Patent Publication Number: US-11027158-B1

Title: Fire retardant proportioning system and apparatus

Description:
BACKGROUND OF THE INVENTION 
     Technical Field 
     The present invention relates in general to liquid fire-retardant concentrate proportioning means for use in fire fighting apparatus having a single pump and for enabling the mixing of the liquid concentrate with water at a vendor specified percentage so that the resulting mixture can be used in ground applied applications without pre-mixing or batch mixing in an apparatus tank. 
     Alternatively stated, the present invention relates to a novel means adapted to provide a pressure controlled stream of water and to use the pressurized stream to proportionately educt liquid long term fire retardant (LTFR) chemicals at a vendor specified percentage from a source of a concentrate thereof, and to simultaneously introduce the educted concentrate directly into the pressurized stream to mix the concentrate with the pressurized water so that the resulting mixture may be immediately dispensed onto fire threatened structures and/or vegetation to suppress or prevent ignition and resulting fire. 
     Prior Art 
     It is well known that various forms of fire retardant or extinguishing chemical powders, gel concentrates, foam concentrates and other solute concentrates can be mixed with water to provide a fire fighting mixture that can be sprayed or otherwise applied to structures and vegetation to suppress, control, and/or extinguish an ongoing or oncoming wildfire. 
     It is further well known that various forms of fire suppressing or extinguishing chemical powders, gel concentrates, and foam concentrates can be mixed with water to provide various fire fighting solutions that can be sprayed or otherwise applied to structures and vegetation to suppress, control, or extinguish an ongoing or oncoming wildfire. 
     For example, in U.S. Pat. No. 3,115,158 issued to A. G. Sheppard, an apparatus is disclosed for making air-foam for fire extinguishing purposes. In the described prior patent, water and a foam liquid are carried in suitable tanks on a fire truck or other vehicle having two centrifugal pumps; one for supplying the water under pressure, and the other for supplying the foam liquid under pressure. Both pumps are driven by the truck engine. As stated in the patent, the water pressure and foam liquid pressure are so correlated by the dual pumps as to establish, in cooperation with a venturi, pressure differentials which control the discharge of the foam liquid. Such control is achieved by means of a check valve located in the foam supply line and adapted to open in a downstream direction in response to pressure drop in the venturi throat occasioned by liquid flow therethrough. 
     However, the Sheppard invention has the disadvantage of requiring the use of two separate pumps to pressurize both water and foam liquid and uses a swing check valve to create a differential pressure to gate the foam input to the mixing element, i.e., to turn on and off the flow of foam so as not to waste the foam when the flow control nozzle is opened and closed. 
     In addition, whereas the Shepard approach is suitable for use with foam liquids that will work over a broad range of mixture proportions, it is not well suited for use with non-foam liquids wherein the mixing ratio is much more critical. 
     Principal Objectives of the Present Invention 
     A principal objective of the present invention is to provide an improved system and apparatus for mixing and applying long term fire retardant (LTFR) solutions to structures and vegetation that may be threatened by wildfire. 
     Another objective of the present invention is to provide an improved system and apparatus for mixing and applying long term fire retardant (LTFR) solutions that can be effective for substantial periods of time. 
     Another objective of the present invention is to provide a relatively light-weight and compact fire-fighting apparatus that can be transported by a wide range of vehicle types into otherwise inaccessible areas threatened by wildfires. 
     Still another objective of the present invention is to provide an apparatus that can reduce the handling and mixing of caustic and corrosive LTFR chemical concentrates and allow them to be drawn directly from their vendor-supplied containers and accurately mixed in the correct proportions with transported or otherwise available water. 
     Yet another objective of the present invention is to provide a simple and compact chemical mixing and proportioning apparatus that can be incorporated into a transportable fire-fighting water pumping and hose carrying skid. 
     Another objective of the present invention is to provide an improved chemical concentrate and water proportioning apparatus that once setup requires little adjustment during use in otherwise inaccessible areas threatened by wildfires. 
     Another objective of the present invention is to provide an improved chemical and water proportioning apparatus that is relatively easy to clean and care for in-between uses. 
     Another objective of the present invention is to provide an improved chemical and water proportioning apparatus that is relatively easy to assemble using readily available tools and component parts. 
     Still another advantage of the present invention is that vender supplied concentrate containers can be used to eliminate the need to pour the water and concentrate material into a separate tank for mixing and/or storage, thereby reducing material waste and simplifying cleanup. 
     BRIEF SUMMARY OF THE INVENTION 
     With the above objects in mind, the present invention presents a novel system and apparatus for enabling the in-line eduction of a long term fire retardant concentrate into a pressurized and diluting water flow stream downstream of a water pressurizing pump so that the resulting mixture of water and liquid concentrate is accurately proportioned to meet a specification dictated by the concentrate vendor and is instantly available for application to fire threatened structures and vegetation. 
     An immediately apparent advantage of the present invention is that it can be used to accurately and predictably withdraw long-term fire-retardant concentrate from one or more containers while simultaneously mixing the concentrate with pressurized water at a specified ratio and proportion, and the mixture can be simultaneously applied directly to structures or vegetation threatened by wildfire. 
     Another advantage of the present invention is that vender supplied concentrate containers can be conveniently used on a skid to eliminate the need to measure and pour the water and concentrate into a separate tank for mixing and/or storage, thereby reducing material waste. 
     These and other objects and advantages of the present invention will no doubt become apparent following an inspection of the ensuing drawing figures together with a reading of the following detailed description and the appended claims, taken in conjunction with the foregoing background discussion. 
    
    
     
       IN THE DRAWING 
         FIG. 1  is a simplified perspective view showing an embodiment of a skid mounted system and apparatus of a type generally contemplated for use with an embodiment the present invention; 
         FIG. 2  is an uncovered frontal view showing an assembly of the various component parts assembled to implement an embodiment of the fluid educting and mixing components of a preferred embodiment of the present invention; 
         FIG. 3  pictorially illustrates an eductor venturi of a type that might be used in an embodiment of the fluid educting and mixing component illustrated in  FIG. 2  of the Drawing. 
         FIG. 4  is a pictorial view generally showing an embodiment of a standard fire hose nozzle modified for use at the end of the fire hose depicted in  FIG. 1 , and 
         FIG. 5  is a schematic diagram illustrating operation of the principal operational components of the presently preferred embodiment of the present invention shown in  FIGS. 2-4  as integrated with the skid apparatus shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
     Referring now to  FIG. 1  of the Drawing, which generally illustrates at 10 a skid mounted fire-fighting system and apparatus designed to be mountable upon otherwide carried by a vehicle (not shown) such as a pickup truck, a modified Utility ATV, a UTV, a Jeep, or a trailer pulled by such vehicles or the like. 
     The depicted skid  10  is of a type designed to extract fire-fighting chemicals or concentrates contained in one or more containers  14 , and to mix the extracted chemicals with pressurized water and to then use the resulting mixture to suppress and/or extinguish wildfires. The illustrated skid is a system and apparatus such as the MTECH POLYTOUGH™ Skid apparatus comprised of a 300-gallon MTECH PolyTough™ water tank  12 ; a water pressurizing pump  17 , such as the Waterax Striker 3, 3-stage centrifugal pump, for pressurizing water withdrawn from tank  12 ; a gasoline engine  20 , such as the Honda, 13HP, electric start engine, for driving the pump  17 ; one or more chemical vendor supplied containers  14  respectively filled with one or more types of chemicals to be withdrawn from and mixed at a pre-specified ratio with pressurized water obtained from tank  12 ; and a suitable proportioning and mixing subsystem such as that generally illustrated at  16 . 
     Skid  10  further includes a hose reel assembly  22  carrying a fire hose  24  having a suitable nozzle  26  affixed to the distal end thereof; and an assembly of plumbing elements and valves  28  for interconnecting the several fluid handling, directing and processing system components. 
     Tank  12  has an outlet port  30  connected to an intake port  32  of pump  17  which in turn has an outlet port  34  connected via suitable tubing, piping or other forms of fluid conduit  36  to a pressurized water inlet port  38  of subsystem  16 . Subsystem  16  has a chemical inlet port  40  connected by a suitable conduit  42  to an outlet port  44  of at least one of the containers  14 . Subsystem  16  also has a water/chemical mixture outlet port  46  connected by a conduit  48  to the proximal end (not shown) of the fire hose  24  wrapped about reel assembly  22 . An example of the hose reel assembly  22  is a Hannay electric hose reel mechanism having 150 feet of ¾″ I.D. Booster Hose wound thereabout. 
     Also mounted on the skid and depicted in  FIG. 1  is a control unit  50  for accommodating various system operator control functions. The unit  50  might for example include inter alia, a master power switch, a means for controlling hose reel rewind, a low power shutdown switch, an engine start button, an engine control throttle, a choke knob, a water pressure gauge, and a low oil indicator light. 
     In operation, water drawn from the tank outlet port  30  is pressurized by the motor driven pump  17  and fed via conduit  36  to the subsystem  16  where it is mixed with chemicals drawn via a suction hose  42  and mixed in the subsystem  16  with the pressurized water drawn from the tank  12 . 
     The resulting mixture is then output at an output port  46  and forced through a conduit  48  connected to the proximal end (not shown) of the fire hose  24  after it is unwound from reel  22 , and then discharged through a nozzle  26  ( FIG. 1 ) connected to the distal end of the fire hose  24 . The liquid mixture discharged from nozzle  26  can be sprayed on structures or vegetation to suppress and/or extinguish an ongoing wildfire. 
     In accordance with a preferred embodiment of the present invention, the illustrated proportioning and mixing subsystem  16  of  FIG. 1  has been replaced with a novel and improved proportioning and mixing system and apparatus depicted in  FIG. 2  of the Drawing, hereinafter described as a retardant proportioning device (RDP)  18 , or the “RDP-18 subsystem” for effecting the proportioning and mixing of chemical concentrates with pressurized water. For convenience and internal consistency, except as explained above, the call-out numbers used in  FIG. 1  will continue to be used in the several Figures of the Drawing. 
     Turning now to  FIG. 2  of the Drawing, an improved fire-fighting system and apparatus including a skid, or the like, having supporting operative components such as those illustrated in  FIG. 1 , is combined with the novel subsystem and apparatus identified herein as the RDP-18. The improved fire-fighting system is specifically designed to educt and mix particular types of chemical concentrates known as liquid long term fire retardant (LTFR) concentrates, such as for example, that manufactured by ICL Performance Products, LP, and marketed as Phos-Chek LC95A-FX. The RDP-18 subsystem is depicted as including a housing  60  with its front cover plate  62  partially broken away to reveal the internal operational components thereof. 
     As illustrated, a 0-300PSI water pressure reading gauge  63  is shown to extend through an opening  64  in the upper wall  65  of housing  60 . The pressurized input water enters housing  60  from line  36  through an opening  38  (entry port  38 ) in the left side wall  66  of housing  60  via a ¾″ street EL 33, a ¾″ high pressure Tee  35 , and a ¾″ nipple  37 . An “excess water” return line to tank  12  ( FIG. 1 ) extends from a regulator branch port  75 , via a ½″ street EL 69, extending through a second opening  39  in the left side wall  66  and thence to the return conduit  68  leading to tank  12 . The mixed solution output from RPD-18 flows through a street EL 49 extending through an output port  46  in the right-side wall  67 , and thence through the discharge hose  48  to reel  22  ( FIGS. 1 and 5 ) where it is joined to discharge hose  24  and nozzle  26 . 
     Returning to  FIG. 2 , a pressure regulator adjustment screw  70  extends through lower housing wall  72  at  71 , and the concentrate input line represented by the conduit  42  extends through another opening  74  in the lower housing wall  72  via a swivel  97 , a metering orifice  96 , ¾″ Tee  93  and a ¾″ nipple  91 . 
     Disposed within housing  60  and extending across the upper portion thereof between the nipple  37  (passing through of the pressurized water input port  38 ), and the water/concentrate mixture outlet port  46  via street EL 49, are (from left to right) a four-way ½″ cross connector  80 , a ½″×¾″ flow expander  81 , a ¾″ check valve (0.5 PSI cracking pressure)  82 , a ¾″×½″ flow reducer  83 , a ½″×¼″ flow reducing adapter  84  connected to the motive port  85  of an eductor venturi  86 , such as that generally illustrated in  FIG. 3 , having its discharge port  89  connected to a ½″×¾″ flow expander  88  coupled to the street EL 49 affixed to the proximal end  47  of discharge hose  48  ( FIGS. 2 and 5 ), which in turn is connected to the proximal end of the fire hose wrapped about the reel  22  shown in  FIG. 1 . 
     As depicted in  FIGS. 2, 3 and 4 , the suction port  87  of eductor venturi  86  is connected via check valve  92  (0.5 PSI cracking pressure), the nipple  91 , the Tee  93 , the street EL 95, the concentrate metering orifice  96  and the swivel  97  to the ¾″ suction hose  42 . The eductor venturi  86  is custom designed and manufactured to allow a constant and fixed flow rate (GPM) therethrough at a given pressure while creating the necessary suction to draw a pre-specified flow of retardant concentrate from container  14 , and through metering orifice  96  and check valve  92 , and into suction port  87  to provide an 18% mix of water and retardant (5.5 to 1) out of the discharge port  89  of eductor venturi  86 . 
     Coupled to the lower branch of cross connector  80  is a 0-300 PSI pressure relief valve  94  used in conjunction with the adjustment screw  70  and gauge  63  as a pressure regulator to control the water pressure input to the RDP-18. The relief valve  94  works to by-pass excess water at the regulator to return via its branch port  75  whereby it is returned through street EL 69 and line  68  to tank  12 . Although pressurized water is provided by pump  17  ( FIG. 1 ) at approximately 125 PSI, it is preferably reduced to 110 PSI by regulator  94  and held constant thereby. 
     Referring now to  FIG. 4 , a standard fire-hose nozzle  26  is shown including an ON/OFF lever  98  and a discharge pattern adjustment screw  100  for controlling the output spray shape as it exits the nozzle at its discharge end  102 . In addition, a metering orifice (flow restrictor)  99  is also included in nozzle  26  to ensure that the fire retardant is discharged at a constant flow rate (GPM) and pressure in all pattern settings. Moreover, the discharge hose  24  ( FIG. 1 ) and metering orifice  99  are sized to allow for a 50% drop in pressure across the eductor venturi  86 . 
     As alluded to above and further explained below with respect to  FIGS. 2 and 5 , another important feature of the present invention is the subsystem flush capability provided by the flow circuit between the branch port  52  of Tee  35 , the ball valve  56 , the flush tube  58  and the branch port  54  ( FIG. 2 ) of Tee  93 . 
     In operation, (as schematically depicted in  FIG. 5  of the Drawing), and with the nozzle  26  opened, water contained in tank  12 , or otherwise obtained from an available source, is pumped through tube  36  by pump  17  at a pressure 10 to 15 PSI higher (for example 125 PSI) than the normal regulated pressure of RPD-18, i.e., 110 PSI for example, water entering RPD-18 through the high-pressure tube  36  at 125 PSI is regulated to a predetermined pressure (e.g., 110 PSI) by reading the pressure gauge  63  while setting the pressure regulator  94  using adjusting screw  70 , and with water flowing through the discharge nozzle  26 . As the pressure is reduced, the unused water by-passes through the regulator and is returned to the tank  12  through the hose  68 . 
     As the pressurized water flows through check valve  82  and into the motive port  85  of eductor venturi  86 , the pressure drops therewithin creating suction at the suction port  87 , thereby drawing retardant concentrate from container  14  through concentrate hose  42 , metering orifice  96 , check valve  92  and into the pressurized water stream passing through venturi  86 . In so doing, the water and concentrate are thoroughly mixed in the venturi  86 , and the mixed solution thereupon passes out of the discharge port  89  thereof and through the conduit  48 , reel  22 , fire-hose  24 , the ON/OFF valve  98 , and the constant flow orifice  99  and pattern adjustment screw  100  of nozzle  26  for spraying on structures and/or vegetation being treated. 
     Following use, in order to clean the entire RPD-18 subsystem, the concentrate hose  42  should be withdrawn from the concentrate container  14 , and the nozzle  26  should be opened. Opening the flush valve  56  will allow the pressurized water input at  38  to flow through the entire subsystem and exit through the open nozzle  26  and suction tube  42 . This will clean the entire subsystem and clear any clogs that may have occurred. 
     Should the pump  17  not be turned OFF before the nozzle  26  is opened, the check valve  82  will stop mixed solution in the discharge line  48  from returning to the excess water return line  68  and contaminating the water tank  12  and pumping system should the flush valve  56  be opened. 
     Similarly, should the suction tube  42  not be removed from the concentrate container  14  before the nozzle  26  is opened, and the flush valve  56  be opened, check valve  92  will stop flow-back of mixed solution back to the concentrate container  14  thereby preventing dilution of the concentrate in the container. 
     It will thus be recognized that the RDP-18 is substantially foolproof in operation, that once setup requires little adjustment during use in otherwise inaccessible areas threatened by wildfires, that it is safer to use in that it reduces the handling and mixing of caustic and corrosive LTFR chemical concentrates by allowing them to be drawn directly from their vendor-supplied containers and accurately mixed in the correct proportions with transported or otherwise available water, that it is relatively easy to clean and care for in between uses, that it is relatively easy to assemble using readily available tools and component parts, that vender supplied concentrate containers can be used to eliminate the need to pour the water and concentrate material into a separate tank for mixing and/or storage, thereby reducing material waste and simplifying cleanup. and that it represents a true advancement over other prior art systems. 
     The preceding description provides a preferred exemplary embodiment of the invention only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the description of the preferred exemplary embodiment is intended to provide those skilled in the art with an enabling disclosure for implementing an embodiment. It is to be understood that various changes may be made in the function and arrangement of the described components and elements without departing from the true spirit and scope of the invention set forth in appended claims.