JP5422548B2 - Reverse osmosis membrane desalination apparatus and reverse osmosis membrane desalination apparatus inspection method - Google Patents

Description

  The present invention relates to a reverse osmosis membrane desalination apparatus and a method for inspecting a reverse osmosis membrane desalination apparatus that can measure the properties of fresh water at low cost even during operation of the desalination apparatus.

In a desalination apparatus using a reverse osmosis membrane, a reverse osmosis membrane element wound in a spiral shape is used. The standard size of the reverse osmosis membrane element is about 8 inches in diameter, about 40 inches in length, and about 16 kg in weight. For example, 4 to 8 of these elements are inserted into a pressure vessel in series and proposed for desalination. Has been.
In such an apparatus, it can produce fresh water 10 to 25 ³ / d per element, for example in plants with production water of 100,000 m ³ / d, to the use of elements of approximately 5,000 Become.

  The reverse osmosis membrane element deteriorates over time or suddenly (for example, due to chlorine inflow, etc.), and the quality of the product water or the amount of produced water decreases due to the scale or foreign matter adhering to the membrane surface or the membrane material deterioration. There's a problem. In order to maintain the quality of the produced water or the quantity of produced water, it is necessary to replace the deteriorated reverse osmosis membrane element, but it is desirable that only the reverse osmosis membrane element with deteriorated performance can be replaced.

The quality of the production water can be evaluated by measuring the electrical conductivity of the production water, and the production water volume can be evaluated by measuring the permeated water volume. However, in order to evaluate the deterioration of a specific reverse osmosis membrane element, a local measurement value of production water is required.
Therefore, an apparatus for detecting a reverse osmosis membrane element having deteriorated performance by inserting an integrated sensor of flow rate and electrical conductivity into a permeation tube of a reverse osmosis membrane element during operation of the RO unit has been proposed (Patent Document 1). ).

Special table 2009-530082

  Since the production water from the reverse osmosis membrane element having degraded performance is diluted with the production water from the normal reverse osmosis membrane element upstream, it is important to improve the measurement accuracy. However, in the apparatus disclosed in Patent Document 1, although the integrated sensor may affect the measurement accuracy unless it is held at the substantially central portion of the osmotic tube of the reverse osmosis element, there is a disclosure about a method for improving the measurement accuracy. Absent. In addition, it is necessary to measure a large number of reverse osmosis membranes, but there is no disclosure of a technique for reducing the labor of measurement work.

  Therefore, it is desired to establish a measurement technique capable of specifying a reverse osmosis membrane element having deteriorated performance with high accuracy and without imposing a great load on a measurement person.

  In view of the above problems, the present invention provides a reverse osmosis membrane desalination apparatus and a method for inspecting a reverse osmosis membrane desalination apparatus that can identify a reverse osmosis membrane element whose performance has deteriorated even during operation of the desalination apparatus. The issue is to provide.

The first invention of the present invention for solving the above-described problem is that a plurality of spiral type reverse osmosis membrane elements that supply permeated water from a central water collecting pipe by supplying supply water to a spiral reverse osmosis membrane at a connecting portion. a reverse osmosis membrane module housed in a cylindrical pressure vessel connected in series, are provided through the ball valve at one end of the reverse osmosis membrane module, it comprises a and a detecting insertion jig The detection insertion jig includes a detection tube hole having the same axis as the central axis of the water collecting tube, a flexible insertion detection tube that can be inserted into and removed from the detection tube hole, and the insertion detection the tube was closed and a sealing portion for sealing, the connection unit may connect the water collecting pipe together, its has ends is enlarged, through the O-ring therein expanded, the water collecting pipe reverse osmosis fresh water, characterized in that connecting the pipe of the same diameter are arranged with Apparatus is in.

  A second invention is the reverse osmosis membrane desalination apparatus according to the first invention, further comprising centering means for centering the tip of the insertion detection tube.

A third invention is, using a reverse osmosis membrane desalination apparatus of the first or 2, the one end portion of the reverse osmosis membrane module via the ball valve equipped with a detecting insertion jig, the detecting insertion jig The insertion detection tube held in the hole for the detection tube is inserted into the water collection tube, and at a predetermined position of each reverse osmosis membrane element, the permeated water in each reverse osmosis membrane element is collected from the opening at the tip, and the water quality or It exists in the test | inspection method of the reverse osmosis membrane desalination apparatus characterized by inspecting a flow volume.

  According to the present invention, when there is an indication of a decrease in the capacity of production water, a quick response can be achieved by installing an insertion jig for detection at the end of the element and measuring it. Moreover, the inspection jig is economical by preparing a necessary amount.

FIG. 1 is a schematic view of a reverse osmosis membrane desalination apparatus. FIG. 2 is a schematic view of the main part. FIG. 3 is a schematic view of the connecting portion. FIG. 4 is a schematic diagram of a main part of the reverse osmosis membrane desalination apparatus according to the second embodiment. FIG. 5 is a perspective view of the centering member. FIG. 6 is a perspective view of another centering member. FIG. 7 is a relationship diagram between each element and product water. FIG. 8 is a diagram showing the relationship between each element and electrical conductivity. FIG. 9 is a relationship diagram between each element and the electric conductivity.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

A reverse osmosis membrane desalination apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a reverse osmosis membrane desalination apparatus. FIG. 2 is a schematic view of the main part. FIG. 3 is a schematic view of the connecting portion.
As shown in FIG. 1, the reverse osmosis membrane desalination apparatus supplies supply water (raw water) 11 to a spiral reverse osmosis (RO) membrane 12 and obtains permeate 14 from a central water collecting pipe 13. A reverse osmosis membrane module (hereinafter referred to as “element”) 15 (15-1 to 15-6) 15 connected in series by a connecting portion 16a and housed in a cylindrical pressure vessel 16 (hereinafter referred to as “element”). 17) and a detection insertion jig 20 provided on one end 13a of the water collecting pipe 13 of the reverse osmosis membrane module 17 via ball valves 18A and 18B. The jig 20 includes a detection tube hole portion (hereinafter referred to as “hole portion”) 21 having the same axis as the central axis of the water collecting tube 13 and a flexible insertion detection tube that can be inserted into and removed from the hole portion 21. 22 and the insertion detection tube 22 Those having a O-ring 23 is a sealing unit for sealing.
In FIG. 1, reference numeral 11a denotes concentrated water, and 19 denotes a product water take-out pipe.

  In each of the elements 15-1 to 15-6, a spiral reverse osmosis (RO) membrane 12 having a spiral mesh spacer is wound around the water collection pipe 13. And the raw | natural water (supply water) 11 of the predetermined pressure supplied is guide | induced between the reverse osmosis membranes 12 by the mesh spacer, The permeated water (fresh water) 14 which permeate | transmitted the reverse osmosis membrane 12 by reverse osmosis action is collected in the water collection pipe 13, It is sent to the rear (right side in FIG. 1) side and taken out to the outside. The concentrated water 11a is also taken out from the rear side.

As shown in FIG. 2, a first ball valve 18 </ b> A is provided at one end portion (right end portion in this embodiment) of the water collecting pipe 13 of the reverse osmosis membrane module 17. Further, a second ball valve 18B is provided at the front end portion (left end portion in FIG. 2) of the detection insertion jig 20. Then, the first and second ball valves 18A, 18B are joined together by fastening means (not shown).
In this embodiment, two ball valves are used, but one ball valve is installed at the end of the water collecting pipe on the module side, and a detection insertion jig is attached to the installed ball valve. It may be.

  When inspecting using the detection insertion tube 22, the first and second ball valves 18 </ b> A and 18 </ b> B are opened so that the detection insertion jig 20 and the water collection tube 13 communicate with each other.

Further, as shown in FIG. 3, the connecting portion 16 a that connects the water collecting pipes 13 has an enlarged end, and an inner diameter d ₁ of the water collecting pipe 13 is connected to the inside 30 via an O-ring 23. A connecting inner pipe 32 having the same diameter d ₂ is provided. The connecting inner pipe 32 is flush with the flow of the permeated water 14.

Here, the insertion detection tube 22 may be a flexible Teflon (registered trademark) tube, vinyl hose, or the like.
When the insertion detection tube 22 is inserted, when the insertion tube 20 is inserted from the rear end (right) portion of the detection insertion jig 20 and is sealed at the sealing portion of the O-ring 23, the first and the first The two ball valves 18A and 18B are opened.
Thereafter, the insertion detection pipe 22 passes through the second ball valve 18B and the first ball valve 18A and is inserted into the water collection pipe 13. After the water collecting pipe 13 is inserted to a predetermined position, the permeated water 14 at each position of each reverse osmosis membrane element 15 is collected from the tip opening 22a, and the water quality or flow rate is examined.

The first and second ball valves 18A and 18B have a spherical valve body and rotate the valve shaft 90 degrees to open and close the valves. The first and second ball valves 18A and 18B By opening, the insertion detection tube 22 can be inserted into the water collection tube 13.
During the operation of the desalination apparatus, since pressure is applied to the inside of the water collecting pipe, means that can withstand pressure fluctuations are provided for the ball valve and the insertion jig.

  In the inspection of the water quality of the permeated water 14, the electrical conductivity at each position is measured by an electrical conductivity measuring instrument (not shown) of the inserted sample water.

  Further, an optical fiber is separately inserted into the insertion detection tube 22 to measure a change in refractive index at each position.

FIGS. 7 to 9 show examples of measurement results of flow rate and electrical conductivity when there is an abnormality in the permeated water in each element of the production water.
FIG. 7 is a diagram showing the relationship between each element and product water, and FIGS. 8 and 9 are diagrams showing the relationship between each element and electrical conductivity.

FIG. 7 shows that when there are six elements 15 (15-1 to 15-6), when normal (solid line), 15-1 to 15-6 from the left, the flow rate of the production water gradually increases. .
On the other hand, in the case of the alternate long and short dash line, the flow rate of the third permeated water of the element is 1/3, and in the case of the double dotted line, the flow rate of the sixth permeated water of the element 15 is The case where it becomes 1/10 is shown.

FIG. 8 shows that when there are six elements 15 (15-1 to 15-6), when normal (solid line), 15-1 to 15-6 from the left, the electrical conductivity of the production water gradually increases. ing.
On the other hand, in the case of the alternate long and short dash line, the first salt concentration of the element is doubled, and in the case of the alternate long and two short dashes line, the second salt concentration of the element 15 is 5 times and 4th. This shows the case where the salt concentration of the salt became 3 times.

FIG. 9 shows that when there are six elements 15 (15-1 to 15-6), when normal (solid line), 15-1 to 15-6 from the left, the electrical conductivity of the production water gradually increases. ing.
On the other hand, in the case of the chain line, the case where the flow rate of the sixth permeated water of the element 15 becomes 1/10 is shown. This is a measurement of the electrical conductivity in the case of the two-dot chain line in FIG.

  Thus, according to the present invention, it is possible to inspect the quality of permeated water while producing product water.

In the present invention, it is not necessary to provide measuring devices for all elements as in the prior art, and the detection insertion jig 20 may be prepared as necessary, which is economical.
In other words, although it is not necessary to measure the module for which the production water is secured above a certain level, the detection insertion jig of the present invention is attached to the end of the element when there is a sign of a decrease in the production water capacity. It is possible to respond quickly by installing in the department and measuring. Moreover, the detection insertion jig 20 is economical by preparing a necessary amount.

A reverse osmosis membrane desalination apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a schematic diagram of a main part of the reverse osmosis membrane desalination apparatus according to the second embodiment. FIG. 5 is a perspective view of the centering member. FIG. 6 is a perspective view of another centering member.
In the present embodiment, the hole 21 of the detection insertion jig 20 is enlarged, and the centering means 41 for centering the tip 22a of the insertion detection tube 22 is provided.
The centering means 41 of the present embodiment is provided with four elastically deformable wing members 41A supported by the support body 41B from the insertion detection tube 22, and holds the center when the insertion detection tube 22 is inserted. While trying to move.
Moreover, you may make it use the member which can be elastically deformed, such as a spring member, as a support body.

  This is because the water quality and pressure fluctuation are large at the central portion of the water collecting pipe 13 and the wall surface portion thereof, so that the measurement accuracy is increased particularly in the case of measuring the flow rate. As a result, it becomes possible to detect abnormal water quality appropriately.

As shown in FIG. 6, the centering means is a cylindrical metal porous body 42. In addition to the metal, a resinous porous body may be used.
In any case, the permeated water 14 flows in the interior so as not to lower the production capacity.

11 Supply water (raw water)
12 Spiral Reverse Osmosis (RO) Membrane 13 Water Collection Pipe 14 Permeated Water 15 Reverse Osmosis Membrane Element (Element)
16 Pressure vessel 16a Connecting part 17 Reverse osmosis membrane module (module)
18A, 18B Ball valve 20 Detection jig 21 Detection tube hole (hole)
22 Insertion detection tube 23 O-ring

Claims (3)

A reverse osmosis membrane in which supply water is supplied to a spiral reverse osmosis membrane and a plurality of spiral type reverse osmosis membrane elements are connected in series at a connecting portion to obtain permeated water from a central water collecting pipe and stored in a cylindrical pressure vessel. Module,
Provided through the ball valve at one end of the reverse osmosis membrane module, it comprises a and a detecting insertion jig,
The detection insertion jig is
A hole for a detection tube having the same axis as the central axis of the water collecting tube;
A flexible insertion detection tube that can be inserted into and removed from the hole for the detection tube;
Have a sealing portion for sealing the insertion inlet sensing tube,
The connecting portion connects the water collecting pipes, the end thereof is enlarged in diameter, and an inner pipe for connection having the same diameter as the water collecting pipe is disposed inside the enlarged diameter via an O-ring. reverse osmosis desalination apparatus characterized by there. In claim 1,
A reverse osmosis membrane desalination apparatus comprising centering means for centering the tip of the insertion detection tube. Using the reverse osmosis membrane desalination apparatus according to claim 1 or 2,
At one end of the reverse osmosis membrane module via the ball valve equipped with a detecting insertion jig,
The insertion detection tube held in the detection tube hole of the detection insertion jig is inserted into the water collection tube, and at a predetermined position of each reverse osmosis membrane element, then the permeated water in each reverse osmosis membrane element from the tip opening. A method for inspecting a reverse osmosis membrane desalination apparatus, wherein water is collected or inspected for water quality or flow rate.

Images