Abstract:
A brine generation system includes a tank having an upper opening configured for receiving salt crystals to fill the tank. A divider separates a tank volume into an upper portion adapted for holding salt crystals a lower portion adapted for holding a brine solution. The divider is adapted to resist movement of salt crystals into the lower portion but is permeable to allow the brine solution to fall into the lower portion. A fluid conduit disposed within the upper portion includes at least one water jet for injecting water in a direction towards the salt crystals. The tank further includes an outlet positioned in the lower portion of the tank for withdrawing brine.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS FIELD 
       [0001]    This patent application claims the benefit of priority to U.S. Provisional Patent Application No. 61/549,504, filed on Oct. 20, 2011, which is incorporated in its entirety herein by this reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This patent disclosure relates generally to systems for generating brine for the treatment of roadways in the winter and, more particularly, to a system and method for rapidly generating brine. 
       BACKGROUND 
       [0003]    Brine, which is a combination of rock salt and water in an aqueous solution containing between 23% and 26% salt, is used for treating roadways during winter storms. When applied before the storm, brine can provide an anti-icing layer that prevents a bonding between the roadway and ice, facilitating ice and snow removal. The use of brine can often reduce the use of salt and sand, lessening environmental damage, and because it can be applied before the storm, may reduce labor costs by allowing road treatment during regular business hours. 
         [0004]    Brine is currently prepared in tanks with open tops through which salt may be loaded. The salt is supported above the bottom of the tank by horizontal screens. Nozzles about the upper lip of the tank may then be used to spray water over the surface of the salt, the latter of which may percolate downward through the screens into the lower portion of the tank. The water may be collected at the bottom of the tank and recirculated one or more times through a second set of nozzles until the desired salinity is obtained. An example of this design is taught by U.S. Pat. No. 7,810,987, which issued on Oct. 12, 2010. 
         [0005]    As noted in the above cited patent, the salt is often contaminated with dirt and silica which can be abrasive and can cause excess wear on pumps, flow meters, and valves in the delivery chain of the brine. Accordingly, these contaminants are allowed to settle in the tank at a point below the brine outlet. Cleaning the sediment from the tank can be facilitated by sloping the tank bottom to a sump channel leading to a sediment outlet in the tank. In use, the tank is drained (possibly without removal of the salt) and spray nozzles are used to force the sediment through the channel and out the sediment outlet. 
         [0006]    Obtaining the necessary salinity using such systems can be significantly delayed by the time it takes to recirculate the brine for multiple passes through the salt. Cleaning the sediment from the tank is time-consuming and requires that the machine be drained and thus remain off-line for a significant period of time. Substantial sediment may accumulate in a few hours of operation, thus significantly affecting the throughput of the device. 
       SUMMARY 
       [0007]    Embodiments of the present disclosure are directed to a high throughput brining system that immerses the freshwater nozzles in the salt near an obstructing divider to create an extreme erosion zone within the salt. This high turbulence zone can provide an accelerated entry of the salt into solution. In addition, the embodiments of a brine generating system according to principles of the present disclosure can provide sediment filtering that catches a significant portion of the sediment at a point above the bottom of the tank allowing the sediment to be automatically discharged periodically, without fully draining the tank and even during operation of the brining system. In this way, a full cleaning of the sump can be delayed, thereby increasing the up-time of the system. 
         [0008]    In some embodiments, a brine generation system includes a tank with an upper opening configured for receiving salt crystals and a divider separating the tank into a salt crystal holding upper portion and a brine holding lower portion. The divider is adapted to resist movement of salt crystals from the upper portion to the lower portion but be permeable to allow the brine solution to fall into the lower portion from the upper portion through the divider. A fluid conduit is disposed within the upper portion. The fluid conduit includes at least one water jet adapted to inject a stream of water provided through the fluid conduit. The stream of water is configured for discharge through the water jet in a direction that is downward into the volume of the tank. An outlet is positioned in the lower portion of the tank for withdrawing the brine solution. In some embodiments, a set of water jets receives fresh water and discharges it downward into the tank at a point below an upper third of a volume of the upper salt crystal holding portion whereby the water jets may be surrounded by salt crystals. 
         [0009]    In other embodiments, a brine generation system includes a tank having an upper opening for receiving salt crystals to fill the tank. A divider separates the tank into an upper salt crystal holding portion and a lower brine holding portion. The divider provides an intermediate channel positioned above the lower brine holding portion. The intermediate channel is adapted for accumulating non-soluble particles that may be mixed with the salt crystals by sedimentation. A set of water jets is disposed within the upper salt crystal holding portion of the tank. The set of water jets is adapted to discharge fresh water or a brine solution into the upper salt crystal holding portion to dissolve salt crystals. A mechanical sweeper is associated with the intermediate channel. The mechanical sweeper is adapted to collect and discharge non-soluble particles from the intermediate channel out of the tank through an opening extending through a wall of the tank. A lower channel is formed below the intermediate channel at a lower position in the lower brine holding portion. The lower channel is adapted for accumulating non-soluble particles found in a brine solution that percolates from the upper salt crystal holding portion when the set of water jets is active. A brine outlet extends through the wall of the tank at an outlet height. The outlet height is above the lower channel and below the intermediate channel. The brine outlet is adapted to withdraw brine solution from the lower portion of the tank. 
         [0010]    It is a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to substantially reduce the amount of extra-tank recirculation required to obtain a given degree of salinity. 
         [0011]    In embodiments, a divider may include a wall portion adjacent to the water jets for providing a region of circulating water drivable by a force of water from the water jets. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to increase the dwell time of turbulent water and salt beyond the limit imposed by simple percolation. 
         [0012]    In embodiments, a divider may include a sump channel and an openable port through the tank wall for ejection of particles accumulated in the sump channel. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to capture particulates at a point above the bottom of the tank permitting their ejection without full tank draining. 
         [0013]    In embodiments, a sump channel may include a mechanical sweeper for moving collected particles off of the sump channel and out of the openable port in the tank. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to permit the ejection of sediment without dilution of existing brine. 
         [0014]    In embodiments, a mechanical sweeper may be an auger extending substantially horizontally along the sump channel. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to provide a compact apparatus for mechanically removing sediment. 
         [0015]    In embodiments, an auger and an openable port may be electronically controllable for automatic ejection of accumulating particles. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to allow optimization of the cycle of sediment removal for minimum downtime. 
         [0016]    In embodiments, at least a portion of a sump channel forming a lowermost portion in a divider may be a screen. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to provide a system concentrating sediment for removal. 
         [0017]    In embodiments, a valve plate may divide an upper portion into an upper erosion chamber receiving water directly from jets and a portion of a sump channel below the upper erosion chamber, a valve plate controlling passage of material from the upper erosion chamber to the lower sump channel. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to controllably limit drainage of brine through the sump to maximize sediment retention without adversely reducing dwell time of liquid in the extreme erosion zone. 
         [0018]    In embodiments, a brine generation system may further include a second screen above and not covering a sump channel and presenting a substantially vertical surface to resist accumulation of particles. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to provide a decanting route for brine from the extreme turbulence zone. 
         [0019]    In embodiments, a brine generation system may include a third screen covering a sump channel above a second screen passing larger particles than a second screen. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to block extremely large damaging particles such as rocks and sticks. 
         [0020]    In embodiments, a brine generation system may further include a secondary sump at a lowermost portion of a tank below a sump channel for accumulating particles passing through a divider. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to permit removal of non-soluble particulates that escape the intermediate trap. 
         [0021]    In embodiments, a port openable through a tank wall may provide for the ejection of particles accumulated by a secondary sump. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to allow simple removal of the fine particulates when the tank is drained. 
         [0022]    In embodiments, a secondary sump may be a horizontally extending channel sloping along its length and further including an ejector for driving accumulated particles within a secondary sump out of an openable port. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to promote complete cleaning of the tank with reduced water usage. 
         [0023]    In embodiments, an ejector comprises a pressurized water nozzle. It is thus a feature of at least one embodiment of a brine generating system according to principles of the present disclosure to provide a simple method of periodic cleaning that may occur after draining. 
         [0024]    In another aspect of the present disclosure, embodiments of a method for generating a brine solution useful for treating roadways against ice accumulation thereon are described. In one embodiment, a tank that is segmented into upper and lower portions is provided. The upper portion is adapted for containing salt crystals, and the lower portion is adapted for containing the brine solution. One or more water jets operate within the upper portion when salt crystals are present in the upper portion. The water jets provide water streams aimed towards the salt crystals such that the water jets dissolve salt crystals to form the brine solution in the upper portion. The brine solution from the upper portion is allowed to percolate through a permeable divider that has a non-permeable section and that separates the upper and lower portions such that the brine solution is collected in the lower portion. The water jets operate such that at least a portion of the water streams impinges the non-permeable portion of the divider to create a turbulent region adapted to promote salt crystal dissolution. One or more screens are provided in the divider through which the brine solution passes such that any non-soluble particles present within the salt crystals can collect on at least one screen. A sweeper device adapted to collect non-soluble particles from the at least one screen and eject the collected non-soluble particles through an openable port extending through a wall of the tank is operated. 
         [0025]    Further and alternative aspects and features of the disclosed principles will be appreciated from the following detailed description and the accompanying drawings. As will be appreciated, the brine generating systems and methods for using the same disclosed herein are capable of being carried out and used in other and different embodiments, and capable of being modified in various respects. Accordingly, it is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and do not restrict the scope of the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a simplified side elevational view in partial cross-section of an embodiment of a brining system constructed according to principles of the present disclosure showing a location of fresh water jets in an upper portion of the tank as buried in salt and close to a divider to create an extreme erosion zone near the divider and further showing two levels of sediment removal; 
           [0027]      FIG. 2  is an elevational view in cross-section of the tank of  FIG. 1  showing details of the divider for creating the extreme erosion zone and a first sediment collection sump for collecting sediment above the bottom of the tank and a second sediment collection zone at the bottom of the tank; 
           [0028]      FIG. 3  is a detailed side elevational view similar to  FIG. 1  showing an auger of the first sump for automatically removing material therefrom and a rock and stick filter positioned above the first sediment collection sump; 
           [0029]      FIG. 4  is a perspective view of an embodiment of a tank constructed according to principles of the present disclosure showing relative locations of a freshwater manifold and recirculation manifold. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    Referring now to  FIG. 1 , an embodiment of a brine generation system  10  constructed according to principles of the present disclosure can include a tank unit  12  providing a tank  14 , for example, made of stainless steel and having an open top through which rock salt  16  or other similar material such as calcium magnesium acetate (CMA) pellets and other salt-containing materials that will dissolve in water (referred to herein, collectively, as “salt crystals” or “crystals of salt”) can be received. In alternative embodiments, other non-corrosive materials such as fiberglass, polymers and the like can be used. An exemplary, but non-limiting, capacity of the tank  14  can be six to eight cubic yards. 
         [0031]    As will be described in greater detail below, the salt  16  is generally contained in a salt-holding upper portion  18  as constrained by a divider  20 . A freshwater source can feed a freshwater manifold  22  extending horizontally into the upper holding portion in an inflow region  24  below an upper third of the volume of the upper holding portion, such that the freshwater manifold  22  can be surrounded by crystals of salt  16 . The manifold  22  provides a series of nozzles  26  discharging high-pressure streams of freshwater downward into the salt  16 . 
         [0032]    Brine  27  collects beneath the divider  20  in a brine-holding lower portion  28  of the tank  14  and can be extracted through brine extraction port  30  above the bottom of the tank  14  in a wall of the tank  14  and communicating with a brine conduit  36 . The brine holding lower portion  28  can, for example, hold up to 380 gallons of brine. The brine  27  can be received by a salinity control system  32  which is adapted to adjust the brine for proper salinity. 
         [0033]    Specifically, the salinity control system  32  is adapted to controllably mix the brine  27  as received from the brine extraction port  30  with freshwater from freshwater metering valve  34  communicating between the manifold  22  and a brine conduit  36 . If the salinity is too high, as checked by a salinity sensor  38  downstream from freshwater inlet from the freshwater metering valve  34  after passing through a mixer  40  within the brine conduit  36 , additional water can be added automatically. The salinity sensor  38  can be any suitable sensor adapted to allow a controller of the salinity control system  32  to determine the salinity of the brine, for example, an electrical salinity gauge providing accuracy of as much as 0.01% or a density sensor adapted to measure the density of the brine, which can be converted to a salinity concentration by a PLC. 
         [0034]    The brine  27  measured by the salinity sensor  38  can be received by a pump  42  to pass to a valve bank  44  having a recycle valve  46  and the tank valve  48 . The former valve  46  conducts the brine  27  to a return manifold  50  that can extend generally parallel to the freshwater manifold  22  but displaced therefrom in the inflow region  24 . The return manifold  50  can include a series of orifices  52  which can be nozzles or simply low-pressure openings that return the brine  27  to the tank to increase its salinity. 
         [0035]    Thus control of the freshwater metering valve  34  and the recycling provided by the valve  46  can be used to adjust the salinity of the brine  27  received by the pump  42 . One or more flow sensors (not shown) can also be placed in the brine conduit  36 , freshwater manifold  22  or return manifold  50  for further control input. 
         [0036]    The valve  48 , when open, can forward the brine to a storage tank  54  possibly by way of a mixing station  56 , the latter which can mix the brine with other additives of types known in the art. Each of the valves  34 ,  46 ,  48 , and the pump  42  can be electrically controlled by pneumatic valves controlled by a controller  58  (such as a programmable logic controller) for automatic operation as will be described herein, based on readings obtained from the salinity sensor  38 , flow sensors (not shown) and inputs received from the operator in a control panel (also not shown). 
         [0037]    The tank  14  provides for two stages of sediment collection. Such sediment includes non-soluble particles that can be mixed with the salt crystals loaded into the tank. A first stage of sedimentation collection occurs above the bottom of the tank near the divider  20  and provides for a capture of intermediate particulates  60  which can be automatically discharged through a port  62  at one end of the tank  14 . The port  62  can have electronically controllable port hatch  64  controlled by an actuator  66  communicating with the controller  58  for automatic discharge of the intermediate particulates  60  at regular intervals. 
         [0038]    Fine particulates  68  can settle to the bottom of the tank  14  and be discharged through a second discharge port  70  below the port  62 . This port can have a manually removable cap or valve  71 . The discharge ports  62  and  70  are shown on the same side of the tank for clarity; however, in a preferred embodiment, discharge port  70  is on the same side as the brine extraction port  30  preventing interference in the collection of sediment between the two ports. 
         [0039]    Referring now to  FIG. 2 , the upper portion of the tank  14  can flare outward to provide a hopper  73  for receiving salt  16  from a back loader, conveyor or the like as discharged downward into the tank  14 . The salt  16  is then guided to the divider  20  which provides a first inwardly sloping wall  72  and opposed second inwardly sloping wall  74  converging in a downward direction to a sump channel  76 . The first sloping wall  72  and second sloping wall  74  thereby approximate a V channel having the sump channel extending downward from its lower vertex. The first sloping wall  72  can be hinged about a hinge point  78  allowing its outer edge to be raised away from a wall of the tank  14  for access to the lower portion  28  of the tank  14  when salt  16  is removed. The second sloping wall  74  provides generally a screen that is permeable to liquid, allowing the latter to pass generally horizontally therethrough as indicated by arrow  75  but resisting the passage of the larger salt particles. This screen can have, for example, 5/32 inch (4 mm) holes staggered on a 3/16 inch (4.75 mm) grid. The vertical extent of the screen of wall  74  helps resist the accumulation of particulate matter against the screen, as the particulate matter migrates generally downward toward the sump channel  76 . 
         [0040]    Referring also to  FIG. 3 , an upper open end of the sump channel  76  communicating with the upper portion  18  can be covered by a rock guard  80  having relatively large openings (on the order of 2 inch (50 mm) diameters) intended to prevent passage of large rocks or sticks or the like into the sump channel  76 . 
         [0041]    Referring to  FIGS. 2 and 3 , the walls of the sump channel  76  can be formed of a perforated sheet of stainless steel formed in an upwardly facing U-shaped cross-section to provide a radiused portion  82  conforming to an outer periphery of a horizontally extending auger  84 . The perforations will generally have similar openings to the openings of the screen of the second sloping wall  74 , both of which can be much smaller than the openings of the rock guard  80 . The auger  84  can be a screw type helix having a cylindrical swept volume formed of molded polypropylene or stainless steel sections assembled on a stainless steel arbor. Rotation of the auger  84  by a gear motor  87  (electronically controllable by the controller  58  shown in  FIG. 1 ) scrapes the inner surface of the radiused portion  82  to transport sediment trapped by the sump channel  76  out of the port  62  when port hatch  64  is opened. It will be appreciated that this operation of the auger  84  can be conducted without a complete draining of the tank  14  of brine  27 . When significant sediment has accumulated in the sump channel  76 , the auger  84  can be operated even with the level of the brine  27  slightly above the auger  84  without undue loss of brine through the port  62 . This allows continued operation of the system  10  without the need to drain the tank and go off-line while substantially decreasing the amount of sediment that will accumulate at the bottom of the tank. 
         [0042]    Referring still to  FIG. 2 , positioned within the sump channel  76  and above the auger  84  is a plate valve  86  controllable by actuator  88  that can also be controlled by controller  58  (shown in  FIG. 1 ). The plate valve  86 , when closed, substantially blocks access to the sump channel  76  from above the divider  20  allowing more access as the plate valve  86  is opened. The result is that the amount of fluid flow indicated by arrows  89  from the upper portion  18  of the chamber into the sump channel  76  can be controlled to permit the collection of intermediate size particulates  60  in the sump channel  76  without providing substantial loss of brine therethrough. The result of the placement of the nozzles  26  of the freshwater manifold  22  adjacent to the divider  20  is to create an extreme erosion zone  90  providing for highly turbulent flow  92  within a pool  94  of brine  27  above the divider  20 . The angle of the nozzles  26  can be adjusted about an axis of the manifold  22  via exterior handle  23  as indicated by arrows  25 . By control of the relative flow through the nozzles  26  and the setting of the plate valve  86 , the dwell-time for liquid above the divider  20  can be controlled allowing desired salinity to be obtained with reduced need to recirculate the brine through the system which can decrease the rate at which the system can produce the brine solution. In the illustrated embodiment, the system is configured to provide at least exceed 100 gallons (380 L) of brine solution per minute. 
         [0043]    Referring still to  FIGS. 2 and 3 , a bottom wall  96  of the tank  14  can provide for an upwardly open channel  98  being a lowermost portion of the bottom wall  96 . Bottom wall  96  outside of the channel  98  can slope toward the channel to facilitate the collection of fine particulates  68  therein. The channel  98  itself slopes downward toward the exit port  70  at one end of the tank  14  to facilitate the migration of fine sediment toward the exit port  70 . A port  100  opposite the port  70  across the channel  98  can provide for the introduction of high-pressure water through a nozzle to force sediment along the channel  98  out of the port  70 . Additional manifolds and nozzles (not shown in  FIG. 2 ) can direct water jets down the slope portions of the bottom wall  96  outside of channel  98  to assist in this discharge process. This sediment removal process typically requires draining of the tank from brine  27  and thus is desirably performed less frequently than operation of the auger  84  described above. 
         [0044]    Referring now to  FIG. 4 , the tank  14  can be supported on outwardly splayed legs  104  fixedly attached to the bottom wall  96 . Retractable caster units  106  can be lowered to allow movement of the tank by lifting it from a surface in contact with the legs  104 . A clear viewport  108  is provided in one side of the tank approximately on level with the brine extraction port  30  to allow monitoring of the sediment buildup of fine particulates  68 . A clear, sight-tube type water height gauge  110  can be placed on the side of the tank  14  showing a brine level height in the lower portion  28 . This water height gauge  110  can be augmented by a pressure sensor type water height gauge  112  (shown in  FIG. 1  communicating with the controller  58 ) to allow automatic adjustment and control of the brine height in the lower portion  28   
         [0045]    During operation, the controller  58  can adjust the salinity of the brine discharged to the tanks  54  and periodically run the auger  84 , possibly with adjustment of the brine level downward below the port hatch  64 , per water height gauge  112 , before such auger runs. A feedback control loop (for example implementing a PID loop) can be used to control the plate valve  86  to minimize the need for recycling brine through return manifold  50  increasing the net throughput of the device. 
         [0046]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper,” “lower,” “above,” and “below” refer to directions in the drawings to which reference is made. Terms such as “front,” “back,” “rear,” “bottom,” and “side” describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology can include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first,” “second,” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0047]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0048]    References to “a controller” and “a processor” can be understood to include one or more controllers or processors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network. 
         [0049]    It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated. 
         [0050]    Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.