Abstract: A control unit, a circulation system, and a method for handling ballast water of one or more ballast tanks. The circulation system includes a control unit; a pipe structure having a first system inlet and a first system outlet; and a pump unit for pumping ballast water between the first system inlet and the first system outlet, the pump unit being connected to the control unit. The control unit is configured to: obtain a volume parameter indicative of pumped volume; determine if a pump criterion is fulfilled, the pump criterion being based on the volume parameter; and operate the pump unit based on whether the pump criterion is fulfilled or not.

Abstract: Ballast water in a ship is treated in at least two ballast tanks with a system for treatment of ballast water. The ballast tanks are in fluid communication with each other so that ballast water can be pumped to each one of the ballast tanks and so that ballast water can be pumped between the ballast tanks either treated or untreated. Ballast water is pumped onboard such that at least one ballast tank is left empty. Next, ballast water is pumped via the system for treatment of ballast water from one ballast tank with untreated ballast water to an empty ballast tank. Pumping and treatment continue until the ballast tank being pumped from is empty.

Abstract: A system for treating ballast water in ballast tanks onboard vessels is provided. The system comprises one or more ballast tanks, a circulation pump circulating or recirculating, via a tubing, ballast water from and to the one or more ballast tanks, a nitrogen and/or carbon dioxide generator connected to the tubing on the delivery side of the recirculation pump in such a manner that nitrogen and/or carbon dioxide can be supplied to the ballast water, and one or more nozzle heads functionally connected to the tubing and arranged in one or more ballast tanks. The one or more nozzle heads comprises at least one nozzle for injecting the gas-containing water into the ballast tanks. At least one nozzle is configured for powered rotation about a first and a second axis which is perpendicular or not perpendicular to the first axis to the effect that a three-dimensional mixer pattern is produced.

Abstract: A system for treating ballast water in ballast tanks onboard vessels and offshore constructions is provided. The system comprises one or more ballast tanks, a circulation pump capable of circulating or recirculating, via a tubing, ballast water from and to the one or more ballast tanks, a gas supply unit which is connected to the tubing on the delivery side of the recirculation pump in such a manner that gas, such as air and/or inert gas such as nitrogen and/or carbon dioxide can be supplied to the ballast water; and one or more nozzle heads that are functionally connected to the tubing and is/are arranged in one or more ballast tanks, said one or more nozzle heads comprising at least one nozzle for injection of the gas-containing water into the one or more ballast tanks, and a device configured for removing and/or killing live organisms in the ballast water.

Abstract: A process plant comprises a tank (1), an outlet conduit (2), a reservoir of cleaning agent (12), or feedstock(s) of additive(s) (13), a loop conduit (3) for returning liquid into the tank, valve means (9) for controlling admission of liquid into the loop conduit and a pump (4) for driving liquid through the loop conduit. Returning of the liquid takes place through a jetting device (5) adapted for introducing jets of liquid into the body of liquid inside the tank in order to cause stirring to the body of liquid. The jet nozzle is adapted for powered rotation about a first axis and about a second axis perpendicular, or non-perpendicular, to the first axis. The jet nozzles may be embodied in a flat jet rotating around one axis only. Upon emptying the tank, the jetting device may serve for cleaning the tank by spraying liquid onto the tank walls. The invention provides a method for treating liquid as well as a process plant.

Abstract: A process plant comprises a tank (1), an outlet conduit (2), a reservoir of cleaning agent (12), or feedstock(s) of additive(s) (13), a loop conduit (3) for returning liquid into the tank, valve means (9) for controlling admission of liquid into the loop conduit and a pump (4) for driving liquid through the loop conduit. Returning of the liquid takes place through a jetting device (5) adapted for introducing jets of liquid into the body of liquid inside the tank in order to cause stirring to the body of liquid. The jet nozzle is adapted for powered rotation about a first axis and about a second axis perpendicular, or non-perpendicular, to the first axis. The jet nozzles may be embodied in a flat jet rotating around one axis only. Upon emptying the tank, the jetting device may serve for cleaning the tank by spraying liquid onto the tank walls. The invention provides a method for treating liquid as well as a process plant.