WO2012044071A2

WO2012044071A2 - Device for injecting ozone into ballast water for a ship

Info

Publication number: WO2012044071A2
Application number: PCT/KR2011/007158
Authority: WO
Inventors: Jae Man Park
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-09-29
Filing date: 2011-09-28
Publication date: 2012-04-05
Anticipated expiration: 2013-03-29
Also published as: WO2012044071A3; KR101050396B1

Abstract

Disclosed is a device for injecting ozone into ballast water for a ship so as to sterilize and purify ballast water used in the ship, which is capable of easily controlling ozone concentration of ballast water in accordance with the level of process and the substantial flow rate of ballast water, by installing an ozone mixer at upstream site in front of a supply pump in a ballast water supplying tube for supplying a ballast water tank with ballast water from the sea-chest of a ship, whereby ozone gas may be merged into ballast water due to a strong absorption force generated during the operation of the supply pump.

Description

DEVICE FOR INJECTING OZONE INTO BALLAST WATER FOR A SHIP

The present invention relates generally to a device for injecting ozone into ballast water for a ship so as to sterilize and purify ballast water used in the ship, which is capable of easily controlling ozone concentration of ballast water in accordance with the level of process and the substantial flow rate of ballast water, by installing an ozone mixer at upstream site in front of a supply pump in a ballast water supplying tube for supplying a ballast water tank with ballast water from the sea-chest of the ship, whereby ozone gas may be merged into ballast water due to a strong absorption force generated during the operation of the supply pump, and it is possible to forcibly aggressively mix ozone gas with ballast water due to a rotational force generated by an impeller provided in the supply pump.

Generally, ship ballast water is fresh water or seawater used for controlling the buoyancy of a ship so as to keep the ship's balance. Once a ship has unloaded cargo in a foreign port, the holds within the ship which previously held good and materials are obviously empty or there are relatively small quantity of good and materials. Under this state, if the ship journeys to the waters of another foreign port, the ship may be likely to lose its balance. In order to this problem, ballast tanks provided at both lower sides of the ship are often filled with fresh water or seawater so as to stabilize the ship.

However, a variety of organisms such as pathogenic bacteria and plankton live in fresh water or seawater contained in the ballast tanks. If ship ballast water is discharged in distant waters including Open Ocean and foreign ports without performing any treatment for treating it, this can create ecological problems for both the marine environment and human health.

In view of the foregoing, in 1996, U.S. Government establishes a law aimed to control the immigration and the diffusion of foreign pathogenic bacteria or plankton present in ship ballast water by enacting it as invading bacteria or plankton.

In the meantime, the International Maritime Organization enters into an engagement on International Convention for sterilizing and purifying ship ballast water in February 2004. According to this convention, the International Maritime Organization has decided to quarantine every incoming ships from 2009 so as to verify whether an incoming ship is provided with a system for treating ship ballast water or not. This convention is enacted for the purpose of strengthening joint inspection of incoming and outgoing ships so as to prevent epidemics from being brought into or out of the country.

In recent years, a variety of endeavors have been given to develop treatment techniques for treating ship ballast water. One approach is, technique for sterilizing and purifying ship ballast water by using Ozone(O₃) has been proposed. A plurality of inventions related to treatment systems for treating ship ballast water has developed. See for example, U.S. Patent No. 6,869,540 registered on March 22^nd 2005, International Patent Publications Nos. WO/2002/010076 laid-open to the public on February 7^th 2002, WO/2006/086073 laid-open to the public on February August 17^th 2006 and WO/2007/049139 laid-open to the public on May 3^rd 2007, which disclose methods and systems for processing ballast water by using Ozone(O₃).

FIG. 1 show an ozone injection system 100 as illustrated in the International Patent Publication no. WO/2006/086073 among the prior arts as described above. Referring to FIG. 1, a side-stream type of branched tube 102 is installed at a ballast water supplying tube 101 for supplying a ballast water tank with ballast water from the Sea-chest. An injection pump 103, a venturi-mixer 107 and a mixing pipe 108 are installed at the branched tube 102 in sequence. An ozone supply tube 105 extends between an ozone generator 104 and a nozzle part of the venturi-mixer 107. At this time, a flow control valve 106 is installed at a middle portion of the ozone supply tube 105.

Meanwhile, a supply pump (not shown) for supplying a ballast water tank with ballast water from the sea-chest of a ship is installed at a middle portion of the ballast water supply tube 101. The injection pump 103, the ozone generator 104 and the flow control valve 106 are connected to a controller 110 via a cable 111, and whereby operations thereof may be controlled by the controller 110. A plurality of partitions 108 are installed in the mixing pipe 108 so as to secure enough time for a reaction of ballast water and ozone gas. An injection nozzle 109 for re-injecting ballast water containing ozone gas into the ballast water supply tube 101 is installed at a distal end of the branched tube 102.

In the ozone injection system 100 as described above, a part of ballast water flowing through the ballast water supply tube 101 due to the operation of the supply pump (not shown) may be induced through the branched tube 102 by using the injection pump 103. The ballast water induced into the branched tube 102 may absorb ozone gas generated from the ozone generator 104 during it passing through the venturi-mixer 107. The ballast water containing ozone gas is secondarily mixed within the mixing pipe 108 and then it is re-injected into the ballast water supply tube 101 via the injection nozzle 109. Consequently, ballast water stored in a ballast water storage tank can be sterilized and purified as a result of the reaction with ozone.

However, in the conventional ozone injection system 100, a practically fixed quantity of ballast water may be induced through the branched tube 102 due to the operation of the injection pump 103 regardless of substantial flow rate or flow velocity of ballast water flowing through the ballast water supply tube 101 and then ozone gas is merged into ballast water. Accordingly, it is hard to properly control the quantity of ozone to be merged into ballast water with considering the level of process and the substantial flow rate of ballast water.

In other words, the ozone concentration to the total flow rate of ballast water flowing through the ballast water supply tube 101 may be controlled by using only a small quantity of ballast water induced through the branched tube 102. Although the substantial flow rate of ballast water flowing through the ballast water supply tube 101 changes frequently, the quantity of ballast water induced through the branched tube 102 is uniform. Accordingly, it is hard to effectively control the quantity of ozone to be merged into ballast water to meet the change of the total flow rate or the substantial flow rate of ballast water.

Other drawback of such known system is that the injection pump 103 is installed at the branched tube 102 in addition to the supply pump disposed in the ballast water supply tube 101, thereby resulting in the use of two pumps for operating the ozone injection system 100. As a result, the cost of installing and operating the ozone injection system 100 has substantially increased. Furthermore, since relatively large space is required to install the ozone injection system 100, it is hard to effectively install the ozone injection system 100 in a narrow space such as an engine room in which there are a large number of pipe lines.

Since the injection pump 103 is installed at the branched pipe 102 so as to obtain a fast flow velocity of ballast water and the mixing pipe 108 and the injection nozzle 109 are installed at the branched pipe 102 so as to mix ballast water with ozone gas, the cost and space required for installing the ozone injection system 100 have substantially increased. Furthermore, it is difficult to repair or replace the ozone injection system 100 and thereby it is hard to provide a reasonable economic ozone injection system.

Meanwhile, ballast water and ozone gas induced through the branched tube 102 are very uniformly mixed by means of the injector type venture-mixer 107 and the mixing pipe 108 installed at downstream site beyond the venture-mixer 107. However, once ballast water returns to the ballast water supply tube 101 via the injection nozzle 109, it is hard to uniformly mix ozone gas with total ballast water.

Ballast water re-injected to the ballast water supply tube 101 via the injection nozzle 109 may be induced as an individual flow in accordance with the total flow of ballast water which can flow fast along the ballast water supply tube 101. At this time, the flow of ballast water re-induced through the injection nozzle 109 and the flow of ballast water flowing through the ballast water supply tube 101 travel side by side. Accordingly, it does not to have much time required for uniformly mixing individual ballast waters. This has resulted in low throughput efficiency of ballast water in spite of using the expensive ballast treatment system.

Besides the ozone injection system 100, this is disclosed in International Patent Publication No. WO/2006/086073, the conventional ozone injection systems as disclosed in U.S. Patent No. 6,869,540, International Patent Publications Nos. WO/2002/010076 and WO/2007/049139 seem to have as much troubles as the problems as described above because they have an ozone injection system installed at downstream site beyond a supply pump disposed at the ballast water supply tube 101.

Finally, although the conventionally ozone injection system 100 can sterilize and purify ballast water by injecting an ozone gas into ballast water, it cannot remove various floating matters or foreign materials existing in ballast water. Consequently, scales can be produced on inner walls of the ballast water tank and pipes in large quantities, this has resulted in high cost of cleaning and repairing the ballast water tank and pipes.

In consideration of the above-mentioned disadvantages or inconveniences of the conventional techniques, an object of the present invention is to provide a device for injecting ozone into ballast water for a ship so as to sterilize and purify ballast water used in the ship, which is capable of easily controlling ozone concentration of ballast water in accordance with the level of process and the substantial flow rate of ballast water, by installing an ozone mixer at upstream site in front of a supply pump in a ballast water supplying tube for supplying a ballast water tank with ballast water from the sea-chest of a ship, whereby ozone gas may be merged into ballast water due to a strong absorption force generated during the operation of the supply pump, and it is possible to forcibly aggressively mix ozone gas with ballast water due to a rotational force generated by an impeller provided in the supply pump, which can simplify the structure of the ozone injection system and can optimize the use of ozone concentration in ballast water, which can significantly reduce the cost and time spent for the manufacture and the repair, and which can provide an excellent purification performance and an excellent sterilizing effect at reasonable and economic costs.

In order to achieve the object, according to the present invention, the present invention provides an ozone injection system for sterilizing and purifying ballast water by injecting ozone gas into ballast water which is supplied from a sea-chest in a ship to a ballast water tank due to the operation of a supply pump installed at a ballast water supply tube, the ozone injection system being installed at the ballast water supply tube extending between the sea-chest provided in a lower part of the ship and the ballast water tank, the ozone injection system comprising; an ozone-mixer being installed at the ballast water supply tube in a position upstream in front of supply pump, in which the ballast water supply tube extends between the sea-chest and the ballast water tank; and an ozone generator being connected to the ozone-mixer via an ozone supply tube.

And, a return branched tube extends from the ballast water supply tube in a position downstream from the supply pump. The return branched tube is connected to the ozone supply tube. A shut-off valve is installed at the return branched tube. A ballast water filter is installed at the ballast water supply tube in a position downstream from the supply pump or the return branched tube. Preferably, the ballast water filter comprises an automatic backwash filter.

As described above, according to the present invention, it is possible to allow ozone gas to be merged into ballast water by using only one supply pump installed at the ballast water supply tube. In comparison with the conventional ozone injection system which employs two pumps and uses the mixing pipe and the injection nozzle as mixing means, it is possible to simplify the structure thereof to the maximum and can obtain sufficient ozone concentration in water by inducing the forceful and active mixing of ozone gas and ballast water.

Since ozone generated from the ozone generator is directly mixed with ballast water flowing through the ballast water supply tube, it is possible to quickly and accurately control the ozone concentration of the ballast water by controlling only the quantity of ozone generated from the ozone generator in accordance with various conditions such as the change in total flow rate and substantial flow rate of the ballast water, and levels of processing ballast water. Although the ballast water supply tube is divided into several branches, it can control all branches by using only one ozone generator.

Accordingly, it is possible to highly reduce the cost of installing and operating the ozone injection system. Furthermore, it is possible to effectively install the ozone injection system in a narrow space such as an engine room in which there are a large number of pipe lines. Furthermore, it is possible to repair or replace the ozone injection system so that this leads to provide a reasonable economic ozone injection system, which can be manufactured at a low cost and has an optimum application, excellent sterilizing and purifying capability.

Meanwhile, in the preferred second embodiment of the present invention which employs the return branched tube, if the ozone concentration of the ballast water supplied to ballast water tank is less than the standard value, a worker can quickly control the ozone concentration at a desired level by re-circulating a part of ballast water into the ozone-mixer. Accordingly, the ozone injection system according to the present invention can quickly handle the change of ozone concentration.

In the case of employing the ballast water filter, it can remove various floating matters or foreign materials existing in ballast water, which cannot be removed by performing only the ozone's processing. Consequently, scales produced on inner walls of the ballast water tank and pipes may be minimized, this has resulted in low cost of cleaning and repairing the ballast water tank and pipes. Since the ballast water filter can function as an additional mixer for mixing ballast water with ozone gas, it is possible to further increase ozone concentration.

The above object and other characteristics and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings, in which:

FIG. 1 shows total piping of an ozone injection system according to the prior art;

FIG. 2 shows piping of an ozone injection system according to a preferred first embodiment of the present invention;

FIG. 3 shows piping of an ozone injection system according to a preferred second embodiment of the present invention;

FIG. 4 shows piping of an ozone injection system according to a preferred third embodiment of the present invention; and

FIG. 5 shows piping of an ozone injection system according to a preferred fourth embodiment of the present invention.

Hereinafter, the constitution and the operation of ozone injection systems according to preferred embodiments of the present invention will be explained in more detail with reference to the accompanying drawings FIGS. 2 to 5.

Prior to proceeding to the more detailed description of the preferred embodiment according to the present invention, it should be noted that, for the sake of clarity and understanding of the invention identical components which have identical functions have been identified with identical reference numerals throughout the different views which are illustrated in each of the attached drawing Figures.

Referring to FIGS. 2 to 5, an ozone injection system 10 according to the present invention is installed at a ballast water supply tube 1 extending between a sea-chest 2 provided in a lower part of the ship and a ballast water tank 3. The ozone injection system 10 can function to sterilize and purify ballast water by injecting ozone gas into ballast water which is supplied from the sea-chest 2 in a ship to the ballast water tank 3 due to the operation of a supply pump 4 installed at a ballast water supply tube 1.

The sea-chest 2 is a rectangular recess in the hull of a vessel that provides an intake reservoir from which piping systems draw raw water to be used as cooling water or ballast water for a diesel engine. The ballast water tank 3 for temporarily holding ballast water is typically installed on a bottom surface of the ship at both sides thereof. For the purpose of illustration only, the sea-chest 2 and the ballast water tank 3 are simply represented as a rectangular block in the attached drawings.

As best seen in FIG. 2, the ozone injection system 10 according to the preferred first embodiment of the present invention comprises an ozone-mixer 5 installed at the ballast water supply tube 1 in a position upstream in front of supply pump 4, and an ozone generator 6 connected to the ozone-mixer 5 via an ozone supply tube 7.

The ozone gas generated from the ozone generator 6 may be merged to the ballast water supply tube 1 via the ozone supply tube 7 due to a suction force generated by operating the supply pump 4. At this time, the ozone-mixer 5 can allow an ozone gas to be mixed with ballast water flowing through the ballast water supply tube 1. It should be appreciated by one of ordinary skill, that the ozone-mixer 5 may vary based on application. Preferably, the ozone-mixer 5 comprises the venturi-mixer 107 as shown in FIG. 1.

It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for construction of peripheries belongs to the ozone-mixer 5 without departing from the scope of the invention.

For example, the ozone supply tube 7 extending from the ozone generator 6 can be directly connected to the ballast water supply tube 1. In detail, one end of the ozone supply tube 7 is inserted into the ballast water supply tube 1 and then it is bent along the flowing direction of the ballast water. Alternatively, the ozone supply tube 7 can be divided into a plurality of ozone supplying tubes and then they may be formed as a circular tube or a spiral tube along an outer peripheral surface of the ballast water supply tube 1 at intervals, respectively.

It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for construction of peripheries belongs to the ozone generator 6 without departing from the scope of the invention.

Typically, the ozone generator 6 can be classified into the plate-type ozone generator and the tube-type ozone generator. In the ozone generator 6, in order to produce ozone gas, a compressed air generated from a compressor is purified by means of a filter and then it is supplied through a discharge tube installed between cooling water passageways, wherein oxygen existing in the cool and fresh air passing through the discharge tube may be decomposed and reunited by colliding with an electrical energy. This is an example of a general principle which applies not only to the plate-type ozone generator but also to the tube-type ozone generator.

Accordingly, it is preferred that the ozone-mixer 5 and the ozone generator 6 are properly selected with consideration of the condition of a place where the ozone injection system 10 according to the present invention is installed. It is to be understood that the technical matters related to the ozone-mixer 5 and the ozone generator 6 may be applied to other embodiments according to the present invention, which will be described below.

The ozone-mixer 5 and the ozone generator 6 are connected to a controller 8 for controlling operation of them via a cable 9. The controller 8 may control operations of the ozone-mixer 5 and the ozone generator 6 on a basis of measured values provided by a flow-meter 1a and a sensor 1b for sensing the ozone concentration, which are installed at the ballast water supply tube 1 in a position downstream from the supply pump 4. It is to be understood that various types of sensors can be employed for the purpose of effectively operating the ozone injection system 10.

FIG. 3 shows piping of an ozone injection system 10 according to a preferred second embodiment of the present invention.

Referring to FIG. 3, in the a preferred second embodiment of the present invention, a return branched tube 11 extends from the ballast water supply tube 1 in a position downstream from the supply pump 4, in which the return branched tube 11 is connected to the ozone supply tube 7, and a shut-off valve 12 is installed at the return branched tube 11. Other constructions are the same as those of the preferred first embodiment according to the present invention as described above.

If a measured value of ozone concentration measured by the sensor 1b is below a standard value, a part of ballast water exhausted from the supply pump 4 returns toward the ozone-mixer 5 via the return branched tube 11 and the ozone supply tube 7. Due to this construction, it is possible to rapidly increase the concentration of ozone contained in the ballast water at a desired level.

It is preferred that the return branched tube 11 is branched off of the ballast water supply tube 1 at a position between downstream site beyond the supply pump 4 and a front side to the sensor instrument including the flow-meter 1a and the sensor 1b. Preferably, the shut-off valve 12 installed at the return branched tube 11 comprises an automatic valve which is operated by the controller 8 on the basis of the value measured by the sensor 1b.

Since the return branched tube 11 is connected to the ozone supply tube 7 without directly connected to the ozone-mixer 5, ballast water introduced through the return branched tube 11 is supplied to the ozone-mixer 5 through the ozone supply tube 7 together with ozone gas. This leads to further long residence time of the ballast water and the ozone gas suitable for enhancing the dissolution of the ozone gas.

It will be fine without installing additional pumps at the return branched tube 11, different from the conventional branched tube 102 as described above. Because the return branched tube 11 is branched off of the outlet side of the supply pump 4 and then it is connected to the ozone supply tube 7 installed at the inlet side of the supply pump 4, a part of the ballast water discharged through the supply pump 4 can be automatically circulated toward the ozone-mixer 5 by opening only the shut-off valve 12 installed the return branched tube 11.

FIG. 4 shows an ozone injection system according to a preferred third embodiment of the present invention and FIG. 5 shows an ozone injection according to a preferred fourth embodiment of the present invention.

As shown in FIG. 4, the constitution of the ozone injection system according to the preferred third embodiment of the present invention is the same as or similar to that of the ozone injection system according to the preferred first embodiment of the present invention, except for the fact that a ballast water filter 13 is installed at the ballast water supply tube 1 in a position downstream from the supply pump 4.

As shown in FIG. 5, the constitution of the ozone injection system according to the preferred fourth embodiment of the present invention is the same as or similar to that of the ozone injection system according to the preferred second embodiment of the present invention, except for the fact that a ballast water filter 13 is installed at the ballast water supply tube 1 in a position downstream from the return branched tube 11 and the sensing instrument including the flow-meter 1a and the sensor 1b is placed upstream in front of the ballast water filter 13.

The ballast water filter 13 can function to remove various floating matters or foreign materials existing in ballast water, which cannot be removed by sterilizing and purifying ballast water with the aid of ozone gas. For example, the ballast water filter 13 comprises a filter having a plurality of plies of net or mesh net, or a wedge filter.

It is preferred that the ballast water filter 13 comprises an automatic backwash filter which is capable of removing various floating matters or foreign materials by using a filter material and of discharging them attached to the surface of the filter by reverse washing type. It is understood that the automatic backwash filter can function as an oil filter for a ship and can be widely used in mechanical industry.

In the automatic backwash filter, pluralities of piped-filters are disposed in a cylindrical tank in circumferential direction. Ballast water may be introduced towards individual filters in consecutive order and thereby resulting in the effective fulfillment of filtering by means of the filters. A circular disc having one drain aperture is installed on a bottom side of the cylindrical tank. If the circular disc rotates at a low speed, the drain aperture corresponds to the individual filters in consecutive order. As a result, floating matters or foreign materials attached to an inner wall of the filter may be released there from and then they may be removed by receiving an outside water pressure.

Hereinafter, the operation of the ozone injection systems according to the preferred embodiments of the present invention will be explained in more detail with reference to the accompanying drawings FIGS. 2 to 5.

At first, if a worker operates the supply pump 4 so as to supply the ballast water tank 3 with ballast water from the sea-chest 2, ballast water stored in the sea-chest 2 begins to be supplied to the ballast water tank 3 through the ballast water supply tube 1. At this time, ozone gas generated from the ozone generator 6 is introduced into the ozone-mixer 5 via the ozone supply tube 7 due to a strong absorption force applied to the inlet side of the supply pump 4. Thereafter, the ozone gas is introduced into the supply pump 4 together with ballast water.

Ballast water and ozone gas introduced into the supply pump 4 may be uniformly and very intensionally mixed together within the supply pump 4 due to a rotational force of an impeller typically installed at the supply pump 4. Since ballast water mixed with ozone gas within the supply pump 4 is supplied to the ballast water tank 3, ballast water stored in the ballast water tank 3 may be sterilized and purified by ozone gas.

By installing the ozone-mixer 5 at upstream position in front of the supply pump 4 and connecting the ozone supply tube 7 extending from the ozone generator 6 with the ozone-mixer 5, ozone gas generated can be introduced into the ozone-mixer 5 due to a strong absorption force applied to the inlet side of the supply pump 4. Thereafter, the ozone gas is introduced into the supply pump 4 together with ballast water. Ballast water and ozone gas introduced into the supply pump 4 may be forcibly and very passionately mixed together within the supply pump 4 due to a rotational force of an impeller typically installed at the supply pump 4.

The ozone injection system 10 according to the present invention is capable of introducing ozone gas and mixing it with ballast water by using only one supply pump installed at the ballast water supply tube 1. In comparison with the conventional ozone injection system 100 which employs two pumps and uses the mixing pipe 108 and the injection nozzle 109 as mixing means, in the ozone injection system 10 according to the present invention, it is possible to simplify the structure thereof to the maximum and can obtain sufficient ozone concentration in water by inducing the forceful and active mixing of ozone gas and ballast water.

Since ozone generated from the ozone generator 6 is directly mixed with ballast water flowing through the ballast water supply tube 1, it is possible to quickly and accurately control the ozone concentration of the ballast water by controlling only the quantity of ozone generated from the ozone generator 6 in accordance with various conditions such as the change in total flow rate and substantial flow rate of the ballast water, and levels of processing ballast water. Although the ballast water supply tube 1 is divided into several branches, it can control all branches by using only one ozone generator 6.

Accordingly, it is possible to highly reduce the cost of installing and operating the ozone injection system 10. Furthermore, it is possible to effectively install the ozone injection system 10 in a narrow space such as an engine room in which there are a large number of pipe lines. Furthermore, it is possible to repair or replace the ozone injection system 10 so that this leads to provide a reasonable economic ozone injection system 100, which can be manufactured at a low cost and has an optimum application, excellent sterilizing and purifying capability.

Meanwhile, in the preferred second embodiment of the present invention which employs the return branched tube 11, if the ozone concentration of the ballast water supplied to ballast water tank 3 is less than the standard value, a worker can quickly control the ozone concentration at a desired level by re-circulating a part of ballast water into the ozone-mixer 5. Accordingly, the ozone injection system 10 according to the present invention can quickly handle the change of ozone concentration.

In the preferred third and fourth embodiments of the present invention which employs the ballast water filter 13, it can remove various floating matters or foreign materials existing in ballast water, which cannot be removed by performing only the ozone's processing. Consequently, scales produced on inner walls of the ballast water tank and pipes may be minimized, this has resulted in low cost of cleaning and repairing the ballast water tank and pipes. Since the ballast water filter 13 can function as an additional mixer for mixing ballast water with ozone gas, it is possible to further increase ozone concentration.

It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the above description or illustrated in the drawings. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof.

Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

The present invention relates to a device for injecting ozone into ballast water for a ship so as to sterilize and purify ballast water, and so the present invention has industrial applicability.

Claims

An ozone injection system(10) for sterilizing and purifying ballast water by injecting ozone gas into ballast water which is supplied from a sea-chest(2) in a ship to a ballast water tank(3) due to the operation of a supply pump(4) installed at a ballast water supply tube(1), the ozone injection system(10) being installed at the ballast water supply tube(1) extending between the sea-chest(2) provided in a lower part of the ship and the ballast water tank(3), the ozone injection system(10) comprising;

an ozone-mixer(5) being installed at the ballast water supply tube(1) in a position upstream in front of supply pump(4), in which the ballast water supply tube(1) extends between the sea-chest(2) and the ballast water tank(3); and

an ozone generator(6) being connected to the ozone-mixer(5) via an ozone supply tube(7).
The ozone injection system as claimed in 1, wherein a return branched tube(11) extends from the ballast water supply tube(1) in a position downstream from the supply pump(4), in which the return branched tube(11) is connected to the ozone supply tube(7), and a shut-off valve(12) is installed at the return branched tube(11).
The ozone injection system as claimed in claims 1 or 2, wherein a ballast water filter(13) is installed at the ballast water supply tube(1) in a position downstream from the supply pump(4) or the return branched tube(11).
The ozone injection system as claimed in claim 3, wherein the ballast water filter(13) comprises an automatic backwash filter.