US3448809A - Dual agent firefighting nozzle and apparatus - Google Patents

Description

June 10, 1969 M. LAMBERT ET AL 3,448,809

DUAL AGENT FIREFIGHTING NOZZLE AND APPARATUS Sheet Filed April 5, 1967 .7 w i M m m N 7 4 6 muaw U M12 3 m w Lm wwfi A wm MMM W Y B June 10, 1969 v M. LAMBERT ETAL 3,448,809

DUAL AGENT, FIREFIGHTING NOZZLE AND APPARATUS Filed April 3, 1967 Sheet 3 of 2 Mayo/v LHMEERT 72/0/1445 GYM/HER [AP/7 Lil/1.051?

aw M4145,

US. Cl. 169-15 4 Claims ABSTRACT OF THE DISCLOSURE The apparatus includes a pair of tubular members vertically aligned at one end and in horizontal alignment at the opposite end. The members are provided with nozzles at said opposite end, one being for the spraying of dry powder and the other for a compatible foam. The foam nozzle is directed somewhat upwardly and is positioned slightly forward of the powder nozzle. The tubular members carry handles or pistol grips which are separated in a lengthwise direction thus permitting ease of operation and minimizing any safety hazards. Additionally, the members have therein valve means for selectively controlling the passage of material therethrough. When the apparatus is attached to sources of both firefighting powder and foam it provides for the simultaneous application of both powder and foam to a liquid hydrocarbon rfire without interference therebetween.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF INVENTION Field of invention This invention relates" to apparatus for the delivery of fire-extinguishing agents to liquid hydrocarbon fires. More particularly, it relates to a novel nozzle and handling arrangement for powder and foam agents wherein both agents may be applied to the fire with a maximum of extinguishment in a minimum time. Additionally it relates to a highly maneuverable apparatus capable of safe use in confined spaces.

DESCRIPTION OF PRIOR ART In prior firefighting apparatus of the type which delivers both dry and foam agents, the arrangement of the elements has extensively limited the maneuverability of the operator in that it was both heavy and bulky. These limitations, additionally make the use of these devices within limited or confined spaces impractical and in some cases extremely dangerous. A problem always present with this type of firefighting equipment is that the firefighter could easily be trapped between the nozzles and the two supply hoses should it be necessary for him to quickly abandon the equipment and retreat from the tfire area. I

Relating now to the fire-extinguishing ability of :prior devices where two' diiferent agents are employed, it has been known that by delivering the agents almost simultaneously extremely rapid extinguishment occurs. However, several unsolved problems have not permitted a satisfactory solution. One of the major difliculties is that the application of the foam to a liquid hydrocarbon fire produces spattering and vaporization. Also where the wetting of the dry powder by the foam occurs the two nozzles have been physically separated which in turn requires the United States Patent "Ice operator to exercise undue strain in directing the agents on the fire.

SUMMARY OF THE INVENTION The invention encompasses a structure which includes a pair of nozzles for dispensing firefighting agents. These nozzles are arranged in proximate horizontal alignment with the foam nozzle slightly forward and directed somewhat upwardly. The conduits for the agents are disposed in vertical alignment at the end opposite that aifixed to the nozzles to facilitate handling, safety and maneuverability. Handles with triggers are carried by the conduit members, with the handles distal from one another.

An object of this invention is to provide an efficient, reliable, low cost firefighting apparatus which is capable of rapidly extinguishing a fluid hydrocarbon fire through the simultaneous use of both foam and powder agents.

Another object is to provide a dual nozzle firefighting apparatus which is easily maneuverable, lightweight, capable of use in confined or limited areas, and may be readily abandoned by the operator without impairing his physical safety.

A further object is to provide a firefighting apparatus having a novel dual nozzle arrangement so as to properly dispense a powder and a foam agent without the necessity of reaiming the apparatus for each agent.

DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a perspective view of an embodiment made in accordance with the principles of this invention;

FIG. 2 is a cross-sectional view of the embodiment illustrating the detail construction thereof; and

FIG. 3 is a perspective view of the foam and powder supply systems attached to the dual nozzle gun.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the illustrated embodiment of the invention shown in FIG. 1, a pair of tubular conduits 10 and 11 are disposed in aligned vertical relation and jointly supported proximate their input ends 12 and 13 by a vertical bracket 14. The conduits are provided with appropriate fittings 15 and 16 to facilitate connection to sources of firefighting agents. The conduits 10 and 11 remain in vertical alignment for approximately one-half the lengths and then at 17 extend in diverging directions with the dry powder conduit 10 directed downwardly so as to be in approximate horizontal alignment with the foam conduit 11. Affixed to the ends of these conduits are the dry powder nozzle 18 and the foam nozzle 19. The nozzles are of the standard design and are presently available from various commercial suppliers and mam1- facturers. The nozzles are held relative to one another by a forward bracket 20 with the foam nozzle directed upwardly at approximately 30 and extending beyond the end of the powder nozzle.

Pistol type handle grips 21 and 22 are provided. One grip 21 disposed forward of the other. Thus a balanced and relatively comfortable support (and control is attained. This permits the device to be held under one arm and directed therefrom without having to hold the .apparatus in front of the firefighter. Each trigger 23 and 24 is attached to a valve and is positioned proximate each handle so as to control the passage of the firefighting agent in each of the conduits and is readily operable.

The dual agent gun illustrated in detail in FIG. 2 is similar to that of FIG. 1 except that an arm rest 25 and right angle couplings 26 and 27, which include swivel joints, have been attached to the ends 15 and 16 of the conduits. Two distinct features of the embodiment are readily ascertainable. The first is evident in that the foam nozzle is inclined aproximately 30 with respect to the horizontal and the powder nozzle. Secondly, the foam nozzle is slightly forward of the powder nozzle with regard to a horizontal plane. These features, in combination, provide this gun with the capability of dispensing on a fire both a dry and a foam agent.

As a general characteristic, firefighting foams and dry powder chemical agents are complementary in their use on hydrocarbon fluid fires. Potassium bicarbonate dry chemical (Purple K) provides the fastest knockdown and extinguishment but does not afford protection against reignition. Foam, on the other hand, has the inherent ability to seal and thereby prevent fire refiash. However, this agent is relatively slow in extinguishment. Combined agent attack, using Purple K to effect rapid extinguishment, and the foam to blanket the burning fuel appear to present outstanding characteristics. Until recently these two agents were incompatible since the foam blanket was rapidly destroyed by the presence of the dry powder.

There are now commercially available, foams which can be employed with Purple K. One of these, manufactured by the National Foam Systems, Inc. of West Chester, Pa, and designated as Aer-O-Foam XL6, is a protein formulation containing oleophobic fluorinated compounds. It is inert to the bicarbonate salts, fluidizing agents and dyes in the dry powder.

The dual agent firefighting apparatus of this invention requires only one operator for both sequential and simultaneous application of foam and dry chemical. The apparatus can be fabricated of aluminum with two separate nozzles, one for foam and the other for dry powder. The agent flow from each nozzle is controlled by a pistol type squeeze grip trigger valve. These nozzles are located in side-by-side relation with the foam nozzle slightly forward and inclined upward about 30 degrees. The foam nozzle is disposed forward of the powder nozzle to thus prevent wetting of the powder nozzle thereby during foam application. The inclination of the foam nozzle provides gentle application with a minimum of foam spattering impingement into the burning fuel. This prevents agitation of the fuel and decreases the chances of intensifying the burning of the fuel by submergence of the foam below the fuel surface. The trigger valves, controlling the foam and powder nozzles, are relatively in line with one another with the foam valve aft of the powder valve. The dry powder is delivered through the powder nozzle chamber whose top has a number of orifices arranged to produce individual streams of powder which impinge on the inner walls thereof. The streams are directed forward to emerge and combine outside of the nozzle to form a high intensity dry powder stream. The foam-liquid solution is delivered to the foam nozzle which is provided with a standard fog foam tip and a double layer screen. Jets of foam-liquid solution pass through the orifices in the tip and collide with each other while impinging on the nozzle screen. The resulting turbulence causes air to be entrained and mixed with the solution thereby forming a foam stream with a dispersed pattern.

Thus, the dual agent gun is compact, maneuverable and easy to operate. It readily permits entry into confined spaces such as thus aboard a naval vessel. Since the unit is designed to be operated underneath one arm of the firefighter and on one side of his body, the apparatus can be easily discarded in an emergency when the firefighter is forced to retreat from the fire area without danger of his being trapped between the gun and the fire hoses connected to it.

FIG. 3, for illustrative purposes, shows the equipment used in conjunction with the dual gun as a total system. The two basic sources of firefighting agents comprise a tank of liquid foam 30 and a dry powder container 31 coupled with a nitrogen cylinder 32. The liquid foam concentrate agent and water are fed via hoses 33 and 34 into a foam liquid proportioner 35 wherein the proper mixture is generated and fed through hose 36 to the foam conduit 11. The dry powder under pressure supplied by the nitrogen is applied via hose 37 to conduit 10. As shown, the foam spray is ejected at a slight upward angle so that it falls on the burning surface without excessively disturbing it and does not wet the dry powder at the nozzles. This dual gun firefighting apparatus provides a vastly improved means for rapid and safe control and security of flammable liquid fuel fire situations. The combined use of a compatible foam and dry powder chemical on hydrocarbon fires results in the optimum utility of the inherent advantages of each of these agents.

It will be understood that various changes in the details, materials and arrangements of parts (and steps), which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the tart within the principle and scope of the invention.

We claim:

1. Firefighting apparatus comprising means for delivering, separately, a firefighting dry powder agent and a firefighting liquid foam compatible therewith,

a foam generating nozzle affixed to the end of said means for delivering and directing upwardly a foam spray, and

a dry powder nozzle affixed to said powder delivering means disposed aft of said foam nozzle, said means for delivering comprising a pair of hollow tubular members vertically aligned upstream of said nozzles and in horizontal alignment at the nozzle end.

2. The apparatus according to claim 1, further including bracket means securing said tubular members in spaced relation.

3. The apparatus according to claim 2, further including a valve disposed in each of said tubular members and controlled by a trigger extending outward of said member,

grip means carried by each of said tubular members proximate said trigger.

4. Firefighting apparatus which comprises a pair of spaced apart hollow tubular members being vertically aligned at one end and in horizontal alignment at the opposite end,

a foam generating nozzle affixed to one of said members at said opposite end and directed vertically upwardly at an angle of approximately 30 with the horizontal,

a dry powder nozzle aflixed to the other of said members at said opposite end and disposed aft of said foam nozzle,

a valve and trigger for control thereof carried by each of said members distal lengthwise along said members, and

pistol grip means disposed proximate each of said triggers for holding said apparatus.

References Cited UNITED STATES PATENTS 6/1966 Tuve et al. 7/1952 Freeman l69l5 US. Cl. X.R.

Images