JPH0478425A - Hollow yarn membrane module - Google Patents

Abstract

PURPOSE:To improve the property to discharge trapped clads, etc., and to effectively utilize internal hollow yarn membranes by providing guiding plate projected between many pieces of the hollow yarn membranes in a water collecting pipe. CONSTITUTION:The water collecting pipe 2 is provided with 4 to 8 pieces of the recessed guiding plates 8 of an L shape which are projected radially and incline downward from 90 deg. to about 60 deg. at nearly the same height. Namely, the clads falling from the upper part deposit in the recessed part of the recessed guiding plates 8 and are forced to be discharged to the outside of a filter by a treated liquid at the time of the discharging of the liquid to be treated in the filter. Then, the clads are discharged without being deposited on the surface in the upper part of a frame body 6 and a bundling part 5 of the hollow yarn membranes 3. The central parts of the hollow yarn membranes are surely and effectively utilized at the time of filtration operation or bubbling operation according to this module. In addition, the deposits, such as clads, are easily discharged during the back washing operation or bubbling operation at the time of regeneration after use.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a hollow fiber membrane module, and is particularly applicable to a non-auxiliary material type prefiltration device such as a condensate purification system of a nuclear power plant. The present invention relates to a hollow fiber membrane module used.

(Prior Art) In boiling water nuclear power plants, measures are taken to prevent various types of crud from being brought into the reactor in order to reduce radiation exposure and maintain the integrity of the fuel. As part of these countermeasures, recent nuclear power plants have installed filters pre-coated with powdered ion exchange resin as prefiltration devices in addition to hot bed ion exchange towers to improve the crud removal performance of condensate purification systems. There is.

However, since this type of prefiltration device generates a large amount of used ion exchange resin as secondary radioactive waste, there is room for improvement in the storage, processing, and operating costs of waste resin. In other words, there is a need for the development of a non-auxiliary material type prefiltration device that generates less secondary radioactive waste, requires less space, and has low running costs.

In response to these demands, hollow fiber membrane filters, which are used in radioactive waste treatment facilities, have recently been used as non-auxiliary prefiltration devices for condensate purification systems.

Figures 4 and 5 show a hollow fiber membrane module 1 used in a conventional hollow fiber membrane filter, and Figure 5 shows a cross section taken in the direction of the V=V arrow in Figure 4. . That is, in the conventional hollow fiber membrane module 1 shown in FIGS. 4 and 5, a water collecting pipe 2 is disposed in the center along the axis line, and a large number of water collecting pipes 2 are arranged on the outer peripheral surface of the water collecting pipe 2 in the axial direction. Four hollow fiber membrane elements 4 made of organic polymer material hollow fiber membranes 3 are bundled together
is located. This hollow fiber membrane element 4 has a binding part 5 in which both the upper and lower ends of a large number of hollow fiber membranes 3 are assembled and integrated with an adhesive, that is, a synthetic resin. is inserted, filled with adhesive, and fixed. Note that a to-be-treated liquid introduction path 7 is provided between each hollow fiber membrane element 4 along the axis.

The hollow fiber membrane module 1 configured in this manner is incorporated into the outer shell of a filter (not shown) and used in the following steps.

However, in the filter configured as described above, when the liquid to be treated flows into the hollow fiber membrane module 1, since the hollow fiber membrane 3 is a valve filter of ~ type, only water of the liquid to be treated flows into the hollow fiber membrane module 1. Let it pass. Solid substances such as cladding contained in the liquid to be treated adhere to the surface of the hollow fiber membrane 3, and are separated and removed. That is, the liquid to be treated is filtered by the hollow fiber membrane 3.

The water that has flowed into the hollow fiber membrane 3 passes through the water collecting pipe 2, etc. inside the hollow fiber membrane module, flows as purified water (processed liquid) to 1-16 of the hollow fiber membrane module 1, and is then purified from the inside of the outer shell. leak to the outside.

When the condensate filtration operation is performed for a long time with this hollow fiber membrane module, a lot of foreign matter such as crud that remains unfiltered adheres to the surface of the hollow fiber membrane 3, and the filtration performance of the hollow fiber membrane 3 decreases. Five. Therefore, in order to restore the filtration performance of the hollow fiber membrane 3, a backwashing operation is performed at regular intervals. During this backwashing operation, a bubbling operation is also performed in parallel to remove foreign substances such as cladding from the hollow fiber membrane 3.

(Problems to be Solved by the Invention) The medium yarn membrane type filter has been described above. As if foreign substances such as cladding are hollow fibers! If a large amount adheres to i@3, backwashing and bubbling operations are performed at regular intervals.

When this bubbling operation is being performed, the hollow fiber membrane 3 is vibrated with bubbles such as air, kneaded on the surface of the hollow fiber membrane 3, and foreign matter is peeled off and removed. Nagara 7
In particular, the distribution density of the hollow fiber membrane 3 is high near the frame 6 for fixing both ends of the hollow fiber membrane 3, making it easy to trap crud in the liquid to be treated, and the hollow fiber near the water collecting pipe 2. The bubbling effect of the membrane 3 becomes low. In such cases, not only the filtration performance deteriorates, but also the hollow fiber membrane module
Conventionally, hollow systems have the problem of significantly shortening the service life of! Lower the packing density in step 3. In other words, it is conceivable to reduce the number of treated liquid introduction passages 7 and increase the number of them.
Since the throughput of one hollow fiber membrane module must be reduced, increasing the number of hollow fiber membrane modules 1 is difficult due to constraints such as the structure of the filter.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a hollow fiber membrane module that improves the discharge performance of trapped crud, etc., and makes effective use of the internal hollow fiber membrane.

[Structure of the invention]

(Means for Solving Problem 11) The present invention provides a water collection pipe, a large number of hollow fiber membranes arranged surrounding the water collection pipe, and both upper and lower ends of the large number of hollow fiber membranes that are tied together and fixed. In the hollow fiber membrane module comprising a frame body, the water collecting pipe is provided with a guiding plate protruding between the plurality of hollow fiber membranes.

(Function) The guide plate installed in the water collection pipe forms a discharge channel for deposits such as crud, an inlet channel for liquid to be treated, and an inlet channel for air during bubbling. Through these channels and introduction channels, crud and the like trapped in the hollow fiber membranes are discharged without being deposited, and the liquid to be treated and air are sufficiently introduced into the interior between the hollow fiber membranes. Therefore, since the air during bubbling is introduced into the deposition of cladding and the like and into the hollow fiber membrane, the deterioration in filtration performance is reduced and the life of the hollow fiber membrane module can be extended.

(Example) An example of a hollow fiber membrane module according to the present invention will be described with reference to FIGS. 1 to 3. In these figures, the same parts in FIGS. 4 and 5 are designated by the same reference numerals, and explanations of overlapping parts will be omitted unless necessary.

Figure 1 shows the overall configuration of the hollow fiber membrane module;
The figure is an enlarged view of the lower frame 6 and its vicinity of the hollow fiber membrane module. That is, both ends of the water collection pipe 2 are fixed to the frame body 6 provided at both ends of the lower L, and the water collection pipe 2 has a diameter of 90" to about 6" that protrudes in the radial direction.
Four to eight 1. A concave guide plate 8 is provided. This concave guide plate 8 forms a deposit discharge path 1, that is, the crud that has fallen from the top is deposited on the four parts of the concave guide plate 8.

When the liquid to be treated in the filter is discharged, it is carried away by the treatment liquid and is discharged outside the filter. Therefore, the crud is discharged without being deposited on the upper surface of the frame 6 and the binding portion 5 of the hollow fiber membrane 3.

On the other hand, in the water collection pipe 2 above the concave guide plate 8, there are 9
Four to eight L-shaped convex guide plates 9 tilted downward from 0" to 60 degrees are provided in the axial direction at appropriate intervals, for example, 10 to 50 degrees. These convex guide plates 9 This serves as an introduction path for the liquid to be treated during operation.

It also serves as an air introduction path during bubbling. Further, the processing liquid and air rise from below and collide with the tip of the protrusion of the convex guide plate 9. The processing liquid and air are guided to the inside of the hollow fiber membrane 3 and the water collection pipe 2 through the lower side of the convex guiding plate 9 . Further, the convex guide plate 9 is provided with a small hole 10 of about 2 m in length so that the liquid to be treated and air can pass upwardly, thereby increasing the effect and widening the introduction range. When the liquid to be treated is drained through the small holes 10, each time a flannel passes through the small holes 10, the drainage performance is improved.

In addition, as shown in an enlarged view in FIG. 3, concave and convex guide plates 8
, 9 can prevent the hollow fiber membrane 3 from being worn out.

Next, the operation of this embodiment will be explained.

In this embodiment, like the conventional example, a large number of hollow fiber membrane modules are housed in a filter to constitute a non-auxiliary material type filtration device. In this case as well, only water of the liquid to be treated that has flowed into the filter permeates into the hollow fiber membrane 3, and solids such as crats adhere to the surface of the hollow fiber membrane 3 and are separated and removed.

The water that has permeated into the hollow fiber membrane 3 flows into the water collecting pipe 2 and moves above the hollow fiber membrane module 1 as purified water (treated liquid).

When the hollow fiber membrane module 1 performs a condensate filtration operation for a long time and the filtration performance of the hollow fiber membrane 3 deteriorates, a backwashing operation and a bubbling operation are performed to restore the filtration performance. Through these regeneration operations, crats etc. deposited on the surface of the hollow fiber membrane 3 are removed.6 In the hollow fiber membrane module of the present invention, a concave guiding plate 8 is provided on the upper part of the frame body 6, and during bubbling, etc. The cladding trapped on the surface of the hollow fiber l113 falls and accumulates. Next, when the processing liquid in the container is discharged, the crud accumulated along the concave guide plate 8 falls to the bottom of the filter together with the backwash water.

In addition, during filtration operation, the liquid to be treated is introduced into the hollow fiber membrane 3 along the upper part from the water collecting pipe 2 by the convex guide plate 9 inclined downward, and during bubbling, air is introduced into the hollow fiber membrane 3 along the upper part. This is a function to be introduced internally.

In this way, according to this embodiment, the water collection pipe 2 has a recess.

By providing the convex guide plates 8 and 9, operation can be performed without unnecessarily increasing the filtration flow rate and the bubbling air flow rate, and the discharge performance of peeled crud and the like can be improved. Therefore, the regeneration period of the hollow fiber membrane module can be extended, and the life span of the hollow fiber membrane module can be extended.

In the above embodiment, the convex guide plate is provided with small holes in one row, but the small holes may not be provided in two to three rows, irregularly, or at different positions. The arrangement of the guide plates does not need to be as shown in the drawings, and may be arranged arbitrarily, rather than in a regular arrangement.

Furthermore, although the guide plate has been described as being L-shaped (chevron-shaped), it may also be an elliptical or flat plate with grooves and slits. moreover,
Only the concave guide plate may be provided at the lowermost end of the introduction path to be treated.

〔Effect of the invention〕

According to the present invention, the central part of the hollow fiber membrane can be reliably used effectively during filtration operation or bubbling operation, and deposits such as crud can be easily discharged during backwashing operation or bubbling operation during regeneration after use. can. Therefore, the regeneration period of the hollow fiber membrane can be extended, and economical efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a hollow fiber membrane module according to the present invention, FIG. 2 is an enlarged vertical sectional view showing the lower end of FIG. 1, and FIG. 3 is a guide plate in FIG. 1. Fig. 4 is a perspective view showing a conventional hollow fiber membrane module, and Fig. 5 is an enlarged longitudinal cross-section taken in the v-■ arrow direction of Fig. 4. It is a diagram. 1...Hollow fiber membrane module 2...Water collection pipe 3...
Hollow fiber membrane 4...Hollow fiber membrane element 5...Bundle portion 6...Frame body 7...Liquid to be treated introduction path 8...Concave guide plate 9...Convex guide plate 10... Small hole 11...Curved view

Claims (1)

[Claims] In a hollow fiber membrane module comprising a water collection pipe, a large number of hollow fiber membranes arranged surrounding the water collection pipe, and a frame body for binding and fixing both upper and lower ends of the large number of hollow fiber membranes, the above-mentioned A hollow fiber membrane module characterized in that a guide plate is provided in the water collecting pipe so as to protrude between the plurality of hollow fiber membranes.