PURPOSE: To reduce electrical influences on adjacent facilities, buildings and, etc., by forming an electric screen intercepting what fishes and shellfishes go in and out so as to be arranged in the direction that plural electrode units are cut at a right angle to the intercepting direction for placing the same in the direction that an electrode row with grounding potential is cut at a right angle in cross proximity to each electrode unit.
CONSTITUTION: Plural wide electrode units 3 are arranged in the direction almost transverse to an intercepting direction that access of fishes and shellfishes is intercepted, and also are placed in the direction that an electrode row 4 with grounding potential comprising plural electrode bars arranged in cross proximity to each electrode unit 3 is cut at a right angle. And one of two adjacent electrode units 3 is connected to a positive power terminal of a d.c. power supply 5, while the another electrode unit 3 and the electrode row 4 are connected to a negative power terminal of the power supply 5 for grounding. Thus, outside the area that fishes and shellfishes are prevented from entering, the intensity of an electric field gets high in no steps with approach to an entry preventing area, while inside the entry preventing area, the intensity of the electric field abruptly gets low into zero due to the electrode row 4 with the grounding potential. That results in avoiding electrical influences in the preventing area.
MAEHATA HIDEHIKO
DAIKU HIROYUKI
SUYAMA HIROYUKI
TSUKAHARA MASANORI
OTANI SEIJI
