Shipboard ice lubrication system and jet pump for use therein
AssigneeOmnithruster, Inc.
InventorCharles M. Aker
Life of this patent
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Abstract
An ice lubrication system for easing the passage of a ship through ice laden waters. A pressurized flow of water passes through a nozzle into the inlet of a mixing chamber comprising a venturi where gas from a gas manifold is mixed with the water. The effect of the venturi is to first cause the gas to mix into the water flow and, after passage of the flow through the venturi, to cause the gas to emerge from the water. A frothy combination of gas bubbles and water is thus created which is discharged through openings in the ship's hull below the waterline. Once discharged, the gas and water combination rises up the side of the hull to provide separation and lubrication between the hull and floating ice.
Claims10
In combination with a ship having a hull and a thruster system including a pipe assembly having an inlet communicating through said hull with the sea and pump means for drawing water through said inlet and selectively discharging said water through first and/or second thruster outlets respectively in the port and starboard sides of said hull, an ice lubrication system comprising:
- a first plurality of discharge openings formed in the starboard side of said hull spaced from one another extending toward the stern from the bow portion of said hull;
- a second plurality of discharge openings formed in the port side of said hull spaced from one another extending toward the stern from the bow portion of said hull;
- a plurality of gas/water mixing devices, each including a converging nozzle mounted adjacent to a different one of said discharge openings;
- a conduit having an intake for receiving water from said pump means and an outlet connected to each of said converging nozzles;
- each of said nozzles including at least one vane means mounted on the inner surface of the nozzle projecting into the flow path therethrough and oriented to impart a swirl component around the outer boundary of a water column flowing therepast through the nozzle;
- a source of nonpressurized gas;
- each of said gas/water mixing devices including a suction chamber coupled to the nozzle thereof downstream therefrom for creating a mixture of gas and water, each of said chambers having a first inlet communicating with said gas source and second inlet means upstream from said first inlet for receiving said water column exiting from the nozzle coupled thereto whereby said column creates a suction to pull gas through said first inlet into said chamber to entrain said gas in said column outer boundary, and outlet means for discharging said mixture of water and entrained gas through the discharge opening adjacent thereto.
In combination with a ship having a hull and pump means for drawing water from the sea through an inlet in said hull, an ice lubrication system for facilitating the passing of said ship through ice laden water, said system comprising:
- a first plurality of discharge openings formed in the starboard side of said hull spaced from one another extending toward the stern from the bow portion of said hull;
- a second plurality of discharge openings formed in the port side of said hull spaced from one another extending toward the stern from the bow portion of said hull;
- a plurality of jet pumps each having a water inlet, a gas inlet, and a gas/water outlet, each of said jet pumps being mounted in said hull with the gas/water outlet thereof adjacent to a different one of said discharge openings;
- a source of nonpressurized gas;
- and
- conduit means for coupling the outlet of said pump means to said jet pump water inlets for causing each of said jet pumps to produce a gas/water mixture and discharge it through the discharge opening adjacent thereto;
- each of said jet pumps comprising:
- a pipe section having a throat defined between an upstream converging portion and a downstream diverging portion defining said gas/water outlet and wherein said gas inlet is proximate to said converging portion;
- and
- a nozzle means including a converging nozzle mounted substantially concentrically within said pipe section for discharging a water flow therein proximate to said pipe section converging portion for producing a suction at said gas inlet to pull a stream of gas from said source of nonpressurized gas;
- said nozzle means including a vortex generating means mounted therein upstream from said converging nozzle, said vortex generating means comprising one or more vanes mounted on the inner periphery of said nozzle means and elongated substantially in the direction of the water flow thereat, each of said vanes defining a surface extending substantially radially inwardly from the inner periphery of said nozzle means and oriented to essentially rotate the outer boundary of said water flow around the direction of flow to create sufficient turbulence to entrain said gas pulled in through said gas inlet to produce a frothy gas/water mixture for discharge through said discharge openings.
Dependencies are inferred from the claim text.