Apparatus and method for treating ballast water

Abstract

An apparatus and method for precisely controlling production, injection, and removal of disinfectants using electrolysis according to the flow rate of ballast water are provided, where the ballast water flows into or is discharged from the ballast tank to manage the ballast water or ships so that destruction or disruption of marine ecosystems can be prevented. An apparatus for treating ballast water and treatment method using the same are provided, the apparatus including: an electrolysis module for producing concentration-controlled sodium hypochlorite; a gas-liquid separator for separating hydrogen gas; a micro bubble generator for mixing and supplying reducing agents while reducing residual chlorine; a vortex generator for generating vortex; and a control system. The control system controls a salinometer, a flow rate meter, a residual chlorine meter, a seawater supply pump, flow rate control valves, an electrolysis module, a residual chlorine meter, a micro bubble generator, and an injection pump.

Description

TECHNICAL FIELD The present invention relates to an apparatus and a method for treating ballast water, and more particularly, to an apparatus and a method for treating ballast water that performs the electrolysis for the seawater from which aquatic organisms, bacteria and general microorganisms are removed at the time of flowing the seawater as the ballast water into a ballast tank during a voyage of a ship, produces a disinfectant through the electrolysis, injects the produced disinfectant into the seawater through precise control to purify the flowing seawater, performs a reducing process for the ballast water discharged from the ballast tank to sea with a reducing agent through precise and reliable control, and discharges the ballast water in a state of harmlessness to the sea.BACKGROUND ART In general, ships such as oil tankers, cargo ships and so on carry cargos like oil to an importing country, and after the cargos are unloaded on a port of the importing country, the ship stor...

AI Technical Summary

Benefits of technology

Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide an apparatus and a method for treating ballast water that produces sodium hypochlorite continuously in accordance with the flow rates of the ballast water flowing to a ballast tank or discharged from the ballast tank to supply the produced sodium hypochlorite to seawater lines, thereby removing the variations of the concentration of the sodium hypochlorite caused by the storing of the sodium hypochlorite, and performs a reducing process for the ballast water discharged through the ballast tank to sea by means of the injection of a reducing agent to allow the ballast water to be discharged in a state of harmlessness, thereby basically preventing the sea pollution.

According to the present invention, preferably, the method for treating ballast water further includes the step of continuously or intermittently circulating a predetermined amount of cooled seawater to the electrolysis module whose activation stops and preventing the pollution of the electrolysis module, after the step of storing the disinfected ballast water in the ballast tank.

Problems solved by technology

In other words, if a ship does not have a predetermined weight, the draft line is lowered to the lower portion of the ship by means of buoyancy, thereby causing some problems that the propeller of the ship is exposed to fail to obtain a propelling force, a wave resistance force during the voyage is lowered to apply much load to the voyage, and the body of the ship is destroyed.

To the contrary, it has some disadvantages in that a high quality of filter is required, the cost of the usage electrode is high, the disinfectant do not have any residual property so that the disinfection is needed again at the time of discharging ballast water, the electrobath is easily polluted, a test for the disinfection effects is required, and hydrogen gas is explosive because of the flow of generated hydrogen into the ballast tank.

To the contrary, it has some disadvantages in that the control of disinfection is difficult, the disinfection speed is low, the residual products after the disinfection are made, the neutralization of the disinfectant is needed, the electrobath is easily polluted, the hydrogen gas is explosive because of the flow of generated hydrogen into the ballast tank, and the electrolysis efficiency is sensitive to a quality of water.

To the contrary, it has some disadvantages in that the disinfection speed is low, the residual products after the disinfection are made, the neutralization of the disinfectant is needed, all of which are common in the direct and indirect chlorine electrolysis, and the injection of a neutralizing agent is needed together with the addition of chemicals in other chemical treatments.

In the conventional methods for treating ballast water, however, the indirect electrolysis of seawater as shown in FIG. 13 does not have any means for precisely controlling an amount of disinfectant to be injected in accordance with a flow rate of the ballast water flowing into the ballast tank, so that the ballast water not treated, that is, the ballast water containing pollution sources may flow into the ballast tank.

Additionally, the prior art apparatus does not have any means for processing hydrogen gas generated after the electrolysis from the generator in which the electrolysis for the seawater is performed to generate the sodium hypochlorite therefrom, so that if the hydrogen gas is accumulated, it may be exploded in the ballast tank.

At this time, the generator generating the sodium hypochlorite may be polluted.

However, the prior art apparatuses do not have any means for preventing the generator from being polluted, thereby causing the durability of the apparatus to be lowered.

In this case, the concentration-decreased disinfectant during the idle time after the activation of the equipment is just injected without any additional treatment at the time of activating the equipment again, and even though the measurement for the concentration of the sodium hypochlorite is made by means of the concentration measurer, it is not easy to perform precise control.

Also, there is no means for recognizing a precise amount of seawater flowing at the time of flowing the seawater into the ballast tank by using the concentration controller and the pump constituting the sodium hypochlorite supplier in accordance with the measured concentration of the sodium hypochlorite through the concentration measurer, so that it is not easy to control whether how much sodium hypochlorite stored per the unit flow rate of the seawater flowing is injected.

So as to perform a reliable process, therefore, the ultraviolet radiator should have a substantially large capacity, and in order to activate the large-sized ultraviolet radiator, further, a great amount of power should be required, which is very difficult to be practically used.

Additionally, the prior art apparatus does not have any means for processing hydrogen gas generated after the electrolysis from the seawater converter in which the electrolysis for the seawater is performed to generate the sodium hypochlorite therefrom, so that if the hydrogen gas is accumulated, it may be exploded in the ballast tank.

At this time, the seawater converter generating the sodium hypochlorite may be polluted.

However, the prior art process does not have any means for preventing the seawater converter from being polluted, thereby causing the durability of the apparatus to be lowered.

Additionally, the prior art apparatus does not have any means for processing hydrogen gas generated after the electrolysis from the electrolysis module in which the electrolysis for the seawater is performed to generate the sodium hypochlorite therefrom, so that if the hydrogen gas is accumulated, it may be exploded in the ballast tank.

Further, since the seawater is not passed through any specific pre-processor, fouling occurs by the sludge in the seawater, thereby decreasing the electrolysis efficiency and producing the ballast water not treated.

At this time, the electrolysis module generating the sodium hypochlorite may be polluted.

However, the prior art process does not have any means for preventing the electrolysis module from being polluted, thereby causing the durability of the apparatus to be lowered.

In case of the direct disinfection wherein the electrolysis for the whole amount of ballast water is performed, accordingly, there is no means for preventing the decrease of the electrolysis efficiency, so that the treatment efficiency is determined by the concentration of the seawater, thereby disadvantageously generating the ballast water not treated.

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