The present invention relates to a water cannon that may be used for irrigation, fire or flood control, large area decontamination, or as a weapon or defense mechanism against incoming missiles or projectiles.
Historically, such devices have been used for close-range defense, firefighting, irrigation, and crowd control by propelling a collimated beam or spray of water. For many applications, prior systems at best were marginally effective due to the inability to pump large volumes of water at ultrahigh pressures of a few thousand psi (pounds per square inch). Operating pressures of conventional centrifugal, axial flow, and mixed-flow pumps having a flow rate of more than a few hundred pounds per second were limited to a few hundred pounds-per-square inch (psi). Such pumps also traded off water pressure with flow volume, or vice versa. Displacement pumps, although producing ultrahigh pressures of 10,000 psi or more pumped only infinitesimal amounts of water in comparison to other pump types.
Due to extremely high flow rates of a few hundred pounds of water per second (or more) and extremely high pressures of a few thousand psi (or more), the present invention may be used as a more effective fire control or irrigation/flood control device; a more effective weapon to fend off small vessels at a greater range than heretofore possible; an artillery mechanism; an excavation tool; a mine sweeping device; or as a defense mechanism to disable or blind incoming missiles or “smart” projectiles by drowning out their turbojet propulsion, disrupting its trajectory path by water mass impact, or shielding against any on-board IR tracking and targeting.
To achieve the above-mentioned objectives, the present invention comprises a water cannon utilizing ultra high pressure to propel a collimated beam of water or other fluid through a collimating nozzle at such high speeds (e.g., mach speeds) in order to project water to a greater distance (e.g., several thousands of feet) or to pierce steel, concrete, or other materials of a target at a closer range. The collimating nozzle, if employed, may be designed to maintain fluid coherency and/or to minimize dispersion of the collimated beam of liquid.
An ultra high discharge pressure required for high fluid velocity is achieved by deploying multiple axial flow pumping stations that successively build fluid pressure within annular chambers of each pump as well as between pumps. The cross-sectional area of the respective annular chambers may decrease between pumps as fluid speed increases in the downstream direction. Each pumping station comprises a multi-stage axially flow pump that may have variable pitch stator vanes and fixed pitch rotor blades. Optionally, the rotor blade pitch may be variable. In addition, the serially communicating pumping stations may be physically arranged in parallel with U-shaped conduits between the stations, or serially (in-line) arranged with interconnecting conduits between the stations. The U-shaped bends in the conduits may also provide moment cancellation to help stabilize an aiming platform for the nozzle. Taps may be located at successive stations to draw a volume and pressure of water generated at the respective stages.
To attain a desired velocity head at the discharge nozzle, a gearbox connected to a multi-megawatt power source, e.g., a gas turbine engine on-board an ocean vessel or an electric motor driven by land-based power station, drives the multi-stage axial flow pumps within the respective pumping stations at successively increasing speeds. Optionally, the axial-flow pumps may include variable inlet guide vanes at their inlets in order to control flow volume, fluid pressure, engine load, and/or impact force delivered by the cannon. The fluid may also include solid projectiles, abrasives, or chemical additives. Further, the collimated beam of water or other fluid exiting the cannon may be electrified with a high voltage in order to disable the target's on-board processing or communication equipment. Depending on design criteria, beam size (e.g., four to six inches, more or less), water ejection speed (300 to 2000 feet/second or more), ejection pressure (e.g., 2,000 to 10,000 psi more or less), mass flow rate (several hundred to several thousand pounds per second), and/or range (e.g., 3,000 to 20,000 feet, more or less) may be adjusted to achieve a desired goal or impact on a target.
Another embodiment of the invention comprises a method of ejecting high pressure liquid from a nozzle comprising the steps of providing at least three serially-communicating multistage axial flow pumps having liquid flow paths therein of decreasing diameters in a downstream direction, operating the pumps to increase liquid pressure between successive pumps, conveying liquid between successive pumps along a path having a decreasing cross-sectional area in the downstream direction whereby to correspondingly increase speed of said liquid along the path, and ejecting the liquid from a nozzle communicating with a final one of said serially communicating pumps. The method of claim 15, further comprising the step of collimating said liquid prior to said ejecting step in order to reduce dispersion after said ejecting. The method may include collimating the liquid prior to ejecting in order to reduce dispersion after ejecting, controlling at least one of a direction and azimuth of ejection of the liquid during ejecting, gearing a common shaft to rotate the serially communicating axial flow pumps at different speeds commensurate with a volumetric rate of flow, or physically arranging the serially communicating pumps to cancel moments generated by acceleration of liquid mass through said pumps.
Other aspects of the invention will become apparent of review of the following description taken in connection with the accompanying drawings. The invention, though, is pointed out with particularity by the appended claims.
Similarly, pumping station 14, which builds upon the fluid pressure generated by pumping station 12, includes a motor 30 that drives a multistage axial-flow pump via gearbox 32 and shaft 34. The exemplary motor 30 produces 40,000 horsepower to drive the second stage pump at about 9600 rpms. Pumping station 14 also includes an auxiliary tap 36 and valve to provide a pressure, for example, of 850 psi. An interconnecting conduit 40 between stations 12 and 14 has a decreasing cross-sectional area to accommodate an increase in flow speed as the water transgresses the pumping stations. The smaller diameter multi-stage pump at station 14 spins at a faster rate, e.g., around 9600 rpms, than the pump at station 12. A third pumping station 16 also includes a multi-stage axial flow pump, a motor 44, gearbox 46, and drive shaft 47. In the exemplary embodiment, the exemplary motor 44 produces 30,000 horsepower to drive the axial flow pump at about 22,000 revolutions per minute to produce a pressure of 3600 to 6000 psi. One or more engines of an ocean vessel, a land-based power grid, or a gas turbine engine may power motor 30.
Conduit 42 between stations 14 and 16 defines a fluid path that decreases in cross-sectional area in the downstream direction as the speed of the water increases. Conduit 43 between station 16 and the nozzle is preferably constant in cross-sectional area and also includes an auxiliary tap 37 and valve. Alternatively, conduit 43 may also define a path having decreasing cross-sectional area in the downstream direction. Nozzle 50, preferably mounted on a turret, has an azimuth control and rotates 360 degrees. For safety reasons, an operator in a protected cage remotely controls the nozzle. Nozzle designs known in the art are employed to collimate the water beam, create a mist or spray, or provide a desired dispersion. Additives may be included in mixing tank 18 via chemical feed tank 60 to enhance conductivity or other properties of the collimated water beam.
Without regard to structure, another embodiment of the invention comprises a method of ejecting high pressure liquid, e.g., water, from a nozzle. Such a method comprises the steps of providing at least three serially-communicating multistage axial flow pumps having liquid flow paths therein of decreasing diameters in a downstream direction, operating the pumps to increase liquid pressure between successive pumps, conveying the liquid between successive pumps along a path having a decreasing cross-sectional area in the downstream direction whereby to correspondingly increase speed of the liquid along the path, and ejecting said liquid from a nozzle communicating with a final one of said serially communicating pumps. Variations may include the step of collimating said liquid prior to the ejecting step in order to reduce dispersion after said ejecting; controlling the direction or azimuth of ejection of the liquid during the ejecting step; gearing a common shaft to drive or rotate the serially communicating axial flow pumps at different speeds commensurate with a volumetric rate of flow; or physically arranging the serially communicating pumps to cancel moments generated by accelerating liquid mass through said pumps.
Various other embodiments may become apparent to those skilled in the art based on the teachings herein. Thus, the illustrated embodiments are not intended to limit the invention defined by the appended claims.
This invention claims the benefit of provisional application Ser. No. 60/606,904 filed in the names of the inventors hereof on Sep. 3, 2004 and entitled “Water Cannon Weapon and Defense System. This invention is also related to U.S. application Ser. No. 10/801,705 filed in the name of Donald Cornell on Mar. 17, 2004 and entitled “Axial Flow Pump and Marine Propulsion Device,” which is incorporated herein by reference.
Number | Date | Country | |
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60606904 | Sep 2004 | US |