JPH0530996B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention utilizes a semipermeable membrane to absorb the energy difference in concentration between a high concentration solution such as seawater and a low concentration solution such as river water or a solvent. The present invention relates to an osmotic device for concentration difference power generation in concentration difference power generation using osmotic pressure, which converts osmosis into mechanical energy to generate power.

[Prior Art] As such concentration difference power generation using osmotic pressure, several methods as described below have been proposed to date. FIG. 3 shows a system diagram of concentration difference power generation using osmotic pressure as disclosed in US Pat. No. 3,906,250. In this method, among two chambers separated by a semipermeable membrane 2 in an infiltration device 1 installed on the ground, a highly concentrated solution 5 such as seawater is pumped into the semipermeable membrane outer waterway 3 using a high pressure pump 7 to give an osmotic pressure. Supply at the following pressure.
At the same time, a low-concentration solution 11 such as river water or a solvent is supplied to the semipermeable membrane inner waterway 9 of the osmosis device 1 by the low-pressure pump 1.
3 and through the semipermeable membrane 2 as shown by the arrow 1 in the figure.
Penetrate in 4 directions and drain the rest.

At this time, since the permeation is performed against the pressure of the water channel outside the semipermeable membrane, the concentration difference energy is converted into mechanical energy. That is, since the discharged solution of the semipermeable membrane outer water channel 3 is a solution in which the osmotic solvent is added to the pressurized supply solution, the concentration difference energy rotates the turbine 15 through the discharged solution, and the energy is transmitted to the same axis of the turbine. Combined generator 17
is converted into electricity by

Figure 4 is by M.Reali [Energy, 6277 (1981)]
This is a system diagram based on the method announced in . In this method, the infiltration device 1 is installed on the seabed 18 where the ambient water pressure is below the osmotic pressure, and the surrounding seawater 5 is pumped into the semipermeable membrane outer water channel 3 inside the infiltration device 1 by a low-pressure pump 13.
Supplied with The pressure in the semipermeable membrane inner waterway 9 in the osmosis device 1 is approximately atmospheric pressure due to the osmosis as indicated by the arrow 14 (there is also a method in which the pressure is opened to the atmosphere to keep the pressure steady).
When the amount of water has decreased, river water 11 is supplied from land through a conduit 19. The turbine 15 is rotated using the head of the river water 11 at that time, and this rotation is converted into electric power by the generator 17. Further, a part of the solution (residual liquid) in the semipermeable membrane inner waterway 9 is discharged into the sea by the high-pressure pump 7.

Here, for convenience of explanation, the method shown in FIG. 3 will be referred to as the land method (A), and the method shown in FIG. 4 will be referred to as the underwater method (B).

Mechanical efficiency ME is defined as the value obtained by dividing the net output (the value obtained by subtracting the power of the pumps 7 and 13 from the output of the generator 17) by the ideal output, as shown in the following equations (1) and (2).
However, if ME (land) is a land method, ME (undersea)
is the mechanical efficiency for the subsea method.

ME (land) = {η _T η _G − (P _H +△P _O )/P _H η _H }・V _S /
△V + η _T η _G − (1 + V _U / △V)・P _L /P _H η _L ...(1) ME (undersea) = {η _T η _G − (P _H +△P _i ) /P _H η _H }・V _U /
△V+η _T η _G −P _L ／P _H η _L・V _S ／△V……(2) Here, η _H is the efficiency of the high-pressure pump 7, and the total pump stroke is P _H + Let the pressure drop be (ΔP _O or ΔP _i ). η _L is the efficiency of the low-pressure pump 13, and the total field of the pump is P _L (same as ΔP _i or ΔP _p ). η _T is the efficiency of the turbine 15, P _H is the head, η _G is the efficiency of the generator 17, V _S is the high concentration solution supply flow rate, V _U is the low concentration solution discharge flow rate, ΔV is the permeation flow rate, and ΔP _p is the permeation device 1, the pressure loss in the semipermeable membrane outer membrane waterway 3 and ΔP _i is the pressure loss in the semipermeable membrane inner membrane waterway 9.

Since the average pressure difference between the semipermeable membrane outer water channel 3 and the semipermeable membrane inner water channel 9 can be regarded as approximately P _H in both equations (A) and (B) above, the ideal output is P _H ·ΔV.

Now, η _H =0.8, η _L =0.8, η _T =0.84, η _G =0.95,
ΔP _p = ΔP _i , (P _H + ΔP _p )/P _H = 1.02, ΔP _p /P _H =
0.02, V _U /ΔV=0.5, the above equation (1) and
(2) becomes the following equations (3) and (4).

ME (land) = 0.7605−0.477・V _S /ΔV (However, P _L
= P _i ) ...(3) ME (undersea) = 0.5595−0.025・V _S /ΔV (However, P _L
= ΔP _p ) ...(4) From both equations (3) and (4), by decreasing the ratio V _S /ΔV of the high concentration solution supply flow rate V _S to the permeation flow rate ΔV,
It can be seen that the mechanical efficiency ME increases, especially in the land method (A) in Figure 3, where V _S /ΔV needs to be 1.594 or less.

In addition, the solution in the semipermeable membrane inner waterway 9 is affected by the permeation of the solvent 11 into the semipermeable membrane outer waterway 3 and the diffusion leakage (leakage) of the solute 5 from the outer waterway 3 due to imperfections in the semipermeable membrane 2. Therefore, the solute concentration increases,
In both methods (A) and (B) above, a portion of the solution is discharged to the outside to suppress the concentration increase and enable continuous operation.

By the way, Mr. Ukai et al.'s [Fuel and Combustion, 47 (11),
865 (1980)], it is pointed out that if a hollow fibrous semipermeable membrane is used as the semipermeable membrane of a reverse osmosis device, the amount of permeable water per volume increases, and the entire device can be made smaller. . Furthermore, in that case, even if the surface flow velocity is low, the surface renewal will be close to the ideal state,
It has been pointed out that the required membrane flow rate can be kept low. Therefore, according to this point, in concentration difference power generation using osmotic pressure, which requires the ratio of the high concentration solution supply flow rate V _S to the osmotic flow rate _ΔV to be as small as possible, it is necessary to use a hollow fibrous semipermeable membrane. is suitable as a semipermeable membrane for an osmotic device.

Hollow fiber type osmosis devices using such hollow fiber semipermeable membranes have already been developed as various types of reverse osmosis separation devices. A typical configuration example is shown in the fifth section.
This will be explained based on the figure and FIG. As shown in this figure, a large number of hollow fibrous semipermeable membranes 21 are arranged and laminated around a porous core tube 23, and both ends thereof are adhesively fixed with adhesive layers 25, 25'. The adhesive layer 25 on the left side of the figure opens only the porous core tube 23 at its end, and the adhesive layer 25' on the right side of the figure opens only the hollow fibrous semipermeable membrane 21 at its end face. In this way, the hollow fiber element 27 divided into the semipermeable membrane outer water channel 3 and the semipermeable membrane inner water channel 9 is connected to the internal connector 29, the water collection spacer 31, and the end plates 33, 3.
3' and is hermetically fixed in the cylindrical container 35.

In this reverse osmosis separation device, a highly concentrated solution is supplied from the semipermeable membrane outer water channel inlet 37 of the end plate 33 on the left side of the figure at a pressure higher than the osmotic pressure, and is distributed in the porous core tube 23 through the internal connector 29. , flows in the radial direction so as to pass through the outside of each fiber of the hollow fibrous semipermeable membrane 21. During this time, the solvent of the high concentration solution is separated by reverse osmosis into the inner water channel 9 through the semipermeable membrane 21, and the remaining high concentration solution that has reached the outer layer of the fiber group of the semipermeable membrane 21 is removed from the end plate on the left side of the figure. It is discharged to the outside from a semipermeable membrane outer water channel outlet 39 provided at 33.

The solvent separated by reverse osmosis in the semipermeable membrane inner water channel 9 in the hollow fibrous semipermeable membrane 21 flows out from the opening at the right end in the figure, is collected in the water collection spacer 31, and is passed through the end plate 33'.
The water is discharged to the outside from the semipermeable membrane inner water channel outlet 41 provided in the semipermeable membrane.

However, with such conventional reverse osmosis separation equipment,
Since the semipermeable membrane inner waterway 9 has only one opening, the waterway outlet 41, an increase in solute concentration cannot be suppressed.
Therefore, it is difficult to use this reverse osmosis separation device as is for concentration difference power generation using osmotic pressure.

Furthermore, when V _S /ΔV is made smaller in the semipermeable membrane outer water channel 3, the flow velocity on the surface of the semipermeable membrane 21 decreases, surface renewal becomes worse, and the area of low concentration due to permeated water increases, that is, concentration polarization occurs. This causes an increase in the amount of water and a shift in the flow. Therefore, the effective differential pressure (the difference in osmotic pressure between the outside and inside of the semipermeable membrane 21 minus the pressure difference between the outside and inside water channels 3 and 9), which acts as a driving force for permeating the solvent, decreases, and the permeation flow rate decreases. Decrease ΔV,
The performance of the semipermeable membrane 21 cannot be fully utilized.

In fact, M. de Gerloni et al. conducted an experiment using the above-mentioned commercially available reverse osmosis separator in an underwater system, and reported that the permeation flow rate ΔV decreased rapidly [Symp.on] Membranes and
Membrane Processes, Peruguia, 1982]. As mentioned above, this is thought to be because the semipermeable membrane inner waterway 9 has only one outlet and no inlet, and therefore the increase in solute concentration could not be suppressed. Furthermore, since V _S /ΔV was relatively small at 3 to 10, it seems that the concentration polarization and flow bias in the semipermeable membrane outer water channel 3 had developed to some extent.

[Problems to be Solved by the Invention] Therefore, a conventional example in which both an outlet and an inlet are provided in the semipermeable membrane inner water channel of a hollow fiber type permeation device will be described with reference to FIGS. 7 and 8. The infiltration device shown in Fig. 7 was developed by Mr. S. Loeb et al. [J.Membrane Sci.1249
(1976)]. With this device,
The bundle of hollow fibrous semipermeable membranes 21 passes through the T-shaped joint tube 43, enters the cylindrical container 35, and returns in a U-shape near the end cap 45 at the right end. Both ends of the bundle of hollow fibrous semipermeable membranes 21 protruding from the left side of the T-shaped joint pipe 43 in the figure are used for supplying and discharging a low concentration solution to the semipermeable membrane inner water channel in the semipermeable membranes 21, respectively. It is connected to a reinforcing cylinder 49 provided with semipermeable membrane inner waterway inlets and outlets 41 and 47. The reinforcing tube 49 and the hollow fibrous semipermeable membrane 21 are hermetically fixed by an adhesive layer 25 on the left side of the T-shaped joint tube 43 in the drawing.

The highly concentrated solution is supplied from the semipermeable membrane outer waterway inlet 37 of the T-shaped joint pipe 43 at a pressure below the osmotic pressure,
The semipermeable membrane outer water channel 3 between the cylindrical container 35 and the hollow fibrous semipermeable membrane 21 flows through the semipermeable membrane outer water channel 3 while collecting the permeated water seeped from inside the semipermeable membrane 21, and flows through the semipermeable membrane outer water channel 3 between the cylindrical container 35 and the hollow fibrous semipermeable membrane 21. It is discharged from the waterway outlet 39.

However, in this osmosis device, in order to investigate the properties of the semipermeable membrane, a large amount of highly concentrated solution is passed through to prevent the osmotic flow rate from decreasing due to concentration polarization. Therefore, V _S /ΔV becomes about 40, which is not practical.

The osmosis device shown in Figure 8 was announced by the present inventor in [Proceedings of the 1985 National Conference of the Institute of Electrical Engineers of Japan, [11] No. 1161], and is an improved version of the reverse osmosis separation device shown in Figure 5 above. This is what I did. As shown in FIG. 8, the hollow fibrous semipermeable membrane 21 is laminated on the porous core tube 23 in a crosswise arrangement, and both ends of the semipermeable membrane 21 are fixed by adhesive layers 25, 25'. A porous core tube 23 opens in the central through hole of the adhesive layer 25 at the left end of the figure, and a hollow fibrous semipermeable membrane 21 opens around the outer end of the adhesive layer 25. Furthermore, a seal 5 for sealing the cylindrical container 35 is provided on the outer periphery of the adhesive layer 25.
1 is arranged. The opening of the porous core tube 23 is
It is connected to the semipermeable membrane outer water channel inlet 37 of the end plate 33 through the through hole of the internal connector 29 .

The semipermeable membrane inner water channel 9 in the semipermeable membrane 21 passes through the annular water collection spacer 31 through the opening of the hollow fibrous semipermeable membrane 21 and enters the semipermeable membrane inner water channel outlet 41 provided on the end plate 33. Connected. In addition, in the adhesive layer 25' at the right end of the figure, only the hollow fibrous semipermeable membrane 21 is open;
The semipermeable membrane inner waterway 9 connects through its opening to the semipermeable membrane inner waterway inlet 47 provided in the end plate 33' through the collection spacer 31' and the internal connector 29'.

The highly concentrated solution supplied to the semipermeable membrane outer water channel inlet 37 at the left end of the figure at a pressure below osmotic pressure passes through the internal connector 29 and is distributed by the porous core tube 23 to each fiber of the hollow fibrous semipermeable membrane 21. It flows in the radial direction, passing through the gaps. During this period, the highly concentrated solution that collected the permeated water that seeped out from the semipermeable membrane inner waterway 9 was
It exits to the semipermeable membrane outer water channel 3 on the outer periphery side of the hollow fiber element 27, passes through the annular gap on the outer periphery of the internal connector 29', and enters the semipermeable membrane outer water channel outlet 3 at the right end in the figure.
It is discharged to 9.

However, in order to investigate the properties of the semipermeable membrane, this osmosis device also flows a relatively large amount of highly concentrated solution so that the osmotic flow rate is constant. Therefore,
V _S /ΔV is 20 or more, and the mechanical efficiency ME of the land method becomes negative (see equation (3) above).

In this way, in conventional reverse osmosis separation equipment and osmosis equipment with a structure similar to it, the ratio of the high concentration solution supply flow rate to the osmotic flow rate, V _S /ΔV, is quite large, making it difficult to use osmotic pressure for concentration difference power generation, especially in land-based methods. It has been difficult to realize power generation using concentration difference.

In addition, in the conventional infiltration device shown in FIG. 8, the entrances and exits of the outer water channel and the inner water channel of the semipermeable membrane are located at the center 37, 47 at the left and right end plates 33, 33', and at the other end 39, 41.
The connection is reversed, which makes it easy for external piping to be incorrectly connected. Furthermore, in the structure of this conventional infiltration device, since the internal connector 29' is thick in the radial and axial directions, it is possible to make the outer diameter and length of the hollow fiber element 27 close to the inner diameter and inner length of the cylindrical container 35. However, even if these diameters are increased, the volumetric efficiency of the infiltration device (semi-permeability relative to the internal volume of cylindrical container No. 5) is The ratio of effective membrane area) is poor, and this also causes problems in pressure resistance and economic efficiency.

In view of the above-mentioned problems, this invention improves the ratio V _S /ΔV of the high concentration solution supply flow rate V _S to the permeation flow rate ΔV without increasing concentration polarization or unbalanced flow in the semipermeable membrane outer water channel of the osmosis device. Hollow fiber type densifier is small and makes full use of the performance of semi-permeable membrane, thereby increasing the efficiency of concentration difference power generation using osmotic pressure, and also eliminates incorrect connection of external piping and makes handling easier. The purpose of the present invention is to provide an infiltration device for differential power generation.

[Means for Solving the Problems] In order to achieve this object, the present invention arranges and laminates semipermeable membranes in the form of hollow fibers around a porous core tube, and adhesively fixes both ends of the semipermeable membranes. As a result, there is a hollow fiber element that separates the semipermeable membrane outer water channel and the semipermeable membrane inner water channel, a cylindrical container in which the hollow fiber element is sealed and fixed, and a semipermeable membrane disposed in the semipermeable membrane outer water channel on the hollow fiber element side. It is equipped with partition parts that evenly divide the membrane outer water channels into even numbers, and plugs that block the semipermeable membrane outer water channels in the porous core tube at the positions of the odd-numbered partition parts, and the porous core tube at one end of the cylindrical container. The inlet of the semipermeable membrane outer water channel opens coaxially with the membrane, the outlet of the semipermeable membrane inner water channel opens around this inlet, and the semipermeable membrane outer water channel opens coaxially with the porous core tube at the other end of the cylindrical container. The semipermeable membrane is characterized in that an outlet is open, and an inlet of the semipermeable membrane inner water channel is open around the outlet.

[Function] In this invention, a partition is formed in the semipermeable membrane outer water channel of the hollow fiber element of the hollow fiber type infiltration device to divide the water channel into an even number of sections, so that the permeation of the high concentration solution supply flow rate is reduced. Reduce the ratio to the flow rate and increase the efficiency of concentration difference power generation using osmotic pressure.

Further, in this invention, the semipermeable membrane outer water channels on the hollow fiber element side are equally divided into even numbers by the partition parts, and plugs are provided in the odd numbered partition parts to block the semipermeable membrane outer water channels in the porous core tube. Therefore, the entrances and exits of the semipermeable membrane outer water channel can be opened at both ends of the cylindrical container at coaxial positions with the porous core pipe, and the semipermeable membrane inner water channel has entrances and exits at both ends of the element.
Therefore, incorrect connection of external piping can be avoided, and the structure is simple, making manufacturing and assembly easy.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Configuration of an Embodiment FIG. 1 shows the configuration of an embodiment of a hollow fiber type concentration difference power generation infiltration device of the present invention. Here, 53 and 5
5 are semipermeable membrane outer waterway partition partitions disposed vertically in the cylindrical container 35;
One of the odd-numbered A-type partitions 53 is a disc-shaped partition consisting of a plug 57 that closes the porous core tube 23 and an adhesive layer 61 to which the hollow fibrous semipermeable membrane 21 is bonded. The other even-numbered B type partition portion 55 is an annular body consisting of an adhesive layer 61 and a seal 59. The partitions 53 and 55 are arranged alternately at a predetermined interval as shown in this figure, so that the highly concentrated solution that has once flowed to the outer periphery is repeatedly guided into the porous core tube 23.

In addition, end plates 3 fixed to both ends of the cylindrical container 35
3, 33' have an inlet/outlet 37 of the semipermeable membrane outer water channel 3,
39 is opened at its center, and entrances and exits 41, 47 for the semipermeable membrane inner water channel 9 are opened at its periphery. A space surrounded by the cylindrical container 35 and the end plates 33, 33' is provided with a hollow fiber element 22 by internal connectors 29, 29' and water collection spacers 31, 31'.
Hold 7.

A large number of hollow fibrous semipermeable membranes 21 are arranged and laminated around the outside of the porous core tube 23 for collecting and distributing high concentration solution water constituting the hollow fiber element 27, and both ends thereof are adhesively fixed with adhesive layers 25, 25'. At this time, the arrangement of the hollow fibrous semipermeable membranes 21 is as follows:
Either the bundles may be bundled parallel to the axial direction of No. 3, or they may be wrapped so as to cross each other.

The adhesive layers 25 and 25' at both ends of the semipermeable membrane 21 include
A porous core tube 23 is passed through the center, an inner water channel 9 of the hollow fibrous semipermeable membrane 21 is opened around the outer end surface, and a seal 51 for sealing the cylindrical container 35 is provided on the outer periphery of the membrane. Membrane outer water channel 3
and a semipermeable membrane inner waterway 9. Porous core tube 23
The internal connectors 29, 29' arranged at both ends of the
The opening of the porous core tube 23 is connected to the semipermeable membrane outer water channel inlets and outlets 37 and 39 of the end plate 33. The water collection spacers 31 and 31' collectively connect a large number of semipermeable membrane inner water channels 9 passing through the openings of the hollow fibrous semipermeable membrane 21 to the end plate 3.
3, 33' are connected to semipermeable membrane inner waterway inlet/outlet ports 41, 47.

The hollow fiber element 27 has adhesive layers 2 on both ends.
5, 25', as mentioned above, there is an A partition section 53 that divides only the semipermeable membrane outer water channel 3, and a B partition section 5.
5 is formed. The A partition section 53 has a plug 57 that seals the inside of the porous core tube 23, and the B partition section 5
5 has a seal 59 that seals between the inner wall of the cylindrical container 35 and the adhesive layer 61. Like this, A,
The B2 type partitions 53 and 55 are arranged alternately and sequentially from the A partition 53, and finally the A partition 53 is arranged to divide the semipermeable membrane outer water channel 3 into an even number of stages in the axial direction.

These partitions 53 and 55 are formed, for example, as follows. A plug 57 is fixed in advance in the porous core tube 23 at a position where the A partition section 53 is provided. next,
The hollow fibrous semipermeable membranes 21 are sequentially adhesively fixed at the locations of the partitions 53 and 55 of A and B using threads or strings impregnated with an epoxy adhesive with an appropriately adjusted viscosity. The partition adhesive layer 61 is obtained by forming the adhesive layer up to the vicinity of the inner diameter. next,
A seal 59 is formed on the outer periphery of the partition adhesive layer 61, which becomes the B partition 55, against the inner wall of the cylindrical container 35 using an O-ring or a single foam sponge.

Functions and features of the embodiment The hollow fiber type infiltration device of this embodiment configured as described above has supply and discharge ports 37, 39, 41, and 47 for high-concentration solutions and low-concentration solutions on both end faces, so that multiple devices can be connected to each other. In addition to easy parallel installation and high-density packaging, it also has the following features:

Semipermeable membrane outer water channel inlet 3 of end plate 33 on the left side of the figure
The highly concentrated solution supplied to 7 at a pressure below osmotic pressure passes through the internal connector 29 and is distributed in the first stage porous core tube 23, passing through the outside of the hollow fibrous semipermeable membrane 21 and collecting the permeated water. , flows radially outward and reaches the outer periphery of the partition adhesive layer 61. Next, in the second stage, the highly concentrated solution flows radially inward from its outer periphery, passes through the outside of the hollow fibrous semipermeable membrane 21, collects permeated water, and reaches the porous core tube 23 again. Thereafter, the highly concentrated solution sequentially flows through each stage while repeating the same flow pattern, and reaches the semipermeable membrane outer water channel outlet 39 of the end plate 33' through the internal connector 29' from the porous core tube 23 at the final stage.

Since the width of the water channel 3 is substantially reduced by the partition plates 53 and 55, the flow rate of the highly concentrated solution in the semipermeable membrane outer water channel 3 of each stage is as follows, even assuming that there is no increase in flow rate due to permeated water. The speed is more than twice as high as the number of stages without the partitions 53 and 55. That is, the same flow rate can be obtained with a lower flow rate of high concentration solution supply than when the partitions 53 and 55 are not provided. Furthermore, the non-uniformity of concentration caused by concentration polarization and uneven flow in the outer peripheral space of each stage and the inner space of the porous core tube 23 is mixed and becomes uniform. , the concentration difference energy is effectively extracted as an increase in osmotic flow rate, resulting in
V _S /ΔV can be reduced, and the efficiency of concentration difference power generation using osmotic pressure can be increased.

The low concentration solution supplied to the semipermeable membrane inner waterway inlet 47 of the end plate 33' on the right side of the figure passes through the water collecting spacer 31', and passes through the water collecting spacer 31', and passes through the semipermeable membrane in the form of a large number of semipermeable hollow fiber elements 27. It is distributed within the inner water channel 9 of the membrane 21 and flows with its solvent permeating into the outer water channel 3. The concentration of the solution in the inner water channel 9 has increased due to the solute that could not permeate or the solute that has diffused and leaked from the semipermeable membrane outer water channel 3 due to the imperfection of the hollow fibrous semipermeable membrane 21. The water passes through an opening in the end face of the semipermeable membrane 21 and is collected by the water collection spacer 31, and is discharged from the semipermeable membrane inner water channel outlet 41 of the end plate 33.

This discharge suppresses the concentration increase in the semipermeable membrane inner waterway 9 and prevents a decrease in the effective differential pressure, which is the driving force for permeating the solvent, so that the permeation flow rate can be kept constant and the osmotic pressure can be used to generate concentration difference power generation. can be operated continuously.

The hollow fibrous semipermeable membrane 21 used in the permeation device of this example must have a large permeation amount per volume of the hollow fiber element 27, that is, if the hollow fiber packing density is the same, the solvent in the hollow fibrous semipermeable membrane 21 must be The value A/d obtained by dividing the permeability coefficient A by the outer diameter d of the fiber is large, and the semipermeable membrane inner water channel 9
It is required to be perfect so that the solute concentration in the water does not increase due to diffusion leakage of solute from the outer water channel 3, that is, to have a good salt removal rate. moreover,
If the semipermeable membrane 21 has an asymmetric structure consisting of a thin active layer that exhibits an osmosis phenomenon and a thick porous support layer, for example, in order to reduce concentration polarization within the support layer, solutes in the support layer may be A large transmission coefficient is required.

The relationship between the number of divisions of the water channel 3 by the partitions 53 and 55 of the permeation device of this example, the hollow fibrous semipermeable membrane 21 and the cylindrical container 35 is considered as follows.
That is, once a high concentration solution or a low concentration solution is determined, the available flow rate and operating pressure are determined. Also,
Once the thicknesses of the cylindrical container 35 and the end plates 33, 33' are determined, the critical dimensions of the hollow fiber element 27 are determined. Once the type of hollow fibrous semipermeable membrane 21 is determined, its filling rate and required surface flow velocity are determined, and the width of both ends of the hollow fiber element 27, the partition portion 53,
The number of divisions is also determined in consideration of the width of the adhesive layer 61 of 55.

Here, the relationship between the outer diameter of the hollow fiber element 27 and the flow rate is as follows. As the outer diameter of the hollow fiber element 27 increases, the flow passage cross-sectional area of the outermost layer increases in proportion to the outer diameter. Also,
Since the volume of the hollow fiber element 27 increases in proportion to the square of its outer diameter, if the filling rate is constant, the membrane area also increases approximately in proportion to the square of the outer diameter.
The amount of penetration increases as well.

Therefore, if V _S /ΔV is kept constant, the high concentration solution supply flow rate will also increase in proportion to the square of the outer diameter, and as a result, the flow velocity in the outermost layer will increase approximately in proportion to the outer diameter. It turns out.

In addition, the outer water channel 3 of the hollow fiber element 27
Since it is calculated that the place where the membrane surface flow velocity is the slowest is in the outermost layer of the first stage, the membrane surface flow velocity at this location will be referred to as the lowest membrane surface flow velocity hereinafter.

Next, assuming that when the lowest membrane surface flow velocity in the hollow fiber element 27 is the same, the same performance of V _S /ΔV can be obtained, and the influence of the partitions 53 and 55 on the number of divisions will be considered. First, when the number of divisions changes, the membrane area corresponding to the partition adhesive layer 61 increases or decreases. Furthermore, the channel width of each section also varies greatly. Now, assuming that the minimum membrane surface flow velocity is 1/N (where N is a real number, the same applies hereinafter), the value A/d is obtained by dividing the solvent permeability coefficient A of the semipermeable membrane 21 by the semipermeable membrane fiber outer diameter d. Either choose a hollow fibrous semipermeable membrane 21 with N times the inner diameter of the cylindrical container 35, or choose one whose inner diameter is about N times, since the outer diameter of the hollow fiber element 27 and the flow velocity on the outermost membrane surface are almost proportional. Depending on the selection, it is possible to obtain V _S /ΔV performance comparable to that before changing the number of divisions.

Furthermore, when changing the type of hollow fibrous semipermeable membrane 21 under the same conditions as described above, if A/d does not change, the same performance can be obtained with the same number of divisions, but when A/d increases The membrane surface flow velocity increases and the performance improves. In other words, V _S /ΔV tends to become smaller. In order to maintain the same performance, the number of divisions should be reduced or the inner diameter of the cylindrical container 35 should be reduced. Similarly, if the inner diameter of the cylindrical container 35 can be increased, the outer diameter of the hollow fiber element 27 can be increased, which increases the membrane flow velocity and improves performance. Therefore, the hollow fibrous semipermeable membrane 21 with a small A/d
When using a cylindrical container, it is more effective to increase the inner diameter of the cylindrical container than to increase the number of divisions, since the volumetric efficiency will not deteriorate.

Furthermore, the partitions 53 and 55 are provided to equally divide the semipermeable membrane outer water channels 3 on the hollow fibrous semipermeable membrane 21 side into even numbers, and the odd-numbered partitions 53 are used to divide the semipermeable membrane inside the porous core tube 23 into equal parts. By providing the stopper 53 that closes the membrane outer water channel 3, the entrances and exits 37 and 39 of the semipermeable membrane outer water channel 3 can be opened at both ends of the cylindrical container 35 at coaxial positions with the porous core tube 23, and the entrance and exit ports 37 of the semipermeable membrane outer water channel 3 can be opened at both ends of the cylindrical container 35 at coaxial positions with the porous core tube 23. , 39 as the semipermeable membrane inner waterway 9
Because it can be clearly distinguished from the entrances and exits 41 and 47,
Misconnection with external piping can be easily avoided.

In addition, as structural parameters,
Division interval by partition parts 53 and 55 and cylindrical container 3
It has a length of 5. This division interval may be changed for each division so that the flow velocity in each division is the same in accordance with changes in the flow rate of the highly concentrated solution, but if the division intervals are equal, a symmetrical structure will result, and the semipermeable membrane will There is no distinction between left and right entrances and exits in each of the inner water channels 3 and 9, which facilitates handling during manufacture and use.

Furthermore, the axial length of the cylindrical container 35 has little to do with the flow rate, but with the division interval, pressure loss, and volumetric efficiency. When the number of divisions is the same, the longer the cylindrical container 35 is, the smaller the proportion occupied by the adhesive layer 61 is, and the better the volumetric efficiency becomes. However, since the pressure loss and concentration increase in the semipermeable membrane inner waterway 9 are directly related to the length of the waterway,
The appropriate length of the cylindrical container 35 is determined in consideration of ease of handling.

Experimental Results of Examples In the example shown in FIG. 1, the hollow fiber element 27 has two A partitions 53 and one B partition 55.
This is a four-part infiltration device in which A, B, and A are formed at equal intervals in that order. With this structure, the hollow fibrous semipermeable membrane 21
Toyobo's HF _X -1 (outer diameter 225μm, penetration amount
² hollow fiber elements with an outer diameter of 10 cm and an effective membrane area of 10 m ² stacked in a cross arrangement using
7 was sealed and fixed in a cylindrical container 35 made of FRP (fiber-reinforced plastic), and an experiment was conducted by supplying 3.5 wt% saline and ion exchange water.

As a result, the maximum net output calculated using the land method for this infiltration device is the effective differential pressure
Ratio of saline supply flow rate to permeate flow rate at 11 atm
This was when V _S /ΔV was approximately 1.1. Moreover, this property was stably obtained continuously (10 hours to 30 hours). At this time, the mechanical efficiency of the land-based method is 0.2358.

Other Embodiments FIG. 2 shows the configuration of another embodiment of the present invention. This example is a two-part infiltration device in which one partition A 53 is provided in the center of the hollow fiber element 27. With this structure, if we try to obtain a performance comparable to or better than that of the above experimental example, the following will occur. If the ratio of the width of one section of the four-division type osmosis device and the width of the partition adhesive layer 61 in the experimental example is 7 to 4, the same cylindrical container 35 and the same hollow fibrous semipermeable membrane 21 can divide the osmosis into two parts. If you make a device, the membrane area will be smaller compared to dividing into 4 parts.
It increases by 1.28 times, and the permeation flow rate increases as well. Now, V _S /
Assuming that ΔV=1.1, the first stage outer circumferential flow rate is
Increases by 1.517 times. However, since the cross-sectional area of the flow path also increases by 2.57 times, the minimum membrane surface flow velocity becomes 1/1.69. Therefore, in the embodiment shown in FIG. 2, it is necessary to select a hollow fibrous semipermeable membrane 21 with an A/d of 1.69 times or more compared to the previous embodiment, or to select a cylindrical container 35 whose inner diameter is approximately 1.69 times that of the previous embodiment. be.

[Effects of the Invention] As explained above, in the present invention, a partition is formed in the semipermeable membrane outer water channel of the hollow fiber element of the hollow fiber type infiltration device to divide the water channel into an even number of sections. It is possible to reduce the ratio of the high concentration solution supply flow rate to the permeation flow rate, thereby increasing the efficiency of concentration difference power generation using osmotic pressure, and also to avoid erroneous connections of external piping.

Furthermore, in the present invention, the sections of the semipermeable membrane outer water channel are made equal, and the inlets and outlets are opened at both ends of the cylindrical container at coaxial positions with the porous core pipe, and the semipermeable membrane inner water channel is provided with inlets and outlets at both ends of the element, so that the inlet and outlet ports are provided at both ends of the osmosis device. Since it is possible to provide entrances and exits on the outside and inside of the semipermeable membrane, it becomes easy to install a large number of them in parallel as a power generation plant, improving the packaging density and reducing the installation area.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views showing the configuration of an embodiment of the present invention, and FIGS. 3 and 4 are system diagrams showing the configuration of concentration difference power generation using osmotic pressure, respectively.
Figure 5 is a sectional view showing the configuration of a conventional hollow fiber type reverse osmosis separator, Figure 6 is a sectional view showing its main parts in detail, and Figure 7 is a sectional view showing the configuration of another conventional osmosis device. The front view shown in FIG. 8 is a sectional view showing the configuration of still another conventional infiltration device. 3... Semipermeable membrane outer water channel, 9... Semipermeable membrane inner water channel, 21... Hollow fibrous semipermeable membrane, 23... Porous core tube, 25, 25'... Adhesive layer, 27... Hollow fiber element , 29, 29'...Internal connector, 3
1, 31'... Water collection spacer, 33, 33'... End plate, 35... Cylindrical container, 37... Semipermeable membrane outer water channel inlet, 39... Semipermeable membrane outer water channel outlet, 41... Semi-permeable Membrane inner water channel outlet, 47... Semipermeable membrane inner water channel inlet, 51... Seal, 53... A partition, 55...
...B partition, 57...Plug, 59...Seal, 61
...adhesive layer of partition, V _S ...high concentration solution supply amount,
ΔV……Permeation flow rate.

Claims (1)

[Claims] 1 a Hollow fibrous semipermeable membranes are arranged and laminated around a porous core tube, and both ends of the semipermeable membranes are adhesively fixed, thereby forming an outer water channel of the semipermeable membrane and an inner water channel of the semipermeable membrane. (b) a cylindrical container in which the hollow fiber element is sealed and fixed; (c) arranged in the semipermeable membrane outer water channel on the hollow fiber element side so that the semipermeable membrane outer water channels are evenly distributed. d) a stopper that closes the semipermeable membrane outer water channel in the porous core tube at an odd-numbered position of the partition, e) the porous core tube at one end of the cylindrical container; an inlet of the semipermeable membrane outer water channel opens coaxially with the semipermeable membrane outer water channel, an outlet of the semipermeable membrane inner water channel opens around the inlet of the semipermeable membrane outer water channel, and f at the other end of the cylindrical container. Concentration difference power generation characterized in that the outlet of the semipermeable membrane outer water channel opens coaxially with the porous core tube, and the inlet of the semipermeable membrane inner water channel opens around the outlet of the semipermeable membrane outer water channel. Infiltration equipment.