NOZZLE MIXING METHODS FOR SHIP BALLAST TANKS

• US 20150336822A1
• Filed: 06/13/2013
• Published: 11/26/2015
• Est. Priority Date: 06/18/2012
• Status: Active Grant

• Current Assignee: The United States Of America As Represented By The Secretary Of The Department Of The Interior
• Original Assignee: Department of Health and Human Services (State of Victoria)
• Inventors: Adams, Noah S., Watten, Barnaby J.
• Granted Patent: US 9,688,551 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01F 25/21 with submerged injectors, e.g. nozzles, for injecting high-pressure jets into a large volume or into mixing chambers
• CPC Class Codes: B01F 35/2111 Flow rate
• CPC Class Codes: B01F 35/2209 Controlling the mixing process as a whole, i.e. involving a complete monitoring and controlling of the mixing process during the whole mixing cycle
• CPC Class Codes: B63J 4/002 for treating ballast water
• CPC Class Codes: C02F 1/50 by addition or application of a germicide or by oligodynamic treatment C02F1/4606, C02F1/467, C02F1/76 take precedence
• CPC Class Codes: C02F 2103/008 Originating from marine vessels, ships and boats, e.g. bilge water or ballast water

Abstract

A system, method, and apparatus for treating ship or barge ballast water. The system includes a ballast tank storing ballast water and one or more nozzles located in the ballast tank. One or more pumps supply a chemical into the ballast tank and water to the nozzles. The nozzles are strategically located in the ballast tank to circulate the ballast water and mix the chemical with the ballast water without removing the ballast water from the ballast tank to a separate mixing and treatment area located outside the tank either onboard or off of the ship or barge.

Claims

1. A system for treating ship or barge ballast water, comprising:

a ballast tank storing ballast water;

one or more nozzles located in the ballast tank; and

one or more pumps to supply a chemical into the ballast tank and to supply water to the nozzles, the nozzles strategically located in the ballast tank to circulate the ballast water and mix the chemical with the ballast water without removing the ballast water from the ballast tank and conveying it to a separate mixing and treatment area located outside the ballast tank.

2. The system of claim 1, wherein the ballast tank comprises multiple sections separated by structural web frames with lightening holes, and wherein the number and locations of nozzles used is a function of the geometry and size of the ballast tank and the shape and number of web frames.

3. The system of claim 1, wherein the nozzles deliver jets of pressurized water to the ballast water to create circulation/mixing currents inside the ballast tank.

4. The system of claim 3, wherein the circulation currents move the ballast water from one section of the ballast tank to adjacent sections through lightening holes in transverse web frames between the ballast tank sections and pull water out of areas in the ballast tank that are nearly hydraulically isolated by support structures within the ballast tank.

5. The system of claim 1, wherein the top of the ballast tank has access ports and the nozzles are deployed in the ballast tank without modifying the ship or barge by lowering the nozzles into the ballast tank through the access ports.

6. The system of claim 1, wherein the water pumped through the nozzles is supplied to the nozzles from a firefighting water supply system on the ship or barge.

7. The system of claim 1, wherein the nozzles are strategically located within the ballast tank to generate transverse flow and rotary circulation currents, and to exploit the geometry of the ballast tank to overcome resistive forces related to drag over structures of the ballast tank.

8. The system of claim 1, wherein the nozzles are strategically located within the ballast tank to generate mixing circulation cells that impart energy and flow into all areas of the ballast tank, that are stable and predictable, and that require relatively low levels of energy input.

9. The system of claim 1, wherein a lateral position of the nozzles within the ballast tank is determined by dividing the length of the ballast tank by the number of nozzles used and placing each of the nozzles respectively at the center of each divided portion of the ballast tank.

10. The system of claim 1, further comprising a pipe installed along a length of a double-bottom area of the ballast tank with a pipe nozzle located at an entrance of the pipe, the pipe nozzle directing water inside the pipe and the water exiting the pipe generating energy that moves the ballast water through tank sections via the lightening holes in the web frames between the tank sections to complete a circulation cell.

11. The system of claim 1, wherein the pump is located in an area of the ballast tank that is isolated by baffles and support structures inside the ballast tank and that is difficult to mix.

12. The system of claim 1, further comprising valves connected to the pump and to a controller, the controller regulating the pump and the valves to operate the nozzles alternately and intermittently by controlling switching frequencies and duration of water flow from the nozzles, the intermittent operation optimizing a mixing rate and minimizing energy consumption of the system while maintaining velocities sufficient for mixing.

13. The system of claim 12, further comprising a flow sensor in the ballast tank to indicate a condition of a bulk circulating flow velocity and to signal turning the valves on and off to minimize energy required by the system.

14. A method for treating ship or barge ballast water, comprising:

providing one or more nozzles in the ballast tank; and

pumping water through the nozzles into the ballast water in the ballast tank and injecting a chemical into the water pumped through the nozzles, the nozzles strategically located in the ballast tank to circulate the ballast water and mix the chemical with the ballast water in the ballast tank without removing the ballast water from the ballast tank to a separate mixing and treatment area located outside the ballast tank.

15. The method of claim 14, wherein said providing one or more nozzles in the ballast tank comprises lowering the nozzles into the ballast tank through access ports located in the top of the ballast tank that are accessible from a deck of the ship or barge.

16. The method of claim 14, wherein said providing one or more nozzles in the ballast tank comprises determining a lateral position of the nozzles by dividing the length of the ballast tank by the number of nozzles used and placing each of the nozzles respectively at the center of each divided portion of the ballast tank.

17. The method of claim 14, wherein said pumping water through the nozzles into the ballast water in the ballast tank creates circulation currents that move the ballast water from one section of the ballast tank to adjacent sections through lightening holes in transverse web frames between the ballast tank sections, and pull water out of areas in the ballast tank that are nearly hydraulically isolated by support structures within the ballast tank.

18. The method of claim 14, wherein said pumping water through the nozzles comprises operating the nozzles alternately and intermittently to optimize a mixing rate and minimize energy consumption while maintaining velocities sufficient for mixing.

19. The method of claim 18, wherein said operating the nozzles alternately and intermittently comprises controlling switching frequencies and duration of water flow from the nozzles.

20. The method of claim 14, further comprising installing a pipe along a length of a double-bottom area of the ballast tank and locating a pipe nozzle at an entrance of the pipe, the pipe nozzle directing water inside the pipe and the water exiting the pipe generating energy that moves the ballast water through tank sections via lightening holes in web frames between the ballast tank sections to complete a circulation cell.

21. An apparatus for treating ship or barge ballast water, comprising:

one or more nozzles located in a ballast tank of a ship or barge, the ballast tank storing ballast water; and

one or more pumps hydraulically connected to the nozzles to supply a chemical into the ballast tank and to supply water to the nozzles, the nozzles strategically located in the ballast tank and operating alternately and intermittently to circulate the ballast water and mix the chemical with the ballast water.

22. The apparatus of claim 21, wherein the nozzles deliver jets of water to the ballast water to create circulation currents inside the ballast tank.

23. The apparatus of claim 21, wherein the water pumped through the nozzles is supplied to the nozzles from a firefighting water supply system on the ship or barge.

24. The apparatus of claim 21, wherein the nozzles are strategically located within the ballast tank to generate transverse flow and rotary circulation currents, and to exploit the geometry of the ballast tank to overcome resistive forces related to drag over structures of the ballast tank.

25. The apparatus of claim 21, wherein the nozzles are strategically located within the ballast tank to generate mixing circulation cells that impart energy and flow into all areas of the ballast tank, that are stable and predictable, and that require relatively low levels of energy input.