JPH0649124B2 - ▲ Ro ▼ Excessive element - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an overelement, and more particularly to an overelement of a over desalting device which is used by precoating with a superauxiliary agent.

[Background of the Invention]

For example, a long tubular element is used in a shell-and-tube type super desalting device used for water purification in a nuclear power plant. FIG. 9 shows an outline of the internal structure of a super desalination device installed in a primary cooling water purification system of a boiling water nuclear power plant as an example of this type of multitubular super desalination device. Tower tanks 2 and 3 are a ceiling plate and a bottom plate respectively provided in the tower tank 1, 4 is a cylindrical overelement, 5 is an element gap (a region between the respective overelements 4), and 6 is a central portion of the bottom plate 3. Provided water supply pipes, 7 and 8 are guide plates for introducing water 9 provided at the mounting part of the water supply pipe 6 of the bottom plate 3, and 10 is superfluous water 11 provided under the bottom plate 3 of the tower tank 1. Meeting room, 12
Shows the discharge pipe of the overwater 11.

This multi-tubular over-demineralizer has an outer diameter of about 50 mm inside the tower tank 1,
Approximately 80 mm of cylindrical over element 4 with a total length of 1.5 to 2.1 m
200 to 300 are installed at intervals of 4, and the upper end of the excess element 4 is fixed to the ceiling plate 2 by a hanging metal fitting, and the lower end has a pipe for extracting excess water penetrating the bottom plate 3. Water pipe 6
The introduced water 9 from the above is guided by guide plates 7 and 8 provided above the bottom plate 3, flows into the inter-element region 5 and flows upward, and while rising in the inter-element region 5, the outer periphery of the excess element 4 is increased. Of the excess element 4 to pass through the overlayer and pass down the flow path (see FIG. 10) in the pipe of the excess element 4 to flow out through the collecting chamber 10.

FIG. 10 is a schematic cross-sectional view of the structure and insertion state of the excess element 4, and the same parts as those in FIG. 9 are denoted by the same reference numerals, 13 is an element receiver, and 14 has a water passage opening 15. A support tube, 16 is a material layer (oversupport layer) provided on the support tube 14, 17 is a precoat layer of an over-assisting material formed on the material layer 16, and 18 is a push plate for pushing the excess element 4 19 Also, fixing rods 21, 22, and 23 fixed between the ceiling plate 2 and the bottom plate 3 using the springs 20 are gaskets, and 24 is a flow path in the excess element 4.
The excess element 4 is made by bundling and twisting ultrafine fiber system and winding it on a right cylindrical support tube 14 made of stainless steel or plastic having a large number of water passage openings 15
The material layer 16 having a thickness is formed. The inside of the support pipe 14 serves as a flow path 24 for the overwater 11. Further, a fixing rod 18 for fixing the excess element 4 to the ceiling plate 2 and the bottom plate 3 is provided so as to penetrate therethrough. The upper end of the excess element 4 is sealed by pressing the pressing plate 19 and the gaskets 21 and 22 with a spring 20. The lower end is fitted to the element receiver 13 with a gasket 23 interposed. The outer diameter of the material layer 16 is about 50 mm. On the material layer 16, a precoat layer 17 of a super-auxiliary agent precoated with a powdery ion-exchange resin having an average particle size of several tens of μm.
Is formed.

The introduced water 9 rises along the outer periphery of the over-element 4 and permeates the over-layer from the outside to the inside due to the pressure difference between the inside and outside of the over-layer consisting of the pre-coat layer 17 and the material layer 16 of the super-auxiliary agent. Desalination is performed.

However, the super-purified water that has passed through each position of the excess element 4 gathers in the flow path 24 and flows down, and the amount of water gradually increases as it approaches the outlet at the lower end of the flow path 24. Since the inner diameter of the support tube 14 is constant, the flow velocity of the flow path 24 gradually increases and reaches the maximum at the outlet at the lower end of the support tube 14. Further, the difference in flow velocity between the upper end portion and the lower end outlet portion in the support pipe 14 becomes larger as the excess element 4 becomes longer.

FIG. 11 shows the relationship between the flow velocity and the excess pressure difference in each part of the excess element 4, and the position of the excess element is shown by the distance from the lower end (outlet) of the excess element to the upper end on the horizontal axis. (mm), the vertical axis shows the flow velocity v (m / s) and the pressure difference ΔP, and respective characteristic curves are shown by v, ΔP = P ₁ -P ₂ . The overpressure difference ΔP in each part of the excess element 4 is a value obtained by subtracting the pressure P ₂ of the flow path 24 in the excess element 4 from the external pressure P ₁ of the excess element 4, but as the flow velocity v in the flow path 24 increases. Since the pressure P ₂ decreases due to the increase in pressure loss due to the velocity head,
As shown in the figure, the overpressure difference ΔP is maximized at the lower end of the overwater flow passage 24. If the over-resistance of the over-element 4 is the same in the length direction, the speed of water permeating the over-element 4 (over-speed) will also be high in the part where the over-differential pressure is large. That is, the excess element 4 is not effectively used from the viewpoint of overflow. FIG. 12 shows the overspeed V at each part of the overelement 4 when the value LV obtained by dividing the total overflow of the overelement 4 by the total overarea of the overelement 4 is changed. There is an excess element position (m) where the element outlet is 0, the horizontal axis shows the filtration speed V (m / h), and the LV is 4, 6, 8 and 10 m / h, respectively. It is shown. As is clear from this figure, the overspeed V is maximum at the outlet of the overelement 4, and the larger the value of LV, the greater the difference from the average value. Since the amount of permeated water per unit time in the region where the overspeed is large is also larger than in other regions, the amount of impurities that are brought into the overlayer and captured is also large, and as a result, the volume in the overprocess is increased. The progress from the excessive trapping (volume excess) to the superficial trapping (surface excess) occurs earlier than at other sites, so that the overlife is reduced.

Moreover, by trapping the impurities, the precoat layer 17 of the super-auxiliary agent locally contracts and becomes consolidated, and cracks (cracks) occur. Pre-coat layer 17 of super-auxiliary agent
When the material layer 16 below is rough, it passes through, so that the overperformance is reduced and the material layer 16 itself is locally soiled.
This accelerates the clogging of the material layer 16, and once the contaminated part cannot be cleaned even in the reverse cleaning, the initial differential pressure in the excess is increased. When the initial differential pressure is increased, the pressure increase due to excessive constant flow rate becomes larger than that when the initial differential pressure is small, and the time to reach the set pressure is shortened accordingly, and the over-life becomes short. Therefore, the time to replace a new over element is shortened in consideration of the over-life.

Further, the over-auxiliary agent precoat layer 17 is peeled and removed from the over-element 4 by the back washing step when the overpressure has reached the set pressure, and the over-element 4 is again pre-coated with a new auxiliary agent. Therefore, the number of precoats increases in the situation as described above. In an actual plant consisting of several tower tanks incorporating a large number of long excess elements of 200 to 300 per tower tank, the amount of precoat super-auxiliary agent wasted is 200 drums per year in terms of 1.1 million kWh power generation. Since the number of over-demineralizers reaches 2000 to 3000, the over-life of the desalinizer is short and the performance is poor, which is a problem from the viewpoint of reducing the amount of waste.

In addition, the above is the desalination in which the direction of the length of the introduced water flowing along the outer circumference of the excess element is opposite to the direction of the flow of the excess water flowing through the pipe inside the excess element after passing through the excess element. Although the vessel has been described, the situation is the same for the super desalinator in which these directions are the same.

[Object of the Invention]

An object of the present invention is to eliminate the drawbacks of the conventional excess element, extend the over-life of the excess element, and improve the performance.

[Outline of Invention]

The present invention relates to a long support having a water-permeable tube wall, a material layer provided on the outer peripheral surface of the support, and a precoat layer of an over-assisting material formed on the material layer. Introduced water that has been supplied along the longitudinal direction of the support along the outer periphery of the precoat layer has a permeation that has passed through the precoat layer and the material layer and flows through the pipe wall in the longitudinal direction thereof, and then exits. In an overelement provided with a superfluid flow path flowing out from an end, the support is composed of a support pipe having a large number of water passage holes, and an opening area of the water passage holes occupies a unit area of the support pipe. Is characterized in that it decreases as it goes toward the outlet end, and it is provided on an elongated support body having a water-permeable pipe wall and on the outer peripheral surface of the support body. A material layer and an over-assisting material precoat layer formed on the material layer, Water supplied along the longitudinal direction of the support along the outer periphery of the coating layer, the permeated water that has passed through the precoat layer and the material layer flows in the pipe wall in the longitudinal direction and flows out from the outlet end. In a pass element having a pass channel, the support comprises a support tube having water permeability and an inner tube having a plurality of water holes provided inside the support tube. The second characteristic is that the ratio of the open area of the inner tube to the unit area of the inner tube is reduced toward the outlet end.

In order to solve the conventional problems and effectively use the over-element in terms of over-flow, it is important to equalize the over-velocity of each part over the entire length of the over-element. It was made paying attention, and it was made based on the following examination results.

FIG. 13 shows the pressure P _{1 in} the outer region of the excess element and the excess element when the excess water in the flow path in the support pipe of the excess element is extracted downward by supplying water to the outer region of the conventional excess element from below. Shows the result of actual measurement of the difference (excess pressure difference) ΔP from the pressure P ₂ of the flow path in the support pipe at each position of the excess element for different LV values, and the horizontal axis indicates the outlet of the excess element. There is an over-element position (m) where 0 is 0, and the horizontal axis shows the excess pressure difference Δ.
P = (P ₁ −P ₂ ) (mmAg) is shown, and LV is 4, 6, 8 and 10 m / h, respectively. In this figure, the excess pressure difference ΔP gradually increases in the direction in which the excess water flows out. It should be noted that even when water is supplied to the outer region of the over-element in an upward flow and the over-water is extracted from the upper end of the support pipe of the over-element, the result is that the over-differential pressure gradually increases in the same direction. This is because the flow rate of the super-water flowing through the flow passage in the support pipe of the excess element, which has a constant flow passage diameter, increases as it approaches the outlet, and the flow velocity in this flow passage increases. This is because it causes a drop and affects the overpressure difference ΔP. If the excess resistance of the overlayer of the excess element is uniform, the overflow velocity increases at the site where the excess differential pressure is large.
Therefore, in order to make the overvelocity uniform over the entire length of the overelement, (1) the flow velocity in the passage in the support pipe of the overelement is made constant, or (2) the overlayer of the overelement is formed. It became clear that it was necessary to change the overresistance in the longitudinal direction.

Based on the results of such studies, the present invention achieves the intended object by gradually increasing the overresistance of the overelement overlayer toward the outlet end.

The applicant of the present application has applied for an invention related to this kind of pass element in Japanese Patent Application No. 58-243349.

Example of Invention

Embodiments will be described below with reference to the drawings. In the drawings, the same parts as those in FIG. 10 are designated by the same reference numerals, and the same parts are designated by the same reference numerals between the drawings.

FIG. 1 (a) is a longitudinal sectional perspective view of the first embodiment, and FIG.
Is also a plan view of the upper and lower ends, and FIG. 2 is a perspective view of an essential part of the second embodiment.

The excess element of the first embodiment has a large number of water passage openings 2
Around the rear material layer 16 in which a material layer 16 having an outer diameter of about 50 mm is formed by winding a stainless steel or non-metal fiber or mesh on the outer peripheral surface of an over-element support tube 25 having a uniform thickness. Is used to form a precoat layer (not shown) of a super-auxiliary agent made of powdery ion exchange resin, and the introduced water is introduced as an ascending flow along the outer surface thereof,
The excess water that has passed through each part is the support pipe 25 of the excess element.
The second embodiment has a large number of through holes 28 shown in FIG. 2 instead of the support tube 25 of the first embodiment. The support tube 27 of the excess element is used.

In these embodiments, the inner diameter and the outer diameter of the support pipe 14 are constant in the longitudinal direction, but the water passage opening 25 of the support pipe 25 or 27 is used.
Alternatively, the ratio of the opening area of 26 or 26 to the unit area of the support tube 25 or 27 (hereinafter simply referred to as the opening area) decreases along the longitudinal flow direction. First
In the embodiment, the opening area is changed by the number of holes having the same diameter,
In the embodiment, the opening area is changed according to the hole diameter. In addition, in FIG. 1 and FIG. 2, the water passage openings 26, 2
8 shows only the upper part and the lower part and the middle part is omitted, and FIG. 2 shows only a part (hereinafter, the same applies to FIGS. 3 to 8) and the opening area A ( It is linearly reduced from 1.3 to 1.5a) to the lower opening area a, whereby the opening area of the water passage hole of the support pipe decreases toward the outlet end.

FIG. 3 (a) is a vertical cross-sectional perspective view of the third embodiment, and FIG. 3 (b).
Is also a plan view of the upper and lower ends, and FIG. 4 is a perspective view of an essential part of the fourth embodiment.

The third and fourth embodiments are different from the first and second embodiments in that the inner and outer diameters are constant in the longitudinal direction of the over-element and the opening area of the water passage hole is in the longitudinal direction of the over-element. An inner pipe 29 or 31 having a large number of water passage holes 30 or 32 is fitted and inserted in a constant support pipe 14, and the opening area of the water passage holes 30 or 32 of the inner pipe 29 or 31 is exceeded. Opening area A (1.3 to 1.5a) at the top to area a at the bottom
The point is that the open area of the inner tube decreases toward the outlet end. The opening area of the inner pipe 29 or 31 is changed by the number of holes having the same diameter in the third embodiment, and is changed by the hole diameter in the fourth embodiment.

When the inner tube is fitted in this way, it is possible to prevent bending of the long excess element and deformation due to external pressure.

FIG. 5 (a) is a perspective view in vertical and horizontal cross section of the fifth embodiment, FIG. 5 (b) is a cross sectional view taken along line XX of FIG. 5 (a), and FIG. It is a perspective view of a part.

The fifth and sixth embodiments are different from the third and fourth embodiments in that the inner pipe 3 having a large number of water passage openings 34, 37.
3, 3 and 36 are formed of a tubular body having a triangular cross section, and the lower end of the inner pipe 33, 36 is provided with the flow passage 24.
5 is provided and linearly decreases from the opening area A (1.3 to 1.5a) at the upper portion in the lengthwise direction of the excess element to the area a at the lower portion thereof, whereby the water passage opening of the support pipe is formed. The area of the open area of the hole decreases as it approaches the outlet end. The opening area of the inner tube 33 is changed by the number of holes having the same diameter in the fifth embodiment, and is changed by the hole diameter in the sixth embodiment.

FIG. 7 (a) is a vertical sectional view of the seventh embodiment, FIG. 7 (b) is a sectional view taken along the line YY of FIG. 7 (a), and the difference from the embodiment of FIG. The inner pipe 38 having a square cross-section and a large number of water passage openings 39 is used in 14 and a push plate 40 having a sealing property is provided at the upper end of the element.

FIG. 8 (a) is a longitudinal sectional view of the eighth embodiment, FIG. 8 (b) is a sectional view taken along the line ZZ of the same (a), and the difference from the seventh embodiment is that the rim 43 is the same. Is provided with a large number of water passage openings 42
The point is that the cylindrical inner cylinder 41 having is used.

As in the first to eighth embodiments, the super-water which seals the end having a large opening area of the water passage opening of the over-element and is guided along the outer region of the over-element and permeates through each part of the over-layer. If it is extracted from the end side where the opening area of the water passage opening is small, the flow rate of the permeate flowing through the flow path in the support pipe or the inner pipe increases as it approaches the outlet end, but the passage of the support pipe or the inner pipe increases. Since the aperture area of the water aperture is reduced toward the outlet end, the permeability is reduced and the overspeed can be controlled, and the overspeed can be kept substantially constant at each portion in the longitudinal direction of the overelement.

In each of the above examples, an example in which the opening area of the support pipe or the inner pipe water passage opening is linearly reduced is shown.
The decrease may be curvilinear (for example, a trapezoidal shape). Further, in the above embodiments, the case was described in which the superfluid flows downward through the flow path in the support pipe and is withdrawn from the lower end.
It is also possible to make the opening area of the water passage opening of the support pipe or the inner pipe smaller toward the upper end, seal the lower end, and drain the excess water from the upper end. .

FIG. 14 is a cross-sectional view of the main part of still another embodiment. In this embodiment, the overresistance is changed by the structure of the material itself formed by winding the ultrafine fiber yarn bundle on the support tube 14. ing. In the material of this embodiment, the material layer 44 is not wound directly on the support tube 14 having a right cylindrical shape, but the material layer 45 having a larger over-resistance than the material layer 44 is wound so as to be thicker toward the outlet end. Then, the material layer 44 is wound so as to have a constant outer diameter. The over-resistance of the material layers 44 and 45 can be changed by the following operation. That is,
When the same fiber yarn is used, it can be changed according to (1) the strength and weakness of twisting of the fiber yarn in the bundle spring, and (2) the number of fiber yarns bundled together. In the method (1), since the gap between the fiber yarns is reduced by strengthening the twisting, the over resistance is increased by winding the product. In the method (2), when the number of fiber yarns to be twisted together is reduced and the winding is performed, the gap between the windings is small and the over resistance is increased.

FIG. 15 shows the over-resistance of the over-element when the material is wound in such a manner that the over-resistance varies depending on the location of the over-element, and the lower end (outlet) is 0 on the horizontal axis of this figure. Is the position (m) of the excess element in the direction of the upper end, and the vertical axis is the excess resistance R (-). From this figure, the over-resistance of the over-element can be increased at the outlet end, and thus over-speed can be made uniform.

As described above, in the over-element of each of the above-described embodiments, the over-velocity at each part in the longitudinal direction can be made uniform, and as a result, the following effects can be obtained.

(1) In order to precoat the material layer 16 of the over-element with the super-auxiliary agent, water in which the super-auxiliary agent is suspended is supplied as described above.
As shown in FIG. 16 in which the horizontal axis and the vertical axis respectively indicate the thickness (mm) and the over-element position (m) where the over-element outlet is 0, when pre-coating a predetermined amount of the super-auxiliary agent, The small portion has a small amount of the super-auxiliary agent brought in and the auxiliary layer thickness is formed thin, whereas the portion with a large overspeed has the auxiliary layer thickness formed thick, whereas in the case of the present invention, the horizontal axis indicates As shown in FIG. 17 in which the vertical axis and the vertical axis are the same, the auxiliary layer thickness is formed uniformly on average.

(2) In the over-element, the amount of impurities trapped is large in the part where the over-speed is large, and the contraction of the precoat resin occurs earlier than the other parts, causing the contraction to move to the side where the over-speed is smaller, Increase the differential pressure quickly to accelerate over-life. However, the horizontal axis and the vertical axis respectively indicate the overtime (days) and the overpressure difference ΔP (kg / cm ² ), and the conventional overelement and the overelement of the present invention are shown in comparison. As is apparent from the above, the overelement of the present invention can prolong the life of the overelement as compared with the conventional overelement.

(3) FIG. 19 and FIG. 20 are cross-sectional perspective views of the main part of the conventional over-element and the over-element of the present invention, respectively, which schematically show the state of the over-element.
Represents a crack, 45 represents a cladding, and 46 represents pollution.

In the conventional over-element, as shown in FIG. 19, a portion where the over-speed is large has a large amount of the clutch 45 brought into it, so that the crack 44 locally occurs.
The generation of the cracks 44 causes deterioration of overperformance and contamination 46 of the overelements due to the entrance of the cladding 45 from the cracks 44. Contamination of the excess element results in an increase in the overpressure differential of the excess element itself.
On the other hand, in the overelement of the present invention having a uniform overspeed, as shown in FIG. 20, it is possible to prevent the generation of cracks, the entrance of the cladding from the cracks, and the contamination of the overelements.

That is, according to the overelements of these examples,
Since the overvelocity at each part in the longitudinal direction of this kind of overelement is made uniform, the transition from volume over to surface over can be delayed as a whole, and the shrinkage of the pre-coat layer of the superauxiliary agent and cracking can be prevented. Occurrence and clogging of the timber layer due to it can be avoided or delayed as much as possible,
It is possible to extend the over-life, and it is possible to reduce the amount of waste, as well as to reduce the required number of times of replacement of the over-element, removal of the over-auxiliary agent and new pre-coating thereof. Further, there is an advantage that a precoat layer having a substantially uniform thickness can be formed in the longitudinal direction even when precoating the super-auxiliary agent.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The over-element of the present invention extends the over-life and enables high performance, and has a great industrial effect.

[Brief description of drawings]

FIG. 1 (a) and FIG. 3 (a) are vertical cross-sectional perspective views of first and third embodiments of an overelement of the present invention, respectively.
1 (b) and 3 (b) are plan views of the upper and lower ends of FIG. 1 (a) and FIG. 3 (a), respectively, and FIG. 5 (a).
Is also a perspective view in vertical and horizontal cross section of the fifth embodiment, and FIG. 5 (b).
Is a sectional view taken along the line XX in FIG. 5 (a), and FIGS. 2, 4, and 6 are perspective views of the essential portions of the second, fourth, and sixth embodiments, and FIG. a) and FIG. 8 (a) are longitudinal sectional views of the seventh and eighth embodiments, respectively, and FIG. 7 (b) and FIG.
7B is a view taken along the line YY of FIG.
FIG. 9A is a sectional view taken along the line ZZ, FIG. 9 is a longitudinal sectional view showing the outline of the internal structure of a multitubular super desalting device, and FIG. 10 is a longitudinal sectional view showing the outline of a conventional superelement. , FIG. 11 is a diagram showing the relationship between the flow velocity and excess pressure in each part of the conventional over-element, FIG. 12 is a diagram showing the over-speed in each part of the conventional over-element, and FIG. FIG. 14 is a diagram showing the overpressure difference in each element portion of the conventional overelement, FIG. 14 is a sub-sectional view of the essential portion of another embodiment of the overelement of the present invention, and FIG. 15 is the element in the embodiment of FIG. 16 and 17 are diagrams showing the over-resistance at each portion, and FIGS. 16 and 17 are diagrams showing the thickness of the precoat layer of the over-assisting material of the over-element of the conventional and the present invention, respectively.
The figure is a diagram showing the over-life of the over-element of the present invention in comparison with the case of the conventional over-element, and FIGS. 19 and 20 schematically show the states of the over-element of the conventional and the present invention, respectively. FIG. 4 ... excess element, 14 ... support tube, 16 ... material layer, 2
4 ... Flow path, 25, 27 ... Support pipe, 26, 28 ... Water passage opening, 29, 31 ... Inner pipe, 30, 32 ... Water passage opening.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuya Ehara 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Co., Ltd. (56) References -177419 (Saikai Sho 57-99713) Microfilm (JP, U), which is a photograph of the description and drawings attached to the application.

Claims (4)

[Claims] 1. A long support having a water-permeable tube wall, a material layer provided on the outer peripheral surface of the support, and a precoat layer of an over-assisting material formed on the material layer. Has and
Introduced water supplied along the longitudinal direction of the support along the outer periphery of the precoat layer, the permeated water that has permeated the precoat layer and the material layer, flows in the longitudinal direction in the pipe wall and flows out from the outlet end. In the excess element provided with a water passage, the support is a support tube having a large number of water passage holes, and the opening area of the water passage hole occupies a unit area of the support pipe. An over-element characterized by decreasing toward the edge. 2. The ratio of the opening area of the water passage holes to the unit area of the support pipe is the number of holes having the same diameter, or
The excess element according to claim 1, wherein the excess element is determined by the diameter of a single hole. 3. A long support having a water-permeable tube wall, a material layer provided on the outer peripheral surface of the support, and a precoat layer of an over-assisting material formed on the material layer. Has and
Introduced water supplied along the longitudinal direction of the support along the outer periphery of the precoat layer, permeated water which has permeated the precoat layer and the material layer, flows in the pipe wall in the longitudinal direction and flows out from the outlet end. In a pass element having a pass channel, the support comprises a support tube having water permeability and an inner tube having a plurality of water holes provided inside the support tube. The ratio of the open area of the inner tube to the unit area of the inner tube is reduced toward the outlet end. 4. The ratio of the open area of the water passage hole to the unit area of the inner pipe is determined by the number of holes having the same diameter or the hole diameter of a single hole. Range third
Excessive element described in paragraph.