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.

1 . An apparatus for treating ballast water wherein a portion of the ballast water flowing from a seawater intake line  20  is controlled at a flow rate thereof under the control of a control system  12  and supplied to an electrolysis module  4  in which sodium hypochlorite having an adjusted concentration is produced; wherein after hydrogen gas produced at the time of producing the sodium hypochlorite is removed through a gas-liquid separator  5 , the sodium hypochlorite is supplied to the seawater intake line  20  flowing into a ballast tank  13  in accordance with an amount of residual chlorine in the ballast water, the ballast water is disinfected with the sodium hypochlorite, and the disinfected ballast water is stored in the ballast tank  13 ; and wherein an amount of reducing agent to be injected is controlled under the control of the control system  12  in accordance with the amounts of residual chlorine of the ballast water, the controlled amount of reducing agent is supplied to a seawater discharge line  21 , a neutralizing process for the ballast water is carried out to obtain a desired amount of residual chlorine, and the neutralized ballast water is discharged to sea. 
     
     
         2 . An apparatus for treating ballast water wherein a portion of the ballast water flowing from a seawater discharge line  21  passed through a ballast tank  13  is controlled at a flow rate thereof under the control of a control system  12  and supplied to an electrolysis module  4  in which sodium hypochlorite having an adjusted concentration is produced; wherein after hydrogen gas produced at the time of producing the sodium hypochlorite is removed through a gas-liquid separator  5 , the sodium hypochlorite is supplied to the seawater discharge line  21  in accordance with an amount of residual chlorine in the ballast water, and the ballast water is disinfected with the sodium hypochlorite; and wherein an amount of reducing agent to be injected is controlled under the control of the control system  12  in accordance with the amounts of residual chlorine of the ballast water, the controlled amount of reducing agent is supplied, a neutralizing process for the ballast water is carried out to obtain a desired amount of residual chlorine, and the neutralized ballast water is discharged to sea. 
     
     
         3 . An apparatus for treating ballast water wherein cooled seawater flowing selectively from a cooling seawater line before heat exchange  22  and from a cooling seawater line after heat exchange  23  passed through a heat exchanger  25  is controlled at a flow rate thereof under the control of a control system  12  and supplied to an electrolysis module  4  in which sodium hypochlorite having an adjusted concentration is produced; wherein after hydrogen gas produced at the time of producing the sodium hypochlorite is removed through a gas-liquid separator  5 , the sodium hypochlorite is supplied to a seawater intake line  20  in accordance with an amount of residual chlorine in the ballast water, the ballast water is disinfected with the sodium hypochlorite, and the disinfected ballast water is stored in a ballast tank  13 ; and wherein an amount of reducing agent to be injected is controlled under the control of the control system  12  in accordance with the amounts of residual chlorine of the ballast water, the controlled amount of reducing agent is supplied, a neutralizing process for the ballast water is carried out to obtain a desired amount of residual chlorine, and the neutralized ballast water is discharged to sea. 
     
     
         4 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the ballast water or the cooled seawater flowing into the electrolysis module  4  is passed through a pre-processing filter for filtering aquatic microorganisms. 
     
     
         5 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein after passing through the pre-processing filter, the ballast water or the cooled seawater is controlled at the flow rate thereof by means of a seawater supply pump  2  controlled under the control of the control system  12 . 
     
     
         6 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein after passing through the pre-processing filter, the ballast water or the cooled seawater is controlled at the flow rate thereof by means of flow rate control valves  3  controlled under the control of the control system  12 . 
     
     
         7 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein after passing through the pre-processing filter, the ballast water or the cooled seawater is controlled at the flow rate thereof by means of a seawater supply pump  2  controlled under the control of the control system  12 , and the ballast water or the cooled seawater supplied from the seawater supply pump  2  is controlled at the flow rate thereof by means of flow rate control valves  3  controlled under the control of the control system  12 . 
     
     
         8 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the sodium hypochlorite used for disinfection is supplied by means of an automatic injector  11  by using the variation of the pressure of the ballast water or the cooled seawater, without having separate power. 
     
     
         9 . The apparatus for treating ballast water according to claim, wherein the seawater intake line  20  along which the ballast water flowing into the ballast tank  13  flows has a salinometer  8 , a flow rate meter  9 , and a residual chlorine measurer  10  mounted thereon, the salinometer  8  being adapted to measure the sodium chloride (NaCl) of the ballast water flowing into the ballast tank  13 , the flow rate meter  9  being adapted to measure the flow rate of the ballast water flowing into the ballast tank  13 , and the residual chlorine meter  10  being adapted to measure an amount of residual chlorine of the ballast water into which the sodium hypochlorite is injected. 
     
     
         10 . The apparatus for treating ballast water according to  claim 2 , wherein the seawater discharge line  21  along which the ballast water passed through the ballast tank  13  flows has a salinometer  8 , a flow rate meter  9 , and a residual chlorine measurer  16  mounted thereon, the salinometer  8  being adapted to measure the sodium chloride (NaCl) of the ballast water, the flow rate meter  9  being adapted to measure the flow rate of the ballast water, and the residual chlorine meter  16  being adapted to measure an amount of residual chlorine of the ballast water into which the sodium hypochlorite is injected. 
     
     
         11 . The apparatus for treating ballast water according to  claim 3 , wherein the cooling seawater line before heat exchange  22  has a salinometer  8  mounted thereon, the salinometer  8  being adapted to measure the sodium chloride (NaCl) of the cooled seawater flowing into the heat exchanger  25 , and the seawater intake line  20  has a flow rate meter  9  and a residual chlorine measurer  10  mounted thereon, the flow rate meter  9  being adapted to measure the flow rate of the ballast water flowing into the ballast tank  13  and the residual chlorine meter  10  being adapted to measure an amount of residual chlorine of the ballast water into which the sodium hypochlorite is injected. 
     
     
         12 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the reducing agent injected at the time of discharging the ballast water is supplied by means of an injection nozzle  14 , and the reducing agent and the ballast water are mixed to form micro bubbles and supplied to the injection nozzle  14  by means of a micro bubble generator  18 , while the residual chlorine in the ballast water is being removed. 
     
     
         13 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the reducing agent injected at the time of discharging the ballast water is supplied by means of an injection pump  15  and a reducing agent-storing tank  17 , the injection pump  15  being adapted to adjust a flow rate of reducing agent supplied to a micro bubble generator  18  and supply the adjusted flow rate of reducing agent under the control of the control system  12 , and the reducing agent-storing tank  17  being adapted to store the reducing agent to be supplied to the injection pump  15  therein. 
     
     
         14 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the reducing agent injected at the time of discharging the ballast water is mixed with the ballast water by means of one or more vortex generators  19  adapted to generate vortexes in the ballast water. 
     
     
         15 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the seawater discharge line  21  has a residual chlorine measurer  16  mounted thereon so as to measure a total amount of residual chlorine of the ballast water finally discharged. 
     
     
         16 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the control system  12  receives the information from a salinometer  8 , a flow rate meter  9  and a residual chlorine measurer  10  and controls a seawater supply pump  2 , flow rate control valves  3  and the electrolysis module  4  under the received information, so as to inject only a desired amount of sodium hypochlorite into the ballast water flowing into the ballast tank  13 ; and the control system  12  receives the information from the residual chlorine measurer  10  to determine an amount of reducing agent and the information from a residual chlorine measurer  16  measuring a degree of harmlessness of the ballast water and controls a micro bubble generator and an injection pump under the received information, so as to inject the reducing agent neutralizing the sodium hypochlorite into the ballast water discharged to the sea and to have only a desired amount of residual chlorine in the ballast water. 
     
     
         17 . The apparatus for treating ballast water according to  claim 2 , wherein the control system  12  receives the information from a salinometer  8  and a flow rate meter  9  and controls a seawater supply pump  2 , flow rate control valves  3  and the electrolysis module  4  under the received information, so as to inject only a desired amount of sodium hypochlorite into the ballast water discharged after passed through the ballast tank  13 ; and the control system  12  receives the information from a residual chlorine measurer  16  and controls a micro bubble generator  18  and an injection pump  15  under the received information, so as to inject the reducing agent neutralizing the sodium hypochlorite into the ballast water discharged to the sea and to have only a desired amount of residual chlorine in the ballast water. 
     
     
         18 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the apparatus further includes a cleaning/injection pump  7  disposed in the line branched from the sodium hypochlorite supply line passed through the gas-liquid separator  5  to the electrolysis module  4 , so as to continuously or periodically circulate the sodium hypochlorite to the electrolysis module  4  in which the production of the sodium hypochlorite stops. 
     
     
         19 . The apparatus for treating ballast water according to  claim 5 , wherein the seawater supply pump  2  adjusts the flow rate of the ballast water or the cooled seawater in accordance with the variations of the amount of current supplied under the control of the control system  12 . 
     
     
         20 . The apparatus for treating ballast water according to  claim 6 , wherein the flow rate control valves  3  include a plurality of flow control valves adapted to be selectively opened and closed to adjust the flow rate of the ballast water or cooled seawater supplied thereto under the control of the control system  12 . 
     
     
         21 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein at the time of producing the sodium hypochlorite from the ballast water or the cooled seawater, the electrolysis module  4  adjusts the concentration and production amount of the sodium hypochlorite, while the amount of current supplied to a power supply rectifier is controlled within a rated range, by the under of the control system  12 . 
     
     
         22 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the electrolysis module  4  adjusts the concentration of the sodium hypochlorite, so as to satisfy a desired chlorine demand in a range of 2 ppm to 10 ppm. 
     
     
         23 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the gas-liquid separator  5  further includes a blower  6  adapted to supply outside air thereto so as to allow the separated hydrogen gas to be diluted. 
     
     
         24 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the reducing agent is one selected from sulfite reducing agents such as sulfite, thiosulfate, sulfite plus idodide, dithionite, and calcium sulfite, or one selected from ascorbic acid, hydroxylamine, and PAO. 
     
     
         25 . The apparatus for treating ballast water according to  claim 14 , wherein the vortex generator  19  is disposed in the interior of the pipe of the seawater discharge line  21  and includes a plurality of screws having rotary blades. 
     
     
         26 . The apparatus for treating ballast water according to any one of  claims 1  to  3 , wherein the desired amount of residual chlorine in the ballast water or the cooled seawater discharged to the sea is in a range of 0.5 ppm to 2 ppm. 
     
     
         27 . The apparatus for treating ballast water according to  claim 13 , wherein the injection pump  15  is adapted to inject a predetermined amount of reducing agent and controls the flow rate of the reducing agent (with chemical equivalent of the ratio of 1 to 1) under the control of the control system  12  in accordance with the values of the total concentration of the residual chlorine measured by the residual chlorine measurer disposed at the ballast tank side, at the time of discharging the ballast water. 
     
     
         28 . The apparatus for treating ballast water according to  claim 13 , wherein during the idle time in the supply of the reducing agent, the injection pump  15  is adapted to circulate the reducing agent-storing tank  17  periodically, thereby preventing salt precipitation from occurring. 
     
     
         29 . An apparatus for treating ballast water, comprising:
 a pre-processing filter  1  adapted to filter aquatic microorganisms from the ballast water flowing thereinto;   a seawater supply pump  2  adapted to adjust a flow rate of the ballast water supplied from the pre-processing filter  1  under the control of a control system  12  and to supply the adjusted flow rate of ballast water to an electrolysis module  4 ;   flow rate control valves  3  adapted to adjust a flow rate of the ballast water supplied from the seawater supply pump  2  under the control of the control system  12  and to supply the adjusted flow rate of ballast water to the electrolysis module  4 ;   the electrolysis module  4  adapted to adjust a concentration of sodium hypochlorite and to produce the concentration-adjusted sodium hypochlorite with an amount of current supply controlled under the control of the control system  12  at the time of producing the sodium hypochlorite from the ballast water supplied from the flow rate control valves  3 ;   a gas-liquid separator  5  adapted to separate hydrogen gas generated as residual products during the production of the sodium hypochlorite in the electrolysis module  4  from the ballast water;   a blower  6  adapted to supply outside air to the gas-liquid separator  5  and to dilute the separated hydrogen gas;   an automatic injector  11  adapted to supply the sodium hypochlorite from which the hydrogen gas is removed through the gas-liquid separator  5  to a seawater intake line  20  connected to a ballast tank  13 ;   a salinometer  8  adapted to measure the sodium chloride (NaCl) of the ballast water flowing into the ballast tank  13  through the seawater intake line  20 ;   a flow rate meter  9  adapted to measure the flow rate of the ballast water flowing into the ballast tank  13  through the seawater intake line  20 ;   a residual chlorine meter  10  disposed in the seawater intake line and a seawater discharge line at the front and back of the ballast tank  13  and adapted to measure an amount of residual chlorine of the ballast water into which the sodium hypochlorite is injected;   an injection nozzle  14  adapted to inject a reducing agent neutralizing the residual chlorine in the ballast water passed through the seawater discharge line  21  at the time of discharging the ballast water stored in the ballast tank  13  to sea;   a micro bubble generator  18  adapted to mix the reducing agent and the ballast water branched from the seawater discharge line  21  to form micro bubbles and to supply the micro bubbles to the injection nozzle  14 , while removing the residual chlorine;   an injection pump  15  adapted to adjust a flow rate of the reducing agent supplied from the micro bubble generator  18  under the control of the control system  12  and to supply the adjusted flow rate of the reducing agent;   a reducing agent-storing tank  17  adapted to store the reducing agent to be discharged by means of the injection pump  15  therein;   a vortex generator  19  disposed in the seawater discharge line  21  at the rear end of the injection nozzle  14  to generate vortexes helping the neutralizing reaction of the reducing agent;   a residual chlorine measurer  16  disposed in the seawater discharge line  21  at the rear end of the vortex generator  19  to measure a total amount of residual chlorine of the ballast water finally discharged and to measure a degree of harmlessness of the ballast water;   the control system  12  adapted to receive the information from the salinometer  8 , the flow rate meter  9  and the residual chlorine measurer  10  and to control the seawater supply pump  2 , the flow rate control valves  3  and the electrolysis module  4  under the received information, so as to inject only a desired amount of sodium hypochlorite into the ballast water flowing into the ballast tank  13 , and adapted to receive the information from the residual chlorine measurer  10  to determine an amount of reducing agent and the information from the residual chlorine measurer  16  measuring a degree of harmlessness of the ballast water and to control the micro bubble generator  18  and the injection pump  15  under the received information, so as to inject the reducing agent neutralizing the sodium hypochlorite into the ballast water discharged to the sea and to have only a desired amount of residual chlorine in the ballast water; and   a cleaning/injection pump  7  connected at one side thereof to the line branched from the sodium hypochlorite supply line between the gas-liquid separator  5  and the automatic injector  11  and connected at the other side thereof to the line branched between the flow rate control valves  3  and the electrolysis module  4 , so as to continuously or periodically circulate the sodium hypochlorite passed through the gas-liquid separator  5  to the electrolysis module  4  in which the production of the sodium hypochlorite stops.   
     
     
         30 . A method for treating ballast water, comprising the steps of:
 allowing the ballast water to flow (at a step S 100 );   filtering aquatic microorganisms from the ballast water flowing (at a step S 101 );   adjusting a flow rate of the ballast water so as to correspond to a desired amount of residual chlorine by means of a seawater supply pump and flow rate control valves under the control of a control system and supplying the adjusted flow rate of ballast water to an electrolysis module (at a step S 102 );   adjusting a concentration of sodium hypochlorite in the ballast water supplied to the electrolysis module to correspond to the desired amount of residual chlorine and producing the concentration-adjusted sodium hypochlorite, while adjusting an amount of current, under the control of the control system to which the information on the measurement of salt, flow rate and residual chlorine in the ballast water is sent (at a step S 103 );   separating hydrogen gas contained in the sodium hypochlorite produced in the electrolysis module (at a step S 104 );   supplying the sodium hypochlorite from which the hydrogen gas is removed to the ballast water flowing into a ballast tank and disinfecting the ballast water (at a step S 105 );   storing the disinfected ballast water in the ballast tank (at a step S 106 );   controlling an amount of reducing agent to correspond to the desired amount of residual amount, mixing the controlled amount of reducing agent with a predetermined amount of ballast water to form micro bubbles from the mixture, injecting the micro bubbles into the ballast water, and performing a reducing process for the ballast water, under the control of the control system to which the information on the amount of residual chlorine measured in the ballast water discharged from the ballast tank to the outside of a ship (at a step S 107 );   generating vortexes in the ballast water to which the reducing agent is mixed to allow the reducing process for the ballast water to be accelerated (at a step S 108 ); and   discharging the ballast water to sea (at a step S 109 ).   
     
     
         31 . The method for treating ballast water according to  claim 30 , further comprising the step of continuously or intermittently circulating a predetermined amount of ballast water to the electrolysis module whose activation stops and preventing the pollution of the electrolysis module (at a step S 110 ), after the step of storing the disinfected ballast water in the ballast tank (at the step S 106 ). 
     
     
         32 . A method for treating ballast water, comprising the steps of:
 filtering aquatic microorganisms from the ballast water flowing (at a step S 100 );   storing the ballast water from which the deleterious substances are removed into a ballast tank (at a step S 101 );   adjusting a flow rate of the ballast water so as to correspond to a desired amount of residual chlorine by means of a seawater supply pump and flow rate control valves under the control of a control system and supplying the adjusted flow rate of ballast water to an electrolysis module (at a step S 102 );   adjusting a concentration of sodium hypochlorite in the ballast water supplied to the electrolysis module to correspond to the desired amount of residual chlorine and producing the concentration-adjusted sodium hypochlorite, while adjusting an amount of current, under the control of the control system to which the information on the measurement of salt, flow rate and residual chlorine in the ballast water is sent (at a step S 103 );   separating hydrogen gas contained in the sodium hypochlorite produced in the electrolysis module (at a step S 104 );   supplying the sodium hypochlorite from which the hydrogen gas is removed to the ballast water flowing along a seawater discharge line discharged to the outside of a ship into a ballast tank and disinfecting the ballast water (at a step S 105 );   firstly generating vortexes in the ballast water having the sodium hypochlorite residual therein (at a step S 106 );   controlling an amount of reducing agent to correspond to the desired amount of residual amount, mixing the controlled amount of reducing agent with a predetermined amount of ballast water to form micro bubbles from the mixture, injecting the micro bubbles into the ballast water, and performing a reducing process for the ballast water, under the control of the control system to which the information on the amount of residual chlorine measured in the ballast water discharged from the ballast tank to the outside of the ship (at a step S 107 );   secondarily generating vortexes in the ballast water to which the reducing agent is mixed to allow the reducing process for the ballast water to be accelerated (at a step S 108 ); and   discharging the ballast water to sea (at a step S 109 ).   
     
     
         33 . The method for treating ballast water according to  claim 32 , further comprising the step of continuously or intermittently circulating a predetermined amount of ballast water to the electrolysis module whose activation stops and preventing the pollution of the electrolysis module (at a step S 110 ), after the step of discharging the ballast water to sea (at the step S 109 ). 
     
     
         34 . A method for treating ballast water, comprising the steps of:
 allowing the ballast water to flow (at a step S 100 );   filtering aquatic microorganisms from the ballast water flowing (at a step S 101 );   selectively allowing cooled seawater from a cooling seawater line before heat exchange and from a cooling seawater line after heat exchange to flow (at a step S 102 );   filtering aquatic microorganisms from the cooled seawater flowing (at a step S 103 );   adjusting a flow rate of the cooled seawater so as to correspond to a desired amount of residual chlorine by means of a seawater supply pump and flow rate control valves under the control of a control system and supplying the adjusted flow rate of cooled seawater to an electrolysis module (at a step S 104 );   adjusting a concentration of sodium hypochlorite in the cooled seawater supplied to the electrolysis module to correspond to the desired amount of residual chlorine and producing the concentration-adjusted sodium hypochlorite, while adjusting an amount of current, under the control of the control system to which the information on the measurement of salt, flow rate and residual chlorine in the cooled seawater is sent (at a step S 105 );   separating hydrogen gas contained in the sodium hypochlorite produced in the electrolysis module (at a step S 106 );   supplying the sodium hypochlorite from which the hydrogen gas is removed to the ballast water flowing into a ballast tank and disinfecting the ballast water (at a step S 107 );   storing the disinfected ballast water in the ballast tank (at a step S 108 );   controlling an amount of reducing agent to correspond to the desired amount of residual amount, mixing the controlled amount of reducing agent with a predetermined amount of ballast water to form micro bubbles from the mixture, injecting the micro bubbles into the ballast water, and performing a reducing process for the ballast water, under the control of the control system to which the information on the amount of residual chlorine measured in the ballast water discharged from the ballast tank to the outside of a ship (at a step S 109 );   generating vortexes in the ballast water to which the reducing agent is mixed to allow the reducing process for the ballast water to be accelerated (at a step S 110 ); and   discharging the ballast water to sea (at a step S 111 ).   
     
     
         35 . The method for treating ballast water according to  claim 34 , further comprising 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 (at a step S 112 ), after the step of storing the disinfected ballast water in the ballast tank (at the step S 108 ).