Abstract:
An integrated around the pump (ATP) foam proportioning system that combines the venturi eductor, metering valve and shut-off valve into a single unit. Furthermore, the metering valve stem is contoured to make the flow read-out substantially linear. The display is also designed with movable components to display a single flow at the selected foam percentage rate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The invention claims priority to U.S. Provisional Patent Application Ser. No. 61/947,693, filed on Mar. 4, 2014, the complete contents of which are herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to the field of firefighting systems, and more particularly to proportioning systems for delivering firefighting foam into a water stream. 
         [0004]    2. Brief Description of the Related Art 
         [0005]    Venturi based eductor systems are commonly used to draw a firefighting foam concentrate into a water stream to enhance the water&#39;s ability to extinguish a fire. A portion of the discharge water from the pump is diverted through the venturi to accelerate the velocity and thus reducing the pressure of the water. Within the region of the water that is below atmospheric pressure, there is a port that introduces the foam concentrate into the water stream. The stream of water and foam agent is returned back to the inlet of the pump. The foam proportioning rate is controlled by a metering valve that limits the flow of concentrate into the venturi. There are usually a complex set of graduations indicating the flow rates and sometimes percentage of concentrate mixed. This system is commonly known as an “Around the pump” (ATP) proportioning system. 
         [0006]    Typical ATP systems are composed of separate components; venturi eductor, metering valve, plumbing components. To stop the flow of foam into the water stream, the metering valve is generally closed off completely. This method works but is inconvenient when the system operator wishes to maintain the same setting and not disturb the metering valve position between activities. To overcome this limitation, a second “shut-off” valve is commonly introduced. This also works well, but adds an additional component and associated plumbing into the system which adds complexity and cost. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention is an integrated ATP foam proportioning system and apparatus that combines the venturi eductor, metering valve and shut-off valve into a single unit. Furthermore, the metering valve stem is contoured to make the flow read-out substantially linear. The display is also designed with movable components to display a single flow at the selected foam percentage rate. 
         [0008]    In addition, some embodiments include a feature, where the inflow inlet, e.g., for supply water, and the outflow outlet, e.g., for the water containing the foam concentrate, are reversible on the unit, to facilitate positioning or connecting lines to the unit, such as, for example, water inlet supply lines and/or outlet lines. 
         [0009]    The system and apparatus may be used to regulate a flow of foam concentrate through the apparatus, and also may be used to regulate a flow of a water input through the unit. A control is provided, preferably in the form of a valve, that may be used to introduce or block foam. The apparatus and system preferably also may include indications of foam percentage. According to a preferred embodiment, a knob with a window that is configured with one or more other components that regulate the flow, is provided to indicate a flow rate. The knob may serve as an adjustment component to position a metering valve to adjust the flow through the apparatus. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0010]      FIG. 1  is a drawing that shows a cross-sectional view of the foam proportioner assembly described in this application, the section being taken through the foam inlet and metering valves, along the section line  1 - 1  of  FIG. 2 . 
           [0011]      FIG. 2  shows a front view of the assembly of  FIG. 1 . 
           [0012]      FIG. 3  shows a side view of the assembly of  FIG. 1 . 
           [0013]      FIG. 4  shows a cross-sectional view of the foam proportioner assembly described in this application that goes through the venturi eductor section, the section being taken through the section line  4 - 4  of  FIG. 3 . 
           [0014]      FIG. 5  shows a rear perspective view of the assembly of  FIG. 1 . 
           [0015]      FIG. 6  shows a front perspective view of the assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Referring to  FIGS. 1-6 , a preferred embodiment of an around the pump proportioner (ATP) assembly  100  according to the invention is illustrated. According to a preferred embodiment, as illustrated in the accompanying figures, the ATP proportioner assembly  100  is shown having a body  2  and three fluid connection points, which include a foam inlet  11 , a water inlet  15  and an outlet  38 . The water inlet  15  shows a connection of a fitting  15   a  (e.g., such as a water supply fitting) to the assembly body  2 , with an o-ring washer  12  sealing the connection. The outlet  38  shows a connection of an outlet fitting  38   a  (e.g., such as an outlet conduit fitting) connected to the assembly body  2 , also with an o-ring washer  12 . The water enters the water inlet  15  and accelerates through the nozzle  1  to a low pressure. The water flow joins with the foam concentrate flow in the mixing chamber  40  and continues to the diffuser  8 . In the diffuser  8  the solution recovers pressure and then flows through the outlet  38  and then travels to the fire-fighting pump inlet. In a preferred embodiment illustrated, the venturi eductor components, such as, for example, the nozzle  1  and diffuser  8 , and body  2 , in which they are housed, are provided in an assembly  100  which includes a foam inlet  11  regulatable by a valve stem  3  and valve seal  4 , and which further includes a metering valve stem  16  that regulates the admission of the flow of foam from the foam inlet  11  (which has passed the valve seal  4 ) to a mixing chamber  40 . 
         [0017]    The foam concentrate enters through the foam inlet  11 . When the valve seal  4  (in  FIG. 1 ) is closed against the seat  5  the flow of foam through the port  11  blocked. The valve seal  4  is biased to the closed position by a spring  10   a  ( FIG. 1 ). Foam flow is regulated by a foam flow component comprising a knob  28 . The foam flow knob  28  is shown connected to the flow valve stem  3 . According to a preferred embodiment, a set screw  25  secures the knob  28  on the valve stem  3 . To initiate foam flow, the foam flow knob  28  is turned CW from “OFF” to “ON”. This movement causes the valve stem  3  to unseat the valve seal  4  ( FIG. 1 ) from the seat  5  due to the threaded section on the valve stem  3 . The foam concentrate may then enter the central cavity  16   a  of the metering valve stem  16 . According to a preferred embodiment, an o-ring  13  is shown disposed on the valve seat  5 . 
         [0018]    The foam flow valve (shown comprising the foam flow stem  3 , seal  4 , seat  5 , and spring  10   a ) and metering valve components (shown comprising the metering valve stem  16  and metering valve seat  7 ) are co-linear in the illustrations. According to a preferred embodiment illustrated, the foam flow valve stem  3  and metering valve stem  16  are co-linear (see  FIG. 1 ). The flow valve stem  3  is shown positioned within the metering valve stem  16  and an o-ring  9  is disposed on the flow valve stem  3  ( FIG. 1 ). A seal  4  and spring  10  are shown provided in conjunction with the metering valve seat  7 , and preferably above the slotted opening  7   a.  As shown in  FIG. 1 , an o-ring  17  is provided on the metering valve  16 , forming a seal between the body  2  and metering valve  16 . 
         [0019]    The metering valve stem  16  is connected to the adjustment wheel  18 . According to a preferred embodiment, screws  21  connect the wheel  18  to the valve stem  16 . To control the aperture opening  16   b  of the metering valve  16 , the adjustment wheel  18  is turned to increase or decrease the opening size (by aligning the position of the opening  16   b ). According to some preferred embodiments, the opening  16   b  may be wider at one radial location and narrower at another, as illustrated in  FIG. 1 . The outside diameter  16   c  ( FIGS. 1 and 4 ) of the metering valve stem  16  is contoured to block more or less of the slotted opening  7   a  in metering valve seat  7  depending on its rotational alignment. The contouring of the metering valve stem  16  is designed to allow the flow range of the proportioner  100  to follow substantially uniform angular increments to linearize the flow on the display label  33 . An o-ring  6  is shown disposed on the valve seat  7 . 
         [0020]    Once through the metering valve seat  7 , the foam concentrate passes by a check valve seal  4  ( FIG. 4 ) and continues into the mixing chamber  40  ( FIG. 4 ) located between the nozzle  1  and diffuser  8 . 
         [0021]    The display label  33  has numbers on it that correspond to total system flow aligned in such a fashion that there are several scales corresponding to various percentage rates of foam concentration. According to one preferred embodiment, the flow rate knob  26  ( FIGS. 1 and 6 ) is rotated in 90° increments to expose various flow rates through the portal  26   a  in the flow rate knob  26 . According to some preferred embodiments, the flow rates may be provided on the face  18   a  of the adjustment wheel  18 , and are visible through the portal  26   a.  As illustrated in  FIG. 2 , for example, the flow rate may be provided in gallons per minute (GPM) (or other suitable measurements, or several scales), and, according to a preferred embodiment, flow adjustments may be made by aligning the knob indicator  26   b  with one of the flow positions, such as, for example, in the embodiment here shown in  FIG. 2  as arrows indicating ¼%, ½% 1%, respectively. A support  19  is provided, and preferably connects the face plate or cover  22  to the body  2 . The support  19  is shown having arms  19   a,  with threaded bores therein for receiving screws  24  that secure the cover  22  thereto. A spacer  20  is shown provided between the body  2  and the support  19  (see  FIGS. 1 and 5 ). 
         [0022]    The nozzle  1  is captured between the body  2  and the inlet fitting  15   a.  The diffuser  8  is captured between the body  2  and the outlet fitting  38   a.  Preferred embodiments provide a configuration, as illustrated, where the nozzle  1  and diffuser  8  may be removed and reversed to allow for ease of plumbing with different arrangements with no change in operation. According to a preferred embodiment, as illustrated in  FIG. 4 , the body  2  may include annular grooves  2   c , 2   d  at each opening thereof configured to engage a flange or ridge of a respective component, such as, for example, the ridge  1   a  of the nozzle  1  and ridge  8   a  of the diffuser  8 . The diffuser  8  and nozzle  1  may be interchanged, if desired, with the nozzle ridge  1   a  and diffuser ridge  8   a  mating with either one of the body ridges  2   b , 2   c.    
         [0023]    A fitting  15   b,  which, according to some preferred embodiments, may be similar or identical to the fitting  15   a  (and fitting  38   a ) is shown connected to a lower opening  2   a  in the body. A plug  14  is shown threaded and received in the threaded bore  15   c  of the fitting  15   b.  The bore  15   c  and/or fitting  15   b  may be provided for cleanout of the assembly  100  (e.g., when the plug  14  or fitting  15   b  is removed) or for facilitating introduction of another line or component (e.g., a cleaning flow of water or other fluid). 
         [0024]    Referring to  FIG. 5 , a mounting flange  45  preferably is provided to facilitate mounting of the assembly  100  onto a frame, pump or other support. The mounting flange  45  may be provided in a plurality of components, as shown according to a preferred embodiment, comprising a first component  45   a  and second component  45   b.    
         [0025]    These and other advantages may be realized with the present invention. While the invention has been described with reference to specific embodiments, the description is illustrative and is not to be construed as limiting the scope of the invention. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention described herein and as defined by the appended claims.