Abstract: This drip-irrigation device has plate-shaped inflow parts, an emission-rate control part, and a first groove section. The long direction of each inflow part is parallel to the lengthwise direction of a circulation tube that has a bottom surface joined to the inside surface thereof and a top surface opposite said bottom surface. The inflow parts are laid out on said top surface and cause an irrigation liquid inside the circulation tube to flow into channels. The emission-rate control part controls the rate with which said irrigation liquid is emitted, via the channels, from emission holes. The first groove section is formed as a recess in the aforementioned top surface, from one lengthwise end thereof towards the other lengthwise end, and is shaped such that the width and depth thereof gradually decrease with decreasing distance from said other lengthwise end.

Abstract: A disk filter (21) has grooves (211) having a curved shape whose curvature gradually increases from the outer peripheral side of the filter disks (21) to the inner peripheral side thereof. The width (Wout) is greater than the width (Win). The width (Wout) is the width of an opening (211a) of each of the grooves (211), the width (Win) is the width of the opening (211a) of each of the filter disks (21). The disk filter includes, in a flow passage for liquid thereof, a stacked body composed of the filter disks (21). The pressure loss of the disk filter (21) is low and the opening ratio thereof is high. The disk filter (21) can appropriately and efficiently filtrate even a low-pressure liquid.

Abstract: This drip-irrigation device has plate-shaped inflow parts, an emission-rate control part, and a first groove section. The long direction of each inflow part is parallel to the lengthwise direction of a circulation tube that has a bottom surface joined to the inside surface thereof and a top surface opposite said bottom surface. The inflow parts are laid out on said top surface and cause an irrigation liquid inside the circulation tube to flow into channels. The emission-rate control part controls the rate with which said irrigation liquid is emitted, via the channels, from emission holes. The first groove section is formed as a recess in the aforementioned top surface, from one lengthwise end thereof towards the other lengthwise end, and is shaped such that the width and depth thereof gradually decrease with decreasing distance from said other lengthwise end.

Abstract: A disk filter (21) has grooves (211) having a curved shape whose curvature gradually increases from the outer peripheral side of the filter disks (21) to the inner peripheral side thereof. The width (Wout) is greater than the width (Win). The width (Wout) is the width of an opening (211a) of each of the grooves (211), the width (Win) is the width of the opening (211a) of each of the filter disks (21). The disk filter includes, in a flow passage for liquid thereof, a stacked body composed of the filter disks (21). The pressure loss of the disk filter (21) is low and the opening ratio thereof is high. The disk filter (21) can appropriately and efficiently filtrate even a low-pressure liquid.