Abstract: A hollow fiber membrane module having a structure, in which raw water is supplied into a filtration chamber containing a hollow fiber membrane and surrounded by a first sealing body having the open ends of the numerous hollow fiber membranes constituting the hollow fiber membrane bundle, a cylindrical case and a second sealing means, through a raw water supply port formed in the cylindrical case at a position near the second sealing body, and in which the drain of backwashing is discharged through a drain port formed in the second sealing body.

Abstract: A fluid separation element assembly comprises a fluid separation element having a membrane unit and a wrapping material formed around the membrane unit, an anti-telescoping plate attached to at least one end of the fluid separation element at a condition free to be detached, and a feed water seal member for preventing feed water from leaking through a gap between the fluid separation element and the anti-telescoping plate. The membrane unit is formed by a separation membrane, a permeate carrier material and a feed carrier material which are spirally wound around a permeate collection tube. By providing the anti-telescoping plate detachably, when the separation membrane has reached its life, it is possible to reuse other members.

Abstract: Disclosed is a liquid separation module of the spiral type which is produced by a simple apparatus requiring no manual operations, so that a mandrel is provided with a spirally and tightly wound layer arrangement consisting of a plurality of layer elements without any abnormal relative shifting between any layer elements, without the occurrence of wrinkles in any layer element and with uniform tightness of the winding along the radius of the wound layer arrangement. The layer arrangement is wound on the mandrel in such way that, while the layer arrangement is being wound on the mandrel by rotating the mandrel with the forward end of the layer arrangement fixed to the mandrel, a portion of the layer arrangement which has not yet been tightly wound is radially pressed just before coming into tight contact with the mandrel or with another portion of the layer arrangement which has been tightly wound, so that the degree of winding tightness is increased separated from each other.

Abstract: Disclosed is a liquid separation module of a spiral type which is produced by a simple apparatus requiring no manual operations, so that a mandrel is provided with a spirally and tightly wound layer arrangement consisting of a plurality of layer elements without any abnormal relative shifting between any layer elements, without occurrence of wrinkles in any layer element and with uniform tightness of the winding along the radius of the wound layer arrangement. The layer arrangement is wound on the mandrel in such way that, while the layer arrangement is being tightly wound on the mandrel by rotating the mandrel with the forward end of the layer arragement fixed to the mandrel, a portion of the layer arrangement which has not yet been tightly wound is forced to bulge just before coming into tight contact with the mandrel or with another portion of the layer arrangement which has been tightly wound, so that at the bulged portion the layer elements are partially separated from each other.

Abstract: There is provided an improvement of a reverse osmosis separation apparatus in that a membrane module or a permeator has spiral passages for a feed solution and a permeated solution respectively, those passages being formed with membrane sheets about a hollow mandrel to allow the feeding solution to flow spirally on a plane perpendicular to the axis of the mandrel thereby performing with a high recovery ratio and preventing the feed solution from passing through the feed solution passage in an unequally distributed flow state, which decreases rejection of the solution. The improved apparatus has a reinforced module in which the spiral sheets are held together with the mandrel in a rigid state by means of sealing members forming the opposite ends of the module thereby preventing the spiral sheets from being subjected to telescoping or axial deformation which results in damage to the membrane sheets.