Abstract: The gravel-or-the-like removing device includes an impeller casing which accommodates an impeller driven by a motor in the inside thereof and has a suction opening at the center of the lower surface, a peripheral wall for preventing collapse and inflow of gravel or the like which is constituted of a cylindrical body which has an upper end thereof connected to a lower portion of the impeller casing and a lower end thereof opened downwardly and forms a water-retention space in the inside thereof, and a water suction pipe which has an upper-end opening thereof opened in water above a gravel-or-the-like piled level and a lower opening thereof communicably connected with the water retention space.

Abstract: An underwater agitation pump comprises an impeller casing in which an impeller driven by a motor is rotatably accommodated, an agitated material suction guide cylinder of a hollow cylinder which has one-end opening portion thereof integrally communicably connected to a center suction opening portion of the impeller while passing through a center opening of the impeller casing and having the other-end opening portion thereof extended downwardly, the suction guide cylinder further forming an agitated material suction passage therewithin, and an agitator mounted on an outer peripheral portion of the other-end opening portion of the agitated material suction guide cylinder. Due to such a constitution, the agitated material suction passage formed in the inside of the agitated material suction guide cylinder can ensure a sufficiently wide agitated material inflow area.

Abstract: The gravel-or-the-like removing device includes an impeller casing which accommodates an impeller driven by a motor in the inside thereof and has a suction opening at the center of the lower surface, a peripheral wall for preventing collapse and inflow of gravel or the like which is constituted of a cylindrical body which has an upper end thereof connected to a lower portion of the impeller casing and a lower end thereof opened downwardly and forms a water retention space in the inside thereof, and a water suction pipe which has an upper-end opening thereof opened in water above a gravel-or-the-like piled level and a lower opening thereof communicably connected with the water retention space.

Abstract: An underwater agitation pump can suck soil, sand or the like which contains block-like material or string-like material in a dredging site or the like while efficiently agitating such soil, sand or the like and thereafter can discharge such sand, soil or the like to a desired place. The underwater agitation pump comprises an impeller casing in which an impeller driven by a motor is rotatably accommodated, an agitated material suction guide cylinder being constituted of a hollow cylinder which has one-end opening portion thereof integrally communicably connected to a center suction opening portion of the impeller while passing through a center opening of the impeller casing and having the other-end opening portion thereof extended downwardly, the agitated material suction guide cylinder further forming an agitated material suction passage in the inside thereof, and an agitator which is mounted on an outer peripheral portion of the other-end opening portion of the agitated material suction guide cylinder.