Hollow fiber membrane module

A hollow fiber membrane module comprising:

• a cylindrical outer case, both ends of which are open;
• a cylindrical inner case, one end of which is open and the other end side of which is closed, and disposed inside the outer case;
• a hollow fiber membrane bundle having a plurality of hollow fiber membranes filled in an annular gap between the outer case and the inner case;
• a first sealing part which seals a gap among the plurality of hollow fiber membranes in a state in which a hollow interior of each of the hollow fiber membranes is open on one end side of each of the outer case and the inner case;
• a second sealing part which seals a gap among the plurality of hollow fiber membranes in a state in which the hollow interior of each of the hollow fiber membranes is open on the other end side of each of the outer case and the inner case,
• wherein the inner case is provided with a first through hole and the outer case is provided with a second through hole such that a membrane exterior passage and a membrane interior passage are formed, the membrane exterior passage passing from the opening of the inner case through the first through hole and then reaching the second through hole through the exteriors of the plurality of hollow fiber membranes, and the membrane interior passage passing through the interiors of the plurality of hollow fiber membranes, and
• wherein a cylindrical member having a plurality of third through holes, each of which forms a part of the membrane exterior passage, is provided between the hollow fiber membrane bundle and the outer case.