JP2007105666A - Ballast water treating apparatus and water treating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ballast water treating apparatus which can treat a large quantity of ballast water, whatever quality the water may have, so that ballast water standards stipulated by IMO can be surely satisfied at a low cost and to provide a water treating apparatus which can make a large quantity of water containing harmful chemical materials, pollutants and sludge or the like harmless by decomposing organic materials in water. <P>SOLUTION: The ballast water treating apparatus is provided with a filtering unit 2 for filtering seawater to capture aquatic organisms, a fungicide supply unit 4 for supplying a fungicide to the filtered seawater to annihilate bacteria in the seawater and a Venturi tube unit 6 for introducing the seawater loaded with the fungicide and generating cavitation in the filtered seawater. The Venturi tube unit is constituted by disposing a plurality of Venturi tubes in parallel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ballast water treatment apparatus for efficiently killing harmful aquatic organisms and microorganisms contained in ballast water loaded in a ship's ballast tank, and harmful substances such as harmful chemical substances, pollutants and sludge in water. The present invention relates to a water treatment device for decomposing and detoxifying.

In general, a ship with an empty load or a small load carries water injection of ballast before leaving the port because of the necessity of ensuring the depth of submersion of the propeller and ensuring safe navigation during empty loading. Conversely, when loading in the port, the ballast water is discharged.
By the way, when ballast water is poured and drained by a ship that goes back and forth between loading and unloading ports in different environments, there is a concern that it may adversely affect the coastal ecosystem due to the difference in microorganisms contained in the ballast water. Has been.
Therefore, an international convention for the regulation and management of ship ballast water and sediment was adopted in February 2004 at an international conference on ship ballast water management, which required the treatment of ballast water.

The standard established by the International Maritime Organization (IMO) as a standard for the treatment of ballast water is that the number of organisms (mainly zooplankton) of 50 μm or more contained in the ballast water discharged from the ship is less than 10 in 1 m ³ , 10 μm or more The number of organisms less than 50 μm (mainly phytoplankton) is less than 10 in 1 ml, the number of Vibrio cholerae is less than 1 cfu in 100 ml, the number of E. coli is less than 250 cfu in 100 ml, and the number of enterococci is 100 cfu in 100 ml Is less than

As a conventional technique related to the treatment of ballast water, an apparatus for sterilizing ballast water by using high-temperature exhaust gas discharged from a main engine of a ship has been proposed (for example, see Patent Document 1).
In addition, methods for sterilizing harmful plankton or harmful algae cysts contained in ballast water using chlorine-based chemicals or hydrogen peroxide when discharging the ballast water have been proposed (for example, Patent Document 2 and Patent Document 3). reference).

On the other hand, cavitation as a water treatment device for decomposing and detoxifying harmful chemicals such as industrial effluents and domestic wastewater, toxic organic substances such as environmental hormones and dioxins, pollutants and sludge A venturi tube that generates water and an apparatus provided with an oxidizing solution injection means upstream thereof have been proposed, and it is also disclosed that there is an effect of killing microorganisms (see, for example, Patent Document 4).
JP 2003-181443 A JP-A-4-322788 JP-A-5-910 JP 2004-174325 A

However, the number of organisms contained in the seawater loaded as ballast water varies greatly depending on the date and place where the seawater is collected and varies from several to several hundred million in 1 ml of seawater. It is difficult to reliably achieve all the items of the standards established by the International Maritime Organization (IMO) with the equipment of No. 4.
In addition, the methods described in Patent Documents 2 and 3 have a problem that they are not effective for relatively large zooplankton and resistant microorganisms, and the remaining drug is discharged together with ballast water, which adversely affects the environment. There is a problem that there is a possibility.
Further, in order to treat a large amount of ballast water using the apparatus described in Patent Document 4, it is necessary to increase the treatment capacity of the venturi pipe. For this purpose, for example, the venturi pipe is large in size while maintaining geometric similarity. Can be considered. However, in this case, there is a possibility that the apparatus becomes large-scale and cost increases and the length becomes long and it becomes difficult to mount on a ship, and vibration noise accompanying cavitation may increase significantly. . In this regard, when processing a large amount of water containing a hazardous chemical substance, there is no problem of mounting on a ship, but there is a problem that the apparatus becomes large and costs increase.

  The present invention has been made in view of such a situation, and a ballast water treatment apparatus capable of treating a large amount of ballast water so as to satisfy the ballast water standard established by IMO reliably and inexpensively regardless of the water quality, and harmful An object of the present invention is to provide a water treatment apparatus capable of detoxifying a large amount of water containing harmful substances such as chemical substances, pollutants and sludge by decomposing the harmful substances in water.

  In view of the above problems, the present inventors can easily apply to existing ships when removing and killing aquatic organisms, harmful microorganisms and bacteria contained in ship ballast water, and have resistance to chemical treatment. As a result of diligent research to provide a large amount of ballast water treatment apparatus for efficiently sterilizing microorganisms, the present invention has been completed. Specifically, the present invention has the following configuration.

(1) A ballast water treatment device according to the present invention includes a filtration device that filters seawater to capture aquatic organisms, a chemical supply device that supplies chemicals that kill bacteria in the seawater into the filtered seawater, And a venturi device that generates cavitation in the filtered water upon receiving the supply of filtered water supplied with a medicine, and the venturi device comprises a plurality of venturi tubes arranged in parallel. Is.

By providing such a configuration, marine aquatic organisms and bacteria in seawater can be killed or removed, and ship ballast water that does not contain pests can be supplied. The main function of each component is as follows, and the function of each component acts organically to enhance the killing effect of aquatic organisms in seawater.
Capturing and removing relatively large aquatic organisms such as zooplankton in seawater with a filtration device, killing bacteria with chemicals, and generating cavitation in the filtered water supplied with chemicals through the Venturi tube It damages or kills relatively small aquatic organisms such as plankton, and further rapidly disperses the drug in the filtered water by cavitation to promote the bactericidal action of bacteria by the drug. In this way, mixing of the drug into the seawater is promoted by the diffusive action of cavitation, so the amount of drug supply can be reduced compared to the case of just injecting the drug, and the impact on the environment can be reduced. It is possible to eliminate or reduce the supply of the neutralizing agent for detoxification.

Further, the structure in which a plurality of venturi pipes are arranged in parallel has the following effects.
1. Miniaturization of Venturi Pipe Device In the venturi pipe device according to the present invention, a plurality of venturi pipes are arranged in parallel. The dimension in the length direction does not become long unlike the case where the size is increased. That is, the length dimension of the venturi pipe device may be the same as that of the small-diameter venturi pipe, and there is no restriction in terms of space when mounted on a ship, and the venturi pipe apparatus can be appropriately arranged.

2. Optimization of the frequency of cavitation bubbles The cavitation bubbles generated in the venturi tube are generated at the throat where the flow velocity is the fastest and the static pressure is low, and grow downstream along the flow. As the pressure rises due to the decrease in flow velocity at the part, the bubble diameter increases and collapses rapidly.
The occurrence of cavitation bubbles is high in the vicinity of the wall surface of the venturi tube throat, and is relatively low in the vicinity of the tube center. This is because there is a pressure distribution in the direction from the wall surface of the tube toward the center, and the static pressure near the tube wall surface is lower than the static pressure at the tube center.
Therefore, the frequency of occurrence of cavitation bubbles changes according to the area of the Venturi tube wall surface. Therefore, if the Venturi tube is simply increased to keep the geometric similarity in order to increase the amount of treated water, the surface area of the Venturi tube wall surface itself increases, but the surface area of the Venturi tube wall surface per unit treated water volume decreases. The frequency of occurrence of cavitation bubbles per unit treated water volume decreases, and the cavitation treatment effect decreases.
In this respect, in the present invention, in order to increase the amount of treated water, instead of enlarging the venturi tube while maintaining geometric similarity, the problem is dealt with by increasing the number of venturi tubes. Therefore, cavitation bubbles per unit treated water amount While the generation frequency is the same as that of a small-diameter venturi tube, a large volume of water can be treated.

3. Control of scale effect on treatment effect When the treatment performance of harmful microorganisms and the decomposition performance of harmful substances by cavitation of small-diameter venturi pipes are known, the flow of treated water in which venturi pipes are installed to increase the treatment amount When the pipe diameter of the pipe to be used is increased and the size of the Venturi pipe is similarly increased in accordance with this pipe diameter, it is predicted that a scale effect will appear on the processing performance.
In this respect, in the present invention, since it is possible to cope with the increase in the number of small-diameter venturi pipes without changing the pipe diameter of the small-diameter venturi pipe, the above-described scale performance influence is suppressed as much as possible, and the processing performance is known. By utilizing the performance of the small-diameter Venturi tube as it is, the performance of the processing apparatus with a large flow rate can be surely exhibited.

(2) In the ballast water treatment device according to (1), the drug supply device has a drug injection port for injecting a drug into a cross section of a flow path for supplying filtered water to the venturi tube device, and the drug injection port Is provided in plural in each of the radial direction and the circumferential direction of the flow path cross section.

(3) Further, in the ballast water treatment apparatus according to (1) or (2), a pump is provided for feeding the filtrate water so that the flow rate of the filtrate water at the throat of the venturi pipe is 10 to 40 m / sec. It is characterized by that.

(4) Further, in the ballast water treatment apparatus according to the above (1) or (2), a pump for feeding filtered water is provided so that the pressure loss head of the venturi pipe is 5 to 40 m. Is.

(5) Further, in the venturi tube device according to any one of the above (1) to (4), a plurality of venturi-shaped openings are formed in the large-diameter cylindrical block by cutting, or a plurality of through circles A small-diameter venturi tube is inserted into a large-diameter cylindrical holder provided with a hole.

(6) Moreover, the water treatment apparatus according to the present invention receives a chemical supply device that supplies chemicals that detoxify harmful chemical substances, pollutants, and organic substances in water, and water supplied with the chemicals. And a venturi tube device for generating cavitation in the water, wherein the venturi tube device comprises a plurality of venturi tubes arranged in parallel.

  In the present invention, a filtration device that filters seawater to capture aquatic organisms, a drug supply device that supplies chemicals that kill bacteria in seawater into the filtered seawater, and filtered water supplied with the chemicals A venturi pipe device that receives supply to generate cavitation in the filtered water, and the venturi pipe device employs a configuration in which a plurality of venturi pipes are arranged in parallel, thereby achieving the conventional method. It is possible to achieve a process that reliably achieves the ballast water treatment standard set by IMO, which is difficult to achieve, and can control the movement of exotic organisms and infectious pathogens, and can efficiently treat a large amount of ballast water. .

  Further, in the water treatment apparatus according to the present invention, a chemical supply apparatus that supplies chemicals that detoxify harmful chemical substances, pollutants, and organic substances in water to the water; A venturi device that generates cavitation, and the venturi device employs a configuration in which a plurality of venturi tubes are arranged in parallel, so that mixing of the drug into water is promoted by the diffusion action of cavitation. Therefore, compared with the case of just injecting the medicine, the supply amount of the medicine can be reduced, the influence on the environment can be reduced, and the supply of the neutralizing agent for detoxifying the medicine can be eliminated or reduced. .

[Embodiment 1]
Hereinafter, an example of the best mode of the ballast water treatment apparatus according to the present invention will be specifically described with reference to the drawings.
FIG. 1 is a view showing a ballast water treatment apparatus according to the present embodiment. As shown in FIG. 1, the ballast water treatment apparatus according to the present embodiment is a seawater intake line 1 for taking seawater into a ship, and a coarse filtration apparatus that removes coarse substances in seawater taken by the seawater intake line 1. 2. Planktons present in the seawater from which coarse substances have been removed by the coarse filter unit 2 for taking in seawater, or for pumping the ballast water in the ballast tank 9 described later to the filter unit 4 described later. Filtration device 4, drug supply device 5 that supplies a chemical that kills bacteria to seawater filtered by the filtration device 4, and venturi that generates cavitation by supplying filtered water filtered by the filtration device 4 Pipe device 6, Neutralizing agent supply device 7 for supplying a neutralizing agent to seawater to which a chemical has been added, treated water feed for feeding treated water to which a neutralizing agent has been added to a ballast tank 9 to be described later IN 8, ballast tank 9 for storing treated water or untreated water sent from treated water feed line 8, ballast water supply line 10 for supplying ballast water in ballast tank 9 to filtration device 4 side, neutralizing agent A treated water drain line 11 for draining the added treated water to the sea is provided.
Hereinafter, each device will be described in more detail.

1. Coarse filter device Coarse filter device 2 receives water from a sea chest (seawater inlet) provided on the side of the ship and is taken by seawater intake line 1 by pump 3 and contains various small and large contaminants and aquatic organisms. Among them, coarse materials of about 10 mm or more are removed.
As the coarse filtration device, a cylindrical strainer (strainer) having a hole of about 10 mm, a hydrocyclone that separates coarse matters in a water flow by a difference in specific gravity, a device that captures and collects coarse matters by a rotating screen, and the like are used. be able to.

2. Filtration device The filtration device 4 removes planktons present in the seawater from which coarse substances have been removed by the coarse filtration device 2, and has a mesh size of 10 to 200 μm.
The reason why the mesh opening is 10 to 200 μm is to reduce the frequency of backwashing and shorten the ballast water treatment time in the port of call while keeping the capture rate of zooplankton and phytoplankton at a certain level. In other words, if the mesh size is larger than 200 μm, the capture rate of zooplankton and phytoplankton is remarkably reduced. If the mesh size is smaller than 10 μm, the frequency of backwashing increases and the ballast water treatment time at the port of call becomes longer. Therefore, it is not preferable. In particular, it is preferable to use one having an opening of about 50 μm because the capture rate and the backwashing frequency can be set optimally.
Moreover, the filtration device 4 is preferably 1 day 200 meters ³ or more filtration rate per filtration area 1 m ² is obtained. However, there is no particular limitation when the size can be further reduced by integrating the filtration modules.

As a specific example of the filtration device 4, it is preferable to use a notch wire filter or a wedge wire filter.
A notch wire filter is a tubular element in which a wire provided with a notch (projection) is wound around a frame and the distance between the wires is maintained by the notch so that the size of the filtration passage is 10 to 200 μm. , Provided with valves and piping for water supply and backwashing. A specific example of this notch wire filter is a notch wire filter manufactured by Kanagawa Kikai Kogyo.
A wedge wire filter is a tubular element in which a wire with a triangular cross section is wound around a frame and the distance between the wires is adjusted so that the size of the filtration passage is 10 to 200 μm. A valve and piping are provided. As a specific example of this wedge wire filter, there is a wedge wire filter manufactured by Toyo Screen Industry.

Another preferred specific example of the filtration device 4 is a laminated disk type filter. A laminated disk type filter is a ring-shaped disk formed by pressing doughnut-shaped disks having a plurality of oblique grooves formed on both sides in an axial direction to form a ring, and a gap formed by grooves of adjacent disks. The aquatic organisms are filtered through the water. By appropriately setting the size of the oblique grooves, the openings are set to 10 to 200 μm and filtered.
In the laminated disk type filter, the disk pressure is released during backwashing to increase the gap and remove the filtration residue.
A specific example of this laminated disk type filter is Spin Klin Filter Systems manufactured by Arkal Filtration Systems.

  In addition to the two types of filtration devices described above, other various filtration devices such as a sealed sand filter, a filter cloth filter, and a metal fiber filter can be used as the filtration device 4.

3. Drug supply device The drug supply device 5 is arranged on the upstream side of the venturi tube device 6 and supplies a drug for killing bacteria to seawater filtered by the filtration device.
FIG. 2 shows the drug injection unit 13 in the drug supply device 5 and the Venturi tube device 6 provided on the downstream side of the drug injection unit 13. 3 is an enlarged view of the drug injection part 13 shown in FIG. 2, and FIG. 4 is a view showing the drug injection part 13 as seen from the upstream pump side. Hereinafter, based on FIGS. 2-4, the chemical | medical agent supply apparatus 5 and the special chemical | medical agent injection | pouring part 13 are demonstrated in detail.

The drug injection unit 13 includes a plurality of doughnut-shaped block bodies 17 each having an opening 15 whose center is a water channel, and a plurality of drug injection tubes 19 that are fixed to the block body 17 at one end and extend to the opening 15 at the other end. I have.
The drug injection tube 19 is supported by a support portion 20 made of a plate-like member extending in the opening 15 in the radial direction. Six support portions 20 are provided in the opening 15 at intervals of 60 ° in the circumferential direction. Each support portion 20 supports two to three drug injection tubes 19, and two to three drug injection tubes 19 supported by one support portion 20 have an opening at the tip of the opening 15 side. A predetermined distance is arranged from the center of 15 toward the outside in the radial direction. Further, the end portion on the opening 15 side of the drug injection tube 19 is bent toward the upstream side, and the tip is opened so as to face the flow, and this opening serves as a drug injection port. Yes.

As described above, a plurality of drug injection tubes 19 are supported by each support portion 20 and supported by one support portion 20 on the support portions 20 provided with a plurality of drug injection tubes 19 in the circumferential direction of the opening 15. Since the injection ports of the plurality of drug injection tubes 19 are arranged at predetermined intervals in the radial direction, a plurality of drug injection ports of the drug supply tube are provided in each of the radial direction and the circumferential direction of the flow path cross section. It has become.
As shown in FIG. 3, the end of the drug injection tube 19 fixed to the block body 17 is disposed so as to open to the outer peripheral surface of the block body 17, and a drug is supplied from a drug supply unit (not shown) to this part. Supplied.

  As the medicine supplied from the medicine injection tube 19, chlorine, chlorine dioxide, sodium hypochlorite, hydrogen peroxide, ozone, peracetic acid or a mixture of two or more of these can be used, but other medicines are used. It is also possible.

In the medicine supply device 5 configured as described above, since the medicine is supplied to the upstream side of the venturi tube device 6, the medicine is diffused to some extent in the tube before reaching the throat of the venturi tube where cavitation occurs. In addition, the diffusion and mixing of the drug can be promoted by cavitation, and the penetration of the drug into bacteria can be further promoted to promote the killing effect of the drug.
In addition, since the medicine supply port in the medicine injection pipe 19 is opened toward the upstream side, when the medicine is injected, it is discharged in a direction opposite to the seawater flowing through the flow path, and diffusion into the seawater is promoted. The

In the above example, the drug supply device 5 supplies the drug to the upstream side of the venturi tube device 6, but the drug is supplied to the throat of the venturi tube in addition to the upstream side of the venturi tube. Alternatively, it may be supplied only to the throat of the venturi tube.
When the medicine is supplied to the throat of the venturi tube, it is self-primed by the ejector action of the venturi tube, so that a supply pump becomes unnecessary.

4). Venturi tube device Venturi tube device 6 causes organisms that have passed through filtration device 4 to be damaged or killed by cavitation generated by the venturi tube and diffuses the drug supplied from drug supply device 5 into seawater. It is.
FIG. 5 is a cross-sectional view of the venturi tube device 6, and FIG. 6 is a view of the venturi tube device 6 as viewed from the upstream side.
As shown in FIGS. 5 and 6, the venturi pipe device 6 of the present embodiment is formed by arranging a plurality of venturi pipes 23 in parallel. Although the method of parallel arrangement is not particularly limited, in this example, as shown in FIGS. 5 and 6, one is arranged at the center of the flow path, and a plurality of Venturi pipes are arranged on each concentric circle on the two concentric circles around it. 23 is arranged. Hereinafter, the venturi tube 23 will be described.

The Venturi pipe 23 is composed of a constricted portion where the pipe cross-sectional area gradually decreases, a throat part which is the minimum cross-sectional area part, and a widened part (diffuser part) where the pipe cross-sectional area gradually increases. Cavitation bubbles are generated by a rapid decrease in static pressure accompanying a rapid increase in flow velocity at the throat, and cavitation bubbles that have grown due to a pressure increase due to a decrease in flow velocity at the spreading portion are collapsed. Aquatic organisms in seawater are damaged or destroyed and killed by the action of OH radicals with impact pressure, shearing force, high temperature, strong oxidizing power due to the collapse of cavitation bubbles.
According to the cavitation of the Venturi tube 23, the outer shell of a protozoan or zooplankton having a relatively hard shell can be destroyed and killed.

  In the venturi pipe device 6 described above, a plurality of venturi-shaped openings are formed in the large-diameter cylindrical block 25 by cutting. For example, the large-diameter cylindrical block 25 is large by providing a plurality of through-holes. A diameter cylindrical holder may be used, and a small diameter venturi tube may be inserted into the large diameter cylindrical holder.

  In the venturi tube device 6 configured as described above, cavitation is generated by each venturi tube 23 to damage or kill relatively small aquatic organisms such as phytoplankton, and in the seawater by cavitation. The drug is rapidly diffused to promote the bactericidal action of the bacteria by the drug. In this way, mixing of the drug into the seawater is promoted by the diffusion action of cavitation, so that the supply amount of the drug can be reduced compared to the case of just injecting the drug, the influence on the environment can be reduced, and the drug is harmless. It is possible to eliminate or reduce the supply of the neutralizing agent for the conversion to the chemical.

In addition, when supplying seawater to the venturi pipe 23, it is preferable to feed the seawater so that the flow rate of seawater at the throat of the venturi pipe 23 is 10 to 40 m / sec.
The reason for this is that when a ballast water treatment device is installed in the middle of a pipe that takes seawater and passes it to the ballast tank, the flow rate of seawater in the pipe is usually 2 to 3 m / s at the venturi pipe entrance. If the flow velocity at the throat of the tube is less than 10 m / sec, the rate of increase in the flow velocity at the throat is not sufficient, and the rapid decrease in static pressure associated therewith is not sufficient, so cavitation does not occur even under atmospheric pressure, If the flow velocity at the throat of the venturi pipe is higher than 40 m / s, the cavitation phenomenon will occur excessively, the pressure loss associated with the passage of the venturi pipe will be excessive, and the energy consumed for water supply will be excessive, resulting in excessive pump power. This is because the cost is high.

Moreover, when supplying seawater to a venturi pipe, it is preferable to feed seawater so that the pressure loss head of the venturi pipe is 5 to 40 m.
The reason for this is that if the head loss is less than 5 m, cavitation cannot be generated, and if it is greater than 40 m, the large flow pump used as a ballast water pump provided in the ship cannot cope with the problem. is there.

Further, the opening ratio of the venturi tube device 6 (ratio of the sum total of the venturi tube throat cross-sectional area to the tube cross-sectional area at the venturi tube device inlet) is preferably 7.5 to 20%. The reason is as follows.
When a ballast water treatment device is installed in the middle of a pipe for taking seawater and passing it through a ballast tank, the flow rate of seawater in the pipe is usually about 2 to 3 m / s at the venturi pipe entrance. On the other hand, in order to generate cavitation having an appropriate strength at atmospheric pressure at the venturi tube outlet, the flow velocity at the throat of the venturi tube needs to be in the range of about 10 to 40 m / s. Thus, in order to make the flow rate at the venturi tube entrance about 2-3 m / s and the flow rate at the venturi tube throat about 10-40 m / s, the venturi tube device 6 has an opening ratio of 7. It is preferable to make it 5 to 20%.

The interval between the adjacent venturi pipes 23 is preferably 1.05 to 1.5 times the venturi pipe inlet diameter D. The reason is as follows.
If the axial interval between the adjacent venturi tubes 23 is too close, the tube wall thickness between the venturi tubes 23 becomes too thin, causing a problem in strength. If the distance is too far, the ratio of the total cross-sectional area of the venturi pipe to the upstream cross-sectional area of the venturi pipe device becomes too small (the cross-sectional area of the flow path is too narrow) and the pressure loss of the venturi pipe increases. However, this is because a large flow pump used as a ballast water pump provided in a ship cannot cope with the problem and causes a problem.

It is possible to use a jet nozzle to generate cavitation, but the pressure loss is high and clogging occurs, so the cost increases due to the increase in pump size and the frequency of backwashing. It is unsuitable for ballast water treatment that requires water.
On the other hand, since the cavitation can be generated with a small pressure loss by using the venturi pipe for generating cavitation, it is suitable for the ballast water treatment requiring a large amount of treatment.

5. Neutralizing agent supply device The neutralizing agent supply device 7 renders harmless by supplying a neutralizing agent to seawater to which a chemical has been added to neutralize the chemical remaining in the seawater.
As a neutralizing agent to be supplied, it is desirable to use sodium thiosulfate, sodium sulfite, or sodium bisulfite from the viewpoints of price and ease of handling, but it is not particularly limited.

The operation of the present embodiment configured as described above will be described.
By moving the pump 3, seawater is taken into the ship from the seawater intake line 1. At that time, the coarse filter 2 removes large and small contaminants and aquatic organisms of about 10 mm or more from seawater.
Seawater from which coarse substances have been removed is supplied to the filtration device 4, and zooplankton, phytoplankton, and the like having a size corresponding to the opening of the filtration device 4 are removed.
Aquatic organisms and the like captured by the coarse filtration device 2 and the filtration device 4 are washed away by backwashing the filters of the coarse filtration device 2 and the filtration device 4 and returned to the sea. Even if it is returned to the sea, it is the same sea area, so there is no adverse effect on the ecosystem. That is, in this example, since the treatment is performed when the ballast water is loaded, the backwash water of the coarse filtration device 2 and the filtration device 4 can be discharged as it is.

The seawater filtered by the filtration device 4 is supplied with a medicine from the medicine supply device 5, and the seawater supplied with the medicine is supplied to the venturi device 6.
In the venturi tube device 6, cavitation bubbles are generated and grown in seawater by the mechanism described above, and further, the grown cavitation bubbles rapidly collapse, thereby causing impact pressure, shear force, high temperature, oxidation on aquatic organisms in seawater. It acts as a powerful OH radical, damaging or destroying aquatic life. At this time, since the drug is supplied to the seawater before being introduced into the venturi tube device 6, the diffusion of the drug into the seawater is promoted by cavitation in the venturi tube device 6, thereby enhancing the killing effect of the bacteria.

  The neutralizing agent is added to the seawater supplied with the chemical by the neutralizing agent supply device 7, and then the seawater is stored in the ballast tank 9 through the treated water supply line 8. However, when seawater is stored in the ballast tank 9, it is preferable that the medicine supplied from the medicine supply device 5 remains. This is because even if harmful microorganisms remain in the ballast tank 9, these microorganisms can be killed by the effect of the remaining drug. The concentration at which the drug remains is appropriately determined according to the type and concentration of the drug, the material of the ballast tank 9 and the type of coating, and the supply amount of the neutralizing agent by the neutralizing agent supply device 7 is adjusted based on this determination. In some cases, the neutralizing agent is not supplied.

The above example is a case where processing is performed when seawater is loaded into the ballast tank 9. However, processing may be performed when discharging seawater from the ballast tank 9 without processing when loading seawater into the ballast tank 9. . In this case, untreated ballast water is supplied to the filtration device 4 through the ballast water supply line 10 and thereafter the same processing as described above is performed. However, in this case, since the ballast water to which the chemical is added on the upstream side of the venturi pipe device 6 is drained to the sea through the treated water drainage line 11, it is necessary to completely detoxify the chemical. Therefore, in this case, the amount of the neutralizing agent supplied by the neutralizing agent supply device 7 is different from the case where the treated water is supplied to the ballast tank 9, and the remaining chemical is neutralized and the ballast water is discharged. It is necessary to make it an amount that does not affect the environment of the port.
Further, the aquatic organisms in the ballast water may be killed both when the seawater is loaded into the ballast tank 9 and when the seawater is discharged from the ballast tank 9. In that case, the treatment at the time of discharging the ballast water may be light.

As described above, in the present embodiment, whether or not zooplankton and phytoplankton having a size of 10 to 200 μm or more are removed by the filtration device 4 and the aquatic organism that has passed through the filtration device 3 by the venturi tube device 6 is damaged. Alternatively, since the aquatic organisms and bacteria are killed by killing them and supplying chemicals, it is possible to reliably and inexpensively treat ballast water that meets the ballast water standards set by IMO regardless of the water quality.
Moreover, since the configuration of the apparatus is simple, it can be easily applied to existing ships, and microorganisms having resistance to chemical treatment and electrical treatment can be efficiently killed.

  In addition, although the example shown in FIG. 1 assumes that the detoxification process of ballast water is performed at the time of water intake and / or drainage, the process is performed at the time of water intake, drainage, or both. Whether to do this can be determined according to the amount of microorganisms inhabiting the water intake area and the operating conditions of the ship.

[Embodiment 2]
FIG. 7 is an explanatory diagram of a water treatment apparatus according to Embodiment 2 of the present invention. In FIG. 7, the same or corresponding parts as those in FIG. 1 showing the first embodiment are denoted by the same reference numerals.
The water treatment apparatus according to the present embodiment has a treated water storage tank 33 for storing treated water containing harmful chemical substances, and treated water in the treated water storage tank 33 to a venturi pipe device 6 described later. A pump 3 for feeding water, a drug supply device 5 for supplying a chemical that decomposes and detoxifies harmful chemical substances in the water to be treated that is provided downstream of the pump 3 and is fed by the pump 3, and a chemical supply And a venturi pipe device 6 that receives the supplied treated water and generates cavitation in the treated water.

  The drug supplied from the drug supply device 5 is preferably a drug with strong oxidizing power, and includes chlorine dioxide and the like. Further, the venturi pipe device 6 is formed by arranging a plurality of venturi pipes in parallel, as shown in the first embodiment.

In this Embodiment comprised as mentioned above, the to-be-processed water stored in the to-be-processed water storage tank 33 is sent by the pump 3 to the venturi pipe apparatus 6 side. And a chemical | medical agent is supplied to to-be-processed water by the chemical | medical agent supply apparatus 5 upstream of the venturi pipe apparatus 6. FIG. The supplied medicine diffuses in the pipe before reaching the throat of each venturi pipe of the venturi pipe device 6.
When the water to be treated in which the chemical is diffused flows into each venturi tube of the venturi tube device 6, the static pressure rapidly decreases with a rapid increase in the flow velocity at the throttle portion. And if the static pressure of this part falls below a saturated water vapor pressure, many fine cavitation bubble nuclei contained in to-be-processed water will be exposed to the low pressure of a throat part, and will grow rapidly. Furthermore, the cavitation bubble that has grown rapidly collapses due to a rapid pressure increase accompanying a decrease in the flow velocity at the spreading portion.

Among the harmful substances contained in the water to be treated, volatile substances that are volatile are taken into the bubbles through the gas-liquid interface between the bubbles and the water to be treated during the growth process of the cavitation bubbles, and are generated at the high temperature and high pressure generated when the cavitation bubbles collapse. And is decomposed by the action of OH radicals. In addition, a non-volatile substance is not taken into the bubble so much and is decomposed by being exposed to high temperature and high pressure generated at the time of cavitation bubble collapse at the gas-liquid interface. In addition, substances with large molecular weight, such as organic substances, are destroyed and decomposed by the action of OH radicals with strong turbulence due to the collapse of cavitation bubbles, impact pressure, cutting force, high temperature, and strong oxidative power. Or solubilized and detoxified.
In addition, harmful substances contained in the water to be treated are oxidized and decomposed and rendered harmless by the chemical having strong oxidizing power that has passed through the venturi tube device 6 and diffused into the water.

As described above, in the present embodiment, since the medicine is supplied from the medicine supply device 5 and supplied to the venturi tube device 6 in which a plurality of venturi tubes are arranged in parallel, the collapse action of cavitation bubbles and the OH radical Due to the above, etc., the detoxification treatment of the harmful substances of the water to be treated can be performed efficiently.
In addition, the diffusion of cavitation promotes mixing of the drug into water, reducing the amount of drug supplied compared to the case of just injecting the drug, reducing the impact on the environment, and making the drug harmless. The supply of the neutralizing agent for the purpose can be eliminated or reduced.

  In the description of the above embodiment, the drug supplied from the drug supply device 5 has been described by taking a drug having strong oxidizing power as an example. However, even if other drugs that render harmful substances harmless are used, There is no doubt that a similar effect can be expected.

It is explanatory drawing of the ballast water treatment apparatus which is one embodiment of this invention. It is explanatory drawing of the chemical | medical agent supply apparatus and venturi tube apparatus which concern on one embodiment of this invention. It is explanatory drawing of the principal part of the chemical | medical agent supply apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the principal part of the chemical | medical agent supply apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the venturi pipe apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the venturi pipe apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the water treatment apparatus which is other embodiment of this invention.

Explanation of symbols

  2 coarse filtration device, 3 pump, 4 filtration device, 5 drug supply device, 6 venturi tube device, 7 neutralizing agent supply device, 9 ballast tank.

Claims (6)

A filtration device that filters seawater to capture aquatic organisms, a drug supply device that supplies chemicals that kill bacteria in seawater into the filtered seawater, And a venturi pipe device for generating cavitation in the filtered water, wherein the venturi pipe device comprises a plurality of venturi pipes arranged in parallel. The drug supply device has a drug injection port for injecting a drug into a cross section of the flow path for supplying filtered water to the venturi tube device, and a plurality of the drug injection ports are provided in each of the radial direction and the circumferential direction of the flow path cross section The ballast water treatment apparatus according to claim 1, wherein the ballast water treatment apparatus is provided. The ballast water treatment apparatus according to claim 1 or 2, further comprising a pump for feeding the filtrate water so that a flow rate of the filtrate water in the throat of the venturi pipe is 10 to 40 m / sec. The ballast water treatment apparatus according to claim 1 or 2, further comprising a pump for feeding filtrate water so that a pressure loss head of the venturi pipe is 5 to 40 m. A venturi tube device is formed by cutting a plurality of venturi-shaped openings in a large-diameter cylindrical block, or by inserting a small-diameter venturi tube into a large-diameter cylindrical holder provided with a plurality of through-holes. The ballast water treatment apparatus according to any one of claims 1 to 4, wherein the ballast water treatment apparatus is characterized by the following. A chemical supply device that supplies a chemical that detoxifies harmful chemical substances, pollutants, and organic substances in water, and a venturi device that generates cavitation in the water upon receiving the supply of chemical-supplied water. The water treatment device is characterized in that the venturi device is formed by arranging a plurality of venturi tubes in parallel.

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