Abstract:
The present invention is directed to a recombinator and a method for using a recombinator, wherein the recombinator comprises a housing operatively associated with a zinc-bromine battery, wherein the housing comprises an outer wall that defines a reaction space therein, means for introducing hydrogen into the reaction space from the zinc-bromine battery, means for introducing bromine into the reaction space from the zinc-bromine battery, means for controlling the delivery of bromine into the reaction space, wherein the delivery control means comprises at least one flow channel associated with the inner surface of the outer wall, means for reacting the hydrogen and the bromine together so as to form hydrobromic acid; and means for distributing the hydrobromic acid back into the zinc-bromine battery for the reacidification of same.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the invention  
           [0002]    The present invention relates in general to zinc-bromine battery systems, and, more particularly, to a device and method for the re-acidification of an electrolyte stream in a zinc-bromine flowing electrolyte battery.  
           [0003]    2. Background Art  
           [0004]    The original concept of utilizing the properties of zinc and bromine in a battery system was patented over 100 years ago in U.S. Pat. No. 312,802. Generally, the battery system has a negative flow loop and a positive flow loop, as well as a separator of some kind in-between. The zinc-bromine electrolyte is circulated through both loops, depositing zinc at the negative electrode, and creating aqueous bromine at the positive electrode, all while creating a voltage difference between the two electrodes. The zinc is collected as a solid, while the aqueous bromine forms a second liquid phase and is separated from the flowing electrolyte.  
           [0005]    Utilizing a circulating electrolyte system, Zinc-Bromine batteries have significant advantages, including ease of thermal management and uniformity of reactant due to electrolyte flow, operation of the system at ambient temperature, rapid system charging, complete system discharging, good specific energy of reactants, and a system that is generally constructed from low-cost and readily available materials. The system did not gain immediate commercial acceptance, however, due to the formation of zinc dendrites upon deposition of zinc at the negative electrode, impeding the flow of electrolyte, and due to the solubility of bromine in the zinc-bromine electrolyte, causing a cell short circuit.  
           [0006]    In the 1970s, Exxon Corp. and Gould Inc. developed techniques that attempted to inhibit the formation of zinc dendrites upon deposition at the negative electrode. Upon operation, the cell could now be operated for significantly longer periods of time without the previous inhibited flow. The zinc-bromine battery was now a commercially reasonable means of storing and recovering power. However, current operation of zinc-bromine batteries still contain significant problems.  
           [0007]    Current operation of a zinc-bromine cell requires specific parameters for continuous operation. Among these requirements is one that the system be operated at or near a pH of two. This requirement exists because at higher pH levels mossy zinc plating develops, as well as bromates within the electrolyte solution. Alternatively, at lower pH values, zinc corrodes at an increasing rate. Although the system reactions do not themselves affect pH, overcharging of the cell during cyclical operation may electrolyze water, creating gaseous hydrogen and hydroxide ions in the water, raising the pH.  
           [0008]    Therefore, it is an object of this invention to create a device and method for the re-acidification of the zinc-bromine electrolyte stream in a flowing electrolyte system to, in turn, facilitate longer and more efficient continuous operation of the battery.  
           [0009]    It is a further object of this invention to create a means for re-acidification utilizing the products of the current battery system so that an ongoing and steady-state system may be developed.  
           [0010]    It is also an object of this invention to create a device for use with a zinc-bromine battery system that reacidifies the electrolyte stream, while maintaining system conditions, and upon failure of the system conditions, a device that will quickly and safely correct the conditions to secure battery operability.  
           [0011]    These and other objects will become apparent in view of the present specification, claims and drawings.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention is directed to a recombinator, comprising a housing operatively associated with a zinc-bromine battery, wherein the housing comprises an outer wall that defines a reaction space therein, means for introducing hydrogen into the reaction space from the zinc-bromine battery, means for introducing bromine into the reaction space from the zinc-bromine battery, means for controlling the delivery of bromine into the reaction space, wherein the delivery control means comprises at least one flow channel associated with the inner surface of the outer wall, means for reacting the hydrogen and the bromine together so as to form hydrobromic acid, and means for distributing the hydrobromic acid back into the zinc-bromine battery for reacidification of same. Preferably, the at least one flow channel comprises a helix around the circumference of the inner surface of the outer wall. It is also preferred that the distributing means comprise a gap associated with the housing. Further, it is preferred that the bromine receiving means comprises an inlet stream coupling operatively attached to the zinc-bromine battery. Additionally, the housing may further comprise a threaded flange, and a wall flange, and the inlet stream coupling then would preferably comprise a ring space formed by the region between the threaded flange and the wall flange.  
           [0013]    Similarly, the hydrogen receiving means may comprise a gap associated with the housing, wherein the gap exposes the reaction space to a hydrogen-rich environment, or the hydrogen receiving means also comprises the inlet stream coupling as disclosed above.  
           [0014]    In a preferred embodiment, the reacting means comprises a catalyst operatively placed within the reaction space. Further, the housing may additionally comprise a central chamber having a base flange, and the catalyst may placed around the central chamber, and on top of the base flange. Preferably, the catalyst comprises a platinized carbon cloth having an area of approximately 40 cm2.  
           [0015]    In yet another preferred embodiment, the reacting means comprises a means for controlling the temperature within the housing, wherein the temperature control means may comprise a heating element in thermal contact with the reaction space. In that embodiment, the housing may additionally comprise a central chamber, wherein the heating element is placed within the central chamber, and the reaction space is defined between the central chamber and the inner surface of the outer wall.  
           [0016]    The present invention also discloses a gas handling unit for use with a flowing-electrolyte zinc-bromine battery having a positive electrolyte loop, a negative electrolyte loop, and electrode stacks, comprising a sealed gas chamber, means for receiving hydrogen into the sealed gas chamber from one of the positive and the negative electrolyte loops, means for receiving bromine into the sealed gas chamber from one of the positive and the negative electrolyte loops, means for reacting at least a portion of the hydrogen and bromine into hydrogen bromide, means for maintaining gaseous products, including unreacted hydrogen, within the sealed gas chamber; and means for distributing the hydrogen bromide and the unreacted bromine back to at least one of the positive and the negative electrolyte loops for the reacidification of same. Preferably, the hydrogen receiving means comprises an inlet stream coupling associated with at least one of the positive and negative electrolyte loops. Further, the electrode stack preferably comprises a hydrogen accumulation reservoir, wherein the hydrogen receiving means comprises an inlet stream coupling associated with the hydrogen accumulation reservoir, and the bromine receiving means comprises an inlet stream coupling associated with at least one of the positive and negative electrolyte loops. Additionally, the maintaining means preferably comprises a means for relieving excess pressure within the gas handling unit, the gas handling unit additionally comprises means for containing liquid overflow, and the distributing means comprises a first conduit and a second conduit, wherein the first conduit provides a fluidic connection between the gas handling unit and the positive electrolyte loop, and the second conduit provides a fluidic connection between the gas handling unit and the negative electrolyte loop.  
           [0017]    In a preferred embodiment, the reacting means comprises a recombinator in operatively associated with the inlet stream coupling, wherein the recombinator comprises a housing, wherein the housing comprises an outer wall that defines a reaction space therein, means for introducing hydrogen into the reaction space, means for introducing bromine into the reaction space, means for controlling the delivery of bromine into the reaction space, means for reacting the hydrogen and the bromine together so as to form hydrobromic acid, and means for distributing the hydrobromic acid into the gas handling unit for the reacidification of an electrolyte stream therein.  
           [0018]    In another preferred embodiment, the pressure relief means comprises a pressure release valve, and a pressure sensor associated with the pressure release valve, such that upon the occurrence of a predetermined condition, the pressure sensor activates the pressure release valve, venting at least a portion of the gaseous contents within the gas handling unit. In this embodiment, the pressure relief means may additionally comprises a filter apparatus associated with the pressure release valve such that vented gaseous contents pass through the filter apparatus before being released from the gas handling unit. Preferably, the filter apparatus a zinc filter.  
           [0019]    In yet another preferred embodiment, the overflow containing means comprises an overflow container associated with the gas handling unit, such that upon the occurrence of the predetermined condition, excess liquid contained within the gas handling unit is introduced into the overflow container for later disposal.  
           [0020]    In still another preferred embodiment, the gas handling unit additionally comprises means for preventing the introduction of bromine into the second conduit, wherein the gas handling preventing means comprises the second conduit extending further into the sealed gas chamber relative to the first conduit.  
           [0021]    The present invention is additionally directed to a method for re-acidifying an electrolyte in a flowing electrolyte zinc-bromine battery, comprising the steps of introducing hydrogen into a reaction chamber, introducing an electrolyte stream at least partially comprising aqueous bromine into the reaction chamber, controlling the delivery of the electrolyte stream into the reaction chamber in such a way so as to increase the residence time of the electrolyte stream within the reaction chamber, reacting the bromine with the hydrogen to create a reaction product, reintegrating the reaction product with at least one of an electrolyte stream or an electrolyte reservoir of the zinc-bromine batter for re-acidification of same. In this embodiment, the step of controlling preferably comprises the step of allowing the electrolyte stream to flow down and through at least one flow channel associated with the reaction chamber. Additionally, the step of reintegrating the reaction product further includes the step of removing the reaction produce and excess reactants through a gap in the reaction chamber. Further, the step of reacting the aqueous bromine and hydrogen preferably includes the step of associating the same with a catalyst. The method also may also include the step of regulating the temperature of the reaction chamber.  
           [0022]    In a preferred method, the at least one flow channel comprises at least one flow channel in the shape of a helix.  
           [0023]    In another preferred method, the step of regulating the temperature further includes the steps of pre-heating the reaction chamber, and maintaining the temperature within the reaction chamber, wherein the step of pre-heating preferably comprises the step of adjusting the temperature of the reaction chamber to between approximately 100 degrees Celsius and approximately 120 degrees Celsius; and the step of maintaining the temperature of the reaction chamber comprises the step of maintaining the temperature between approximately 100 degrees Celsius and approximately 120 degrees Celsius.  
           [0024]    In a final preferred method, the catalyst comprises at least one of a platinized carbon cloth, and heat.  
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 is a schematic view of the recombinator device of the invention; and  
         [0026]    [0026]FIG. 2 is a schematic view of the gas handling unit of the invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]    While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and described herein in detail several specific embodiments with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.  
         [0028]    The present invention comprises a recombinator device  10  for use with a flowing electrolyte zinc-bromine battery system, gas handling unit  100  for use with a flowing electrolyte zinc-bromine battery system, and a method for re-acidifying an electrolyte stream in the zinc-bromine battery system. The devices and method described below provide a novel, simple and continuous means for prolonging the uninterrupted operation of a zinc-bromine battery system, while reducing the unwanted byproducts of the system reactions.  
         [0029]    Specifically, and is shown in FIG. 1 of the drawings, recombinator device  10  comprises housing  20 , bromine receiving means  36 , hydrogen receiving means  42 , delivery control means  48 , reacting means  52 , and distributing means  72 . When in operation, recombinator device  10  is capable of receiving the secondary bromine phase from the positive loop of a zinc-bromine battery, vaporizing the bromine phase, and causing the vaporized bromine to react with hydrogen to form hydrogen bromide. Thereafter, the hydrogen bromide is returned to the electrolyte streams of the battery, reacidifying them, as well as removing unwanted hydrogen during the process.  
         [0030]    Housing  20  is shown in FIG. 1 as comprising outer wall  22 , reaction chamber  24 , threaded flange  26 , wall flange  28 , central chamber  30  and base flange  68 . Housing  20  is shown generally in a tubular or cylindrical shape, a shape that is selected in order to increase the uniformity of heating of outer wall  22  by heating element  58  (discussed below). However, another shape could similarly suffice, without deviating from the teachings of the invention.  
         [0031]    Outer wall  22  helps to form the shape of housing  20 . Outer wall  22  comprises the main portion of housing  20 , and is a substantially uniform, rigid wall surrounding reaction chamber  24 . Near the top portion of outer wall  22  is wall flange  28 , extending perpendicularly outward from outer wall  22 . As will be discussed further below, wall flange  28  enables the secure placement of recombinator device  10  within gas handling unit  100  (shown in FIG. 2).  
         [0032]    Also associated with the top portion of outer wall  22  is threaded flange  26 . Threaded flange  26  is shown as being associated with inner surface  23  of outer wall  22 , having at least one flow channel  50  (discussed below) therebetween. Threaded flange  26  may be affixed in the specified location by conventional means, such as welding or adhesive, or may be removably affixed by the use of small threads to coincide with the at least one flow channel  50 . However, if the use of small threads is employed, those small threads must leave at least some empty space within the at least one flow channel  50 , as will be discussed below.  
         [0033]    At the center of housing  20  is central chamber  30 . Central chamber  30  is constructed from a rigid material capable of conducting heat, such as aluminum. Central chamber  30  is formed in substantially the same shape as outer wall  22 , having opening  31  therethrough where heating element  58  (discussed below) is inserted. The similarity in shape between central chamber  30  and outer wall  22  allows heating element  58  to convey consistent and even heat out of central chamber  30 , and towards inner surface  23  of outer wall  22 . Reaction chamber  24  comprises the open area between central chamber  30 , and inner surface  23  of outer wall  22 .  
         [0034]    Bromine receiving means  36  is shown in FIG. 1 as comprising inlet stream coupling  38 . Inlet stream coupling  38  is formed by the space between threaded flange  26  and wall flange  28  of housing  20 . This space is also called ring space  40 . Ring space  40  allows access to reaction chamber  24  through inlet stream coupling  38  by allowing bromine to flow into ring space  40 , down inner surface  23  of outer wall  22 , and into at least one flow channel  50 .  
         [0035]    Hydrogen receiving means  42  is shown in FIG. 1 as comprising gap  44 . In its preferred embodiment, recombinator  10  is surrounded by a substantially hydrogen-rich environment. Gap  44  provides access to reaction chamber  24 , by exposing chamber  24  to the environment. In FIG. 1, gap  44  is shown as being located near the bottom ends of housing  20  and heating element  58 . Additionally, FIG. 1 depicts gap  44  as being a single, isolated circumferential opening into reaction chamber  24 . However, it is also contemplated that gap  44  could comprise a number of openings of various sizes and shapes, which could be located in outer wall  22 , or in other portions of housing  20  or heating element  58 .  
         [0036]    As would be known by a person of ordinary skill in the art, hydrogen receiving means  42  could also comprise inlet stream coupling  38 . While in operation, a flowing electrolyte zinc-bromine battery produces hydrogen at the zinc electrodes. This hydrogen is at least partially dissolved within the electrolyte of the system. Therefore, as the bromine-rich second phase is fed into inlet stream coupling  38 , it carries with it at least a small amount of hydrogen. This hydrogen can also be utilized in the reacidification of the electrolyte stream. Similarly, the hydrogen produced in the stacks can be collected in a separate hydrogen tank, which can then be introduced into reaction chamber  24  through inlet stream coupling  38 , or gap  44 .  
         [0037]    Delivery controlling means  48  is shown in FIG. 1 as comprising at least one flow channel  50 . The at least one flow channel comprises one or more channels running in a helix-like design down inner surface  23  or outer wall  22 . These channels are shown in cross-section in FIG. 1 in their preferred embodiment, with the at least one flow channel  50  making several revolutions around inner surface  23  of outer wall  22  before being exposed to reaction chamber  24 . However, a steeper path may also be taken, reducing the residence time of any bromine that may be flowing down and through at least one flow channel  50 . As was discussed above, channel  50  may additionally provide a means for securing threaded flange  26  to outer wall  22  of housing  20 , by allowing threaded flange  26  to couple with channel  50  via a standard screw and thread design. However, as stated previously, securing threaded flange  26  to outer wall  22  cannot block channel  50  so that bromine cannot thereafter flow through channel  50 .  
         [0038]    Reacting means  52  is shown in FIG. 1 as comprising catalyst  54  and temperature control means  56 . Reacting means  52  provides energy to reaction chamber  24  to help vaporize bromine that enters the chamber. Further, reacting means  52  provides the necessary precursors to help gaseous bromine and hydrogen to react to form hydrogen bromide.  
         [0039]    Catalyst  54  is shown in FIG. 1 as a series of parallel lines surrounding central chamber  30 . The parallel lines in FIG. 1 represent the preferred configuration of catalyst  54  as being substantially wrapped around central chamber  30  in a spiral-like fashion. Catalyst  54  is preferably made from platinized carbon cloth, with an area of approximately 40 cm 2 , and an active surface area of greater than 1200 m 2 /g. Although the total area and surface area given are the preferred parameters of catalyst  54 , any number of configurations or platinum loadings could similarly suffice, as long as the free movement of gaseous hydrogen and bromine is not inhibited. For example, in the preferred embodiment, such free movement is facilitated through the use of a cloth for catalyst  54 . In order to additionally facilitate the movement of gasses, it is preferable to maintain some degree of spacing between the spirals of catalyst  54  through the use of spacers  55 .  
         [0040]    Temperature control means  56  is shown within central chamber  30  of housing  20  as additionally comprising cover  58 , heating element  60 , and base flange  68 . During the operation of recombinator device  10 , temperature control means  56  seals the top portion of reaction chamber  24 , senses the current temperature of reaction chamber  24 , and adjusts the temperature with reaction chamber  24  to a predetermined value. Further, temperature control means  56  provides a means for supporting catalyst  54  within reaction chamber  24 .  
         [0041]    Cover  58  seals the top of housing  20  using o-ring  59 . As seen in FIG. 1, cover  58  fits securely inside of threaded flange  26 , and completes the top seal of reaction chamber  24  with o-ring  59 . Cover  58  may be constructed from any number of materials, but is preferably constructed from the same or similar materials as outer wall  22 . O-ring  59  is preferably constructed from a flexible material (such as rubber) so as to help seal recombinator  10 .  
         [0042]    Heating element  60  generally comprises the central portion of temperature control means  56 . Heating element  60  comprises heater  62  and temperature sensor  64 , inserted within heating cartridge  66 . Heater  62  is preferably a resistor, which creates heat by standard electrical resistance, heating up heater  62  and therefore the material surrounding heater  62 . However, other forms of heat could also be used. Temperature sensor  64  detects the temperature of heater  62 , as well as reaction chamber  24 . Based on predetermined data, temperature sensor  64  can elect to alter the heating characteristics of heater  62  to maintain a predetermined temperature within reaction chamber  24 . Heating cartridge  66  holds and secures heater  62  and temperature sensor  64  within central chamber  30 . Heating cartridge  66  may be constructed from any rigid, heat conductive material, but is preferably constructed from an inexpensive material, as the heating element  60  may require replacement from time to time.  
         [0043]    Base flange  68  is a flange extending perpendicularly outward from the bottom portion of heating cartridge  68 . Base flange  68 , along with the bottom end of outer wall  22 , helps to define gap  44  discussed above. Further, base flange  68  is at least partially defined by base area  70 , which forms a flat area immediately below central chamber  30 . Base area provides a support means for catalyst  54 , while remaining substantially apart from the bottom edge of inner surface  23  of outer wall  22 . As will be discussed further below, this arrangement ensures that catalyst  54  remains dry and separate from any bromine that is not vaporized.  
         [0044]    Distributing means  72  is shown in FIG. 1 as comprising gap  44 . As discussed above, gap  44  is located near the bottom end of outer wall  22 , and provides the environment access to reaction chamber  24 . Unlike hydrogen receiving means  42 , however, distributing means  72  should be located at the bottom end of outer wall  22 , as that location allows liquid bromine to pass into the reaction chamber  24  through channel  50 , to flow down inner surface  23  of outer wall  22 , and to flow out of recombinator  10  through gap  44  in bottom.  
         [0045]    Recombinator  10  can be used in association with gas handling unit  100 , shown in FIG. 2, to reacidify an electrolyte stream in a flowing electrolyte zinc-bromine battery. Gas handling unit  100  comprises sealed gas chamber  110 , bromine receiving means  120 , hydrogen receiving means  124 , reacting means  128 , gas maintaining means  130 , and distributing means  144 . When properly situated, gas handling unit  100  allows for continuous operation of the zinc-bromine battery by ensuring constant pH within the electrolyte streams, while still allowing for operational irregularities such as improper or unpredictable gas production, or even irregular electrolyte flow due to gas production.  
         [0046]    Sealed gas chamber  110  is shown in FIG. 2 as a generally rectangularly-shaped container having top side  112 , walls  114 , and bottom side  116  forming a sealed enclosure. The sealed enclosure is capable of holding a number of fluids, including gaseous hydrogen and bromine, as well as liquid bromine and hydrogen bromide. The shape of the container is not particularly important, as any shape having sufficient volume to contain an operational amount of zinc-bromine battery materials will suffice.  
         [0047]    Bromine receiving means  120  is shown in FIG. 2 as comprising bromine stream coupling  122 . Bromine stream coupling  122  provides a fluidic connection between sealed gas chamber  110  and the positive electrolyte loop of a zinc-bromine battery. Bromine stream coupling  122  allows the introduction of complexed bromine from the positive electrolyte loop into the sealed gas chamber  110 .  
         [0048]    Hydrogen receiving means  124  is shown in FIG. 2 as comprising a hydrogen stream coupling  126  connecting to the positive electrolyte loop of a zinc-bromine battery.  
         [0049]    The bromine coupling  122  provides a fluidic connection between the positive electrolyte loop and the sealed gas chamber  110 . For example, the positive electrolyte loop of the zinc-bromine battery may have gas collecting tubes on top of the battery stacks, and hydrogen coupling  126  can connect those tubes with sealed gas chamber  110 . As is known, the battery stacks of a zinc-bromine battery also produce hydrogen that is dissolved in the electrolyte itself. In a preferred embodiment of the invention, hydrogen receiving means  124  additionally comprises bromine stream coupling  122 , wherein hydrogen is introduced into sealed gas chamber  110  dissolved into or along with the complexed bromine phase.  
         [0050]    Reacting means  128  is shown in FIG. 2 as comprising recombinator  10 , described in detail above. As noted, recombinator  10  helps to vaporize incoming complexed bromine, and to react that bromine with present hydrogen to form hydrogen bromide. Recombinator  10  is therefore in fluidic communication with both the bromine receiving means  120  and the hydrogen receiving means  124 . Specifically, as noted above, ring space  40  may receive both hydrogen and bromine from the positive electrolyte loop by placing reaction chamber  24  in fluidic communication with bromine stream coupling  122 . Additionally, gap  44  also acts to introduce hydrogen into reaction chamber  24  from the surrounding environment in sealed gas chamber  110 . Hydrogen stream coupling  126  introduces hydrogen into sealed gas chamber  110  from the positive electrolyte loop for use by recombinator  10 .  
         [0051]    Gas maintaining means  130  is shown in FIG. 2 as comprising pressure relieving means  132  and opening  140 . Gas maintaining means  130  ensures that in all but the most extreme circumstances, all gas products, whether they are from the positive electrolyte loop, or from the vaporizing action of recombinator  10 , are maintained in gas handling unit  100 . Since resources within the closed system are limited, maintaining means  130  is extremely helpful to continuous, effective operation of the system.  
         [0052]    Pressure relieving means  132  comprises pressure sensor  134 , pressure valve  136 , and filter apparatus  138 . During operation of gas handling unit  100 , pressure release means  134  ensures the operating pressure of gas handling unit  100  is maintained within predetermined limits, and if those limits are breached, enables the emergency release of gasses contained within sealed gas chamber  110  to the environment by pressure release valve  136 .  
         [0053]    Pressure sensor  134  is mounted on or near top side  112 , walls  114 , or bottom side  116  of gas handing unit  100 , such that sensor  134  is in contact with the interior of sealed gas chamber  110 . Pressure sensor  134  is in communication with pressure valve  136  in order to control the opening or closing of valve  136 . Pressure valve  136  is located between sealed gas chamber  110 , and opening  140 . Pressure valve  136  substantially seals sealed gas chamber  110  from the surrounding environment.  
         [0054]    Filter apparatus  138  is located between pressure valve  136  and opening  140  so that all gasses that could be released from sealed gas chamber  110  would pass through filter apparatus  138  before passing through opening  140  into the surrounding environment. Filter apparatus  138  is preferably comprised of a zinc powder suspended in a container such that the gas vented by pressure valve  136  can pass through and around the zinc powder. Other similar filters can also be used also. Filter apparatus  138  ensures that gaseous bromine is transferred into bromide (either in solution or as a salt) before release of the excess gas to the environment. After the bromine is converted into bromide in solution, or complexed bromide, it is maintained within filter  138  for later removal.  
         [0055]    Opening  140  is a small (approximately 2 mm in diameter) opening in top side  112  of sealed gas chamber  110  which permits gas released from the interior of sealed gas chamber  110  to escape to the environment. Opening  140  is disclosed as having a relatively small diameter due to the need for secure sealing of sealed gas chamber  110 . As is known by those of ordinary skill in the art, a zinc-bromine flowing electrolyte system depends upon a consistent, low pH. Variations in pH values cause performance problems in the battery, including formation of mossy zinc plating on the electrodes, as well as increased corrosion of the electrodes. In order to maintain the pH within the system, it is necessary to reacidify the streams using hydrogen produced at the zinc electrodes. If hydrogen escapes, for example through opening  140 , it is no longer available for reacidification. Therefore, care must be taken to ensure containment of all gasses except in the most extreme circumstances.  
         [0056]    Gas handling unit  100  is shown in FIG. 2 as additionally comprising liquid overflow containing means  142 . Liquid overflow containing means  142  comprises a basin or similar container that is configured to receive overflow electrolyte from gas handling unit  100 . Therefore, the container should be constructed from a material that is substantially non-reactive and stable relative to the components of a zinc-bromine battery system, including bromine, bromide, hydrogen bromine, zinc bromide, and hydrogen. The container  142  is shown in FIG. 2 as substantially surrounding filter apparatus near top side  112  of gas handling unit  100 . However, the container  142  may additionally be placed in an external location relative to the sealed gas chamber  110 , so long as it is in communication with the chamber  110 .  
         [0057]    Distributing means  144  is shown in FIG. 2 as comprising first conduit  148 , and second conduit  150  extending into and through bottom side  116  of sealed gas chamber  110 . First conduit  148  and second conduit  150  are tubes or pipes that connect sealed gas chamber  110  to the positive and negative electrolyte loops, respectively. As will be discussed in more detail in the operations section below, the complexed bromine phase passes into sealed gas chamber  110 , and into recombinator  10  where at least some of the complexed bromine is vaporized from liquid to gas. Unvaporized bromine, however, passes through recombinator  10 , and is collected in the bottom portion of gas handling unit. It is preferable that the complexed bromine is not introduced into the negative electrolyte loop of the zinc-bromine battery. Therefore, second conduit  150  also comprises means for preventing introduction of bromine. Preferably, this introduction preventing means comprises second conduit  150  extending into sealed gas chamber  110  a distance such that the level of liquid complexed bromine is below the top of second conduit  150 . Thereafter, liquid complexed bromine should be able to flow into first conduit  148 , but not second conduit  150 .  
         [0058]    In operation, a flowing electrolyte zinc-bromine battery is shown in FIG. 3, wherein the battery has a positive electrolyte loop, a negative electrolyte loop, a set of electrode stacks, and hydrogen collection pipes. The zinc-bromine battery produces electricity and occasionally hydrogen during the charge and discharge cycles, as well as forming a second layer of liquid within the electrolyte consisting of complexed bromine.  
         [0059]    As the battery operates, it passes the generated electricity out of the battery to an external load. While the electricity is produced, the battery collects hydrogen in the hydrogen collection pipes, and accumulates complexed bromine within the positive electrolyte loop.  
         [0060]    Complexed bromine is passed into sealed gas chamber  110  through bromine receiving means  120 . Complexed bromine generally comprises Br 2 , formed into a second phase within the electrolyte of the positive electrolyte loop of the battery, which is pumped out of the positive electrolyte loop and into bromine stream coupling  122  for introduction into gas handling unit  100 . Simultaneously, hydrogen is passed into sealed gas chamber  110  through hydrogen receiving means  124  from the hydrogen collection pipes. However, complexed bromine may also contain certain amounts of hydrogen, dissolved within the bromine phase. Additionally, as complexed bromine is passed into sealed gas chamber  110  via bromine receiving means  120  it may also carry with it packets of hydrogen gas that are not dissolved, but instead are simply carried with the bromine flow.  
         [0061]    The bromine and hydrogen components are introduced into sealed gas chamber  110 . The complexed bromine stream is preferably fed to recombinator  10  via ring space  40 . From ring space  40 , bromine flows into flow channel  50 , through channel  50 , and down inner surface  23  of outer wall  22  within reaction chamber  24 . Reaction chamber  24  has already been brought up to reaction temperatures, between 80 and 130 degrees Celsius. As bromine flows through channels  50  and down inner surface  23 , it is vaporized into gaseous bromine.  
         [0062]    Simultaneously, hydrogen is introduced into recombinator  10 . The hydrogen stream can be fed to sealed gas chamber  110  itself, and therefore to recombinator  10  directly through gap  44 , or hydrogen may be introduced to recominbator  10  along with the complexed bromine stream through bromine stream coupling  38 . In any case, hydrogen is present within reaction chamber  24  when the complexed bromine stream is vaporized.  
         [0063]    Hydrogen and gaseous bromine naturally react to form hydrogen bromide. However, reaction chamber  24  includes catalyst  54  that helps to improve the conversion of the bromine/hydrogen reaction. Bromine gas and hydrogen gas flow through and around catalyst  54 , reacting to form hydrogen bromide. The hydrogen bromide created, along with unreacted gaseous bromine and unvaporized bromine, pass out of recombinator  10  through gap  44  into sealed gas chamber  110 .  
         [0064]    Once in sealed gas chamber  110 , gaseous components generally remain within sealed gas chamber  110 , with the possibility that some gas may escape dissolved in electrolyte solution. The liquid components, including complexed bromine solution and hydrogen bromide, collect on bottom side  116  of sealed gas chamber  110 . As discussed above, second conduit  150  extends into sealed gas chamber  110  above the liquid level in bottom  116  of sealed gas chamber  110 , so no liquid should pass into the negative electrolyte loop. However, the collected liquid is allowed to enter the positive electrolyte loop through first conduit  148 , reacidifying the electrolyte and maintaining the operation of the system.  
         [0065]    Under certain circumstances, pressure relieving means  132  and liquid overflow containment means  142  may be required. For example, under certain circumstances, usually inefficient battery operation, an overabundance of gaseous products may be collected within sealed gas chamber  110 . In that case, pressure sensor  134  detects the increase of pressure within sealed gas chamber  110 , and opens pressure valve  136 . The gaseous components within sealed gas chamber  110  are vented out of chamber  110 , and through filter apparatus  138 . As the gaseous components pass through filter apparatus  138 , any gaseous bromine is complexed with zinc contained within filter apparatus  138 , turning it into the complexed bromide species and maintaining the species within filter apparatus  138 . Thereafter, the remaining gaseous components are vented out of opening  140  to the surrounding environment, substantially free of gaseous bromine, and therefore reducing any malodorous characteristics of the exiting gas.  
         [0066]    In another similar situation where the battery stack is producing an excess amount of hydrogen, bubbles of hydrogen may push an inordinate amount of electrolyte out of the stack and into gas handling unit  100 . In that case, the liquid level at bottom side  116  of sealed gas chamber  110  increases to the point where it is exposed to liquid overflow containment means  142 . The excess liquid is collected in overflow container, where it can later be removed and processed. Preferably, if such an event occurs, overflow containment means  142  additionally includes a leakage sensor (not shown) capable of sensing such an overflow condition, and indicating the presence of overflow liquid to an outside system or controller for removal and/or correction of the battery conditions. Once removed, overflow liquid can be returned to the battery system.  
         [0067]    The foregoing description merely explains and illustrates the invention and the invention is not limited thereto except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications without departing the scope of the invention.