Marine debris collection device

Abstract

A marine debris collection device includes an outer container, an inner container provided inside the outer container so as to be movable in an upward-downward direction with respect to the outer container, a pump to move the inner container downward and cause seawater and debris to flow into the inner container via an opening, and a lower buoyant body detachably attached to a lower portion of the inner container to maintain the opening of the inner container above a water surface when the pump is not driven.

What is claimed is: 
     
         1 . A marine debris collection device that collects debris floating on a sea by allowing the debris to flow together with seawater into the marine debris collection device, the marine debris collection device comprising:
 an outer container installed in a vicinity of or adjacent to a water surface to maintain a height of the outer container;   an inner container including, in an upper portion thereof, an opening to allow the seawater and the debris to flow into the inner container, the inner container being provided inside the outer container so as to be movable in an upward-downward direction with respect to the outer container to store the debris that flows into the inner container via the opening;   a pump driven to move the inner container downward such that the opening is located at a height equal to or lower than a height of the water surface and cause the seawater and the debris to flow into the inner container via the opening; and   a lower buoyant body detachably attached to a lower portion of the inner container to provide buoyancy to the inner container so as to maintain the opening above the water surface when the pump is not driven.   
     
     
         2 . The marine debris collection device according to  claim 1 , wherein the lower buoyant body includes a plurality of lower buoyant bodies detachably attached to a lower surface of the inner container. 
     
     
         3 . The marine debris collection device according to  claim 2 , wherein
 the inner container includes a water passage to allow the seawater to pass therethrough; and   the plurality of lower buoyant bodies surround the water passage.   
     
     
         4 . The marine debris collection device according to  claim 3 , wherein
 the lower surface of the inner container has an annular shape to surround the water passage; and   each of the plurality of lower buoyant bodies includes an inner peripheral surface and an outer peripheral surface each having an arcuate shape extending along the lower surface and having a plate shape with the upward-downward direction corresponding to a thickness direction of the plate shape.   
     
     
         5 . The marine debris collection device according to  claim 1 , further comprising:
 a stopper attached to the inner container to restrict upward movement of the inner container at a predetermined height by contacting the outer container; wherein   the lower buoyant body is detachably attached to a lower surface of the inner container together with the stopper.   
     
     
         6 . The marine debris collection device according to  claim 5 , further comprising:
 a fastener to detachably fix the lower buoyant body together with the stopper to the lower surface of the inner container.   
     
     
         7 . The marine debris collection device according to  claim 1 , wherein the inner container includes an upper surface including:
 an annular flat portion that includes a horizontal or substantially horizontal surface and extends along the opening to surround the opening; and   an annular protrusion that surrounds the flat portion, protrudes upward from the flat portion, and is connected to an outer peripheral edge of the flat portion from above.   
     
     
         8 . The marine debris collection device according to  claim 7 , wherein the protrusion has an arcuate shape that protrudes upward in a direction perpendicular to a direction in which the protrusion extends around the opening. 
     
     
         9 . The marine debris collection device according to  claim 7 , wherein
 the inner container includes:
 a cylindrical inner container body; and 
 a mesh container detachably installed inside the cylindrical inner container body to store the debris and including an upper end located below the flat portion when the mesh container is installed inside the inner container body; and 
   the flat portion of the inner container guides, inward of the mesh container, the seawater and the debris that flow over the protrusion into the inner container by contacting the seawater and debris flowing inward and directing a flow of the seawater and debris obliquely upward and inward.   
     
     
         10 . The marine debris collection device according to  claim 7 , wherein
 the protrusion is internally recessed upward such that a lower side of the protrusion is open, and includes an outer surface including a through-hole; and   when the seawater flows into the inner container, internal air is drawn via the through-hole into the seawater that flows into the inner container, and the seawater flows into the protrusion from the open lower side.   
     
     
         11 . The marine debris collection device according to  claim 1 , further comprising:
 a slider provided between the outer container and the inner container to smooth a movement of the inner container with respect to the outer container.   
     
     
         12 . The marine debris collection device according to  claim 1 , further comprising:
 an upper buoyant body that is provided on the upper portion of the inner container to provide buoyancy to the inner container, is located below the water surface when the pump is driven, and maintains the opening above the water surface when the pump is not driven.   
     
     
         13 . The marine debris collection device according to  claim 12 , wherein
 the inner container includes:
 an annular flat portion that includes a horizontal or substantially horizontal surface and extends along the opening to surround the opening; and 
 a sealed, hollow, and annular protrusion that surrounds the flat portion, protrudes upward from the flat portion, and is connected to an outer peripheral edge of the flat portion from above; and 
   the upper buoyant body includes a sealed, hollow, and annular portion of the protrusion.   
     
     
         14 . The marine debris collection device according to  claim 1 , wherein the pump is directly attached to a lower surface of the outer container from an outside of the outer container. 
     
     
         15 . The marine debris collection device according to  claim 1 , wherein the pump includes:
 a pump body; and   a branch discharge pipe to divide the seawater discharged from the pump body into a plurality of branches and discharge the seawater in a plurality of horizontal directions different from each other.   
     
     
         16 . The marine debris collection device according to  claim 1 , wherein the lower buoyant body is solid. 
     
     
         17 . The marine debris collection device according to  claim 1 , further comprising:
 a bracket to fix the outer container to a pier.   
     
     
         18 . The marine debris collection device according to  claim 1 , wherein
 the pump includes a suction port provided directly below a central or substantially central portion of a bottom surface of the inner container; and   the inner container includes:
 a water-impermeable portion provided on the bottom surface directly above the suction port to prevent the seawater from passing therethrough; and 
 a bottom water passage provided on the bottom surface around the water-impermeable portion to allow the seawater to pass therethrough. 
   
     
     
         19 . The marine debris collection device according to  claim 1 , wherein
 the inner container includes a water passage to allow the seawater to pass therethrough; and   the water passage includes:
 a bottom water passage provided on a bottom surface of the inner container; and 
 a side water passage provided on a side surface of the inner container. 
   
     
     
         20 . The marine debris collection device according to  claim 1 , wherein the pump includes:
 a pump body; and   an outer discharge pipe including a discharge port provided outside an outer peripheral surface of the outer container in a horizontal direction to discharge the seawater discharged from the pump body to an outside of the pump via the discharge port.