Hollow fiber membrane module

Patent metadata

Field	Value
Publication number	US-9707518-B2
Application number	US-201314412288-A
Country	US
Kind code	B2
Filing date	Jun 27, 2013
Priority date	Jul 5, 2012
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

There is provided a hollow fiber membrane module including a cylindrical case having at least a discharge port for raw water in a side face thereof; a fixing member to which open ends of a large number of hollow fiber membranes forming a hollow fiber membrane bundle housed inside the cylindrical case are fixed; and a flow straightening cylinder which is provided between the discharge port for the raw water and an outer periphery of the hollow fiber membrane bundle, which is fixed to the fixing member, and which has a plurality of flow straightening holes. The flow straightening cylinder includes a large inner diameter portion and a small inner diameter portion and the small inner diameter portion is mounted to the fixing member with a lower face of the fixing member positioned at the small inner diameter portion.

First claim

The invention claimed is:

1. A hollow fiber membrane module including:
a cylindrical case having one nozzle at the minimum in a side face thereof;
a hollow fiber membrane bundle provided in the cylindrical case; and
a flow straightening cylinder provided between the one nozzle at the minimum and an outer periphery of the hollow fiber membrane bundle and having a plurality of flow straightening holes,
in which the hollow fiber membrane bundle includes a plurality of hollow fiber membranes, that are open at one end and sealed at the other end, or at least one U-shaped hollow fiber membrane, that is open at opposite ends, and includes a hollow fiber membrane open end fixing member for fixing the open end of each of the hollow fiber membranes,
a side peripheral face of the hollow fiber membrane open end fixing member is joined to an inner peripheral face of the cylindrical case,
each of the hollow fiber membranes passes through the hollow fiber membrane open end fixing member,
each of the open ends is positioned at an outer surface of the hollow fiber membrane open end fixing member, the outer surface positioned outside the cylindrical case, and
the flow straightening cylinder is fixed to the hollow fiber membrane open end fixing member,
wherein the flow straightening cylinder includes a large inner diameter portion and a small inner diameter portion having a smaller inner diameter than an inner diameter of the large inner diameter portion at least at a part in an axial direction of the flow straightening cylinder,
an inner surface of the hollow fiber membrane open end fixing member positioned on an opposite side from the outer surface and inside the cylindrical case is positioned at the small inner diameter portion of the flow straightening cylinder,
the flow straightening cylinder has a step between the small inner diameter portion and the large inner diameter portion, and
clearance is formed between the flow straightening holes of the flow straightening cylinder and the hollow fiber membrane bundle.

2. The hollow fiber membrane module according to claim 1 ,
wherein the hollow fiber membrane bundle includes a plurality of hollow fiber membranes that are open at one ends and sealed at the other ends,
the sealed end of each of the hollow fiber membranes is fixed to a hollow fiber membrane sealed end fixing member,
a side peripheral face of the hollow fiber membrane sealed end fixing member is joined to an inner peripheral face of the cylindrical case, and
the hollow fiber membrane sealed end fixing member has an inner surface positioned inside the cylindrical case and an outer surface positioned outside the cylindrical case.

3. The hollow fiber membrane module according to claim 2 ,
wherein, when the inner diameter of the large inner diameter portion is LD, the inner diameter of the small inner diameter portion is SD, a hollow fiber membrane length between the inner surface of the hollow fiber membrane open end fixing member and the inner surface of the hollow fiber membrane sealed end fixing member is FL, and a distance, in the axial direction, of the cylindrical case between the inner surface of the hollow fiber membrane open end fixing member and the inner surface of the hollow fiber membrane sealed end fixing member is CL, the flow straightening cylinder satisfies a relationship, (LD−SD)>(FL−CL)/2.

4. The hollow fiber membrane module according to claim 1 , wherein a length, in an axial direction of the cylindrical case, of the small inner diameter portion from the inner surface of the hollow fiber membrane open end fixing member toward the large inner diameter portion is in the range of 3 mm to 40 mm.

5. The hollow fiber membrane module according to claim 1 ,
wherein, when a cross-sectional area of the small inner diameter portion of the flow straightening cylinder is SA and a cross-sectional area of the large inner diameter portion is LA, a ratio between SA and LA satisfies a relationship, 0.6≦SA/LA≦0.9.

6. The hollow fiber membrane module according to claim 5 ,
wherein the flow straightening cylinder has an inner diameter length transition zone in which an inner diameter of the flow straightening cylinder changes from an inner diameter satisfying the cross sectional area SA of the small inner diameter portion to an inner diameter satisfying the cross-sectional area LA of the large inner diameter portion between the small inner diameter portion and the large inner diameter portion.

7. The hollow fiber membrane module according to claim 1 ,
wherein all of the plurality of flow straightening holes of the flow straightening cylinder are provided at the large inner diameter portion.

8. The hollow fiber membrane module according to claim 1 ,
wherein a filling rate of the hollow fiber membranes in the hollow fiber membrane bundle positioned at the small inner diameter portion is in the range of 30% to 80%.

9. The hollow fiber membrane module according to claim 1 ,
wherein an outer diameter of the flow straightening cylinder at a portion where the small inner diameter portion is formed is smaller than an outer diameter of the flow straightening cylinder at a portion where the large inner diameter portion is formed.

Assignees

• Toray Industries

Inventors

• Kanai Hiroaki
• Itakura Junji

Classifications

• B01D2313/12

  Specific discharge elements · CPC title

• B01D2319/04

  Elements in parallel · CPC title

• C02F2303/16

  Regeneration of sorbents, filters · CPC title

• C02F1/444

  by ultrafiltration or microfiltration · CPC title

• B01D2313/10

  Specific supply elements · CPC title