JP2509204Y2 - Hollow fiber membrane module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hollow fiber membrane module.

<Prior Art> Among the membrane modules, a module using a hollow fiber membrane bundle has a large membrane area per unit volume, which is advantageous for making the module compact. In particular, the vertical hollow fiber membrane module is advantageous in improving the treatment capacity per unit installation space. For example, water treatment in a nuclear power plant (particularly, condensate purification system water treatment in a BWR-type nuclear power plant). ) And semiconductor ultrapure water production (especially pretreatment of RO treatment in ultrapure water production process).

FIG. 4 shows an example of a conventionally known vertical (suspended) hollow fiber membrane module. In FIG. 4, 1 ', ... Numerals are a large number of hollow fiber membranes, 2', ... Are communication tubes arranged in a hollow fiber membrane bundle, and 4'is a protective tube. 31 'and 32' are an upper partition wall and a lower partition wall, respectively, and the upper end of the hollow fiber membrane and the upper end of the communication pipe are opened on the upper surface of the upper partition wall,
The lower end of the hollow fiber membrane and the lower end of the communication pipe are open on the lower surface of the lower partition wall. 7'is a cap attached to the lower end of the protective cylinder, 9'is an air receiver attached to the lower end of the protective cylinder, 5'is a raw water supply hole provided in the protective cylinder, 9'is an air introduction hole, and 10 'is a scale discharge. It is a hole.

The hollow fiber membrane module has a partition plate as shown in FIG.
11 'is used by suspending it in the pressure vessel 12'. Thus, the raw water is pressed from the raw water inlet 13 'mainly through the raw water supply hole 5' into the protective cylinder 4 ', the raw water is filtered by the hollow fiber membranes 1', ... Directly in the upward direction, the remaining portion is guided in the downward direction, water is collected once by the cap 7 ', and then upwards via the communication pipe 2'. in this way,
Since the permeated water flows in the upward and downward directions separately, the pressure loss in the hollow fiber membrane can be reduced and the permeation efficiency can be increased even though the hollow fiber membrane has a small inner diameter.

In the filtration treatment, it is indispensable to wash the membrane in a timely manner, because the filtration performance is reduced due to the adhesion of scale to the membrane surface as the filtration operation is continued. In the above module, the method of introducing air from the air introducing nozzle 14 'into the module through the air receiver 8'and the air introducing hole 9', that is, air scrubbing cleaning is adopted. In this method, the air introduced into the module is made into bubbles to rise in the module, and this is discharged from the hole 5 '(raw water supply hole) in the upper part of the protective cylinder, and the rising bubbles cause convection of raw water, It is intended that the scale layer on the surface of the hollow fiber membrane is peeled off by shaking of the hollow fiber membranes 1 ', ... And the peeled scale is removed from the scale discharge holes 10'.

<Problems to be Solved> As described above, in the hollow fiber membrane module shown in FIG. 4, since permeated water flows in both directions in the hollow fiber membrane, the permeated water flows toward one side (upper side). The permeated water flow resistance inside the hollow fiber membrane is much lower than that of the hollow fiber membrane module that is only directed to flow, and the permeated water flow rate is accordingly large, resulting in a large permeation flux per unit area of the membrane. The amount of scale adhered to the film surface also increases. Therefore, the air scrubbing cleaning for scale removal requires more rigorous cleaning than the hollow fiber membrane module in which the permeated water is made to flow only toward one end side on the upper end side in the hollow fiber membrane.

However, conventionally, as shown in FIG. 4, an air introduction hole 9'is provided on the lower side surface of the protective cylinder 4 ', and most of the air introduced into the module is at the top of the hollow fiber membrane bundle 1' ,. The hollow fiber membrane bundle 1 ', ... It is difficult to perform satisfactory cleaning near the center of the. Further, in the hollow fiber membrane module shown in FIG. 4, the amount of scale adhered is large, and therefore the amount of peeled scale at the time of air scrubbing is also large, but conventionally, as shown in FIG. The air inlet hole 9'from the upper surface of the lower partition wall 32 'to the hole 10'.
Since the position of the scale discharge hole 10 'is considerably higher than the upper surface of the lower partition wall 32',
The peeled scale easily accumulates on the upper surface of the lower partition wall 32 ', and it becomes difficult to smoothly discharge the peeled scale, and the efficiency of air scrubbing cleaning is unavoidably lowered.

An object of the present invention is to provide a suspended hollow fiber membrane module which can remove the scale of the entire hollow fiber membrane bundle well and can sufficiently remove the residual scale on the upper surface of the lower partition wall.

<Means for Solving the Problems> A hollow fiber membrane module according to the present invention has a vertical communication tube arranged in a vertical hollow fiber membrane bundle, and the hollow fiber membrane bundles have an upper end and a lower end. While maintaining the open state of the upper and lower ends of the bundle and the open state of the upper and lower ends of the communication pipe, an upper partition wall and a lower partition wall are provided respectively, and a protective cylinder is provided across both partition walls.
A cap is attached to the lower end of the protective cylinder at the upper end of the cap, an air receiving portion is provided around the lower surface of the cap, and an air introducing pipe portion is provided from the lower surface of the cap to the lower partition wall. And a scale discharge hole is provided at the lower end of the protective cylinder.

<Description of Embodiments> Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.
The drawing is a sectional view taken along line II-II in FIG. 1 and 2, 1, ... are vertical hollow fiber membranes (inner diameter 0.1 to 0.5).
mmφ, outer diameter 0.2 to 1.0 mmφ), 2, ... Are communication tubes arranged in the hollow fiber membrane bundle, and a hollow fiber membrane or a water pipe having a larger diameter than the hollow fiber membrane can be used. Reference numeral 31 denotes an upper partition provided at the upper end of the bundle of hollow fiber membranes, and the upper ends of the hollow fiber membranes 1, ... And the communication tubes 2, ... Are open at the upper surface of the upper partition. Reference numeral 32 denotes a lower partition wall provided at the lower end of the hollow fiber membrane bundle, and the lower ends of the hollow fiber membranes 1, ... And the communication pipes 2, ... Are open at the lower surface of the lower partition wall. The upper partition wall 31 and the lower partition wall 32 can be formed by, for example, casting a curable resin (epoxy resin).
Reference numeral 4 is a protective cylinder provided over both partition walls 31, 32, and raw water supply holes 5, ... Are provided in the upper part thereof. Reference numeral 6 is an upper metal fitting screwed to the upper end of the protective cylinder 4 via an O-ring 61. 7
Is a cap disposed at the lower end of the protective tube 4 via an O-ring 71, and includes the entire hollow fiber membrane and the lower end opening of the communication pipe. Reference numeral 8 denotes an air receiving portion provided on the outer periphery of the lower surface of the cap 7. Reference numeral 9 denotes an air introducing pipe portion provided from the bottom surface of the cap 7 toward the lower partition wall 32, and the tip of the pipe portion 9 is watertightly inserted into the air introducing hole 320 of the lower partition wall 32 through the O-ring 91. Is. The lower partition wall 32 has a plurality of air introduction holes 320, which are provided in a dispersed manner.

If the cross section of the hole has an arc shape (in this case, the cross section of the air introduction pipe section also has an arc shape), only one may be provided. Thus, the number of the air introduction holes 320 is usually 1 to 8, and 10 is a scale discharge hole provided in the protective cylinder 4, which is provided close to the upper surface of the lower partition wall.

In FIG. 1, 11 is a partition plate, 12 is a pressure vessel, 13 is a raw water inlet, and 14 is an air introduction nozzle. In the above, as shown in FIG. 3, an air receiver 8 separate from the cap 7 may be attached to the cap 7 by adhesion or screwing. Further, the air introducing pipes 9, ... Are embedded in the lower partition wall 32 by penetration,
It is also possible to seal between the cap 7 and the air introduction pipe 9 by the packing 72.

<Effects of the Invention> The vertical hollow fiber membrane bundle module according to the present invention is configured as described above, and since air for air scrubbing cleaning can be introduced from the lower partition wall side, Can introduce air as rising bubbles, can also induce convection of raw water in the central portion, and can clean the entire hollow fiber membrane bundle well. In addition, since the upper end of the cap is connected to the lower end of the protective cylinder, despite the mounting of the cap, the protective cylinder can be provided with a scale discharge hole at a position close to the upper surface of the lower partition wall. It can be discharged smoothly without being left on the upper surface of.

Therefore, the hollow fiber membrane module is a system in which the permeated water in the hollow fiber membrane is caused to flow toward both the upper and lower sides, and the permeated flux can be increased because the permeated water flow resistance in the hollow fiber membrane is low, Accordingly, although the amount of scale attached to the membrane is large, the scale can be reliably washed and removed, and the permeation flux can be easily restored to the initial flux.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, and FIG.
FIG. 3 is a sectional view taken along line II-II in FIG. 3, FIG. 3 is an explanatory view showing a main part of another embodiment of the present invention, and FIG. 4 is an explanatory view showing a conventional example. 1 ... Hollow fiber membrane, 2 ... Communication tube, 31 ... Upper partition wall, 32 ...
... Lower partition wall, 4 ... Protective cylinder, 7 ... Cap, 8 ... Air receiving part, 9 ... Air introducing pipe part.

Claims (1)

(57) [Scope of utility model registration request] 1. A vertical communication pipe (2) is arranged in a bundle of vertical hollow fiber membranes (1), and the upper and lower ends of the hollow fiber membrane bundles are open at the upper and lower ends of each hollow fiber membrane bundle. In addition, the upper partition wall (31) and the lower partition wall (32) are maintained by maintaining the open state of the upper and lower ends of the communication pipe.
And a protective cylinder (4) provided over both of these partition walls, and a cap (7) is provided at the lower end of the protective cylinder (4).
Is attached to the upper end of the cap, an air receiving portion (8) is provided around the lower surface of the cap (7), and an air introducing pipe portion (9) is provided from the lower surface of the cap (7) to the lower partition wall (32). The air introduction pipe portion (9) is communicated with the inside of the protection cylinder (4) through the lower partition wall (32), and the scale discharge hole (10) is provided at the lower end of the protection cylinder (4). Hollow fiber membrane module.