JPH0573369B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric screen generating device that generates an electric screen for blocking fish from swimming into a prohibited area in the water.

[Conventional technology]

In general, fish invade the water supply ports of hydropower facilities such as hydroelectric power plants that block water with dams and take in the dammed water from the water supply ports, or hydraulic facilities that supply seawater to large-scale aquariums for aquaculture. If this happens, the water supply line may become clogged, leading to malfunctions in various parts of the hydraulic equipment, which may cause the equipment to stop functioning. It has been proposed that a net be placed near the water supply inlet to prevent fish from entering the water supply inlet, which is a prohibited area.

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 blocking method.

That is, multiple electrode rows are arranged in parallel near the underwater no-entry zone, and a voltage is applied to each electrode row by an electric screen generation power source to form an electric screen with a predetermined electric field strength between each electrode row. The electric screen is intended to prevent fish from swimming in areas where entry is prohibited.

[Problem that the invention seeks to solve]

However, when fish are startled by something or when they are feeding, they sometimes swim at extremely high speeds, and if they rush into the electric screen while swimming at such high speed, they will not receive electrical stimulation from the electric screen. In order to eliminate this inconvenience, it is possible to increase the electric field strength of the electric screen, but do not make the electric field strength too strong. If the electric screen is exceeded, the fish that enter the electric screen will be put into a state of asphyxia or death due to the intense electrical stimulation, resulting in unnecessary damage to the fish.

Therefore, the technical object of the present invention is to make it possible to reliably block fish from swimming in a prohibited area without causing damage to the fish due to electrical stimulation.

[Means for solving problems]

This invention has been made with the above points in mind, and includes a plurality of electrode rows arranged in parallel in water, and a power source for generating an electric screen that applies voltage to each of the electrode rows. The electric screen generating device is characterized in that two adjacent electrode rows excluding both outer sides are made to have the same potential.

[Effect]

Therefore, according to the present invention, a voltage is applied to each electrode row by the electric screen generation power source so that two adjacent electrode rows except for the outer electrode rows have the same potential, and different fish Even if the electrical potential rushes between the electrode rows at high speed, it is possible to revive the electrode rows at the same potential to a normal state before the electrical stimulation between the electrode rows leads to asphyxia or a fatal state. This prevents damage to fish caused by fish, and reliably blocks fish from swimming in areas where they are prohibited from entering.

〔Example〕

Next, the present invention will be described in detail with reference to drawings showing embodiments thereof.

Example 1 First, FIGS. 1 to 3 showing Example 1 will be explained.

In FIG. 1, 1a, 1b, 1c, and 1d are examples of the first to fourth electrodes of the same length arranged in parallel near the underwater no-entry zone, and each of them is a plurality of rod-shaped conductive electrodes in the vertical direction. The electrodes 2 are arranged at equal intervals, and the lower ends of the conductive electrodes 2 in each of the electrode rows 1a to 1d are electrically connected by the connecting bodies 3, respectively.

4 is a power source for generating an electric screen, one end is connected to the first and fourth electrode rows 1a and 1d on both outer sides and grounded, and the other end is connected to the second and third electrode rows 1b and 1c; first and fourth electrode rows 1a,
1d is set as a ground potential, and a DC voltage is applied such that, for example, the potential of the second and third electrode arrays 1b and 1c becomes _Vp .

At this time, with the first electrode row 1a as a reference, the first
From the electrode row 1a to the second, third, and fourth electrode rows 1b, 1
If the distances to c and 1d are, for example, L, 2L, and 3L, the potential distribution in the vertical cross section perpendicular to each electrode row 1a to 1d will be as shown in FIG.
Since the second and third electrode rows 1b and 1c have the same potential, the electric field strength between the second and third electrode rows 1b and 1c becomes 0, and between the first and second electrode rows 1a and 1b and between the third and third electrode rows 1b and 1c. The electric field strengths between the fourth electrode rows 1c and 1d are E3 (=V _p /L) and E2 (=V _p /3L-2L=V _p /L=E1
) becomes.

For example, in the water supply passage portion of the above-mentioned hydraulic equipment, each electrode row 1a to
1d, the first and second electrode rows 1a,
1b, the fish immediately takes repellent behavior and returns to its original position due to the electrical stimulation received between both electrode rows 1a and 1b.
The fish that has entered between a and 1b is exposed to both electrode arrays 1a and 1b.
Although the electric stimulation received between them causes paralysis and makes it difficult to swim, due to the high speed, it passes between the first and second electrode rows 1a and 1b, and the second and third electrode rows 1b,
1c, but it revives to a normal state between the second and third electrode rows 1b and 1c, where the electric field strength is 0, takes repellent action, and then rushes into the space between the third and fourth electrode rows 1c and 1d at the same speed. There is nothing to do, second
It remains between the third electrode rows 1b and 1c.

Therefore, even if fish rush into the electric screen at high speed, the fish will not be damaged by electrical stimulation, and furthermore, swimming in the prohibited area for fish can be reliably blocked.

In addition, in order to return the fish that has stayed between the second and third electrode examples 1b and 1c to the outside of the original first electrode array 1a, the first, second, and third electrode arrays 1a, 1b, and 1c must be moved for a certain period of time.
with the same potential and the first, second and third electrode rows 1a, 1
The electric field strength between b and 1c may be set to 0.

Example 2 Next, FIGS. 4 and 5 showing Example 2 will be explained.

In Fig. 4, the same symbols as in Fig. 1 indicate the same or equivalent parts, and the difference from Fig. 1 is that the third and fourth electrode rows 1 and 1 are closer to the prohibited area.
With respect to the lengths c and 1d, the first and second electrode arrays 1a and 1b that are farther from the prohibited area are shortened, and the first and second electrode arrays 1a and 1b are shortened.
This is because avoidance areas are formed at both outer ends of the second electrode arrays 1a and 1b.

At this time, the fourth electrode row 1d is used as a reference.
The potentials at each point on the A-A' line and the B-B' line in FIG. 4 with respect to the distance from the electrode row 1d to each electrode row 1c, 1b, and 1a are the solid line and the dashed-dotted line in FIG. 5, respectively. The potential distribution on the line A-A' is the same as in Example 1, and the distribution of potential on the line A-A' is as shown in FIG.
In the potential distribution on the line B', the potential gradient in the avoidance region, that is, the electric field strength, is approximately zero.

As in the case of Example 1, when each of the electrode rows 1a to 1d is arranged in the water supply passage portion of the hydraulic equipment such that the fourth electrode row 1d is located on the prohibited area side, the first, A fish that rushes between the second electrode rows 1a and 1b at high speed passes between the first and second electrode rows 1a and 1d, and then passes through the second and third electrode rows 1b and 1c with an electric field strength of 0.
When the fish reaches between the first and second electrode rows 1a and 1b, the paralyzed fish is paralyzed by the strong electrical stimulation between the first and second electrode rows 1a and 1b.
Resuscitate the animal to a normal state between the electrode rows 1b and 1c, take repellent behavior, and then return to the outside of the original first electrode row 1a through the avoidance zone and follow the route shown by the arrow in FIG. 4. become.

Note that there may be five or more electrode rows, and in this case, two adjacent electrode rows excluding the electrode rows on both sides may have the same potential.

〔Effect of the invention〕

As described above, according to the electric screen generating device of the present invention, since the two adjacent electrode rows excluding the outer sides are set to the same potential, even if the fish rushes into the electric screen at high speed, the electric stimulation by the electric screen does not occur. This makes it possible to resuscitate fish to a normal state before they reach an asphyxia or lethal state, and prevent damage to fish caused by electrical stimulation.
It is possible to reliably block fish from swimming in areas where entry is prohibited.

[Brief explanation of the drawing]

The drawings show embodiments of the electric screen generator of the present invention, and FIGS. 1 to 3 show embodiment 1,
Figures 4 and 5 show Example 2, Figure 1 is a perspective view, Figure 2 is a potential distribution diagram, Figure 3 is an operation explanatory diagram, Figure 4 is a plan view, and Figure 5 is a potential distribution. It is a diagram. 1a to 1d...first to fourth electrode rows, 4...power supply.

Claims (1)

[Claims] 1. In an electric screen generation device comprising a plurality of electrode rows arranged in parallel in water and a power source for electric screen generation that applies voltage to each of the electrode rows, both external measurements are performed. An electric screen generating device characterized in that two adjacent electrode rows except for one are made to have the same potential.