Spiral membrane element and membrane separation system
AssigneeNitto Denko Corporation
InventorsMakoto Katagiri, Yoshihiro Nakamura, Shinya Nishiyama
Life of this patent
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Abstract
The present invention provides a spiral membrane element suitable for suppressing a decrease in a permeation rate (or a permeation flux) of a permeated fluid from a separation membrane. A spiral membrane element of the present invention includes: a central tube; a membrane leaf that has a separation membrane and a permeation spacer and is wound around the central tube; and a flow passage spacer that is connected to the permeation spacer and is wound around the central tube on a side closer to the central tube than the membrane leaf is. A pressure loss of the flow passage spacer measured by a predetermined test is smaller than a pressure loss of the permeation spacer.
Claims14
A spiral membrane element comprising:
- a central tube;
- a membrane leaf that has a separation membrane and a permeation spacer and is wound around the central tube;
- and
- a flow passage spacer that is connected to the permeation spacer and is wound around the central tube on a side closer to the central tube than the membrane leaf is,
- wherein a pressure loss P1 of the flow passage spacer measured by a test below is smaller than a pressure loss P2 of the permeation spacer measured by the test below;
- Test:
- A specimen is prepared by laminating, on a polyethylene terephthalate film, a spacer (the flow passage spacer or the permeation spacer) that is rectangular and is 150 mm in length and 47 mm in width;
- A nitrogen gas is delivered to a space adjacent to the polyethylene terephthalate film of the specimen in such a manner that a pressure in the space is 0.1 MPa while a nitrogen gas is delivered to the spacer at a flow rate of 2.5 L/min;
- A pressure loss caused by that the nitrogen gas moves in the spacer in a longitudinal direction of the spacer is measured.
A spiral membrane element comprising:
- a central tube;
- a membrane leaf that has a separation membrane and a permeation spacer and is wound around the central tube;
- and
- a flow passage spacer that is connected to the permeation spacer and is wound around the central tube on a side closer to the central tube than the membrane leaf is, wherein a pressure loss P1 of the flow passage spacer measured by a test below is 30 kPa or less;
- Test:
- A specimen is prepared by laminating, on a polyethylene terephthalate film, the flow passage spacer that is rectangular and is 150 mm in length and 47 mm in width;
- A nitrogen gas is delivered to a space adjacent to the polyethylene terephthalate film of the specimen in such a manner that a pressure in the space is 0.1 MPa while a nitrogen gas is delivered to the flow passage spacer at a flow rate of 2.5 L/min;
- A pressure loss caused by that the nitrogen gas moves in the flow passage spacer in a longitudinal direction of the flow passage spacer is measured.
Dependencies are inferred from the claim text.