PURPOSE: To prevent the reproduction of organisms by radiating a laser beam to the aquatic organism-containing water flowing in a conduit from the perpendicular direction or the oblique direction to the conduit, and scanning the laser beam in the width direction or the height direction.
CONSTITUTION: A laser beam L emitted from a laser head 8 is reflected on a polygonal rotary mirror 6. The reflected beam is reflected on a fixed mirror 5 having a recessed arc face shape, and it is radiated to the light reception section 11 of a radiation water pipe 3. The laser beam is fed into the pipe via the transparent plate 10 of the light reception section 11, and it is scanned in the light reception section 11 in the width direction in conjunction with the rotation of the mirror 6. The laser beam destroys the aquatic organisms in the sea water flowing in the pipe 3. The sticking, growth, and reproduction of the aquatic organisms to an apparatus and the pipe can be surely prevented, and a device can be made compact. The organisms are exterminated in the larval stage, the quantity of wastes is reduced, and the occurrence of environmental pollution problems can be prevented.
FUJITA TSUTOMU
ONIZUKA SHIGENORI
TOMINAGA SHINICHI
HITACHI SHIPBUILDING ENG CO