JPH0427120Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an electric screen generating device that generates an electric screen for blocking fish from entering a prohibited water area.

[Conventional technology]

In general, in hydropower facilities such as hydroelectric power plants, where water is dammed up by a dam and the dammed water is taken in through the water inlet, if fish enter the water inlet from the waterway near the water inlet, the water supply line becomes clogged and the hydraulic power equipment This could lead to abnormalities in various parts of the equipment, causing the equipment to stop functioning completely.Therefore, as a method to prevent fish from entering the water supply ports of such hydropower equipment, similar to conventional aquaculture cages, it is necessary to create a prohibited area. It is being considered to install nets in waterways near water supply ports to prevent fish from entering.

However, in this case, it is necessary to target fairly small fish, so a very fine mesh net is required, which requires maintenance and maintenance of the net.
The drawback is that inspection requires a great deal of cost and effort, and is very time-consuming.

Therefore, the applicant has proposed the following method.

That is, as shown in FIG. 2, a plurality of rod-shaped conductive electrodes 1 are arranged at approximately equal intervals and two electrode rows 2a and 2b are arranged in parallel in an underwater area where entry is prohibited, and an electric screen is formed. The generation power supply 3 causes the potentials of both electrode rows 2a and 2b to be different.
By applying a voltage to both electrode rows 2a and 2b, both electrode rows 2
An electric screen with a predetermined electric field strength is formed between a and 2b, and the electric screen is used to prevent fish from entering the prohibited area.

At this time, the distribution of electric field intensity in a cross section passing through electrode 1 of both electrode rows 2a, 2b and perpendicular to both electrode rows 2a, 2b is as shown in FIG.

However, the horizontal axis in Fig. 3 is the electrode 1 of one electrode row.
indicates the distance from the center line of electrode 1 of the other electrode row.
The distance to the center line is L.

[Problem that the invention attempts to solve]

However, in this case, as is clear from FIG. 3, the electric field strength near electrode 1 is much larger than that near the middle of both electrode rows 2a and 2b, and fish receive excessive electricity near electrode 1. There is a problem that the fish may become paralyzed or asphyxia or even die due to physical stimulation, and the fish may be unnecessarily damaged.

Therefore, the technical challenge of this invention is to prevent fish from coming close to conductive electrodes with high electric field strength, and to prevent paralysis or asphyxia in fish due to excessive electrical stimulation.

[Means for solving problems]

This invention was made with the above-mentioned points in mind, and includes a plurality of electrode rows each formed of a plurality of rod-shaped conductive electrodes arranged at approximately equal intervals in water and arranged in parallel to each other; In an electric screen generating device comprising a power source for generating an electric screen that applies a voltage to each of the electrode columns so that the potential of each electrode column is different, each of the conductive electrodes is surrounded by an insulating enclosure having water permeability. This is an electric screen generator.

[Effect]

Therefore, according to this invention, a voltage is applied to each electrode row by a power source for generating an electric screen, an electric screen with a predetermined electric field strength is formed between each electrode row, and the inside of the electric screen is drawn from outside the prohibited water area. Fish that invade the area receive electrical stimulation and take repellent behavior.

At this time, since each conductive electrode is surrounded by an enclosure, fish that have entered the electric screen will be
The enclosure prevents access to each conductive electrode with a high electric field strength, thereby protecting the fish from paralysis or asphyxia caused by excessive electrical stimulation.

[Example] Next, this invention will be explained in detail with reference to FIG. 1 showing one example.

In Fig. 1, the same symbols as in Fig. 2 indicate the same or corresponding parts, and the difference from Fig. 2 is that each conductive electrode 1 constituting both electrode rows 2a, 2b is This is a point surrounded by a surrounding body 4 made of a sexual net.

By the way, for example, when we investigated the electric shock reaction of a red sea bream with a body length of 10 cm, we found that when the electric field strength reached 0.05 V/cm, it became startled by a light electrical stimulation and began to take repellent behavior, but when the electric field strength doubled to 0.1 V/cm, , they become paralyzed, making it somewhat difficult to swim and unable to take sufficient repellent actions.

Therefore, when the voltage applied to both electrode rows 2a, 2b is set so that the electric field strength near the middle of both electrode rows 2a, 2b with a spacing L becomes the value Es at which fish begin to take repellent behavior, Columns 2a, 2b
In order for the electric field strength between the lines to be approximately twice the Es mentioned above at maximum, the effective width of the electric screen should be approximately
The amount should be 0.1L to 0.9L.

Therefore, by using a cylindrical net with a radius of 0.1L as the enclosure 4, fish that have entered between the electrode rows 2a and 2b will not be able to approach within 0.1L from the center line of the electrode 1. However, an electric screen with a maximum electric field strength of approximately 2Es prevents the animal from receiving excessive electrical stimulation, making it possible to take sufficient avoidance actions before paralysis or asphyxia occurs.

In the above embodiment, the case where there are two electrode rows has been described, but it goes without saying that the number of electrode rows may be three or more.

Furthermore, it goes without saying that the enclosure 4 is not limited to the above-mentioned net.

[Effect of idea]

As described above, according to the electric screen generator of this invention, since the rod-shaped conductive electrodes constituting each electrode row are surrounded by an enclosure, fish can be prevented from approaching the conductive electrodes with high electric field strength, and excessive electricity can be prevented. It is possible to protect fish by preventing paralysis and asphyxia of fish due to physical stimulation.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the electric screen generator of this invention, FIG. 2 is a plan view of a conventional example, and FIG. 3 is a diagram showing the electric field intensity distribution in FIG. 2. 1... Conductive electrode, 2a, 2b... Electrode row, 3...
...Power supply, 4...Envelope.

Claims (1)

[Scope of utility model registration request] A plurality of electrode rows are formed by disposing a plurality of rod-shaped conductive electrodes at approximately equal intervals in water and are arranged in parallel to each other, and a voltage is applied to each of the electrode rows so that the potential of each electrode row is different. What is claimed is: 1. An electric screen generating device comprising: a power source for generating an electric screen, the electric screen generating device having each of the conductive electrodes surrounded by an insulating enclosure having water permeability;