Porous multi-layer hollow fiber, filtering moudle and method for producing porous multi-layer hollow fiber

A filter layer and fiber technology, which is applied in the field of manufacturing porous multi-layer hollow fibers and improving the filtration performance of porous multi-layer hollow fibers, can solve the problems of reduced flow rate, insufficient durability, and reduced fluid permeability, etc., so as to prevent the decrease of flow rate , small change in flow rate, and excellent filtration performance

Inactive Publication Date: 2004-06-30
SUMITOMO ELECTRIC IND LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this case, however, the porosity is inevitably reduced due to the reduced expansion ratio
Therefore, the disadvantage is that the permeability of the fluid is reduced
[0016] The disadvantage of porous Teflon tubes of the kind described above is that they are not very durable against internal or external pressure, bending, etc. due to their formation simply by winding Teflon sheets on flat Teflon tubes. enough
Braiding and threading are used for reinforcement to improve durability, but such reinforcement is disadvantageous due to the accumulation of particles (suspended solids) which reduce the flow rate

Method used

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  • Porous multi-layer hollow fiber, filtering moudle and method for producing porous multi-layer hollow fiber
  • Porous multi-layer hollow fiber, filtering moudle and method for producing porous multi-layer hollow fiber
  • Porous multi-layer hollow fiber, filtering moudle and method for producing porous multi-layer hollow fiber

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0098] A porous multilayer hollow fiber according to the invention is produced. The support layer was made of a porous expanded polytetrafluoroethylene tube with an inner diameter of 1 mm and an outer diameter of 2 mm, a porosity of 80%, and an average maximum fibril length of 40 μm. At a filtration pressure of 0.1 MPa, when beads with a particle diameter of 2 μm were used as trapped particles, the trapping performance of the support layer was 90%.

[0099] The thickness of the porous expanded polytetrafluoroethylene sheet used as the filter layer is 30 μm, the width is 10 mm, the porosity is 60%, and the average value (L) of the maximum fibril length of the fibrous skeleton is 2.5 μm, and the skeleton surrounds the filter layer. every hole in the surface. At a filtration pressure of 0.1 MPa, when beads having a particle diameter (X) of 0.2 μm were used as trapped particles, the trapping performance of the filter layer was 90%. That is, the relative fibril length (RFL) is 12...

Embodiment 2

[0103] A porous multilayer hollow fiber according to the invention is produced.

[0104] The inner diameter of the porous expanded polytetrafluoroethylene tube used as the support layer is 1 mm, the outer diameter is 2 mm, the porosity is 80%, and the average value of the maximum fibril length of the fibrous skeleton surrounding each hole in the outer surface of the filter layer (L ) is 40 μm. At a filtration pressure of 0.1 MPa, when beads with a particle diameter of 2 μm were used as trapped particles, the trapping performance of the support layer was 90%.

[0105] The porous expanded polytetrafluoroethylene tube used as the filter layer has a thickness of 30 μm, a width of 10 mm, a porosity of 75%, and an average value (L) of the maximum fibril length of the fibrous skeleton surrounding the pores is 15 μm. At a filtration pressure of 0.1 MPa, when beads having a particle size (X) of 5 μm were used as trapped particles, the trapping performance of the support layer was 90%....

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Abstract

A porous multilayered hollow fiber for outer side pressed filtration is made of a multilayer comprising a supporting layer constituted of the thickness of an expanded porous polytetrafluoroethylene tube, and a filtration layer provided on the outer surface of the supporting layer, wherein pores surrounded by fibrous frameworks in the filtration layer are smaller than those of the supporting layer, and the mean of the maximum fibril length (L) of the fibrous frameworks surrounding each pore in the outer surface of the filtration layer is designed to be small such that (X) and (Y) fall within the range on the XY plane, where (X) is a particle diameter of particles captured when the particle trapping ratio is equal to or more than 90% in the case where the filtration is done under an elevated pressure of 0.1 MPa, and (Y) is a value designated as RFL obtained by dividing (L) by (X). Thus, the degradation of flow rate due to the elapse of time can be prevented, since solid particles to be separated do not enter into pores, and dogging and blockade of the pores do not occur even in the case of filtering a solution of high turbidity. As a result, it is possible to recover filtration property easily by performing back-wash reverse filtration and to maintain excellent filtration property for a long time.

Description

technical field [0001] The present invention relates to porous multilayered hollow fibers and filtration modules containing porous multilayered hollow fibers, and methods of manufacturing porous multilayered hollow fibers. In particular, the present invention relates to the improvement of the filtration performance of porous multilayer hollow fibers composed of porous tubes such as polytetrafluoroethylene, which are used in filtration equipment for solid-liquid separation treatment in the fields of environmental protection, pharmacy and food. Background technique [0002] A porous material made of polytetrafluoroethylene has properties such as non-stickiness and a low coefficient of friction, in addition to excellent chemical resistance, heat resistance, weather resistance, flame retardancy, and the like. Also, due to their porous structure, they not only have excellent permeability and flexibility, but also show excellent performance in trapping and filtering of fine partic...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/08B01D63/02B01D63/04B01D63/12B01D69/10B01D69/14B01D71/26B01D71/34B01D71/36B01D71/64
CPCB01D63/12Y10T428/24091B01D69/08B01D69/141B01D63/04B01D63/022B01D71/36
Inventor 森田彻井田清志船津始
Owner SUMITOMO ELECTRIC IND LTD
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