JP2794537B2 - Method and apparatus for heat treatment of ballast tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment method for killing pests such as harmful plankton and cholera living in a ballast tank of a ship, and an apparatus therefor.
In particular, the present invention relates to a method and apparatus for heat treatment of a ballast tank that can be effectively treated with a small amount of heat.

[0002]

2. Description of the Related Art In recent years, the occurrence of shellfish poisoning in Tasmanian waters in Australia has caused ballast water and sediment (sedimentation) containing harmful plankton such as dinoflagellate (dinoflagellates) in Australia, New Zealand or Chile. There is a movement to regulate the emission of chemicals in domestic waters.

Among the harmful planktons of this type, hatched ones die within a relatively short time (about three days) in a ballast tank without light, but exist as dormant cysts or spores in sediments. Those that survive without light. And when it is discharged into the sea with ballast water, it settles on the sea floor until it is in a good condition for hatching, and eventually the spores float freely in the water and become bait for the shellfish, which accumulate inside the shell. Will be.

[0004] By the way, spores form poison in shellfish, and when eaten, spores cause paralysis of poisonous shellfish, and in some cases, kill humans. For this reason, harmful plankton needs to be killed in the ballast tank. In addition, it is necessary to prevent cholera bacteria and the like from being killed in the ballast tank to prevent the spread of infectious disease contaminated areas.

Conventional methods for killing this kind of pests, especially harmful plankton, include, for example, the publication of a paper by the Faculty of Agriculture of Kagawa University (the Spring Meeting of the Japan Society of Fisheries Science, held on April 1-5, 1994). No. 318 of "Abstracts"
Page), an ultraviolet treatment method for irradiating the ballast water with ultraviolet light, a heat treatment method for heating the ballast water to a predetermined temperature, an electric treatment method for applying a predetermined voltage to the ballast water, or A chemical treatment method for introducing a chemical such as sodium chlorite or salad powder has been proposed.

[0006] Since all of the above-mentioned conventional methods for killing harmful plankton target the entire amount of ballast water in the ballast tank, the installation cost and running cost of the apparatus are reduced in the case of other treatment methods except the chemical treatment method. The cost is enormous and impractical, and the chemical treatment method may kill useful plankton and the like by the chemicals in the ballast water when the ballast water is discharged. Therefore, as effective measures that can be taken at present, for example, it is said that there is no other method except for using a method of replacing the ballast water with clean tropical seawater in the middle latitudes of the ocean.

[0007]

However, even if ballast water is refilled using clean seawater, the sediment in the ballast tank cannot be completely discharged when the ballast water is refilled. The problem is that dormant cysts or spores present in the sediment cannot be removed and are not always an effective treatment method.

The present invention has been made in view of the above situation, and has as its object to provide a ballast tank heat treatment method and apparatus capable of almost completely killing pests in a ballast tank at low cost. .

It is another object of the present invention to enable pests to be killed more completely in a shorter time.

Still another object of the present invention is to make it possible to effectively use hot water normally discarded outboard to reduce costs.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an empty or bottomed state in a ballast tank of a ship.
After a small amount of ballast water is left in the part, the temperature of the sediment remaining in the ballast tank is directly or indirectly increased, and the temperature is maintained for a predetermined time or more at the temperature at which pests such as harmful plankton and cholera bacteria are killed. It is characterized by doing so.

The present invention is also characterized in that a predetermined amount of hot water is injected into the bottom of the ballast tank as a method for raising the temperature of the precipitate.

[0013] The present invention also provides a method for raising the temperature of the sediment by using a heating element disposed at the bottom of the ballast tank.
The sediment at the bottom of the ballast tank is heated directly or indirectly via ballast water existing at the bottom of the ballast tank.

According to the present invention, as a method for raising the temperature of the precipitate, hot water, steam or hot air is discharged toward the inner wall surface of the ballast tank.

The present invention is also characterized in that the atmosphere in the ballast tank is heated by spraying hot water or steam, introducing hot air or using a heating element as a method for raising the temperature of the precipitate.

The present invention also provides a hot water generation source mounted on a ship, and an injection pipe for guiding hot water from the hot water generation source to the bottom of the ballast tank.
Empty or small amount of ballast water left at bottom
It is characterized in that a predetermined amount is injected in a state where it is set.

The present invention is also characterized in that a fixed or movable injection nozzle disposed in a ballast tank and a supply pipe for supplying hot water to the injection nozzle are provided.

The present invention is further characterized in that a heating means for heating hot water is provided in the supply pipe.

The present invention is further characterized in that a water-cooled engine cooler is used as a hot water generating source.

[0020]

According to the present invention, the precipitate remaining in the ballast tank is directly or indirectly heated, but is maintained for a predetermined time than killing the pests temperature, the process, empty the ballast tanks of a ship Condition or small roses at the bottom
This is performed with the strike water remaining . For this reason,
Pests in the sediment in the ballast tank can be killed with a small amount of heat.

In the present invention, as a method for raising the temperature of the precipitate, a predetermined amount of hot water is injected into the bottom of the ballast tank. By the way, since almost all of the sediment exists at the bottom of the ballast tank, it is possible to almost completely kill the pests in the ballast tank by a simple method and in a short time.

In the present invention, as a method of raising the temperature of the sediment, the sediment at the bottom of the ballast tank is directly discharged by the heating element disposed at the bottom of the ballast tank or the ballast water existing at the bottom of the ballast tank is removed. Heated indirectly via For this reason, even if a large amount of sediment exists, it is possible to surely kill the pest.

In the present invention, as a method for raising the temperature of the precipitate, hot water, steam or hot air is discharged toward the inner wall surface of the ballast tank. For this reason, not only the bottom of the ballast tank but also pests in the sediment present on the top surface and side surfaces can be killed, resulting in more reliable heat treatment.

In the present invention, the atmosphere in the ballast tank is heated as a method for raising the temperature of the precipitate. For this reason, sufficient heat treatment is possible even for the sediment that has entered the uneven portion in the ballast tank.

In the present invention, the hot water from the hot water generating source may be filled with a small amount of ballast water in an empty state or at the bottom.
Is injected through the injection pipe into the bottom portion of the ballast tank in a state in which the residual amount remains . For this reason, the pests in the ballast tank can be almost completely killed with a small amount of hot water.

In the present invention, hot water is sprayed from a spray nozzle disposed in the ballast tank. For this reason, the inner wall surface other than the bottom of the ballast tank is also heated directly by the warm water or indirectly through the atmosphere, so that the pests can be more completely killed.

In the present invention, the hot water flowing through the supply pipe is heated by the heating means. For this reason, it is possible to compensate for a decrease in the temperature of the hot water due to the injection.

Further, in the present invention, engine cooling water is used as hot water. Since the heated engine cooling water is usually discarded outside the ship, it is not necessary to newly install a boiler or the like by using this. Further, since the engine cooling water has a water temperature of 46 to 50 ° C., harmful plankton can be used as hot water for heat treatment without requiring an auxiliary heater or the like.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a ballast tank heat treatment apparatus according to a first embodiment of the present invention.
And a marine vessel having a main engine 3. The ballast tank 2 is configured to inject and drain ballast water 6 through a ballast pump 4 and a ballast line 5.

On the other hand, the main engine 3 is cooled by an engine cooling system 7 as shown in FIG. 1, and the engine cooling system 7 circulates a primary coolant through a heat exchanger 8. It is composed of a primary circuit 9 and a secondary circuit 11 for introducing seawater from the outside of the ship to the heat exchanger 8 via a pump 10 and discharging the seawater heated by heat exchange to the outside of the ship.

The above-described structure is a structure widely used in a conventional ship, and in this embodiment, the following structure is added to the above structure.

That is, the heat exchanger 8 of the secondary circuit 11
As shown in FIG. 1, a hot water injection pipe 12 having an on-off valve 13 is connected between the outlet side position and the ballast line 5, and the temperature is increased by heat exchange in the heat exchanger 8. Seawater as secondary cooling water (hereinafter referred to as hot water)
Through the hot water injection pipe 12 and the ballast line 5, the empty
Condition or condition where only a small amount of ballast water 6 remains at the bottom
At the bottom of the ballast tank 2, the water is injected at a water depth of 40 to 200 cm. And this gives
The sediment at the bottom of the ballast tank 2 is heated and maintained at a temperature equal to or higher than the harmful plankton death temperature for a predetermined time.

Next, the operation of the present embodiment will be described.
When the ship 1 such as an ore carrier departs from the loading place to the unloading place, the ballast water 6 is not usually filled into the ballast tank 2 depending on the weight of the cargo.

On the other hand, in the case of unloading at the port at the port of unloading, the draft becomes gradually shallower according to the amount of unloading, and the ship 1 may collide with port facilities such as unloaders. The ballast water 6 flows into the ballast tank 2.
At this time, some ports have a deep water depth and some have a shallow water depth. Therefore, in the case of a shallow port, it is likely that sediment will be taken together with the ballast water 6. The ballast water 6 is discharged outside the ship when loading cargo at the loading point, and at this time, a part of the sediment also flows out together with the ballast water 6, which poses a serious problem.

Therefore, in this embodiment, when the ballast tank 2 is heat-treated by the following method and the ballast water 6 is discharged at the loading point, even if the sediment is discharged together with the ballast water 6, it is harmful. Plankton damage is not to occur.

That is, for example, in order to transport iron ore and the like from Australia to Japan, a ballast voyage from Japan to Australia (the ballast water 6 is loaded into the ballast tank 2 and sailed in an empty state). In such a case, when the ship 1 approaches the middle latitude of the ocean (tropical waters of the open sea), the ballast water 6 in the ballast tank 2 is discharged, and the ballast tank 2 is empty or a small amount of ballast is provided at the bottom. Water 6 remains
Just state .

Thereafter, the normally closed on-off valve 13 is opened. Then, hot water from the heat exchanger 8 of the engine cooling system 7 is injected into the ballast tank 2 through the hot water injection pipe 12 and the ballast line 5. When the depth of the injected hot water reaches about 40 to 200 cm, the injection of the hot water is stopped, and the hot water is maintained for about 3 to 5 minutes.

Incidentally, the temperature of the hot water discharged from the heat exchanger 8 is about 46 to 50 ° C., and even if the temperature drops in the middle,
It has been confirmed by the present inventors that a temperature of 5 ° C. or more is ensured. Generally, harmful plankton is 45 ° C
It has been confirmed by various experiments that the above-mentioned temperature can be completely killed by maintaining the above temperature for 3 minutes. Therefore, the harmful plankton in the sediment can be completely killed only by injecting the hot water from the heat exchanger 8 into the ballast tank 2 without heating it with an auxiliary heater or the like. It should be noted that even with warm water of less than 45 ° C., some, but not complete, killing effect of harmful plankton can be expected.

After the harmful plankton has been killed in this manner, clean seawater from the tropical waters of the open ocean is poured over the warm water as ballast water 6. When there are a plurality of ballast tanks 2 to be subjected to the heat treatment, the above operations are sequentially performed.

However, the harmful plankton can be killed by merely introducing the engine cooling water, which has conventionally been discarded outside the ship, to the ballast tank 2 by additionally providing the hot water injection pipe 12, so that equipment costs and running costs are reduced. Can be kept extremely low. In the heat treatment, the ballast tank 2 is empty or a small amount of ballast water 6 is placed at the bottom.
Since the process is carried out only in the remaining state , a large effect can be obtained with a small amount of hot water.

By the way, almost all of the sediment exists at the bottom of the ballast tank 2, so that harmful plankton in the ballast tank 2 can be almost completely killed only by injecting hot water into the bottom of the ballast tank 2. However, since the inner surface of the ballast tank 2 is not a flat surface, there may be some sediment on the top surface and the peripheral side of the ballast tank 2, and even in this small amount of sediment, harmful plankton is contained. May be inhabited. Therefore, in order to more completely kill harmful plankton, it is preferable to heat-treat these precipitates.

FIG. 2 shows a second embodiment of the present invention which is made in consideration of the above points. Hot water is sprayed toward the inner wall surface of the ballast tank 2, It is intended to be sprayed in the air.

That is, the hot water from the main engine 3 is injected into the ballast tank 2 through the ballast line 5 as shown in FIG. 2
And is sprayed from the spray nozzle 23 toward the inner wall surface of the ballast tank 2 or scattered in the air in the ballast tank 2.

As shown in FIG. 2, a heater 25 which uses exhaust gas of the main engine 3 discharged from the chimney 24 as a heat source is installed at a position on the outlet side of the pump 22 of the supply pipe 21. The hot water sent to the injection nozzle 23 is further heated by the heater 25.

The injection of hot water by the injection nozzle 23 is as follows.
As shown in FIG. 2, hot water may be injected into the ballast tank 2 at the bottom, or only hot water injection may be performed alone. In other respects, the configuration is the same as that of the first embodiment, and the operation is the same.

However, since the hot water is sprayed from the spray nozzle 23 toward the inner wall surface of the ballast tank 2, there is a case where sediment exists on the top surface or the peripheral side surface of the ballast tank 2. However, the temperature of the sediment rises due to the hot water poured down, and harmful plankton can be killed. In addition, since the hot water from the injection nozzle 23 is sprayed into the air in the ballast tank 2, the temperature of the atmosphere in the ballast tank 2 rises to 45 ° C. or more, and the sediment in places where the hot water cannot be directly poured down Again, heat treatment can be applied.

The temperature of the hot water discharged from the injection nozzle 23 is slightly lowered at the time of discharge. However, since the water is heated by the heater 25, the temperature does not drop below 45.degree. When sprayed in the air in tank 2,
The temperature of the atmosphere can be raised to 45 ° C. or higher in a shorter time.

FIG. 3 shows a third embodiment of the present invention. Instead of the injection nozzle 23 in the second embodiment, a fixed spray type injection nozzle 33 and a movable spray type injection nozzle 34 are used. It was done.

That is, as shown in FIGS. 3 and 4, the fixed spray type injection nozzle 33 is provided with a large number of nozzle portions 33b provided on the peripheral surface of a long pipe 33a. Is horizontally fixed, for example, directly below the top surface of the ballast tank 2 so that hot water can be sprayed in the air.

As shown in FIGS. 3 and 5, the movable spray type injection nozzle 34 is
A plurality of nozzle portions 34b are provided on the peripheral surface of the injection nozzle 34, a flexible hose 35 for supplying hot water is connected to the base end of the injection nozzle 34, and Has, for example, two moving ropes 36 connected thereto. Then, by operating each of the moving ropes 36 outside the ballast tank 2 by an operator 37, the spray nozzle 34 can be moved to an arbitrary position, and hot water can be sprayed or sprayed to a required location. In other respects, the configuration is the same as that of the second embodiment, and the operation is the same.

However, since the fixed spray type spray nozzle 33 is provided, it is possible to spray hot water over a wide range, which is particularly effective when raising the temperature of the atmosphere. In addition, since the movable spray type spray nozzle 34 is provided, hot water can be sprayed to a required location, and in particular, a portion where a sediment is likely to exist, such as a portion where the beam on the top surface of the ballast tank 2 is arranged. However, this is effective when hot water is intensively sprayed.

In each of the above embodiments, the case where the hot water from the main engine 3 is used for the heat treatment of the ballast tank 2 has been described. However, the hot water generated by a boiler or the like may be used. Further, since the boiler is permanently installed in the ship 1 and the steam can be always used, the steam is supplied to each of the injection nozzles 23, 33, 3.
4 may be injected. In addition, the steam is led to the ballast line 5 and the sediment at the bottom of the ballast tank 2 is directly heated by the steam, or a small amount of ballast water 6 having a water depth of about 50 cm is left at the bottom of the ballast tank 2. The ballast water 6 may be heated by injecting steam into the ballast water 6.

Further, hot air or the like may be used in place of steam, and a heating element such as a heating pipe or an electric heater through which a high-temperature fluid such as hot water, steam or hot air flows may be used.
It may be installed at the bottom of the ballast tank 2 or suspended in the ballast tank 2 and subjected to heat treatment using this heating element.

In each of the above embodiments, the heat treatment in the case where the ballast water 6 is filled in the ballast tank 2 has been described. However, during the loading voyage, the ballast tank 2 is completely empty. Heat treatment may be performed in this state. In this case, since there is no need to discharge the ballast water 6 before the heat treatment or to fill the ballast water 6 after the heat treatment, there is no great limitation on the sea area where the heat treatment can be performed, and a plurality of ballast tanks 2 can be heat-treated at the same time. This is effective when heat treatment is performed more completely.

In each of the above embodiments, the heat treatment for harmful plankton was described. For example, for cholera bacteria, see the document “Latest Food Hygiene”, published by Tsuseisei, pages 132 and 133. As shown, it has been found that heat treatment at 55 to 56 ° C. for 30 minutes causes death, and heat treatment at 60 ° C. for 30 minutes is extremely effective. Therefore, the present invention can be applied to pests such as cholera bacteria. However, when using the hot water from the main engine 3, as described above,
Since only a water temperature of about 50 ° C. can be obtained, it is necessary to heat the hot water to 60 ° C. or higher using, for example, the heater 25 shown in FIG.

In each of the above embodiments, a dedicated ship or a tanker of ore or coal or the like in which the ballast tank 2 is completely empty during the full voyage of cargo is described as an example. In this case, the ballast tank 2 is constantly filled with the ballast water 6 for trim adjustment and the like even during the full voyage of cargo. The present invention can be similarly applied to this type of ship, and the same effects can be obtained.

[0057]

As described above, according to the present invention, the ballast tank of a ship is empty or a small amount of ballast is placed on the bottom.
After the water remains, the sediment remaining in the ballast tank is directly or indirectly heated to maintain the temperature above the temperature at which the pests die, so that the amount of heat in the ballast tank can be reduced with a small amount of heat. Pests in the sediment can be killed.

According to the present invention, as a method for raising the temperature of the sediment, a predetermined amount of hot water is injected into the bottom of the ballast tank. Can be almost completely killed.

The present invention also provides a method for raising the temperature of the precipitate by using a heating element disposed at the bottom of the ballast tank.
Since the sediment at the bottom of the ballast tank is heated directly or indirectly via ballast water at the bottom of the ballast tank, even if a large amount of sediment exists, pests can be reliably and efficiently removed. Can be killed.

According to the present invention, as a method of raising the temperature of the sediment, hot water, steam or hot air is discharged toward the inner wall surface of the ballast tank. And the pests in the sediment existing on the side surface can be killed, and a more reliable heat treatment effect can be obtained.

According to the present invention, as a method for raising the temperature of the precipitate, the atmosphere in the ballast tank is heated by spraying hot water or steam, introducing hot air or a heating element. Sufficient heat treatment can be applied to the sediment that has entered the part.

The present invention also provides hot water from a hot water source.
Empty interior or small amount of ballast water left at bottom
Since a predetermined amount is injected into the bottom of the ballast tank through the injection pipe, the pests in the ballast tank can be almost completely killed by a small amount of hot water.

According to the present invention, since the injection nozzle is arranged in the ballast tank and hot water is supplied to the injection nozzle through the supply pipe, the inner wall surface other than the bottom of the ballast tank is also injected. It can be heated directly by hot water from the nozzle or indirectly through the atmosphere, and can kill the pest more completely.

In the present invention, since the heating means for heating the hot water is provided in the supply pipe, even if the temperature of the hot water is reduced by the injection from the injection nozzle, the temperature is maintained at or above the pest killing temperature. In addition, the heating time can be further reduced when heating the atmosphere.

Further, in the present invention, a water-cooled engine cooler is used as a hot water generating source, so that engine cooling water normally discarded outside a ship can be effectively used as hot water, and a boiler or the like can be used. There is no need to newly establish
Further, the engine cooling water has a water temperature of about 46 to 50 ° C. and has a temperature sufficient to kill harmful plankton. Therefore, an auxiliary heater is not required for harmful plankton. It can be used as it is as hot water for heat treatment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a heat treatment apparatus for a ballast tank according to a first embodiment of the present invention.

FIG. 2 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 3 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 4 is a detailed view of an injection nozzle of a fixed spray type.

FIG. 5 is a detailed view of a movable spray type spray nozzle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ship 2 Ballast tank 3 Main engine 4 Ballast pump 5 Ballast line 6 Ballast water 7 Engine cooling system 8 Heat exchanger 9 Primary circuit 10, 22 Pump 11 Secondary circuit 12 Hot water injection pipe 13 On-off valve 21 Supply pipe 23, 33, 34 injection nozzle 24 chimney 25 heater 35 flexible hose 36 moving cable 37 worker

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-175394 (JP, A) JP-A-62-149597 (JP, A) JP-A-58-37488 (JP, A) JP-A-5-37488 910 (JP, A) Japanese Utility Model Showa 50-104394 (JP, U) Japanese Utility Model Application Hei 3-8093 (JP, U) Japanese Patent Publication 50-18271 (JP, B1) Japanese Patent Publication 51-18712 (JP, B1) JP-B-45-16026 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) B63B 57/00 A01N 59/00 B63B 13/00

Claims (9)

(57) [Claims] Claims 1. An empty or empty vessel in a ballast tank of a ship.
After a small amount of ballast water remains at the bottom , the temperature of the sediment remaining in the ballast tank is directly or indirectly increased, and maintained for a predetermined time above the temperature at which pests such as harmful plankton and cholera bacteria are killed A ballast tank heat treatment method. 2. The method for heat treating a ballast tank according to claim 1, wherein a predetermined amount of hot water is injected into the bottom of the ballast tank as a method of raising the temperature of the precipitate. 3. A method for raising the temperature of the sediment, wherein the sediment at the bottom of the ballast tank is directly heated by a heater disposed at the bottom of the ballast tank, or indirectly via ballast water existing at the bottom of the ballast tank. The method according to claim 1, wherein the ballast tank is heated. 4. A method for raising the temperature of the precipitate, comprising:
4. The heat treatment method for a ballast tank according to claim 1, wherein steam or hot air is discharged toward an inner wall surface of the ballast tank. 5. The method of raising the temperature of the precipitate, wherein the atmosphere in the ballast tank is heated by spraying hot water or steam, introducing hot air or using a heating element. The ballast tank heat treatment method described. 6. A hot water generating source mounted on a ship, and a injection pipe for guiding hot water from the hot water source to the ballast tank bottom, hot water, also in the ballast tank is empty
Is a ballast tank heat treatment apparatus wherein a predetermined amount is injected with a small amount of ballast water remaining at the bottom . 7. A fixed or movable injection nozzle disposed in a ballast tank, and a supply pipe for supplying hot water to the injection nozzle.
A ballast tank heat treatment apparatus as described. 8. The heat treatment apparatus for a ballast tank according to claim 7, wherein the supply pipe has heating means for heating hot water. 9. The heat treatment apparatus for a ballast tank according to claim 6, wherein a water-cooled engine cooler is used as the hot water generation source.