JP2001137671A - Water treating device, water making method and piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water treating device having piping which is adequate as piping materials, such as pipes for introducing high-pressure fluid including corrosion components, such as seawater, of a high pressure and high salt- component concentration and their joints, consists of an inexpensive and rigid structure and is highly corrosion resistant. SOLUTION: This piping consists of the composite structure having a cylindrical corrosion resistant water pipe 11 consisting of a corrosion resistant material, such as super-austenitic stainless steel or titanium material, a metallic pressure resistant shell 12 disposed so as to cover the inner pipe body and a sealing material 14 consisting of a plastic cement material, etc., packed between the shell pipe body and the inner pipe body. Its end is provided with a bushing consisting of the corrosion resistant material to assure the corrosion resistance in the joint part as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment apparatus for obtaining treated water of raw water through, for example, a reverse osmosis membrane, a fresh water producing method using the water treatment apparatus, and a pipe suitable for use in the method.

[0002]

[Related background art] Generation of freshwater from seawater / brine,
Alternatively, for generating water from river / lake water, for example, a reverse osmosis treatment device equipped with a reverse osmosis membrane module unit is used. The reverse osmosis membrane module unit includes a reverse osmosis membrane that exhibits a reverse osmosis action with respect to seawater (supply water) supplied to a predetermined pressure and supplied through the reverse osmosis membrane. ).

[0003]

However, the operating pressure of this type of reverse osmosis membrane module unit, that is, the reverse osmosis membrane module unit exhibits reverse osmosis, and converts permeated water (fresh water) from seawater (supply water). The supply pressure of the seawater (supply water) necessary for permeation generation is extremely high, for example, about 6 MPa. Moreover, the salt concentration of seawater supplied to the reverse osmosis membrane module unit is generally about 3.5%, and excess seawater discharged after generating permeated water (fresh water) in the reverse osmosis membrane module unit. Is concentrated and discharged to a salt concentration of about 5.8%. Incidentally, in the reverse osmosis treatment apparatus having the configuration in which the reverse osmosis membrane module unit is provided in two stages, the operation pressure may be increased to about 9 MPa in the second stage, and the salt concentration of the surplus seawater may be 8. It can be as high as 8%.

[0004] However, as pipes and joints for guiding seawater (supply water) to the reverse osmosis membrane module unit and discharging excess seawater (concentrated water) from the reverse osmosis membrane module unit, there are conventionally known pipe materials. Generally, only stainless steel is used, and its corrosion (hole corrosion and crevice corrosion) poses a serious problem. In this regard, it is conceivable to construct the piping material using a highly corrosion-resistant material such as super austenitic stainless steel or titanium material, but the material itself is very expensive, and how to withstand the pressure resistance The issue is how to ensure reliability.

The present invention has been made in view of such circumstances, and has as its object to provide a pipe for guiding a high-pressure fluid containing corrosive components such as seawater having a high salt concentration and a high pressure, and a piping material such as a joint thereof. It is an object of the present invention to provide an inexpensive, robust structure that is suitable as the above, and that is excellent in corrosion resistance. Another object of the present invention is to provide a water treatment apparatus and a fresh water producing method which are robust and have excellent corrosion resistance.

[0006]

In order to achieve the above-mentioned object, a water treatment apparatus according to the present invention comprises a treatment means for treating raw water to obtain the treated water, and at least a raw water side pipe and / or a raw water side pipe of the treatment means. A treated water-side pipe, wherein the raw water-side pipe and / or the treated water-side pipe are provided with a corrosion-resistant water pipe, a pressure-resistant outer shell covering the water pipe, and a pressure-resistant outer pipe between the pressure-resistant outer shell and the corrosion-resistant water pipe. It is characterized by including an interposed sealing material.

Preferably, the processing means comprises a processing means using a reverse osmosis membrane. As described in claim 3, the pressure-resistant outer shell has a hole for interposing a sealing material between the pressure-resistant outer shell and the corrosion-resistant water pipe. Furthermore, as described in claim 4, the pressure-resistant outer shell has a joint at at least one end.

[0008] Further, a fresh water producing method according to the present invention is carried out by using a water treatment apparatus having the above-described structure. Further, the pipe according to the present invention comprises, as described in claim 6, a corrosion-resistant water pipe, a pressure-resistant outer shell that covers the water pipe, and a sealing material interposed between the pressure-resistant outer shell and the corrosion-resistant water pipe. It is configured with.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A water treatment apparatus according to one embodiment of the present invention will be briefly described below with reference to the drawings. As shown in FIG. 2, this water treatment apparatus treats raw water such as seawater and obtains permeated water or concentrated water as treated water, and a reverse osmosis membrane module using a reverse osmosis membrane as a treatment means. It is a reverse osmosis treatment device using a unit. FIG.
In the above, supply water (seawater) which has been subjected to pretreatment such as sterilization and turbid component removal is supplied to a first reverse osmosis membrane module unit 2 via a booster pump 1 and the first reverse osmosis membrane module -Permeated water (fresh water) permeated by reverse osmosis in the unit 2 is obtained. Then, the concentrated water (seawater) discharged from the first reverse osmosis membrane module unit 2 is further pressurized through the turbocharger 3 and supplied to the second reverse osmosis membrane module unit 4 at the next stage. The second reverse osmosis membrane module unit 4 is configured to further obtain permeated water (fresh water) permeated by reverse osmosis.

The above reverse osmosis membrane module unit is
A spiral type element as shown in FIG. 3 is arranged in series in a pressure vessel, and has a structure as shown in FIG.
3, the element 30 has a spiral structure in which a membrane unit including a reverse osmosis membrane 33, a raw water flow path material 33, and a permeated water flow path material 34 is wound around the water collection pipe 11. In FIG. 4, the reverse osmosis membrane module unit 40 includes a plurality of elements 30 which are separated by a brine seal 35 while a pressure vessel 41 is connected in series via a joint 42.
It is arranged within. One end of the water collecting pipe 31 is sealed by a product tube cap 46, and the pressure vessel 41 has a raw water port 43 for supplying seawater, concentrated water, and the like, and a permeated water port 44 for extracting permeated water permeated through the reverse osmosis membrane. When,
A concentrated suction port 45 for taking out concentrated water is provided.

The supply water such as seawater or concentrated water introduced from the raw water inlet 43 is subjected to reverse osmosis treatment by the element 30, and the permeated water is guided to the permeated water port 44 through the water collecting pipe 31. On the other hand, the concentrated water is sequentially supplied to the element 30, and the permeated water is taken out through the water collecting pipe 31 in the same manner as described above, and the concentrated water is finally taken out from the concentrated water port 45.

The turbocharger 3 is driven by using concentrated water (seawater) discharged from the second reverse osmosis membrane module unit 4, and the driving force of the turbocharger 3 is the second. Reverse osmosis membrane module unit 4
The flow rate is controlled by a valve 5 for adjusting the flow rate of the concentrated water (excess seawater) discharged from the tank and a valve 6 for controlling the bypass flow rate of the concentrated water to the turbocharger 3.

Incidentally, in the above reverse osmosis treatment apparatus, the pressure of the supply water (sea water) which is supplied to the first reverse osmosis membrane module unit 2 after being pressurized through the pressure increasing pump 1, in other words, the first reverse osmosis The operating pressure of the membrane module unit 2 is set to a high pressure of, for example, about 6 MPa. It is discharged from the first reverse osmosis membrane module unit 2,
The pressure of the supply water (seawater) that is boosted by the turbocharger 3 and supplied to the second reverse osmosis membrane module unit 4, that is, the operating pressure of the second reverse osmosis membrane module unit 4 is increased to about 9 MPa. Can be

Under such conditions, for example, the permeated water (fresh water) can be obtained from the first reverse osmosis membrane module unit 2 at a recovery rate of about 40% with respect to the supplied water amount. From the reverse osmosis membrane module unit 2, the permeated water (fresh water) can be obtained from the remaining 60% concentrated water discharged from the first reverse osmosis membrane module unit 2 at a recovery rate of about 33%. it can. As a result, a total recovery of about 60% can be achieved.

If the salt concentration of seawater supplied to the first reverse osmosis membrane module unit 2 is about 3.5%, the permeated water ( The salt concentration of surplus seawater discharged after producing freshwater) is concentrated to about 5.8%. In addition, the second reverse osmosis membrane module unit 4 using the concentrated water having a salt concentration of about 5.8% as a supply water discharges excess seawater having a salt concentration of about 8.8% by the reverse osmosis action. I do.

The pipes used for the reverse osmosis treatment apparatus constructed as described above and having high salt concentration and high-pressure seawater or high-concentration seawater, and pipes such as joints thereof are shown in FIG. It has a structure as shown. The piping generally includes a corrosion-resistant water pipe 11, a pressure-resistant outer shell 12 covering the water pipe 11, and a sealing material interposed between the pressure-resistant outer shell 12 and the corrosion-resistant water pipe 11. Become.

That is, the pipe has a cylindrical corrosion-resistant water pipe 11 made of a corrosion-resistant material such as super austenitic stainless steel or titanium material, and has an inner diameter slightly larger than the outer diameter of the corrosion-resistant water pipe 11. And a metallic pressure-resistant outer shell 12 having a high pressure-resistant strength and having a cylindrical pressure-resistant structure provided so as to cover the metal. At both ends of the pressure-resistant outer shell 12, metal flanges 13 forming joints are provided. The flange body 13 has a thick disk-shaped flange part 13a fitted into the end of the corrosion-resistant water pipe 11, and a tapered part 13b provided at the base of the flange part 13a and forming a connection part with the pressure-resistant outer shell 12. Consists of Then, the tip of the tapered portion 13b is butted against the pressure-resistant outer shell 12, and is welded over the entire outer periphery of the butted portion to be firmly joined and integrated with the pressure-resistant outer shell 12.

The flange 13a is provided with a plurality of connection holes 13c at equal angular intervals in the circumferential direction. As will be described later, a plurality of pipes which are connected by mutually abutting the flange bodies 13 via a ring-shaped gasket 21 are pressed by bolts 22 and nuts 23 which are inserted and fastened to these connection holes 13c, respectively. The butted surfaces are firmly connected via a gasket 21 in a watertight manner and can withstand high pressure.

On the peripheral surface of the cylindrical pressure-resistant outer shell 12 provided so as to cover the corrosion-resistant water pipe 11, a plurality of filling holes 1 are formed.
2a is pierced. These filling holes 12a are used to fill a gap between the corrosion-resistant water pipe 11 and the pressure-resistant outer shell 12 with a sealing material 14 such as a resin. Thus, the sealing material 14 filled into the inside of the pressure-resistant outer shell 12 from the filling hole 12 a is formed by the corrosion-resistant water pipe 11 and the pressure-resistant outer shell 12.
And the pressure-resistant outer shell 1
2 and plays a role of firmly joining the two.

By filling the sealing material 14, the corrosion-resistant water pipe 11, the sealing material 14, and the pressure-resistant outer shell 12 are formed.
A three-layer composite structure withstand pressure and corrosion resistance is realized. The pressure-resistant / corrosion-resistant pipe has a sufficiently high corrosion resistance against high-pressure seawater with a high salt concentration, which is guided into the inside thereof, by a corrosion-resistant water pipe 11 made of a corrosion-resistant material such as super austenitic stainless steel or titanium material. In addition, a metal pressure-resistant outer shell 12 that covers the corrosion-resistant water pipe 11 via a sealing material 14 ensures a sufficient pressure-resistant strength.

In particular, only the corrosion-resistant water pipe 11 which is in direct contact with seawater having a high salt concentration is made of super-austenitic stainless steel, titanium material or the like having high corrosion resistance, and a high-pressure seawater 12 is formed by a pressure-resistant outer shell 12 covering the periphery thereof. Since the pressure-resistant outer shell 12 has a structure that ensures the pressure resistance against the pressure, an inexpensive non-corrosion-resistant metal material can be used as the pressure-resistant outer shell 12. Therefore, it is sufficient for the pressure-resistant outer shell 12 to be made of inexpensive general stainless steel or the like in consideration of exposure to the weather. Therefore expensive super austenitic
The member to be formed using stainless steel, titanium material, or the like can be only the corrosion-resistant water pipe 11, and the overall manufacturing cost can be reduced.

The sealing material 14 filled between the corrosion-resistant water pipe 11 and the pressure-resistant outer shell 12 acts as a buffer against high pressure applied to the corrosion-resistant water pipe 11, so that the pressure-resistant outer shell 12 reduces the pressure of the seawater. It can be received almost uniformly and stably from the corrosion-resistant water pipe 11 via the sealing material 14. Therefore, no local stress is applied to the pressure-resistant outer shell 12, and the pressure-resistant strength thereof is stably maintained. Therefore, there is no possibility of causing a fatigue crack or the like of the pressure-resistant outer shell 12, so that safety and reliability are improved. The effects such as excellent in terms of properties can be obtained. Furthermore, even when the seawater leaks due to deterioration of the corrosion-resistant water pipe 11 or the like, since the surrounding area is sealed by the sealing material 14, the seawater hardly reaches the pressure-resistant outer shell 12, and the life of the pipe is reduced. There is also an effect that can be lengthened.

When connecting a plurality of pipes to each other through the above-mentioned flange body 13, the ends of the pipes, that is, the ends of the corrosion-resistant water pipes 11 into which the flange bodies 13 are fitted as shown in FIG. Ring-shaped bushes 24 each having a flange made of a corrosion-resistant material such as super austenitic stainless steel or titanium material are fitted into the respective portions to secure the corrosion resistance of the ends thereof. What is necessary is just to make it match through 21. The bush 24 may be mounted in advance on the end of the pressure-resistant / corrosion-resistant pipe, and its periphery may be welded and integrated over the entire circumference.

With such a structure in which the pressure-resistant and corrosion-resistant pipes are interconnected via the bush 24, it is possible to ensure sufficiently high corrosion resistance not only inside the pressure-resistant and corrosion-resistant pipe but also at the joint thereof. All high-pressure seawater (concentrated water) flow paths constructed using pressure-resistant and corrosion-resistant piping can be made excellent in pressure resistance and corrosion resistance, effectively preventing accidents such as water leakage. This makes it possible to stably operate the reverse osmosis treatment device for a long period of time by preventing the reverse osmosis treatment device. In addition, effects such as the ability to construct a flow path system for high-pressure seawater (concentrated water) at low cost can be obtained.

The present invention is not limited to the above embodiment. Here, a cylindrical pipe has been described as an example of a pressure-resistant and corrosion-resistant pipe, but is not limited to a straight pipe.
A bent pipe having a predetermined curvature may be used. Further, the present invention can be similarly applied to a joint or the like for branching a flow path. In the above-described embodiment, the corrosion-resistant water pipe 11
Although a corrosion-resistant material such as super austenitic stainless steel or a titanium material has been exemplified as a material for forming, a duplex stainless steel or a Hastelloy alloy, for example, can also be used. In addition, the above super austenitic
As stainless steel, [ASTM A3127],
Those equivalent to [UNS S31254] can be used, and specifically, [254SMO] manufactured by Avesta and [HR254] manufactured by Sumitomo Metal Industries, Ltd. can be used.

The material for forming the pressure-resistant outer shell 12 is as follows.
Carbon steel or the like can also be suitably used. Further, as the sealing material 14, a resin is preferably used, and for example, a silicone-based, modified silicone-based, or polysulfide-based polymer can be used. It is also possible to use a resin adhesive. Further, the inner diameter and the like of the corrosion-resistant water pipe 11 may be determined according to the specifications and the like for the high-pressure fluid flowing through the inside. In short, the present invention can be variously modified and implemented without departing from the gist thereof.

In the above description, the concentrated water two-stage method using the reverse osmosis membrane module units arranged in two stages is taken as an example, but only one reverse osmosis membrane module unit is used. It can be suitably used for a reverse osmosis membrane device. Further, in the above description, a reverse osmosis treatment apparatus using a reverse osmosis membrane module / unit using a reverse osmosis membrane has been described as a treatment means for treating raw water to obtain treated water. Can be used. In addition, not only a spiral type but also a tubular type, a plate and frame type, and the like can be used. Further, in addition to using the flat membrane as described above, a hollow fiber membrane may be bundled and then incorporated into an element for use.

[0028]

As described above, according to the water treatment apparatus of the present invention, the inner pipe directly in contact with the high-pressure corrosive fluid of the pipe used is made of a material having high corrosion resistance, and covers the inner pipe. Since the outer tube has a composite structure in which the pressure resistance is ensured and the filler filled between them has a buffering action against pressure, high pressure seawater with a high salt concentration may be introduced. However, the corrosion resistance can be maintained sufficiently high and the pressure resistance can be sufficiently increased. As a result, it is possible to realize an inexpensive and highly safe pipe suitable for use in a reverse osmosis treatment apparatus or the like,
Fresh water can be safely produced at low cost from seawater or the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration example of a reverse osmosis treatment device (water treatment device) using a pipe according to the present invention.

FIG. 2 is a partial sectional view showing a structure of a pipe according to one embodiment of the present invention.

FIG. 3 is a diagram showing a configuration example of a reverse osmosis membrane element incorporated in a reverse osmosis membrane module.

FIG. 4 is a diagram showing a general structure of a reverse osmosis membrane module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Corrosion resistant water pipe 12 Pressure-resistant outer shell 13 Flange body (joint part) 14 Sealing material 21 Gasket 24 Bush 30 Element 31 Water collecting pipe 32 Reverse osmosis membrane 33 Raw water channel material 34 Permeated water channel material 35 Brine seal 40 Reverse osmosis membrane module Unit 41 Pressure vessel 42 Fitting 46 Product tube cap

Claims (6)

[Claims] 1. A treatment means for treating raw water to obtain treated water, and at least a raw water side pipe and / or a treated water side pipe of the treatment means, wherein the raw water side pipe and / or the treated water side pipe are provided. A water treatment apparatus comprising: a corrosion-resistant water pipe; a pressure-resistant outer shell that covers the water pipe; and a sealing material interposed between the pressure-resistant outer shell and the corrosion-resistant water pipe. 2. The water treatment apparatus according to claim 1, wherein the treatment means is a treatment means using a reverse osmosis membrane. 3. The water treatment apparatus according to claim 1, wherein the pressure-resistant outer shell has a hole for interposing a sealing material between the pressure-resistant outer shell and the corrosion-resistant water pipe. 4. The water treatment apparatus according to claim 1, wherein the pressure-resistant outer shell has a joint at at least one end. 5. A fresh water producing method using the water treatment apparatus according to claim 1. 6. A piping comprising: a corrosion-resistant water pipe; a pressure-resistant outer shell covering the water pipe; and a sealing material interposed between the pressure-resistant outer shell and the corrosion-resistant water pipe.