JP3904693B2 - Hollow fiber membrane module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hollow fiber membrane module used when filtering highly polluted liquids such as filtering of river water and lake water, filtering of industrial water, and high-level treatment and wastewater treatment of sand filtration water.
[0002]
[Prior art]
Hollow fiber membrane modules are used in the field of microfiltration such as the production of sterile water, high-purity water, drinking water, high-level treatment, and air purification, as well as secondary treatment, tertiary treatment in sewage treatment plants, and solidification in septic tanks. It is also applied to the field of highly polluting water treatment such as liquid separation.
[0003]
In high-pollution water treatment, the hollow fiber membrane module is likely to be clogged during filtration, so after filtration for a certain time, air is sent from the bottom of the module to vibrate the hollow fiber membrane to wash the membrane surface, Membrane cleaning such as backwashing that allows water to flow in the direction opposite to the filtration direction is repeatedly performed.
[0004]
However, when a hollow fiber membrane module in which hollow fiber membrane knitted fabrics are converged and arranged in a columnar or concentric shape used for conventional microfiltration is used for highly polluting water treatment, the membrane surface increases as the treatment time elapses. The hollow fiber membranes adhere to each other due to deposits such as organic matter adhering to the surface, reducing the effective area of the hollow fiber membrane in the module, causing a sharp drop in filtration flow rate, and even if the membrane is periodically cleaned The membrane function was not easily recovered, resulting in a significant reduction in filtration efficiency.
[0005]
As a solution to the reduction of the effective area and the reduction of the washing efficiency, a rectangular flat plate in which the hollow fiber membrane knitted fabric is spread in a sheet shape and the hollow fiber membrane at one or both ends thereof is kept open and fixed to the frame. A type of hollow fiber membrane module has been proposed, and by disposing the hollow fiber membrane module at an appropriate interval, the membrane surface can be easily cleaned, and a reduction in filtration efficiency can be suppressed.
[0006]
However, when a flat hollow fiber membrane module is housed in a cylindrical container, the proportion occupied by parts other than the hollow fiber membrane increases, so that the volumetric efficiency is deteriorated. Cost. Therefore, multiple flat-type hollow fiber membrane knitted fabrics are stacked in parallel or folded in a zigzag shape and stored in the module, and scrubbing with air supplied from the air header maintains a high filtration function over a long period of time. A hollow fiber membrane module that can be used has been proposed in JP-A-9-141633.
[0007]
The hollow fiber membrane knitted fabric used in these hollow fiber membrane modules is formed by a known knitting method or weaving method in which the hollow fiber membrane is disposed on one of the warp and the weft and the other on the other.
[0008]
Usually, the knitting position of the warp yarn in the hollow fiber membrane knitted fabric is set to a certain position for the efficiency of the knitting work. When a module was created using this hollow fiber membrane knitted fabric, it was fixed with a fixing member so that the positions of the warp yarns of all the hollow fiber membrane knitted fabrics were adjacent to each other.
[0009]
The pitch of the knitted yarn of the hollow fiber membrane knitted fabric is preferably smaller in order to prevent the adjacent hollow fiber membranes from intermingling with each other due to scrubbing. When the hollow fiber membranes cross each other, the deposit starts to stick from that portion, and the filtration flow rate rapidly decreases.
[0010]
On the other hand, since the hollow fiber membranes are in contact with each other in the portion woven with the warp yarn, the effective membrane area as a filtration membrane is reduced. In order to suppress the reduction of the effective membrane area, it is preferable to reduce the number of knitting yarns, that is, the pitch of the knitting yarn is large, but there is a problem that it cannot be set large in order to prevent the above-mentioned adjacent hollow fiber membranes from intermingling. It was.
[0011]
[Problems to be solved by the invention]
The present invention relates to a hollow fiber membrane module made of a flat knitted fabric housed in a container, which reduces the effective membrane area by reducing the number of braided yarns without crossing adjacent hollow fiber membranes even by scrubbing. As a result of the study to suppress the hollow fiber, the hollow fiber that prevents the crossing of the hollow fiber membranes with fewer knitting yarns, and maintains a high filtration function over a long period of time, and is easy to recover the filtration function. It is to provide a membrane module.
[0012]
[Means for Solving the Problems]
Gist of the present invention, Ri Do from overlock yarn and hollow fiber membranes, arranged hollow fiber membranes to one of the warp and weft, parallel hollow fiber membrane knitted fabric formed by using the overcasting thread to the other plurality An arrayed element in which at least one end of the hollow fiber membrane constituting the hollow fiber membrane knitted fabric is kept open and fixed by a fixing member, a container for storing the element, and air is supplied into the container A hollow fiber membrane module comprising: a hollow fiber membrane module, wherein the yarns of adjacent hollow fiber membrane knitted fabrics are arranged in a staggered position relative to each other It is in.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an example of a hollow fiber membrane module of the present invention, and FIG. 2 is a perspective view showing an example of an element.
[0014]
The hollow fiber membrane module of the present invention includes an element in which a plurality of hollow fiber membrane knitted fabrics 1 composed of a hollow fiber membrane 1a and a warp yarn 1b are fixed in parallel by a fixing member 2, and a container 3 for storing the element, It is comprised from the air supply header 9 for supplying air in a container.
[0015]
As the hollow fiber membrane 1a constituting the hollow fiber membrane knitted fabric 1, for example, those made of various materials such as polyolefin, cellulose, polyvinyl alcohol, polysulfone, and polymethyl methacrylate are used. From the viewpoint of properties, it is preferable to use a polyolefin-based hollow fiber membrane such as polyethylene having a high strength and elongation. Moreover, if a hollow fiber membrane can be used as a filtration membrane, there will be no restriction | limiting in particular in a hole diameter, a porosity, a film thickness, an outer diameter, etc.
[0016]
As the warp yarn 1b which is the other constituent member of the hollow fiber membrane knitted fabric 1, those used for ordinary knitted fabrics and fabrics can be used, but they are hard in order not to damage the hollow fiber membrane 1a during production or handling. Preferably, multifilament, spun yarn, processed yarn, etc. are used more preferably.
[0017]
The hollow fiber membrane knitted fabric 1, the hollow fiber membrane 1a is arranged on one hand of the warp and weft, if the function of the hollow fiber membrane is held, what knitting method, it is those was by weaving methods May be. However, the weaving pitch of the warp yarn 1b is preferably 10 to 500 mm, and more preferably 50 to 200 mm.
[0018]
When the knitting pitch of the warp yarn 1b in the hollow fiber membrane knitted fabric 1 is constant and the distance from the fixing member to the warp yarn is constant as in the prior art, as shown in FIGS. It arrange | positions so that the position of the warp yarn 1b of the textile fabric 1 may adjoin (closest). In this case, in order to prevent the adjacent hollow fiber membranes 1a from intermingling, it is necessary to make the weaving pitch of the warp yarn 1b shorter than a predetermined length.
[0019]
On the other hand, in the hollow fiber membrane module of the present invention, as shown in FIGS. 5 and 6, the yarns 1b of the adjacent hollow fiber membrane knitted fabrics 1 are arranged at staggered positions relative to each other. For this reason, one warp thread 1b will be located in the middle part of the adjoining hollow fiber membrane knitted fabric, and the crossing of the hollow fiber membranes 1a can be prevented. The knitting pitch of the warp yarn can be increased, and thereby the reduction of the effective membrane area of the hollow fiber membrane 1a can be suppressed.
[0020]
As used herein, the term “mutual staggered position” as used in the present invention refers to a position corresponding to each bent portion of a so-called zigzag-shaped broken line composed of diagonal lines at a constant angle. A constant angle in a strict sense is not required, and it means a state satisfying a positional relationship such that the position of four warp yarns adjacent to one warp yarn is substantially the same distance.
[0021]
In the case of the hollow fiber membrane module shown in FIG. 1, one end (the upper end in the figure) of the hollow fiber membrane 1a of the hollow fiber membrane knitted fabric 1 is fixed in the upper part of the container 3 by the fixing member 2 while maintaining an open state. A plurality of hollow fiber membrane knitted fabrics 1 are arranged in parallel.
[0022]
The fixing member 2 functions as a member for fixing the hollow fiber membrane knitted fabric 1 and partitioning raw water and treated water without liquid leakage. For example, urethane resin, epoxy resin, unsaturated polyester resin, or the like is used.
[0023]
The container 3 in which the element is stored is not particularly limited as long as the material has corrosion resistance to highly polluted water of raw water and can be a pressure-resistant constituent material at the time of processing, but polycarbonate resin, ABS resin, It consists of a synthetic resin such as vinyl chloride resin or a metal such as stainless steel. The container 3 includes a raw water supply port 4, a treated water outlet 5, a deposit discharge port 6, an air outlet 7, an air supply port 8, and the like. Moreover, the container 3 is good also as a structure separable in a site | part suitably.
[0024]
The element and the container 3 may be integrated with the fixing member 2, but the element may be detachably stored in the container 3 with an O-ring or the like so that the element can be easily replaced.
[0025]
In the hollow fiber membrane module of the present invention, the highly polluted raw water supplied from the raw water supply port 4 is filtered through the hollow fiber membranes of the hollow fiber membrane knitted fabric 1 arranged in a plurality of elements, and filtered water. And discharged from the treated water outlet 5. On the other hand, the scrubbing air is supplied from the air supply port 8 to the air supply header 9. Air is discharged from the air header 9, scrubbing the hollow fiber membrane knitted fabric 1 while passing through the hollow fiber membrane knitted fabric 1 in the form of bubbles, cleaning the membrane surface of the hollow fiber membrane 1, and discharging from the air outlet 7 Is done. Deposits such as organic substances peeled off from the hollow fiber membrane surface by scrubbing are taken out from the deposit outlet 6.
[0026]
【The invention's effect】
In the hollow fiber membrane module of the present invention, the hollow fiber membranes are prevented from crossing and adhering to each other by scrubbing with a smaller amount of yarn, and high filtration efficiency can be maintained over a long period.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a hollow fiber membrane module of the present invention.
FIG. 2 is a perspective view showing elements used in the hollow fiber membrane module of the present invention.
FIG. 3 is a perspective view showing an example of adjacent hollow fiber membrane knitted fabrics in a conventional hollow fiber membrane module.
FIG. 4 is a cross-sectional view showing an example of adjacent hollow fiber membrane knitted fabrics in a conventional hollow fiber membrane module.
FIG. 5 is a perspective view showing an example of adjacent hollow fiber membrane knitted fabrics in the hollow fiber membrane module of the present invention.
FIG. 6 is a cross-sectional view showing an example of adjacent hollow fiber membrane knitted fabrics in the hollow fiber membrane module of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hollow fiber membrane knitted fabric 1a Hollow fiber membrane 1b Overlock yarn 2 Fixing member 3 Container 4 Raw water supply port 5 Treated water outlet 6 Deposit outlet 7 Air outlet 8 Air supply port 9 Supply header

Claims (1)

Ri Do and a whip yarn hollow fiber membranes, arranged hollow fiber membranes to one of the warp and weft, the hollow fiber membrane knitted fabric formed by using the overcasting thread on the other are parallel arrayed, hollow fiber An element in which at least one end of a hollow fiber membrane constituting the membrane knitted fabric is held open and fixed by a fixing member, a container for storing the element, and an air supply header for supplying air into the container A hollow fiber membrane module, wherein the yarns of adjacent hollow fiber membrane knitted fabrics are arranged in a staggered position relative to each other.

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