JPH0739726A - Apparatus for concentration and separation of solution - Google Patents

Abstract

PURPOSE:To decrease temp. polarization which means local decrease in temp. of a distillation membrane or a soln. in the neighborhood of the distillation membrane as small as possible and to avoid decrease in concn. and separation functionality in taking the local temp. polarization and local inhibiting of vaporization into consideration. CONSTITUTION:A rotor 40 wherein a vaporization space with reduced pressure is provided is arranged in a treating container 20 wherein a soln. is stored and on the other hand, the vaporization space communicates with a condenser 70 arranged out of the treating container 20 through a recovery path 14 and the vaporization space is faced to the soln. in the treating container 20 through a distillation membrane fitted on the rotor 40 and the vaporization membrane is moved relatively to the soln. by rotating the rotator in the treating container 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentrating / separating device for evaporating and concentrating a solution which is a stock solution using a reduced pressure method among membrane distillation methods.

[0002]

2. Description of the Related Art The membrane distillation method uses a hydrophobic porous membrane, a pervaporation membrane (hereinafter referred to as "distillation membrane") or the like to permeate vapor in vapor phase but permeate in liquid phase. This is a method of concentrating and separating by utilizing the characteristic of the distillation membrane that it does not. The depressurization method is one of membrane distillation methods, and is a method of condensing vapor permeated outside the vaporization module with a condenser or the like.

The structure and principle of the apparatus using the depressurization method are generally as follows. First, regarding the structure,
A vessel for processing the solution, that is, a distillation membrane in the processing vessel 2
It is divided into chambers, one room is filled with a solution for concentration and separation, and the other room is kept in a vapor phase state without a solution.
Then decompress. As described above, the distillation membrane has a characteristic that it does not permeate in the liquid phase state, but it can permeate in the gas phase state. From this characteristic, the solution cannot permeate this distillation membrane in the liquid phase state. . On the other hand, in the vicinity of the distillation membrane, a phenomenon occurs in which the solvent content in the solution absorbs heat from the surroundings and evaporates in the vicinity of the distillation membrane due to the decompression of the other chamber. Therefore, the solvent component becomes in a gas phase and can pass through the distillation membrane, and thus passes through the distillation membrane. The permeated solvent is led to the condenser further downstream,
Here, it is cooled, condensed, and returned to the liquid state again. Through the above process, the solution is concentrated in one room and separated / collected in the other room and the condenser.

[0004]

However, in the above apparatus, when the solvent component evaporates, a large amount of latent heat of vaporization is taken from the surroundings to evaporate, so that the temperature of the distillation membrane or the solution near the distillation membrane is locally lowered. (Hereinafter referred to as "temperature polarization"). For this reason, further evaporation is locally hindered in the vicinity, and as a result, the overall concentration and
There is a weak point that the separation function deteriorates.

The present invention has been made in view of the fact that a rapid temperature drop locally occurs due to evaporation.
The purpose is to alleviate temperature polarization as much as possible and prevent deterioration of the concentration / separation function.

[0006]

In order to achieve the above object, a solution concentrating / separating apparatus according to a first aspect of the present invention is a processing container in which a solution is contained in a rotating body having a depressurized evaporation space therein. On the other hand, the evaporation space and the condenser arranged outside the processing container are connected to each other through a recovery passage, and the evaporation space is exposed to the solution in the processing container through a distillation membrane attached to the rotation member. Is rotated in the processing container to move the distillation membrane relative to the solution.

[0007]

In the vicinity of the distillation membrane, the solvent in the solution evaporates, and the heat of vaporization is taken from the solution and the distillation membrane near the distillation membrane. Therefore, there is a temperature difference between the part where this evaporation phenomenon occurs and the part where it does not occur. That is, temperature polarization occurs. However, since the distillation membrane rotates together with the rotating body, the distillation membrane moves in the circumferential direction relative to the solution near the distillation membrane, and the relative movement causes the solution near the distillation membrane to be stirred by the distillation membrane, The polarization is relaxed.

[0008]

1 to 5 show a concentrating / separating apparatus according to a first embodiment of the present invention, which is a so-called vertical type in which a rotary shaft is vertically arranged as described later. is there. Figure 1
The first embodiment will be described below with reference to FIGS.

Reference numeral 10 is a solution tank, 20 is a closed cylindrical processing container, 40 is a rotating body, 70 is a condenser, and 80.
Is a vacuum pump. The solution tank 10 and the processing container 20 are in constant communication with each other via the solution supply passage 12, and the processing container 20 and the condenser 70 are in constant communication with each other via the recovery passage 14. Then, in the solution tank 10,
The solution is filled to be separated, and its own weight is used to supply and fill the processing container 20 through the solution supply passage 12, so that the processing container 20 is constantly filled with the solution. On the other hand, the condenser 70 is sucked by the vacuum pump 80, and 10 to 350 Torr (1.3 to 46.7 k) depending on the state of the solution and the like.
The pressure is reduced to Pa). In this embodiment, about 60 Tor
The pressure is held at r (8.0 kPa). By this suction, the inside of the circumferential groove 51a and the radial groove 51b, which will be described later, which are evaporation spaces, are also under reduced pressure via the recovery passageway 14. A drain valve 74 is a valve that opens when the liquid collected in the condenser 70 is discharged to the outside. Further, 26 is also a discharge valve, which is a valve for opening the solution when it is discharged to the outside after being concentrated by the principle described later.

As shown in FIGS. 1 and 2, the rotary body 40 includes a rotary shaft 42 whose center extends vertically and a rotary shaft 42.
And a plurality of flat membrane plates 50 (four sheets in this embodiment) which are fitted to each other and are held at predetermined intervals by a plurality of spacers 44. The rotating body 40 is disposed inside the processing container 20, and the rotating shaft 42 thereof projects upward from the opening at the center of the upper surface of the processing container 20 to the outside. The rotary shaft 42 is immovable in the axial direction and rotatably rotatably through a bearing (not shown).
It is pivoted at 0. The four flat film plates 50 are fixed to the rotary shaft 42 by being clamped between the flange portion of the rotary shaft 42 and the four spacers 44 by tightening the fixing bolts 48 (see FIG. 2). ). The processing container 20 is provided with an oil seal or the like at a portion where the rotary shaft 42 projects to the outside, thereby making a liquid-tight seal. Therefore, the inside of the processing container 20 is in a hermetically sealed state except for the recovery passage 14a, the intake port 22 and the discharge port 24 which are formed in the rotary shaft 42.

Four stud bolts 32 are vertically planted from the upper end on the upper wall of the processing container 20, and three collars 34 of substantially the same length are fitted into the stud bolts 32, respectively. Three baffle plates 30 each having an annular shape are sandwiched between 34, and a lock nut 36 at the lower end is tightened to fix them.
The three puffer plates 30 are arranged at the same intervals, and are arranged just in the middle of the flat film plate 50 and the flat film plate 50 (see FIGS. 2 and 3).

In addition, a circular tubular heating coil 38 is arranged in the processing container 20 so as to surround the rotating body 40 and the baffle plate 30 in a spiral shape, and end portions 38a, 3 thereof are provided.
8b is led out from the right (in FIG. 3) wall surface of the processing container 20. A heat medium (for example, steam) passes through the heating coil 38, enters from the end portion 38a, circulates spirally inside the processing container 20, and is discharged to the outside from the end portion 38b. During that time, the solution in the processing container 20 is heated to prevent the temperature from being lowered by removing the latent heat of vaporization. In addition, four baffle plates 28 having vertical surfaces are integrally erected from the processing container 20 on the inner surface of the side wall of the processing container 20 (see FIGS. 2 and 3).

The rotating shaft 42 is provided with a pulley 84 at a position outside the processing container 20, and is rotationally driven by the pulley 84 receiving a rotational driving force from a drive motor 82 via a belt or the like. A rotary joint 86 is connected to the upper end of the rotary shaft 42, and the rotary shaft 4 is connected via the rotary joint 86.
The recovery passage 14a on the rotating side and the recovery passage 14b on the non-rotating side formed in the inside 2 are connected.

Next, the structure of the flat film plate 50 will be described with reference to FIGS. 2, 4 and 5. Support substrate 51, distillation film 52,
The flat film plate 50 composed of the net 53 has a disk shape, and has a center hole 51e at the center thereof so as to be fitted to the outer periphery of the rotary shaft 42. On both side surfaces located above and below the flat film plate 50,
A plurality of concentric circular grooves (five in this embodiment) 51a,
A plurality of (18 in this embodiment) radial grooves 51b extending in the radial direction from the center and an annular confluent groove 51c close to the center are formed.
The circumferential groove 51a and the radial groove 5 are formed to have substantially the same depth.
1b and the radial groove 51b and the merging groove 51c intersect with each other and communicate with each other at their intersections (see FIG. 5). The circumferential groove 51a and the radial groove 51b form the evaporation space of the present invention. Reference numeral 51d denotes a key groove, which is fixed to the flat film plate 50 and the rotary shaft 42 so as not to rotate at a predetermined angle by fitting a key (not shown).

A disk-shaped net 53 and a distillation film 52 are provided on both sides of the support substrate 51, and a circumferential groove 51a and a radial groove 5 are provided.
It is arranged so as to cover 1b, and its outermost diameter is welded to the supporting substrate 51 over the entire circumference. This prevents the solution from leaking to the evaporation space at the outermost diameter end portions of the net 53 and the distillation film 52. On the other hand, although the net 53 and the distillation film 52 are not welded to the support substrate 51 at the central portions thereof, the flat film plate 50 is instead inserted into the rotating shaft 42, and the spacers 44 are alternately assembled in the spacer 44. The leakage is prevented by pressing the net 53 and the distillation film 52 with the O-ring 46 attached to the side surface of the. Therefore, when the rotating body 40 is assembled and fixed by the fixing bolts 48, the processing container 20
The solution inside is communicated with the circumferential groove 51a and the radial groove 51b only through the distillation membrane 52 and the net, and does not communicate (leak) without passing through them. In addition, the net 53
Here, when the pressure on the recovery passage 14 side is reduced, the distillation membrane 5
2 functions as a distillation membrane supporting member for holding the original shape so as not to sink into the circumferential groove 51a or the radial groove 51b, but a nonwoven fabric or the like may be used instead of the net. If the distillation membrane 52 itself has sufficient rigidity to maintain the original shape, the net 53 may not be provided.

In this embodiment, the distillation membrane 52 has a diameter of 3 mm.
A hydrophobic porous membrane made of polytetrafluoroethylene having a thickness of 00 mm, a film thickness of 40 μm, an effective membrane surface area of 0.1 m ² , a pore diameter of 0.1 μm and a porosity of 70% was used. As the distillation membrane 52, a hydrophobic porous membrane such as polyvinylidene fluoride, polypropylene or polyethylene may be used. Furthermore, you may use what is called a pervaporation membrane. As the pervaporation membrane, a Nafion membrane-based ion exchange membrane, a thin film such as a silicone polymer, or polyethylene, polypropylene, polysulfone, polyether sulfone, polyvinylidene fluoride used as a microfiltration membrane or ultrafiltration membrane, etc. A composite film in which a thin film made of polyvinyl alcohol, chitosan, acetyl cellulose, polyion complex, polyimide, polyamide, polyacrylonitrile or the like is formed on the dense base film of is conceivable. Although the pervaporation membrane is slightly different from the hydrophobic porous membrane in the principle of permeation, it is the same in that the permeation of the liquid phase component is blocked and the permeation of the gas phase component is possible, and therefore the details of the principle are described. Detailed description is omitted.

Although the solution tries to enter the recovery passage 14 side due to the differential pressure generated inside and outside the distillation membrane 52, the action of the distillation membrane 52 prevents the entry in the liquid phase state. That is, for example, in the case where the distillation membrane 52 is a hydrophobic porous membrane, a large number of small through holes formed in the thickness direction exist in the distillation membrane 52, from which the solution tries to enter in a liquid phase state. However, the surface tension of the solution acts in the direction of blocking the invasion, and this force overcomes the differential pressure, and as a result, the invasion is blocked.

On the other hand, since the distillation passage 52 side of the distillation membrane 52, that is, the evaporation space is in a decompressed vapor phase state, the solvent content in the solution removes latent heat of vaporization from the solution and the distillation membrane 52 in the vicinity thereof. Evaporate. Since the vapor is in a vapor phase state, the surface tension is now at a negligible value, so that the vaporized component passes through the through hole in the direction of the pressure gradient. Then, the solvent component in the solution becomes vapor, enters the circumferential groove 51a or the radial groove 51b, and passes through the radial groove 51b to reach the confluent groove 51c. It is guided to the condenser 70 through the joint 86 and the recovery passage 14b. A coil through which the refrigerant passes is installed in the condenser 70, and the condenser 70 is installed there.
The steam that has entered the inside is cooled and condensed, and changes from the gas phase state to the liquid phase state. This collects at the bottom of the condenser 70. In addition, the amount of the solution that has been discharged as vapor and decreased is the solution tank 1
It is replenished from 0. Thus, the solution is sequentially concentrated in the processing container 20, while the solvent component in the solution is in a liquid phase state in the condenser 70 to be separated and collected.

By the way, since the latent heat of vaporization is very large, the vaporization near the distillation membrane 52 causes the vaporization of the distillation membrane 52.
Alternatively, the temperature of the solution locally drops significantly. On the other hand, there is almost no decrease in temperature where this phenomenon does not occur.
For this reason, the temperature is remarkably different between the place where it is generated and the place where it is not generated. That is, temperature polarization occurs. But,
In this embodiment, since the flat plate 50 is rotating in the solution, a relative flow is generated between the solution and the distillation film 52 in the circumferential direction of the rotating shaft 42, whereby the solution is stirred, Temperature polarization is relaxed. Therefore, the temperature in the vicinity of the distillation film 52 is made uniform, and the deterioration of the evaporation function is suppressed.

A heating coil 38 is provided in the processing container 20.
Is installed and the solution is heated by the heating coil 38 to compensate for the latent heat of vaporization lost by the vaporization, so that the temperature of the entire solution does not drop and is kept substantially constant.

Further, when the rotating body 40 rotates in the processing container 20, the solution tends to rotate together with the rotating body 40, particularly the flat membrane plate 50, but the stationary baffle plate 30.
Is interposed between the flat plate 50 and the flat plate 50,
The baffle plate 30 suppresses the accompanying rotation of the solution. The baffle plate 28 also has the same function. By these, the solution can maintain the velocity gradient with respect to the flat membrane plate 50.

By the way, the diameter of the distillation membrane is 300 m.
m, effective membrane surface area 0.1 m ² polytetrafluoroethylene hydrophobic porous membrane (porosity 70%, pore diameter 0.1
μm), solution 62 ° C., reduced pressure 60 Torr (8.0
When the evaporation amount is measured in kPa), the rotary body 40 shows 0
It was 0.3 kg / h at RPM (non-rotation),
Good data of 2.5 kg / h was obtained at 90 RPM.
Therefore, it was confirmed that the evaporation amount increased about 8 times depending on the presence or absence of rotation of the rotating body.

Next, a second embodiment of the present invention will be described with reference to FIG. As can be seen from FIG. 6, the rotating shaft of the second embodiment is of the so-called horizontal type. Since the basic structure and operation of this embodiment are substantially the same as those of the first embodiment described above, the same parts are designated by the reference numerals obtained by adding 100 to the reference numerals of the first embodiment. Therefore, the description thereof will be omitted.

The processing container 120 is formed in a cylindrical shape as in the first embodiment, but is different in that the center thereof is arranged substantially horizontally and the rotary shaft 142 is also arranged substantially horizontally. A plurality of (four in this embodiment) flat film plates 150 are arranged orthogonal to the rotary shaft 142, and are fixed by fixing bolts through the spacers 144.

Further, the distillation membrane 152 is installed in parallel with the flat membrane plate 150, and is arranged so as to cover the disk-shaped net 153 and the circumferential groove 151a and the radial groove 151b forming the evaporation space.

When the condenser 170 is sucked by the vacuum pump 180, a negative pressure is also applied to the circumferential groove 151a and the radial groove 151b which are evaporation spaces. The solution evaporates in the vicinity of the distillation film 152, passes through the distillation film 152, enters the circumferential groove 151a and the radial groove 151b, and exchanges heat in the condenser 170 through the recovery passage 114a, the rotary joint 186, and the recovery passage 114b. It is liquefied and collected.

Since the distillation film 152 is rotating around the rotary shaft 142, the distillation film 152 moves in the circumferential direction relative to the solution in the vicinity of the distillation film 152 and stirs the solution, as in the first embodiment. . Therefore, temperature polarization is reduced as in the first embodiment. Further, the following effects are added in the second embodiment. That is, the solute that is concentrated and crystallized in the vicinity of the distillation membrane 152 falls. Since the distillation membrane 152 is arranged vertically here, the solute that has fallen reaches the bottom of the processing container without being hindered by the distillation membrane and is deposited. In the vicinity of the distillation membrane,
The solution before concentration is introduced in place of the solute to prepare for a new evaporation phenomenon. Therefore, the concentration / separation function in the vicinity of the distillation membrane is maintained. Since the other actions are similar to those of the first embodiment, the description thereof will be omitted here.

Next, a third embodiment of the present invention will be described with reference to FIG. Since the basic structure and operation of this embodiment are substantially the same as those of the first embodiment described above, the same parts are designated by the reference numerals obtained by adding 200 to the reference numerals of the first embodiment. Therefore, the description thereof will be omitted.

As can be seen from FIG. 7, in the third embodiment, like the second embodiment, the rotary shaft 242 is of the so-called horizontal type, and the other constructions are substantially the same. The main difference is that no heating coil is provided in the processing container 220, and instead,
A heat exchanger 239 for heating is provided. When the solution supply pump 211 is driven, the solution is supplied from the solution tank 210 to the processing container 220 through the solution supply passage 212, and the excess solution in the processing container 220 is supplied to the solution tank 210 through the solution circulation passage 213. Will be returned. This is the so-called forced circulation system. As the solution passes through the solution supply passage 212, it passes through the heat exchanger 239 between them, so that the solution is heated here. The amount of temperature increase at this time is a degree to compensate for the amount of temperature decrease caused by evaporation in the vicinity of the distillation film 252 in the processing container 220.

In the third embodiment, since the heating coil is not provided in the processing container 220, the processing container 220 becomes small in size, and the compactness in this portion is achieved. Further, since the solution is forcibly circulated by the action of the solution supply pump 211, the solution in the processing container 220 is also forcibly circulated, and the temperature distribution in the processing container 220 becomes more uniform.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. 8, 9 and 10. Since the basic structure and operation of this embodiment are the same as those of the first embodiment described above, the same parts are designated by the reference numerals obtained by adding 300 to the reference numerals of the first embodiment. , The description is omitted.

As can be seen from FIG. 8, the fourth embodiment is an eclectic embodiment of the second and third embodiments. That is, the heating coil is not provided in the solution supply passage 312 or the solution circulation passage 313. Instead, the baffle plate 330 substitutes that function. That is, the baffle plate 330 is formed in a hollow shape, and this also serves as the heating coil 338. The heat medium advances from the inlet 338a of the heating coil 338 through a plurality of (7 in the present embodiment) passages 338c formed in the puffle plate 330 or the processing container 320 in parallel to the axial direction of the rotating shaft 342, and successively. It is sequentially discharged from the outlet 338b through a passage 338d toward the tip of the baffle plate 330, and further through a passage 338e formed in the puffle plate 330 or the processing container 320. While the heat transfer medium is passing through the passage 338d, the baffle plate 33
Heat 0 and heat the solution. The amount of temperature rise at this time is
The solution can be maintained at a constant temperature by compensating for the temperature drop caused by evaporation near the distillation film 352 in the processing container 320.

In the fourth embodiment, since the puffle plate 330 also serves as the heating coil, it is not necessary to secure a volume for the heating coil in the processing container 320, and the processing container 320 can be made compact. . Further, unlike the third embodiment, it is not necessary to separately provide the heat exchanger 239 in the solution supply passage 312, and the size can be made compact also from this point.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. 11 and 12. Since the basic structure and operation of this embodiment are substantially the same as those of the first embodiment described above, the same parts are designated by the reference numerals of the first embodiment.
The description thereof will be omitted by adding reference numbers including 00.

As can be seen from FIG. 11, the fifth embodiment is the first
It is an eclectic embodiment of the embodiment and the fourth embodiment. That is, the baffle plate 430 is common to the fourth embodiment in that the function of the heating coil is substituted, but unlike the fourth embodiment, the solution circulation passage 313 is not provided, which is the first point.
The same as the embodiment.

In each of the above embodiments, an example in which the evaporation space and the distillation film are installed on a disk-shaped flat film plate orthogonal to the rotation axis in the rotating body is shown, but the present invention is not limited to this. For example, a distillation film may be installed on the outer peripheral surface of the rotating shaft, and an evaporation space may be installed in the rotating shaft.

In each of the above-mentioned embodiments, a container whose inside constitutes a closed space is shown as a processing container, but the present invention is not limited to this, and may be a tank having an open upper part. .

Further, the apparatus of the present invention is particularly effective for treating a liquid containing a high concentration of salt, a high concentration fermentation waste liquid, a heavy metal waste water, a plating waste water, a dye waste water, a pulp bleaching waste water and the like.

In particular, when a solution containing a salt such as NaCl in the solvent is processed by the above-mentioned concentrating / separating apparatus, the concentrated solution containing the salt remains in the processing container and the solvent is recovered in the condenser 70. Therefore, it is possible to easily and highly concentrate and separate salt such as NaCl, which is difficult to concentrate and separate.

[0040]

As described above in detail, according to the concentration / separation apparatus of the present invention, temperature polarization is alleviated, and deterioration of the concentration / separation function can be prevented.

[Brief description of drawings]

1 to 12 are drawings according to the present invention, in which FIGS. 1 to 5 show a first embodiment of the present invention, FIG. 6 shows a second embodiment of the present invention, and FIG. 7 shows the present invention. 8 to 10 show a fourth embodiment of the present invention, and FIGS. 11 and 12 show a fifth embodiment of the present invention.

FIG. 1 is an overall schematic explanatory diagram of a solution evaporation / separation apparatus according to a first embodiment.

FIG. 2 is an enlarged cross-sectional view of the processing container of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a cross-sectional view for explaining an assembled state of a flat membrane plate, a distillation membrane, a spacer and a rotating shaft.

FIG. 5 is a front view of a single support substrate.

FIG. 6 is an overall schematic explanatory diagram of a solution evaporation / separation apparatus according to a second embodiment.

FIG. 7 is an overall schematic explanatory diagram of a solution evaporation / separation apparatus according to a third embodiment.

FIG. 8 is an overall schematic explanatory diagram of a solution evaporation / separation apparatus according to a fourth example.

9 is an enlarged cross-sectional view of the processing container in FIG.

10 is a cross-sectional view taken along line XX of FIG.

FIG. 11 is an overall schematic explanatory diagram of a solution evaporation / separation apparatus according to a fifth example.

12 is a sectional view taken along line XII-XII in FIG.

[Explanation of symbols]

 10 ... Solution tank 12 Solution supply passage 14 Recovery passage 20 Processing container 28 Baffle plate Baffle plate 32 Stud bolt 34 ... Collar 38 ... Heating coil 40 ... Rotating body 42 ... Rotating shaft 44 ... Spacer 46 ... O-ring 48 ... Fixing bolt 50 ... ..Flat membrane plate 51..support substrate 51a.circumferential groove 51b.radial groove 51c.confluence groove 51d.key groove 51e.center hole 52..distillation membrane 53 ... Net 70 ... Condenser 72 ... Cooling coil 74 ... Exhaust valve 80 ... Vacuum pump 82 ... Drive motor 84 ... Pulley 86 ...・ Rotary joint 211 ・ ・ ・ Solution supply pump 2 13 ... Solution circulation passage 239 ... Heat exchanger

Claims (8)

[Claims] 1. A rotating body having a depressurized evaporation space inside is arranged in a processing container containing a solution, while the evaporation space and a condenser arranged outside the processing container are connected by a recovery passage. , Through the distillation membrane attached to the rotating body,
A solution concentrating / separating device, characterized in that an evaporation space is exposed to a solution in a processing container, and a rotating body is rotated in the processing container to move a distillation membrane relative to the solution. 2. The solution concentrating solution according to claim 1, wherein the rotating body includes a rotating shaft and a disk-shaped flat film plate substantially orthogonal to the rotating shaft, and the evaporation space is provided in the flat film plate. -Separation device. 3. A solution concentrating / separating apparatus according to claim 2, wherein a plurality of the flat membrane plates are provided, and these flat membrane plates are fixed to the rotary shaft at predetermined intervals. 4. The solution concentration / separation device according to claim 2 or 3, wherein the distillation membrane is attached to both sides of the flat membrane plate. 5. The solution concentration / separation device according to claim 2, wherein the recovery passage is provided in the rotation shaft. 6. The solution concentration / separation device according to claim 2, wherein the rotary shaft is arranged horizontally. 7. The solution concentration / separation device according to claim 2, wherein the rotating shaft is arranged vertically. 8. A solution concentrating / separating apparatus according to any one of claims 1 to 7, wherein a heating means is provided in the processing container.