Membrane distillation module and membrane distillation apparatus

A membrane distillation module comprising,

• a membrane cartridge for membrane distillation, comprising a flat sheet or hollow fiber hydrophobic porous membrane, and
• a membrane distillation housing which houses the membrane cartridge for membrane distillation, wherein
• the membrane cartridge for membrane distillation:
• has a substantially columnar or substantially polygonal columnar shape, and
• has a membrane affixation part which affixes the hydrophobic porous membrane to the axial direction ends of the substantially columnar or substantially polygonal columnar shape with an affixation resin,
• the membrane distillation housing is composed of metal,
• the membrane distillation housing has a housing body for housing the membrane cartridge for membrane distillation and two housing lids attached to the housing body,
• the membrane distillation module has a support unit which, when the membrane cartridge for membrane distillation is housed within the membrane distillation housing, affixes the membrane cartridge for membrane distillation within the membrane distillation housing by supporting an outer surface of the membrane affixation part on an inner surface of the membrane distillation housing via a sealing member,
• the membrane distillation module is divided into a liquid phase unit through a treatment target liquid circulates and a gas phase unit in which vapor generated from the treatment target liquid passes through the hydrophobic porous membrane and diffuses by the hydrophobic porous membrane, the membrane affixation part, and the sealing member,
• there is a gap between the membrane distillation housing and the membrane cartridge for membrane distillation, and
• in a cross-section of the support unit perpendicular to the axial direction of the membrane cartridge for membrane distillation, when an equivalent circle diameter of an outer circumference of the membrane affixation part is dF (mm), the coefficient of linear expansion of the affixation resin is kF (1/° C.), an equivalent circle diameter of an inner circumference of the membrane distillation housing is dE (mm), and the coefficient of linear expansion of a material constituting the membrane distillation housing is kE (1/° C.), a value C represented by the following formula:
• C
• =
• d
• E
• -
• d
• F
• d
• F
• ⁡
• (
• k
• F
• -
• k
• E
• )
• [
• Formula
• ⁢
• ⁢
• 2
• ]
• is 80° C. or higher and 1,000° C. or lower,
• provided that when the gap between the inner surface of the housing and the outer circumference of the membrane affixation part differs depending on the measurement location, the value of the location where “dE-dF” is minimum is used for the values of dE and dF.