growth vessel with clean cold tap water just prior to the addition of the solid biological product initiating the preferred 24-hour operational cycle. 
         [0054]    Zero Jet water inlets  116 ,  118  mounted to or received through apertures in upper support plate  66  are preferably positioned diametrically opposite and equidistant from the geometric center of mixing tank  56 , with liquid overflow tube  120  positioned at the center of that circle. Water inlets  116 ,  118  are positioned a minimum of 1 inch above the highest anticipated liquid level inside mixing tank  56  to comply with plumbing code regulations requiring a one-inch air gap and are preferably directed perpendicular to the intersecting horizontal diameter line on which they are positioned to induce a ‘spinning’ water movement which is conducive to mixing and aerating of the resulting solution/mixture. It should be understood that the number or size of jets, and the corresponding positional relations can vary provided that the objectives of enhanced dissolution, mixing and aeration are achieved so as to promote bacterial growth. 
         [0055]    The vegetative bacteria contained in the aqueous bacterial slurry thus formed is then directed to application injection sites, e.g., floor drain, waste pit, grease trap, grease interceptor, process waste streams, municipal. waste streams, and the like. Feeder driver base  72 , rotating feeder cup  74 , pellet dam  78  and mixing tank  56  are all disposable and recyclable components that can be replaced whenever it is necessary during normal interval maintenance to minimize cleaning. 
         [0056]    Although particulate matter feeder unit  70  as disclosed herein is a preferred feeder unit for apparatus  20  of the invention, it should be appreciated by those of skill in the art upon reading this disclosure that feeders incorporating structural elements that are equivalent to those disclosed herein likewise have applicability to many other devices and systems in which a controllable gravitational feeder for particulate solids is desired for other applications. Accordingly, the design and use of a feeder unit similar to feeder unit  70  disclosed herein for purposes other than for growing and harvesting aqueous slurries of bacterial is also contemplated to constitute part of the subject invention in the absence of prior art disclosing same. 
         [0057]    Other modifications and improvements to the system and apparatus disclosed herein will likewise become apparent to those of ordinary skill in the art upon reading this disclosure and it is intended that the scope of the invention be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled.