Patent Publication Number: US-2021178343-A1

Title: Brine machine and method

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/963,538 filed Apr. 26, 2018, which claims the priority benefit of U.S. Provisional Patent Application No. 62/662,546 filed Apr. 25, 2018, both of which are hereby incorporated by reference herein as if fully set forth in their entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to machines for making brine for use as a melting agent for managing snow and ice on roadways, parking lots, and sidewalks, and more particularly, to self-cleaning brine machines that can continuously making brine. 
     BACKGROUND OF THE INVENTION 
     Salt Brine is a common solution used as a melting agent in managing snow and ice on surfaces such as roadways, parking lots, and sidewalks. Salt brine is made by combining NaCl and H2O into a solution, typically 23.3% solution weight/weight, when used as a melting agent for snow and ice control. 
     When used on roadways the volume of product required can exceed over 1,000,000 gallons per season for a single user. The solution at 23.3% saturation contains 2.288 lbs. of salt per gallon of solution. In many areas the most cost effective source of NaCl available is mined rock salt. Mined rock salt may typically have 5% foreign material, i.e. material other than salt (“MOS”), such as sand, calcium sulfate, and shale, in addition to other debris from transportation in trucks such as corn, wheat, etc. With a production rate being 50 to 100 GPM for a typical brine machine, the foreign material build-up can be expected to be 5 to 12 lbs. of MOS per minute. The brine machine must therefore periodically be shut down so that the MOS can be cleaned out of the machine. This clean out can be labor intensive and difficult, is non-productive use of time of the operators, and results in downtime of the brine machine. 
     The process of making a salt brine solution is fairly simple in that all that is required is to suspend salt into water. This can be done by 2 primary methods: either by soaking the salt in water, or by eroding the salt away with water. Typically, the erosion method produces brine faster and at high concentrations. 
     As the salt goes into suspension the non-dissolvable materials remain behind inside of the brine machine or become suspended into the solution. These non-dissolvable materials may also bind up the salt so it does not go into solution, plugging up flow paths, etc. As foreign material accumulates typically the brine production process slows to a point where the machine must be shut down and the MOS removed, so that production may resume. 
     Removing the MOS as wetted material verses a slurry is ideal so that handling of this product is minimized. 
     It is desired to produce clean brine. With salt having non-dissolvable material taken into suspension during the brine production process, these solids create maintenance issues. Storage tanks have sediment build up on the bottom of the tanks, and application equipment uses flow meters, pumps, and spray nozzles that get damaged or suffer from premature wear due to abrasives in the solution. Therefore, filtration of the solution to reduce the contamination is desirable. 
     The objective is to make clean brine rapidly at a desired concentration without the need to periodically shut the system down to clean it, thereby having the system continuously operating at peak performance. 
     SUMMARY OF THE INVENTION 
     The objective is attained by providing a brine machine that is continuously self-cleaning and thus continuously operational. 
     In one aspect, a brine machine comprises a salt hopper, a source of water for wetting salt in the salt hopper, a brine hopper positioned in side-by-side relation relative to the salt hopper, a filter providing fluid communication between the salt hopper and the brine hopper, a generally horizontal auger positioned in a base of the salt hopper, and an upwardly directed lift auger having a first end in operable association with an end of the horizontal auger and a second discharge end positioned above a level of brine in the brine hopper. The augers convey solid material from the base of the salt hopper and discharge the material from the machine. 
     The filter can be a multi-stage filter, for example a three-stage filter. The three-stage filter can comprise a first filter element having a first set of openings therein, a second filter element, spaced horizontally from the first filter element, and having a second set of openings therein, and a third filter element, spaced horizontally from the second filter element, and having a third set of openings therein. The openings of the first set of openings are larger than the openings of the second set of openings, and the openings of the second set of openings are larger than the openings of the third set of openings. Thus, unfiltered brine in the salt hopper passes through the first filter element, then the second filter element, and then the third filter element to enter the brine hopper as filtered brine. The first, second, and third filter elements are configured such that material collected on their respective filter surfaces falls downwardly toward the base of the salt hopper. 
     The brine machine can have a first water spray bar in the salt hopper positioned adjacent an inlet side of the filter for flushing the inlet side of the filter. The brine machine can have a second water spray bar in the brine hopper positioned adjacent an outlet side of the filter for flushing the outlet side of said filter. The second water spray bar can be rotatable. The brine machine can have a damper positioned in the salt hopper above the horizontal auger for selectively metering material from the salt hopper to the horizontal auger. The brine machine can have a third water spray bar in the salt hopper positioned above the damper for dissolving undissolved salt and sweeping material into the damper. The third water spray bar can be rotatable. The brine machine can have a grate positioned above the damper and below the third water spray bar. 
     In another aspect, a brine machine comprises a salt hopper, a source of water for wetting salt in the salt hopper, a brine hopper positioned in side-by-side relation relative to the salt hopper, a filter providing fluid communication between the salt hopper and the brine hopper, a generally horizontal auger positioned in a base of the salt hopper, a damper positioned in the salt hopper above the horizontal auger for selectively metering material from the salt hopper to the horizontal auger, an upwardly directed lift auger having a first end in operable association with an end of the horizontal auger and a second discharge end positioned above a level of brine in the brine hopper, and a controller operable to control opening and closing of the damper. The augers convey solid material from the base of the salt hopper and discharge the material from the machine. 
     The brine machine can have a first upper damper and a second lower damper, with the controller being operable to open and close the first damper and then open and close the second damper. The brine machine can have a first water spray bar in the salt hopper positioned adjacent an inlet side of the filter for flushing the inlet side of the filter, a second rotatable water spray bar in the brine hopper positioned adjacent an outlet side of the filter for flushing the outlet side of the filter, and a third rotatable water spray bar in the salt hopper positioned above the first damper for dissolving undissolved salt and sweeping material into the first damper, with the controller being operable to control rotation of the second and third rotatable water spray bars. The brine machine can have a grate positioned above the first damper and below the third rotatable water spray bar. The brine machine can have a fourth water spray bar positioned above the second damper for dissolving undissolved salt and sweeping material into the second damper. The filter can be a multi-stage filter, for example a three-stage filter of the type described above. The brine machine can have a first upper three-stage filter and a second lower three-stage filter, with each three-stage filter having a respective first water spray bar in the salt hopper positioned adjacent the inlet side of the filter for flushing the inlet side of the filter, and a respective second rotatable water spray bar in the brine hopper positioned adjacent the outlet side of the filter for flushing the outlet side of the filter. 
     In yet another aspect, a brine machine comprises a salt hopper, a source of water for wetting salt in the salt hopper, a brine hopper positioned in side-by-side relation relative to the salt hopper, the salt hopper and brine hopper in fluid communication having a fluid inlet on a salt hopper side and a fluid outlet on a brine hopper side, a generally horizontal auger positioned in a base of the salt hopper, and an upwardly directed lift auger having a first end in operable association with an end of the horizontal auger and a second discharge end positioned above a level of brine in the brine hopper. The augers convey solid material from the base of the salt hopper and discharge the material from the machine. 
     In yet another aspect, a brine machine comprises a salt hopper, a source of water for wetting salt in the salt hopper, a brine hopper positioned in side-by-side relation relative to the salt hopper, the salt hopper and brine hopper in fluid communication having a fluid inlet on a salt hopper side and a fluid outlet on a brine hopper side, a generally horizontal auger positioned in a base of the salt hopper, a damper positioned in the salt hopper above the horizontal auger for selectively metering material from the salt hopper to the horizontal auger, an upwardly directed lift auger having a first end in operable association with an end of the horizontal auger and a second discharge end positioned above a level of brine in the brine hopper, and a controller operable to control opening and closing of the damper. The augers convey solid material from the base of the salt hopper and discharge the material from the machine. 
     In yet another aspect, a method of producing brine comprises wetting salt in a salt hopper with water to form unfiltered brine, filtering the unfiltered brine with a filter as it moves from the salt hopper to a filtered brine hopper, opening a damper to allow filtered material to drop onto a horizontal auger, closing the damper, conveying the filtered material with the horizontal auger to an upstanding auger, conveying the filtered material with the upstanding auger, and discharging the filtered material from an upper end of the upstanding auger. 
     The method can further comprise rinsing an inlet side and an outlet side of the filter with water spray. The method can further comprise sweeping the filtered material into the damper with water spray. 
     In yet another aspect, a method of producing brine comprises wetting salt in a salt hopper with water to form unfiltered brine, filtering the unfiltered brine with a filter as it moves from the salt hopper to a filtered brine hopper, opening an upper damper to allow filtered material to drop onto a lower damper, closing the upper damper, opening the lower damper to allow filtered material to drop onto a horizontal auger, closing the lower damper, conveying the filtered material with the horizontal auger to an upstanding auger, conveying the filtered material with the upstanding auger, and discharging the filtered material from an upper end of the upstanding auger. 
     The method can further comprise rinsing an inlet side and an outlet side of the filter with water spray. The method can further comprise sweeping the filtered material into the upper damper with water spray. The method can further comprise sweeping the filtered material into the lower damper with water spray. 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the summary of the invention given above, and the detailed description of the drawings given below, serve to explain the principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a left, front, top perspective view of a brine machine embodying the principles of the present invention. 
         FIG. 2  is a right, front, top perspective view of the brine machine of  FIG. 1 . 
         FIG. 3  is a side cross-sectional view of the brine machine of  FIGS. 1 and 2  showing unfiltered brine in the salt hopper passing through the filters to enter the brine hopper as filtered brine. 
         FIG. 3A  is an enlarged side cross-sectional view showing the upper and lower dampers and the lower filter and showing unfiltered brine in the salt hopper passing through the filter to enter the brine hopper as filtered brine. 
         FIG. 3B  is a view similar to  FIG. 3A  showing solid material being filtered by the filter, the inlet side of the filter being flushed by a water spray bar in the salt hopper, the outlet side of the filter being back flushed by a rotating water spray bar in the brine hopper, and the material dropping down onto the closed upper damper. 
         FIG. 3C  is a view similar to  FIG. 3B  but showing the upper damper opened and the material being swept down onto the closed lower damper by a rotating water spray bar in the salt hopper. 
         FIG. 3D  is a view similar to  FIG. 3C  but showing the upper damper closed and the lower damper opened and the material being swept down onto the horizontal auger by a water spray bar. 
         FIG. 4  is an enlarged side cross-sectional view showing one of the filters. 
         FIGS. 5-7  are cross-sectional views similar to  FIG. 3  but from various perspectives. 
         FIG. 8  is a block diagram of a control system for the brine machine. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring first to  FIGS. 1 and 2 , there is illustrated a brine machine  10  embodying the principles of the present invention. The brine machine  10  includes a salt hopper/unfiltered brine hopper  12  and a filtered brine hopper or tank  14  positioned in side-by-side relation relative to the salt hopper  12  (as opposed to below the salt hopper as in another type of brine machine). Salt is supplied to the salt hopper  12  through an upper opening  16 . Water is supplied to the salt in the salt hopper via a water spray bar  18  to dissolve the salt into a brine solution. Filtered brine passes out of the filtered brine hopper  14  through a lower outlet  20 . 
     Referring to  FIGS. 3-7 , unfiltered brine passes from the salt hopper/unfiltered brine hopper  12  through an upper multi-stage filter  30  and preferably, but not necessarily, a lower multi-stage filter  32  and into the filtered brine hopper  14 . By way of example, the multi-stage filters  30 ,  32  are three-stage filters. By way of example, each three-stage filter  30 ,  32  has a first stage filter element or screen  40  having 3/16 inch diameter circular openings, a second stage filter element or screen  42  having ⅛ inch wide by 1 inch long obround openings and that is horizontally spaced from the first stage filter element or screen  40 , and a third stage filter element or screen  44  having number  50  mesh size openings and that is horizontally spaced from the second stage filter element or screen  42 . More or less than three stages can be used for the filters  30 ,  32 , and different sized openings can be used for the filter elements, depending on the MOS content of the salt supplied to the machine  10 . The filter elements or screens  40 ,  42  are generally planar and are oriented such that their planes are generally vertical. Filter element or screen  44  includes first and second generally planar portions, the first planar portion being oriented such that its plane is generally vertical and the second planar portion being oriented at an angle relative to the first planar portion of between about 90 degrees and about 180 degrees. MOS and/or undissolved salt can drop downwardly off of the filter surfaces of the filter elements or screens  40 ,  42 ,  44  and out of the filters  30 ,  32  due to the spaced apart nature of the filter elements or screens  40 ,  42 ,  44 . 
     The upper filter  30  has a water spray bar  50  located above it in the salt hopper  12 . The water spray bar  50  is used to flush undissolved salt particles and/or MOS off of the first stage filter element  40  of the upper filter  30 . Similarly, the lower filter  32  has a water spray bar  52  located above it in the salt hopper  12 . The water spray bar  52  is used to flush undissolved salt particles and/or MOS off of the first stage filter element  40  of the lower filter  32 . 
     The upper filter  30  also has a rotatable water spray bar  60  located above it in the brine hopper  14 . The water spray bar  60  is used to flush (or back flush) undissolved salt particles and/or MOS off of the third stage filter element  44  of the upper filter  30 . Similarly, the lower filter  32  has a rotatable water spray bar  62  located above it in the brine hopper  14 . The water spray bar  62  is used to flush (or back flush) undissolved salt particles and/or MOS off of the third stage filter element  44  of the lower filter  32 . 
     Salt particles and/or MOS too large to pass through all three stages of the filters  30 ,  32  drop out of the bottom of the filters  30 ,  32  and down onto a grate  70 . See  FIG. 3B . Grate  70  has 1.875 inch diameter by 2.813 inch long obround openings. Grate  70  is positioned along the lower edge of a slanted floor  72  of the salt hopper  12 . Salt and/or unfiltered brine is thus directed by gravity onto grate  70 . Below grate  70  is an openable and closable upper damper  80  and, preferably but not necessarily, an openable and closable lower damper  82 . Below lower damper  82  is a generally horizontally oriented auger  84  positioned in a base or sump or lower channel  85  of salt hopper  12 . One end of horizontal auger  84  is operably associated with a lower end of an upwardly directed lift auger  86  ( FIGS. 1 and 2 ). Auger  86  has an upper discharge end  88  that is positioned above a level of brine in the brine hopper  14 . The augers  84 ,  86  convey the MOS from the base of the salt hopper  12  and discharge the material from the machine  10 . 
     The upper damper  80  has a rotatable water spray bar  90  located above it in the salt hopper  12 . The water spray bar  90  dissolves undissolved salt on the grate  70  and sweeps material through the grate and into the upper damper  80 . 
     The lower damper  82  has a water spray bar  92  located above it in the salt hopper  12 . The water spray bar  92  dissolves undissolved salt and sweeps material into the lower damper  82 . 
     Referring to  FIG. 8 , a control system  100  includes a controller  102  operably associated with water spray bars  18 ,  50 ,  52 ,  60 ,  62 ,  90 , and  92 , with upper damper  80 , with lower damper  82 , with horizontal auger  84 , and with lift auger  86 , via respective pumps, rotary motors, etc. known to those skilled in the art. Thus, the controller  102  controls water output through the water spray bars  18 ,  50 ,  52 ,  60 ,  62 ,  90 , and  92 , controls rotation of water spray bars  60 ,  62 , and  90 , controls opening and closing of dampers  80 ,  82 , and controls rotation of augers  84 ,  86 . 
     The controller  102  causes the augers  84 ,  86  to rotate continuously or periodically. The controller  102  periodically opens the upper damper  80  allowing MOS to drop down onto lower damper  82 . See  FIGS. 3B and 3C . The controller  102  then closes the upper damper  80  and opens the lower damper  82  allowing MOS to drop down onto horizontal auger  84 . See  FIG. 3D . The controller  102  then closes the lower damper  82  in preparation for the next self-cleaning cycle. The auger  84  conveys the MOS out of the salt hopper  12  to the lift auger  86 . The lift auger  86  conveys the MOS upwardly where it drops out of discharge end  88  of auger  86 . Since the discharge end  88  of auger  86  is above the brine level in the brine hopper  14 , no brine escapes out. 
     The time intervals between opening dampers  80 ,  82 , the time duration each damper  80 ,  82  is open, the amount and timing of water supplied via the water spray bars  18 ,  50 ,  52 ,  60 ,  62 ,  90 , and  92 , and the time intervals between rotating the water spray bars  60 ,  62 , and  90  and the time duration each water spray bar  60 ,  62 ,  90  is rotated vary depending on the desired rate at which brine is being made, the MOS in the salt supplied to the machine  10 , and the desired salinity. 
     By continuously supplying salt and water to the machine  10 , continuously or periodically running the augers  84 ,  86 , continuously filtering the brine with filters  30 ,  32 , periodically opening and closing upper damper  80  then opening and closing lower damper  82 , and periodically rotating water spray bars  60 ,  62 , and  90 , the brine machine  10  can continuously produce brine in a continuously self-cleaning fashion, without the need to be shut down to clear the machine  10  of MOS. 
     The present invention can be incorporated into either of the two types of brine systems. In one type of system, a flow through system, the salinity of the mixture is controlled by the addition of salt or water to the mixing tank until the correct salinity is reached. In the other type of system, a re-circulation system, the brine mixture is re-circulated back through the salt until the proper salinity is reached. Once the proper salinity is reached in either system, the brine can be pumped to a storage tank. 
     The assignee&#39;s US Patent Publication No. 2014/0251177, US Patent Publication No. 2013/0099155, and U.S. Pat. No. 9,890,310 are all hereby incorporated by reference herein as if fully set forth in their entireties, and may be consulted for additional details of brine systems that can be incorporated into the brine machine of the present invention. 
     The various embodiments of the invention shown and described are merely for illustrative purposes only, as the drawings and the description are not intended to restrict or limit in any way the scope of the claims. Those skilled in the art will appreciate various changes, modifications, and improvements which can be made to the invention without departing from the spirit or scope thereof. The invention in its broader aspects is therefore not limited to the specific details and representative apparatus and methods shown and described. Departures may therefore be made from such details without departing from the spirit or scope of the general inventive concept. The invention resides in each individual feature described herein, alone, and in all combinations of any and all of those features. Accordingly, the scope of the invention shall be limited only by the following claims and their equivalents.