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 betwen the hull and floating ice.
Claims4
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 passage of said ship through ice laden water, said system comprising:
- a first plurality of discharge openings formed in the starboard side of said hull below the chine of said ship and 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 below the chine of said ship and 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 gas source means including a plurality of air holes in the sides of said hull above said discharge openings and a plurality of air pipes each connecting a different one of said air holes to the gas inlet of a different one of said jet pumps;
- 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 gas therethrough, said nozzle means including a vortex generating means mounted upstream from said converging nozzle for creating sufficient turbulence in the outer boundary of the water flow discharged therefrom to entrain in the water flow the gas pulled through said gas inlet;
- and
- valve means associated with each of said jet pumps for selectively directing the water flow supplied thereto either to the gas/water outlet thereof or through the air pipe connected thereto for discharge through one of said air holes.
Dependencies are inferred from the claim text.