PURPOSE: To uniformize the flow of fluid to be treated and to make the flow velocity large and to prevent the local drift current by opening the end parts of a feed duct and a discharge duct arranged in the central part of a core to a hollow yarn layer and covering the outer peripheral cylinder part of the assembly of a hollow yarn membrane by a nonpermeable film.
CONSTITUTION: The outer peripheral surface of the hollow yarn layer 5 of the assembly 1 of a hollow yarn membrane is covered by a nonpermeable film 9 except in the vicinity 12 of a resin wall 7 and holes 11 are provided to a core pipe 6 in the end part of the hollow yarn layer 5. The hollow yarn group is tightly fitted to the resin wall 7 in an opened state and to a resin wall 8 in a closed state. The fluid to be treated is passed through the holes 11 from an inlet 15 and a conduit 17 and introduced into the hollow yarn layer 5 and firstly distributed in the radius direction in the vicinity of the resin wall 8 and allowed to flow in the axial direction of the core pipe. The fuid is again made to the flow in the radius direction in the vicinity of the resin wall 7 and allowed to flow through an annular flow path 19 between the inner face of a circular vessel 2 and the outer peripheral face of the assembly 1 from the part 12 which is not covered by the nonpermeable film and discharged to the outside of the system through an outlet 16 of concentrated fluid. The fluid permeated through the hollow yarn membrane is collected in a fluid chamber 14 and drained through a discharge port 13 of the permeated fluid.
NUMATA KATSUHISA
UKAI TETSUO
