JPH01117734A - Treatment of water for transportation of living fish - Google Patents

Abstract

PURPOSE:To enable increase in the fish density, when living fishes are transported over a long distance, by blowing air or oxygen into marine or fresh water cooled at a specific temperature, mixing them, and separating bubbles therefrom. CONSTITUTION:In the figure, cleaned water is sent along the dotted line into cooler 1 where the water is cooled down at about 3-10 deg.C, the optimal temperature for fish living. Then, the water is pressurized with a pump 2, sent into the chamber 9 where air and/or oxygen are blown into the water. The mixture of the water and the gas are sent to a static mixer 10 to promote the mixing statically and increase the dissolved oxygen in the water. The water is sent into an air separator 12 where bubbles, even of relative small sizes, are separated off by their density difference, the bubbles separated are excluded through the air trap 13.

Description

[Detailed Description of the Invention] <Object of the Invention> Industrial Field of Application The present invention relates to a method for treating water for transporting live fish, and more specifically, the present invention relates to a method for treating water for transporting live fish, and more specifically, the present invention relates to a method for treating water for transporting live fish. To provide a method for treating water for transporting live fish that is suitable for transporting live fish, maximizes the density of the fish and shellfish to be transported at the time of consumption, and does not pose any problem even during considerable long-distance transport.

In addition, in the following, water includes anything suitable for the main window of seafood, including natural water such as rivers, natural seawater, tap water, artificial seawater, etc.

BACKGROUND OF THE INVENTION Recently, as a method of preserving seafood, in addition to the method of preserving seafood in a live state for a long period of time, a method of transporting seafood while keeping it alive has been attracting attention. The reason for this is that seafood can be preserved in a live state, and if it is in a live state, the taste and flavor of the seafood can be fully utilized, increasing its commercial value.

However, methods for transporting live fish, for example,
As described in Publication No. 227228, an air blowing device is installed in a storage container for seafood placed on a truck, etc., and the fish and shellfish are transported while blowing air etc. into water from this blowing device. It is.

With this method, it is said to be extremely difficult to transport general seafood in a live fish state at high density for a long period of time, with the exception of some seafood such as eel. Therefore, conventionally, live fish have been transported at a low density during transportation, but the low density increases the price of live fish and is extremely uneconomical.

Further, Japanese Patent Publication No. 54-30959 describes a method for preserving seafood in a live state for a long period of time with high efficiency. As shown in FIG. 2, this method connects a water adjustment tank 15 to a fixed water tank 1, cools the water with a cooling coil 16 in adjustment W415, and at the same time sends air through an air supply vibrator 17. At the same time, nitrogen compound removal 'lAl
118 removes nitrogen compounds, and the water-soluble organic matter removal device 19 achieves the removal of organic matter, keeping the water temperature in the aquarium tank 1 low, and at the same time keeping the nitrogen compound concentration, organic matter concentration, and carbonate concentration below a certain value, and the oxygen concentration constant. This is a method of keeping it above the value. This preservation method has the advantage that the metabolism of the fish and shellfish is kept considerably lower than the standard metabolism due to the low water temperature, and the activity of the fish and shellfish is suppressed, so that the fish and shellfish can be stored at high density.

However, since this preservation method is based on a fixed aquarium 1, it is more or less dependent on photography during transportation, which makes it extremely difficult to apply it directly to the transportation of live fish. To explain in more detail,
When transporting live fish, the seafood is subjected to more or less vibration. This vibration can be alleviated if there is a certain amount of flow in the aquarium, but it is impossible to simply lower the water temperature to reduce the activity of the fish and shellfish and to house them at a high density. In other words, drastically lowering the activity of fish and shellfish by lowering the water temperature extremely as in the above method actually increases the mortality rate of fish and shellfish.

Furthermore, for high-density housing, it is necessary to increase the oxygen moisture content to some extent, but even if only the amount of air supplied is increased alone, seafood cannot necessarily be housed at high density. That is, it is known that when air is supplied, lowering the water temperature increases the saturated oxygen concentration. However, as shown in FIG. 2, simply adding air through an air pipe and stirring blade at the same time as cooling does not sufficiently dissolve oxygen, making it impossible to maintain a high dissolved oxygen concentration in the water. In other words, when the air supply amount is increased, the diameter of the bubbles increases, the dissolved state of M element is insufficient, and the dissolved oxygen concentration cannot be increased. For this reason, F! If the dissolved state of oxygen is insufficient and air bubbles adhere to the gills of fish and shellfish in the water, the ability of the fish and shellfish to absorb oxygen will decrease.

Furthermore, due to the stress caused by vibrations during transportation, it becomes difficult to keep seafood in a live state for a certain period of time due to its reduced ability to absorb oxygen. Furthermore, even if the bubbles are small, if they exist in the water, fish and shellfish will swallow them, causing their internal organs to swell and often die.

From the point of view, as shown in Japanese Unexamined Patent Publication No. 59-227229@, a device has been proposed in which air is mixed with water sent to an aquarium, and air bubbles are removed from the water using a gas-liquid separator. Although this device has been shown to have the potential to be used during transportation, it was developed for fixed aquariums.
It is difficult to completely remove air bubbles, and the dissolved oxygen level in the water cannot be increased, making it unsuitable for transporting high-density live fish.

To summarize, as mentioned above, in the past, long-term storage methods and devices have been developed for fixed aquariums, but methods for transporting live seafood, etc.
No. 227228 and Japanese Unexamined Patent Application Publication No. 62-8383G are merely proposals. For this reason, a high-density live fish transport method suitable for transporting seafood over considerable distances, such as transporting seafood between fish farms or between fish farms and markets, has not yet been proposed.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned drawbacks. Specifically, the present invention aims to solve the above-mentioned drawbacks. When transporting live fish, it is extremely difficult to increase the density of the fish and shellfish to be transported using conventional methods, and furthermore, water and seawater treatment methods suitable for transporting live fish have not yet been researched or developed. The purpose is to solve problems.

<Structure of the Invention> Means for solving the problem and its operation, that is, the present invention provides for cooling turbid water or water to a temperature approximately 3 to 10 degrees Celsius lower than the optimal habitat temperature of seafood to be transported in a live state. Then, air and/or oxygen is blown into this cooled seawater or water, and then this air and/or
Alternatively, it is characterized by mixing oxygen and seawater or water, and then separating air and/or oxygen bubbles from the seawater or water to create seawater or water in which air and/or oxygen are sufficiently dissolved.

Therefore, the structure of these means and their operation will be explained in more detail as follows.

First, the inventors of the present invention have observed that the transportation conditions for live seafood between a farm or an INL farm and the market are considerably harsher than those for transportation between small stores. ,
When we searched for conditions suitable for this, we found that water that satisfies the following conditions is required.

(11) Oxygen molecules of air are sufficiently dissolved in the water, and the amount of dissolved oxygen is close to the saturation limit and sufficiently high; +21: Oxygen or air does not exist in the water as bubbles, especially those with relatively small diameters. (3) 3 to 10 degrees Celsius lower than the optimum habitat temperature for fish and shellfish;
Limiting the standard metabolism of seafood to a certain degree,
(4) In order to make transportation equipment smaller, lighter, and more compact, storage containers such as aquariums should be as small as possible, and fish and shellfish can be stored in such small aquariums. The goal was to be able to accommodate as much space as possible.

Further, the present invention was established based on research conducted on manufacturing conditions for obtaining water that satisfies these conditions.

Further, the present invention will be explained in detail with reference to FIG. 1 as follows.

In addition, FIG. 1 is a flow sheet of an example of a processing apparatus used when carrying out the method of the present invention, in which reference numeral 1 denotes a cooling section, 2
is a pump, 3 is a flow needle, 4 is an air source, 5 is a regulating valve, 6 is a flow needle, 1 is an oxygen source, 8 is a regulating valve, 9 is a blowing chamber, 10 is a static mixer, 11 is a sight glass, 12
1 is an air separator, 13 is an air trap, and 14 is a tank or other aquarium for storing live fish and shellfish.

First, in FIG. 1, the aquarium indicated by the reference numeral 14 is usually transported on a transport vehicle such as a truck or a freight car, and the seafood is placed in the water W414 in a live state, and the seafood is transported in this way. For example, they are transported by car between fish farms. During transportation, water treated by the method of the present invention as described later circulates in the aquarium 14, and healthy live fish can be maintained in the aquarium 14 without dying even if transported over a considerable distance. That is, the water discharged from the water W114 contains organic substances and other harmful substances, but these are removed and purified, and the purified water is introduced into the cooling unit 1 through the dotted line path. Cooling section 1 is a warm habitat for seafood! The cooled water is then pressurized by the pump 2 into the blowing chamber 9, where air and/or oxygen is blown into the blowing chamber 9. .

That is, it is known to lower the water temperature or increase the water pressure in order to increase the dissolved oxygen concentration.

For this reason, water is normally cooled using a cooling coil or the like at the same time as air or oxygen is blown into the water (as shown in Figure 2). However, in high-density transportation of seafood, the water is simply It is necessary to not only increase the amount of dissolved oxygen, but also to minimize the generation of bubbles and increase the amount of dissolved oxygen.

Therefore, in order to satisfy this condition, the inventor of the present invention lowered the water temperature in advance, rather than cooling the water at the same time when air etc. is blown into the blowing chamber 9, and furthermore, the inventor of the present invention lowered the water temperature in advance so that the state became steady. It has been found that when air is blown into the reactor, the dissolved acid Nil can be greatly increased. That is, as shown in FIG.
When this water reaches the blowing chamber 9 through the pipeline, it is stabilized at the cooling temperature and air and/or oxygen is blown into it.

Note that air and oxygen are supplied to the blowing chamber 9 from the air source 4 and the oxygen source 7 via the control valve 5.8. In addition, in cooling section 1, the optimum habitat temperature for fish and shellfish is 3 to 10
The reason for cooling to low humidity is that when the temperature is 3 degrees Celsius or higher, the temperature is suitable for the habitat of fish and shellfish, and the metabolism of fish and shellfish is rapid, making high-density transportation difficult. Also, 10
If the temperature is lower than 0.degree. C., the fish and shellfish will lose their activity considerably, and there is a risk that they will die due to photography during transportation, water flow in the aquarium 14, etc.

Next, after air and I' or oxygen are blown in as described above, water is sent in a mixed state with air, etc., to, for example, the static mixer 10 to statically promote mixing of air, etc., and dissolve the dissolved oxygen. Increase quantity.

In other words, in order to mix air, etc. into water and to disperse the air, etc. uniformly in water, it is generally necessary to perform stirring along with the mixing, and in this sense, it is not possible to use a conventional mixer or agitator. , mixing and stirring using conventional methods may be considered.

However, for high-density transportation of live fish, it is necessary to increase the amount of dissolved oxygen and to minimize air entrainment and bubble formation during mixing. In addition, since the mixer is mounted on a truck or the like, it is necessary to have a minimum weight, and in the case of constantly flowing circulating water, mixing can be performed without blocking the flow. From this point, blow chamber 9
A static mixer 1 with no driving force is installed in the pipeline between the air separator 120 and the air separator 120.
0 promotes mixing of air, etc. without stopping the flow of circulating water during this period. Further, the static mixer 10 has a buffer plate 10b provided in the radial direction at a distance from the inner wall surface of the cylindrical main body 10a, and a zigzag passage is formed between the buffer plate 10b and the inner wall surface of the main body. This promotes mixing of air and the like while the water passes through the zigzag passage, and furthermore, air and the like are not drawn in during this mixing, minimizing the generation of air bubbles.

Next, the mixed water is sent to the air separator 12,
Even relatively small bubbles are separated due to the difference in specific gravity,
The air bubbles after the separation are discharged through the air trap 13. That is, the air separator 12 is provided with a buffer plate 12a in the axial direction, and the buffer plate 12a has holes 12b.
is formed.

Therefore, the water after mixing collides with the buff 1 plate 12a and the air bubbles contained in the water are separated, while the water passes through the pores 12b and air etc. are completely dissolved in the water tank 14 continuously. Sent.

In addition, as described above, after cooling the water in advance, the cooling temperature is stabilized after a predetermined period of time, after which air, etc. is blown in, statically mixed, and air bubbles are removed from the water using an air separator. However, during this static mixing, the amount of dissolved oxygen can be increased by increasing the pressure of the water passing through the static mixer section to promote dissolution of air and the like. However, even in this case, it is not preferable to increase the pressure too much because the aquarium is transported on a C1 transport vehicle, unlike in aquaculture farms where the aquarium is fixed.

In other words, it is known that increasing the pressure increases the dissolved amount of air, etc. For example, for rainbow trout, the amount of dissolved oxygen can be increased from 8 to 10.511111 by pressurizing only about 0.3 kg 1'cl with circulating water at 11°C. In addition, 1.
When the pressure is increased to about 0klJ,'[7, it increases to about 11 ppm.

However, the present invention maintains fish and shellfish at a temperature lower than the optimum habitat temperature and houses them at high density.
If a pressure of about 100 liters is applied, the fish and shellfish will move violently, making them unsuitable for long-term transportation. Therefore, it is preferable to keep the pressure to about 2.0 kg or less than 'cl' at most.

<Effects of the Invention> As explained in detail above, the present invention cools purified water in advance to a temperature approximately 3 to 10'C lower than the optimal habitat temperature for fish and shellfish, and then cools the water after a predetermined period of time. The temperature is stabilized, then air and/or oxygen is blown into the water, statically mixed, and air bubbles are separated and removed using an air separator or the like to produce water for transporting live fish.

Therefore, since air and/or oxygen are blown into the water where the cooling has become steady, the generation of air bubbles is sufficiently suppressed and the amount of dissolved oxygen is increased.Furthermore, mixing is performed statically, and air bubbles are removed from the air separator. Since the water is removed by water, water with almost no air bubbles and sufficient amount of air and t' or oxygen dissolved therein can be obtained.

In addition, with this type of water, it is possible to store live fish and shellfish at a high density in the aquarium, and because the water temperature is kept below the suitable habitat temperature, the activity of the fish and shellfish is suppressed, and the fish and shellfish are kept at a high density. However, there is no problem at all, and it has the effect of facilitating recovery of activity after long-distance transport.

Furthermore, a static mixer can be used to mix air and/or oxygen, and an air separator can be used to separate air bubbles, making it possible to reduce the weight of the equipment.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram of an example of a device implementing the present invention, and FIG. 2 is a layout diagram of one example of a conventional example. Code 1...Cooling part 2...Pump 3...YL meter 4...Air source 5...Adjusting valve 6... ...Flow rate meter 1...Oxygen H8...Control valve 9...
...Blowing chamber 10 ...Static mixer 11 ...Sight glass 12 ...Air separator 13 ...Air trap 14 ...Water tank

Claims (1)

[Claims] 3~ from the optimum habitat temperature for seafood that should be transported in live fish state
After cooling the seawater or water to a temperature approximately 10°C lower, air and/or oxygen is blown into the cooled seawater or water, and then this air and/or oxygen is mixed with the seawater or water. A method for treating water for transporting live fish, which comprises: separating air and/or oxygen bubbles from seawater or water to produce seawater or water in which air and/or oxygen are sufficiently dissolved.