Abstract:
The delivery system includes a blender assembly which can be fitted within a bucket or other container an aircraft. The blender assembly includes a combiner which receives water from within the container and gel concentrate from a gel inlet. The combiner brings the water and gel concentrate together upstream of a pump. The pump pressurizes and mixes the water and gel concentrate together to provide a hydrated fire suppression gel ready for application. An outlet of the pump leads through appropriate conduits to a nozzle. The nozzle includes a downwardly extending spout which sprays the hydrated gel down onto the ground beneath the aircraft. When the water within the container has been depleted, the aircraft is flown to a water source and the container is refilled. Then the blender can again be used to manufacture and deliver the fire suppression gel to an area to be treated.

Description:
FIELD OF THE INVENTION 
     The following invention relates to fire suppression systems and particularly fire suppression systems carried by aircraft, such as for use in fighting wildfires. More particularly, this invention relates to fire suppression gel blenders which mix a gel concentrate with water and systems which mount such fire suppression gel blenders upon an airborne delivery system for delivery of fire suppression gel from fire fighting aircraft and other platforms. 
     BACKGROUND OF THE INVENTION 
     In the fighting of wildfires, a variety of fire suppression materials are known, as well as equipment for delivery of such fire suppression materials. Perhaps the most common fire suppression material is liquid water. Water can be delivered on a fire, or a space which is to be treated in advance to stop the progression of a fire, in a variety of different ways. For instance, hoses can deliver water from a stationary source such as a fire hydrant, or from a mobile source such as a fire truck. Water trucks are known which can deliver water from tanks on the vehicle to ground adjacent the vehicle, with or without use of hoses. 
     Aircraft can also be used for delivery of water for fire suppression. While fixed wing aircraft are sometimes used, most often water is delivered by rotating wing aircraft. In a typical such system, a bucket is suspended from a helicopter. The bucket can be dipped into a water reservoir to fill the bucket. The helicopter then transports the bucket to an area to be treated with the water. A floor or other portion of the bucket is openable to drain the bucket of water and treat the area beneath the bucket. The helicopter then repeats the filling procedure for additional treatment of areas with water. One such line of buckets is provided by S.E.I. Industries, Ltd. of Delta, British Columbia, Canada under the trademark BAMBI BUCKET. 
     Fire suppression gels are known in the art to have a greater effectiveness in suppressing fire than water alone. Such gels typically begin in the form of a concentrate which can be a solid or a liquid having a high concentration of gel compositions therein. This gel is hydrated to a most desirable water and gel mixture ratio and then is applied to an area to either directly extinguish fire or to treat an area in advance of an approaching fire to impede the progress of the fire, or otherwise suppress fire in the area being treated. Such fire suppression gels, when mixed with water, greatly enhance the effectiveness of the water in suppressing the fire. In particular, the water in the hydrated gel does not evaporate as quickly as water alone, thus maintaining a coating of the area to be treated and discouraging the combustion of combustible materials in the area being treated. 
     One such fire suppression gel is provided by Ansul Canada Limited of Toronto, Ontario, Canada (dba “Wildfire”) under the trademark AFG FIREWALL in the form of a liquid emulsion. 
     While the use of such fire suppression gels is known when treating an area with fire hoses either coupled to stationary sources of water or hydrated gel; or from mobile ground sources (such as tanker trucks), a need exists for an effective airborne fire suppression gel delivery system. While a bucket or other container filled with hydrated gel could be utilized, such an arrangement would be inefficient in that frequent return trips to a source of hydrated gel would be required. Accordingly, a need exists for a system for onboard manufacture of such a water and fire suppression gel mixture on an airborne platform. 
     Furthermore, water buckets and fixed tanks deliver water to an area to be treated for fire suppression in a rather imprecise manner, merely involving the opening of a lower portion of the bucket or tank. While generally effective for water having a lower fire suppression capacity, with the utilization of fire suppression gel is it desirable that a mixture of water and fire suppression gel be applied to an area to be treated in a precise manner to maximize the fire suppression capability of the gel and minimize the number of repeat trips required and maximize the area being treated by an airborne vehicle. 
     SUMMARY OF THE INVENTION 
     With this invention a fire suppression gel blender is provided suitable for use in an airborne delivery system to provide high efficiency delivery of fire suppression gel in fire fighting situations, where the urgency of the situation greatly benefits from efficiency and effectiveness of the delivery system. The overall delivery system includes known prior art aircraft, and particularly rotating wing aircraft, as well as water containing buckets for suspension beneath such aircraft or other known water containing structures. With this invention, the aircraft is modified to include a tank of gel concentrate or other gel source. The bucket or other water containing structure is modified to include a fire suppression gel blender assembly adjacent thereto. 
     This blender assembly includes a water inlet for receiving water contained within the bucket or other container. A combiner adds concentrated fire suppression gel from the source of gel carried by the aircraft, such as by supplying the gel concentrate along a conduit line extending from the aircraft down to the blender assembly within the bucket. A pump is provided, preferably downstream of the water inlet and gel inlet. This pump both pressurizes the water and gel mixture, as well as functioning to enhance the mixing of the water and fire suppression gel mixture. 
     The pressurized water and fire suppression gel mixture, referred to herein as hydrated gel, is then delivered to a discharge. This discharge is preferably in the form of a nozzle, typically adjacent the bucket and pointed generally downward. When the blender assembly is powered by powering of the pump, the hydrated gel is simultaneously manufactured and sprayed downward from the bucket. The aircraft can be flown at a variable height to adjust a width of lines being treated with fire suppression gel, a process called “striping.” When the aircraft flies lower this line is narrower. When the aircraft flies higher this line is wider. A density with which hydrated gel is applied to the area to be treated can be adjusted by adjusting a speed at which the aircraft travels. 
     When the supply of water has been depleted, the aircraft returns to a water reservoir to refill the water container such as by dipping the bucket into the water reservoir as is known in the prior art. The aircraft can then be returned to the area to be treated and the system again commences operation. The aircraft most preferably carries a supply of fire suppression gel concentrate which lasts at least an amount of time similar to an amount of time that a fuel supply for the aircraft lasts. In this way, when the aircraft is required to return to a base for refueling, the source of gel concentrate can also be replenished. 
     While the preferred embodiment of this invention involves the installation of the blender assembly within or adjacent a water containing bucket, as an alternative to such fitting within existing buckets, a separate customized structure could be combined with the blender assembly to function according to this invention. Such an assembly could be suspended below the aircraft or mounted to an underside or other portion of the aircraft, or to some other mobile platform, such as a truck. 
     While the hydrated gel is preferably delivered from a nozzle having a predictable spray pattern emanating therefrom, other forms of discharges could be provided downstream of the pump. As an alternative, the pump could discharge back into the bucket and the water and fire suppression gel combination could be delivered by opening of the bucket as water alone is currently known to be dispensed from an aircraft borne bucket. 
     Other details of this invention and various embodiments of this invention are described in conjunction with the further written description of this invention provided below. 
     OBJECTS OF THE INVENTION 
     Accordingly, a primary object of the present invention is to provide a fire suppression gel delivery system which can be coupled to an aircraft and spray fire suppression gel onto an area to be treated. 
     Another object of the present invention is to provide a fire suppression gel delivery system which manufactures fire suppression gel by hydrating gel concentrate onboard a mobile platform immediately before discharge of the hydrated gel onto an area to be treated. 
     Another object of the present invention is to provide a method for fighting wildfires which involves spraying fire suppression gel in stripes of varying densities and widths upon an area to be defended or directly around the fire perimeter itself. 
     Another object of the present invention is to provide a method for blending and delivering fire suppression gel from an airborne delivery platform. 
     Another object of the present invention is to provide a fire suppression gel discharge coupleable to a water containing bucket or other structure and with a water and fire suppression gel blender upstream of the discharge to utilize water from the container to hydrate the fire suppression gel before delivery from the discharge. 
     Another object of the present invention is to maximize the efficiency with which water is utilized by fire fighters in fighting fires. 
     Another object of the present invention is to provide a fire suppression gel blender which can be used on mobile platforms to blend water with gel concentrate immediately before spraying. 
     Another object of the present invention is to provide a method for controlling a width and density of striping of fire suppression gel upon an area to be treated with fire suppression gel. 
     Other objects of the present invention will become apparent from a careful reading of the included drawing figures, the claims and detailed description of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an environment where the system of this invention is being utilized to provide a fire suppression barrier line between a house and an advancing wildfire according to an embodiment of this invention. 
         FIG. 2  is a full sectional view of a water bucket containing the gel blender and discharge nozzle coupled thereto, according to the  FIG. 1  embodiment of this invention. 
         FIGS. 3 and 4  are perspective views of the gel blender assembly of an embodiment of this invention shown separate from the bucket or related equipment. 
         FIG. 5  is a front elevation view of that which is shown in  FIGS. 3 and 4 . 
         FIGS. 6 and 7  are perspective views from alternate perspectives of an outlet nozzle associated with the fire suppression gel delivery system of one embodiment of this invention. 
         FIG. 8  is a full sectional view of the bucket of  FIG. 2 , but shown with water being delivered directly from the bucket in one alternative use according to this invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral  10  is directed to a delivery system for manufacture and delivery of fire suppression gel. The delivery system  10  can be mounted within a bucket  20  suspended from an aircraft A. The system  10  discharges fire suppression gel from a nozzle  70  in the form of a spray S of hydrated fire suppression gel. This spray S can form a line L in a process referred to as “striping” to provide a barrier between an advancing fire F and a house H or other structure to be defended. 
     In essence, and with particular reference to  FIG. 2 , basic details of the fire suppression gel blending and delivery system  10  of this invention are described, according to a preferred embodiment. The delivery system  10  and associated blender assembly  30  can be mounted to various different water containing structures, but are most preferably configured in this preferred embodiment to be mounted to a bucket  20  configured to be suspended from an aircraft A, such as a helicopter ( FIG. 1 ). 
     The blender assembly  30  includes a combiner  40  which is configured to receive water W from the bucket  20  and gel concentrate from a gel reservoir, typically borne by the aircraft A and transported to the combiner  40  along a gel concentrate supply line  32 . The combiner  40  mixes water with the gel concentrate upstream of a pump  50 . The pump  50  pressurizes the now hydrated gel as well as performing a mixing function to thoroughly mix the water W and gel concentrate to form the hydrated fire suppression gel ready for delivery and use in fire suppression. Various interconnect conduits  60  lead from the pump  50  to a nozzle  70 . The nozzle  70  is a preferred form of discharge that includes a spout  80  pointing generally downward to provide the spray S of hydrated gel downward from the aircraft A, or otherwise away from a vehicle carrying the entire delivery system  10 . 
     More specifically, and with continuing reference to  FIG. 2 , details of the bucket  20  for supporting the delivery system  10  of this invention, are described according to this preferred embodiment. While the delivery system  10  of this invention could be mounted to other structures, in this embodiment shown in  FIGS. 1-8 , the delivery system  10  is configured to be mounted to a bucket  20  (or other container) which has been configured for fire suppression by dumping water W in an area to be treated. 
     In particular, the bucket  20  includes side walls  22  extending up from a floor  24 , so that the bucket  20  has a generally cylindrical form. The walls  22  extend approximately vertically while the floor  24  extends approximately horizontally. A suspension assembly  28 , also referred to as a “spider” holds open an upper end of the bucket  20  defined by a lip  26 . Suspension lines  29  are coupled to the bucket  20  and extend up to an aircraft A ( FIG. 1 ) such as a helicopter. 
     The bucket  20  is configured so that it can be dipped into a water reservoir, such as a river, pond, lake or the ocean. The bucket  20  falls over sideways and water pours into the bucket. Once the bucket  20  is full, the aircraft A can lift up and carry the water to an area to be treated. The floor  24  is coupled to an aperture control line  25  and an aperture in the floor  24  can be opened by pulling on the aperture control line  25  ( FIG. 8 ). This aperture control line  25  typically extends up to the aircraft A so that both suspension of the bucket  20  and control of the aperture in the floor  24  of the bucket  20  are provided from the aircraft A. 
     With this invention, the aperture in the floor  24  of the bucket  20  is typically not used. Rather, the blender assembly  30  fits within the bucket  20  and pumps water out of the bucket  20  and hydrated gel is sprayed from the delivery system  10  mounted on the bucket  20 . Typically, the aperture control line  25  would not be disabled when utilizing the bucket  20  with the delivery system  10  of this invention. Thus, should it be desired to dump remaining water W from the bucket  20 , such as after fire suppression gel concentrate has been depleted, the aperture control line  25  can still be utilized to open the floor  24  and allow release of water W from the bucket  20 . 
     As an alternative to the bucket  20 , the aircraft A can be fitted with fixed tanks for containing water. Such tanks are known which are filled by a snorkel pump extending down from the aircraft A and dipped into a water reservoir, such as a pond, lake or river. The blender assembly  30  would be installed within such a tank or adjacent thereto with access to water from the tank. The blender assembly in such a fixed tank embodiment could be within or adjacent the tank. As another alternative, the snorkel pump could be replaced by the blender assembly  30  appropriately modified. In such an embodiment, the pump motor  58  would be sized to lift the water up the snorkel to the tank. Gel concentrate could be added to the pump so that the fixed tank stores hydrated gel. 
     With continuing reference to  FIG. 2 , as well as  FIGS. 3-5 , details of the blender assembly  30  of the delivery system  10  of the preferred embodiment are described. This blender assembly  30  is shown mounted within the bucket  20 , but could alternatively be located within a tank of water W mounted to either an aircraft A or some other mobile or stationary platform. The blender assembly  30  could be permanently affixed to the bucket  20  or integrally formed within the bucket  20 , but most preferably is removably attachable to the bucket  20  so that the blender assembly  30  can be moved from one bucket  20  to another bucket  20  when desired. Attachment of the blender assembly  30  to the bucket  20  is sufficiently adapted to work with the bucket  20  so that the bucket  20  does not require modification and is not damaged or altered by removal of the blender assembly  30  from the bucket  20 . 
     The blender assembly  30  includes a series of lines which supply power and materials for utilization of the blender assembly  30 . In particular, a gel concentrate supply line  32  extends from the blender assembly  30  to a source of gel concentrate. Typically this source of gel concentrate is adjacent the aircraft A, such as in a tank mounted to or carried within or under the aircraft A (see broken lines in  FIG. 1  generally depicting such a tank). Thus, the gel supply line  32  typically extends vertically up from the blender assembly  30  within the bucket  20  up to the aircraft A. Hydraulic lines  34  are preferably utilized to power a hydraulic motor which drives the pump  50 . The hydraulic lines  34  preferably include a supply and return line bundled together and also extend up to the aircraft A where pressurized hydraulic fluid from the aircraft A can be utilized to drive the motor  58  of the pump  50 . Typically, also a color dye line  75  extends down to the bucket  20  from the aircraft A. The color line  75  supplies a colorant which can be added to the hydrated gel before being sprayed from the discharge, such as in the form of the nozzle  70 , so that areas that have been treated can more easily be seen. 
     The blender assembly can include a mounting bracket  36  for attachment of the blender assembly  30  to adjacent structures or for mounting of auxiliary equipment to the blender assembly  30 . Preferably, a plate with a bungee hole  35  therein is provided as part of the blender assembly  30 . A bungee cord or other line can pass through this bungee hole  35  and secure the blender assembly  30  to a side of the bucket  20  so that the blender assembly  30  is prevented from flopping around too much within the bucket  20 . 
     A hose support arch  38  is configured along with the blender assembly  30  which is generally in the form of a truss and helps to hold an outlet hose from the blender assembly  30  relative to other portions of the blender assembly  30 . The hose support arch  38  is carried at an upper end by a spider tube  36  which can have a leg of the spider assembly  28  passing therethrough so that the entire blender assembly  30  can be suspended from one of the spider legs of the suspension assembly  28 . The hose support arch  38  extends down from this spider tube  39  and various different portions of the blender assembly  30  are carried by the hose support arch  38 . 
     Preferably, the spider tube  39  is coupled to the hose support arch  38  through a pivotable connection, such as with a series of concentric tubes with a pin passing therethrough and with cotter pins to capture this pin within these co-linear tubes. One of the tubes has the spider tube  39  coupled thereto, one of these tubes is at an upper end of the hose support arch  38  and one of these tubes is coupled to an upper elbow  66  of interconnect conduits  60  that join the blender assembly  30  to the nozzle  70 . The pivotable attachment of these parts together allows for the blender assembly  30  to pivot somewhat to a desired position and accommodate slightly different geometries for the side walls  22  of the bucket  20  and otherwise avoid damage when bumping or jostling of the blender assembly  30  occurs, such as during dipping of the bucket  20  to fill the bucket  20  with water W. 
     The blender assembly  30  generally includes a combiner  40  and a pump  50 . The combiner  40  provides the basic function of bringing together water W and gel concentrate for hydrating of the gel concentrate to form the fire suppression gel to be utilized by the delivery system  10  of this invention. The combiner  40  is generally in the form of a “T” junction conduit  48  that allows two pathways to come together to form a single pathway. In this most preferred embodiment, this combiner  40  includes a gel inlet conduit  42  and a water inlet  44 . A debris preclusion screen  46  is preferably provided surrounding the water inlet  44 . The junction conduit  48  acts to bring the gel concentrate inlet conduit  42  together with the water inlet  44  and join the water W with the gel concentrate to allow for hydration of the gel concentrate. This junction conduit  48  is preferably provided upstream of the pump  50  on a suction side of the pump  50 . 
     The pump  50  includes an inlet  52  and outlet  56 . Both the inlet  52  and outlet  56  are joined to an impeller housing  54  therebetween. The motor  58  drives an impeller within the housing  54  between the inlet  52  and the outlet  56 . A drive sleeve  59  extends between the motor  58  and the impeller housing  54  to space the motor from the impeller housing  54 . 
     The pump  50  in this preferred embodiment is a centrifugal pump. In one embodiment the pump  50  has a flow rate of 400 gallons per minute. The impeller includes a series of vanes which rotate and change the fluid from extending axially at the inlet  52  to extending circumferentially at the outlet  56 , by action of the impeller blades on the fluid within the housing  54 . By providing the pump  50  at least as a dynamic style pump, and most preferably as a centrifugal pump, the impeller blades of such a dynamic pump  50  both act to pressurize the hydrated gel, but also act to promote mixing of the water with the gel concentrate to form the hydrated gel as a substantially homogeneous mixture. While less desirable, a positive displacement pump, such as a piston pump, could also conceivably be utilized. 
     Hydraulic fluid is supplied from the aircraft A down the hydraulic lines  34  to drive the motor  58 . The motor  58  in turn causes the impeller to move within the impeller housing  54  so that the pump  50  causes water to be drawn into the pump  50 . A typical flow rate for the pump  50  is four hundred gallons per minute, but could be scaled to meet the capacity of the aircraft and the needs of the user. If beneficial, multiple blender assemblies  30  could be used in parallel to optimize such scaling of this technology. While the motor  58  is disclosed as a hydraulic motor, an electric motor could alternatively be utilized, or conceivably an internal combustion motor. 
     The water W mixes with the gel concentrate to form hydrated gel which then passes out of the outlet  56  of the pump  50 . Because the motor  58  is a hydraulic motor, it is inherently submersible without complex seals being required. By placing the pump  50  downstream of the combiner  40  the pump  50  pulls the water W into the inlet  44  and pulls gel concentrate into the gel inlet  42 . To ensure the proper gel concentrate to water mixture ratio, the gel concentrate is preferably supplied by a positive displacement pump, such as a gear pump. The speed of this gear pump is preferably adjustable to meet the needs of the user. Such speed adjustment in turn modifies the hydrated gel viscosity. 
     While the hydrated gel could conceivably be delivered to some form of storage vessel, most preferably the hydrated gel is immediately utilized after manufacture by the blender assembly  30 . In particular, interconnect conduits  60  are provided to direct the hydrated gel from the outlet  56  of the pump  50  to the nozzle  70 . These interconnect conduits  60  include a lower elbow  62  adjacent the impeller housing  54  which converts the hydrated gel from traveling horizontally to traveling vertically adjacent the pump  50 . A riser hose  54  then extends up from the lower elbow  62  up to a top of the bucket  20 . An upper elbow  66  is coupled to the riser hose  64  and transitions the flow of the hydrated gel from vertical travel to substantially horizontal travel. The upper elbow  66  is preferably pivotably coupled to the suspension assembly  28  of the bucket  20  along with the spider tube  39  and hose support arch  38 . A lateral hose  68  extends from the upper elbow  66  across a top of the bucket  20 , typically from one side of the bucket  20  to an opposite side of the bucket  20 . The interconnect conduit  60  terminates at the nozzle  70  where the lateral hose  68  joins with the inlet elbow  72  of the nozzle  70 . 
     With particular reference to  FIGS. 6 and 7 , details of the nozzle  70 , providing a preferred form of discharge for the hydrated gel, is described according to this preferred embodiment. The nozzle  70  acts to direct the hydrated gel downward for treatment of an area below the aircraft A, or otherwise function to direct the hydrated gel from the blender assembly  30  to an area to be treated. The nozzle  70  begins with an inlet elbow  72  which redirects the hydrated gel from traveling horizontally to traveling downward typically substantially vertically. 
     A support bracket  74  includes an inner plate  76  parallel with and opposite an outer plate  78 . The inner plate  76  and outer plate  78  are spaced apart sufficient to allow them to straddle the lip  26  of the bucket  20  so that the support bracket  74  can merely rest upon the lip  26  of the bucket  20  with the nozzle  70  outboard of the bucket  20 . If desired, mechanical fasteners can also be utilized. 
     The inlet elbow  72  is coupled to a spout  80  of the nozzle  70 . This spout  80  is typically a generally rectangularly cross-sectioned elongate tube extending from the inlet elbow  72  down to an outlet  82 . The outlet  82  and associated spout  80  have a shape which cause the hydrated gel to exit the nozzle  70  as a spray S which is generally in the form of a fan having a substantially constant thickness and diverging width ( FIG. 1 ). 
     A width of a lower end of this fan of the spray S can be controlled by adjusting the elevation of the aircraft A. As an alternative, the spout  80  could be attached to other portions of the nozzle  70  through a quick connect coupling and different spouts  80  could be substituted for each other to change spray patterns for the spray S discharged from the nozzle  70 . 
     Most preferably, a color port  73  is provided adjacent the inlet elbow  72 . A color line  75  is coupled to this color port  73 . A source of colorant, such as a colored dye liquid is preferably supplied onboard the aircraft A or adjacent the aircraft A. This source is preferably delivered by a gear pump or other adjustable positive displacement pump. This pump mixes an appropriate amount of colorant to the hydrated gel. In this way, the hydrated gel is colorized and a line L of hydrated gel ( FIG. 1 ) that has been applied to the treatment area can be readily visually identified. 
     The striping technique disclosed herein can be performed from aircraft fitted with fixed tanks or a bucket with appropriate modification of mounting hardware. The striping technique could be used with hydrated gels of various concentrates, and also could be used with water only if desired. This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this invention disclosure. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together or coupled together through intervening structures. Such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment, unless specifically restricted.