Hollow fiber membrane module, hollow fiber membrane module unit, membrane filtration device using the same and method of operating the same

• US 20050161389A1
• Filed: 03/24/2005
• Published: 07/28/2005
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Rayon Company Limited (Mitsubishi Chemical Holdings Corporation)
• Inventors: Takeda, Satoshi, Kinoshita, Ikuo, Nakahara, Yoshihito, Kamata, Masatoshi, Sueyoshi, Shinya, Kobayashi, Masumi
• Granted Patent: US 7,294,267 B2
• Time in Patent Office: Days
• US Class Current: 210/321.750
• CPC Class Codes: B01D 2313/21 Specific headers, end caps
• CPC Class Codes: B01D 63/02 Hollow fibre modules
• CPC Class Codes: B01D 63/022 Encapsulating hollow fibres
• CPC Class Codes: B01D 63/024 with a single potted end
• CPC Class Codes: B01D 63/04 comprising multiple hollow fibre assemblies
• CPC Class Codes: B01D 63/043 with separate tube sheets

Abstract

A hollow fiber membrane module using a sheet-form hollow fiber membrane having excellent cleaning properties in which the pressure resistance of a hollow fiber membrane anchor section does not deteriorate, even when the membrane area increases; a hollow fiber membrane module unit using the module; a membrane filtration device using the unit; and an operation method therefor are provided. The hollow fiber membrane module comprises sheet-form hollow fiber membranes and an anchoring member which anchors the sheet-form hollow fiber membranes in a roughly parallel manner while maintaining in an open state at least one end portion of the sheet-form hollow fiber membranes. The shape of an end face of a side of the anchoring member from which the hollow fiber membranes are exposed is roughly rectangular, and the shape of an end face of a side of the anchoring member toward which the hollow fiber membranes open is roughly circular.

Claims

1. A hollow fiber membrane module comprising:

a plurality of sheet-form hollow fiber membranes; and

an anchoring member that fastens the plurality of sheet-form hollow fiber membranes substantially parallel to each other while leaving at least one end of the sheet-form hollow fiber membranes open,

wherein an end face of the anchoring member on a side where the hollow fiber membranes are exposed is substantially rectangular, and an end face of the anchoring member on a side where the hollow fiber membranes open is substantially circular.

2. The hollow fiber membrane module according to claim 1, wherein the anchoring member comprises a rectangular parallelepiped section of substantially rectangular parallelepiped shape on the side where the hollow fiber membranes are exposed, and a cylindrical section of substantially cylindrical shape on the side where the hollow fiber membranes open.

3. The hollow fiber membrane module according to claim 2, wherein the relationship 0.2≦

L/D≦

1.0 is satisfied where D (mm) is a diameter of the cylindrical section and L (mm) is a length of the cylindrical section.

4. The hollow fiber membrane module according to claim 2, wherein the relationship 1.0≦

W/D≦

2.0 is satisfied where W (mm) is a length of a longer side of an end face of the rectangular parallelepiped section where the hollow fiber membranes are exposed and D (mm) is a diameter of the cylindrical section.

5. A hollow fiber membrane module unit comprising a plurality of hollow fiber membrane modules according to claim 2, wherein a plate-like member having a hole through which the cylindrical section passes is provided on a side of the sheet-form hollow fiber membranes perpendicular to sheet surfaces, so that the hollow fiber membrane modules are secured in place by the plate-like member.

6. The hollow fiber membrane module unit according to claim 5, wherein the cylindrical section and a water collecting cap that engages with the cylindrical section sandwich and fasten the plate-like member.

7. The hollow fiber membrane module unit according to claim 6, wherein the cylindrical section and the water collecting cap are fastened to each other by screw engagement.

8. The hollow fiber membrane module unit according to claim 6, wherein a plurality of hollow fiber membrane module units are stacked in the vertical direction,

the sheet surfaces of the sheet-form hollow fiber membranes are disposed in the vertical direction, and

water collecting caps that adjoin each other in the vertical direction are connected to each other by a water collecting member that extends in the vertical direction, and

a side frame is disposed on a side face parallel to the sheet surfaces of the sheet-form hollow fiber membranes.

9. The hollow fiber membrane module unit according to claim 8, wherein vertical distance between the sheet-form hollow fiber membranes of the hollow fiber membrane module adjacent to each other in the vertical direction is 70 mm or less.

10. A membrane filtration device comprising a membrane module unit disposed in a water tank, wherein

the membrane module unit comprises a plurality of hollow fiber membrane modules,

each of the hollow fiber membrane modules comprises:

a plurality of sheet-form hollow fiber membranes; and

an anchoring member that fastens the plurality of sheet-form hollow fiber membranes substantially parallel to each other while leaving at least one end of the sheet-form hollow fiber membranes open, and an end face of the anchoring member on a side where the hollow fiber membranes are exposed is substantially rectangular, and an end face of the anchoring member on the a where the hollow fiber membranes open is substantially circular, and

the following three relationships are satisfied where S (m²) is the membrane area of the membrane module unit, A (m²) is the area of projection of the membrane module unit, V′

(m³) is the volume of the membrane module unit, and V (m³) is the capacity of the water tank;

1000≦

S/A≦

2000 

 

Equation (1)
500≦

S/V′

≦

800 

 

Equation (2)
0.70≦

V′

/V≦

0.99 

 

Equation (3).

11. A method of operating a membrane filtration device comprising a membrane module unit disposed in a water tank, the method comprising the steps of:

forming the membrane module unit by a plurality of hollow fiber membrane modules;

forming the hollow fiber membrane modules such that a plurality of sheet-form hollow fiber membranes are fastened substantially parallel to each other by an anchoring member with at least one end of the sheet-form hollow fiber membranes being left open, while an end face of the anchoring member on a side where the hollow fiber membranes are exposed is substantially rectangular, and an end face of the anchoring member on a side where the hollow fiber membranes open is substantially circular;

setting S (m²), being a membrane area of the membrane module unit, J (m/d), being a filtration flux, T (h), being a filtration time, N, being the number of cycles per draining of water, D (m³), being the volume of draining, J′

(m/d), being the backwash flux, and T′

(h), being the backwash time so as to satisfy the following relationship

N≧

22.8D/{S(0.05JT−

J′

T′

)} 

 

Equation (4); and

operating the membrane filtration device.