Abstract: A distributor pipe includes: a main pipe including a cylindrical part; and a plurality of branch pipes communicating with the main pipe and arranged, on a cylindrical curved surface of the main pipe, side by side along a longitudinal direction of the main pipe. A pipe diameter ratio D1/D0 of a pipe diameter D1 of the branch pipe to a pipe diameter D0 of the main pipe is greater than 0.2 and less than 0.8, and the plurality of branch pipes are arranged according to: respective effluent flow ratios, at a time a liquid flows into the main pipe in a predetermined flow velocity range, determined in accordance with respective arrangement orders of the plurality of branch pipes along a direction in which the liquid flows and along the longitudinal direction of the main pipe; and respective areas of circular or hollow-circular sections allotted to the plurality of branch pipes.

Abstract: A distributor pipe includes: a main pipe including a cylindrical part; and a plurality of branch pipes communicating with the main pipe and arranged, on a cylindrical curved surface of the main pipe, side by side along a longitudinal direction of the main pipe. A pipe diameter ratio D1/D0 of a pipe diameter D1 of the branch pipe to a pipe diameter D0 of the main pipe is greater than 0.2 and less than 0.8, and the plurality of branch pipes are arranged according to: respective effluent flow ratios, at a time a liquid flows into the main pipe in a predetermined flow velocity range, determined in accordance with respective arrangement orders of the plurality of branch pipes along a direction in which the liquid flows and along the longitudinal direction of the main pipe; and respective areas of circular or hollow-circular sections allotted to the plurality of branch pipes.