JPH0240896A - electric screen generator - Google Patents

Abstract

PURPOSE:To inhibit fishery product from penetrating the raising area by providing two electrodes placed underwater, a shield conductor disposed therebetween and surrounding the raising area and a power source for generating electric screen applying different potentials to the electrodes. CONSTITUTION:A power source 3 for generating electric screen applies different potentials to electrodes 1a and 1b to cause the intensity of the electric field inside a shield conductor 2 to be zero or extremely weakened, that in the inner space between the periphery of the shield conductor 2 and the electrodes 1a and 1b to be strengthened and that in the space between the electrodes 1a and 1b, the space being the upper part of the shield conductor 2, to be relatively weakened. Therefore, when fishery product living in the vicinity of the bottom of the sea tries to penetrate the raising area S, the space having intense electric field between the shield conductor 2 and the electrodes 1a and 1b inhibits the penetration. While, when they tries to penetrate there from the upper part of the shield conductor 2, the space having weak electric field between the electrodes 1a and 1b upper part of the shield conductor 2 inhibits the penetration. The penetration of the fishery product to the raising area is thus inhibited without fail.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to forming an area for cultivating algae, seaweed, etc. on the seabed, and installing an electric screen to prevent the intrusion of fish and shellfish into the aquaculture area. This invention relates to an electric screen generator.

[Conventional technology]

Generally, when carrying out aquaculture, a method to prevent fish and shellfish from entering or escaping the specified aquaculture area is to form electric screens instead of conventional nets. electrode rows are arranged in parallel, different potentials are applied to each electrode row by a power supply, an electric screen with a predetermined electric field strength is formed between each electrode row, and the electrical stimulation of the electric screen causes This is to block the swimming of species.

[Problem to be solved by the invention]

The method of forming an electric screen using a plurality of electrode rows described in the conventional technology is advantageous for marine farms in fairly wide water areas for the purpose of large-scale aquaculture, but when cultivating algae and seaweeds, The problem is that the scale is too large and the power consumption is too high, making it unsuitable for cultivating algae, seaweed, etc.

Therefore, the present invention has been made with the above-mentioned points in mind, and an object of the present invention is to more reliably prevent the intrusion of fish and shellfish into the aquaculture area formed on the seabed.

[Means to solve the problem]

In order to achieve the above object, the electric screen generator of the present invention includes two electrodes consisting of electrode plates or electrode rows provided in parallel in seawater, and a screen arranged on the seabed between the two electrodes. It is characterized by comprising a shielding conductor that is lower in height than the electrodes and whose lower part surrounds the culture area, and a power source for generating an electric screen that applies different potentials to the picture electrodes.

[Effect]

With the above configuration, when different potentials are applied to the picture electrodes by the power source for generating the electric screen, the potential of the shielding conductor becomes a potential between the potential of one electrode and the potential of the other electrode, In the area inside the shield conductor, the electric field strength is zero or extremely weak, and in the area between each picture electrode and the circumferential surface of the shield conductor, the electric field strength is low because the distance between the electrode and the shield conductor is very short. The area between the two electrodes on the upper side of the shield conductor has a relatively weak electric field strength.

Therefore, the inside of the shielding conductor has no electric field strength or ultra-weak electric field strength, and is suitable as an area for cultivating algae, seaweed, etc.
When fish and shellfish that live in the vicinity of the ocean floor try to invade the aquaculture area, the strong electric field between the picture electrode and the shielding conductor prevents the fish from entering the aquaculture area from above. In this case, the weak electric field strength area between the two electrodes on the upper side of the shield conductor prevents the intrusion, and moderate stimulation is applied to fish and shellfish that are resistant to electrical stimulation, and to fish and shellfish that are relatively weak to electrical stimulation, respectively. Entry of these fish and shellfish into the aquaculture area is reliably prevented.

〔Example〕

Examples will be described with reference to the drawings.

(Example 1) First, FIG. 1 and FIG. 2 showing Example 1 will be explained.

Figures 1 (a) and (b) show a plan view and a front view. Two electrodes (2+ are placed on the seabed between both sides (Ia) and (lb), and both sides [(Ia), (lb) are also low in height and surround the aquaculture area +8). A rectangular cylindrical shielding conductor with a rectangular horizontal cross section, +31 is a power source for generating an electric screen, and applies different potentials to the picture electrodes (Fa) and (xb).

The center lines of the IMs (la) and (lb) of both sides and the shielding conductor r2+ are shown by dashed lines in Figure 1 (a) and (b).
Install the shielding conductor (21) and connect it to the power supply (3) so that the center line of
When the potential of the shielding conductor (2) becomes Vp/2, the potential of the shielding conductor (2) becomes Vp/2, and on the A-A' line and the B + B/edge line in The electric field strengths are as shown by M and N in FIG. 2, respectively. However, the horizontal axis in FIG. 2 indicates the distance from the left electrode (1a).

At this time, if the distance between the picture electrodes (IB), (lb) is 1, and the distance between both electrodes (lb), (lb) and the shielding conductor (2) is L/8, then on the line A + A' The electric field strength becomes relatively weak at a constant value E (=Vp/L) at any point on the A A' line, as shown by M in Fig. 2, and B
-B' The electric field strength on the edge line is a very high series of 4E (= 4VP/L) between each of the electrodes (IB) and (lh) and the shielding conductor (2+), as shown by N in Figure 2. , becomes 0 inside the shield conductor (2).

Therefore, according to the first embodiment, the inside of the shielding conductor (2) has zero electric field strength and is suitable as a cultivation area (S) for seaweed, algae, etc., and has a living area near the seabed.

If fish and shellfish that are resistant to electrical stimulation attempt to invade the aquaculture area (S), the invasion can be prevented by the strong electric field strength areas between both sides (la) and (tb), respectively, and the shielding conductor +21. If fish try to enter the aquaculture area (S) from above, the shield conductor (21
a).

Invasion can be prevented by the weak electric field strength region between (1b), and moderate stimulation can be given to fish and shellfish that are resistant to electrical stimulation, and fish that are relatively weak to electrical stimulation, respectively. It is possible to reliably prevent fish and shellfish from entering the aquaculture area.

(Example 2) Next, FIGS. 3 and 4 showing Example 2 will be explained.

In FIG. 3, the same symbols as in FIG. 1 indicate the same things, and the difference from FIG. , Arranged at regular intervals on each side of the square, welded the connecting conductor C51 to each arranged conductive rod (4) to join each conductive rod (4), and connected each conductive rod (4) and connection body r51. This is the point where a shield conductor (6) is formed and the aquaculture area (S) is surrounded by the shield conductor (6).

And, as in the first embodiment, a picture electrode (18).

The shield conductor (6) is installed so that the center line of (1b) and the center line of the shield conductor (6) match, and the voltage of 0 Vp and Vp are applied to the picture electrodes (Ia) and (lb) by the power supply (3), respectively. When a potential is applied, the potential of the shielding conductor (6) becomes Vp/2,
Assuming that the distance between both sides' 1ffi (la) and (Ib) is L'/4 and the distance between both electrodes (la) and (lb) and the shielding conductor (6) is L'/4, c-c line and D
The electric field strength on the D edge line is as indicated by P and R in Fig. 4, respectively, and the electric field strength on the C-C line is approximately at any point on the C-C line, as indicated by P in Fig. 4. Constant F,'
(= Vp/L), and the electric field strength on the D-D line is as shown by R in FIG.
b) 2 E (= 2
Vp/L') and becomes very strong, reaching almost O inside the shield conductor (6).

However, the horizontal axis in FIG. 4 indicates the distance from the left electrode (lB).

Therefore, according to the second embodiment, effects equivalent to those of the first embodiment can be obtained.

(Example 3) Next, FIGS. 5 and 6 showing Example 3 will be described.

In Fig. 5, the difference from Fig. 3 is that the shield conductor (6)
In addition to the conductive rod (4) that forms the
7) are arranged at regular intervals on each side of a square larger than the shielding conductor (6), and the left half of each arranged electrode rod (7) is welded to the connecting conductor (8a) to form an electrode. One electrode (9a) of the row structure was constructed, and similarly, each electrode rod (7) on the right half was welded to a connecting conductor (8h) to construct the other electrode (9h) of the electrode row structure. It is a point.

At this time, as in Example 1, both sides 1i (9a)
.

(9b) A strong electric field strength region is formed between each of the shielding conductors (6) and the crosshatching in FIG. (9b
), a weak electric field strength region is formed with rightward hatching in FIG. 6, and the electric field strength in the cultivation region (S) inside the shielding conductor (6) is almost zero.

Therefore, according to the third embodiment, it is possible to obtain the same effect as in the first embodiment, and it is also possible to prevent fish and shellfish from entering the aquaculture area (S) from all sides and from above.

Note that the shielding conductors (2) and (6) are not limited to the above-described rectangular tube shape, but may be cylindrical or hemispherical shell shaped like a colander turned upside down.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

It is possible to give appropriate stimulation to fish and shellfish that are resistant to electrical stimulation, and fish that are relatively weak to electrical stimulation, to induce them to take repellent behavior, and it is possible to reliably prevent these fish and shellfish from entering the cultivation area. This makes it extremely effective for cultivating algae and seaweed.

[Brief explanation of the drawing]

The drawings show an embodiment of the electric screen generator of the present invention, FIG. 1 and FIG. 2 show Example 1, and FIG. 1(a)
, (b) is a plan view and a front view, Fig. 2 is a distribution diagram of electric field strength, Figs. 3 and 4 show Example 2, and Fig. 3 (
a) and (b) are a plan view and a front view, FIG. 4 is a distribution diagram of electric field strength, and FIGS. 5 and 6 are a plan view and a front view for explaining the operation of the third embodiment. (la), (lb), (9B), (9b)--electrode,
(21, (61...shielding conductor, (3)...power supply, (
8)...Aquaculture area.

Claims (1)

[Claims] (1) Two electrodes consisting of electrode plates or rows of electrodes installed in parallel in seawater, and an electrode placed on the seabed between the two electrodes, which is lower in height than the two electrodes and whose lower part surrounds the aquaculture area. An electric screen generating device comprising: a shielding conductor; and a power source for generating an electric screen that applies different potentials to the two electrodes.