Patent ID: 8042695

Claim:
An external pressure type hollow fiber membrane module of an external pressure type having a membrane occupying rate set to between 0.3 to 0.6, comprising: a hollow fiber membrane bundle formed of a plurality of hollow fiber membranes, a cylindrical housing, and a nozzle for allowing a fluid to enter into and exit therefrom, wherein the hollow fiber membranes are adhesively-fixedly adhered to each other and to the inner wall of the housing at ends of the hollow fiber membrane bundle and form a membrane chargeable region in the inner side of the adhesively-fixed ends; wherein a hollow part is opened in one side or both sides of the adhesively-fixed ends; and wherein the nozzle for allowing the fluid to enter and exit therefrom is installed on a side face of the housing of at least one adhesively-fixed end at which the hollow part is opened; wherein a membrane-occupying rate in the housing is set at 0.3 to 0.6, wherein a ratio PB/PA of membrane-occupying rates is 0.50 or more but 0.95 or less when each of PA and PB is defined as the membrane-occupying rate in a neighboring region (A) of the nozzle and a non-neighboring region (B) of the nozzle which includes all regions other than the neighboring region (A) in the membrane chargeable region in the inner side of an adhesively-fixed end of the opened hollow part, wherein a partial portion of a circumference of the hollow fiber membrane bundle is within the neighboring region (A), and the rest of the circumference of the hollow fiber membrane bundle is within the non-neighboring region (B), the membrane-occupying rate at the partial portion of the circumference of the hollow fiber membrane bundle is higher than the membrane-occupying rate at the rest of the circumference of the hollow fiber membrane bundle, and the membrane-occupying rate at the rest of the circumference of the hollow fiber membrane bundle is not higher than the membrane-occupying rate at the center of the hollow fiber membrane bundle.