JPS6380825A - Concentrator - Google Patents

Abstract

PURPOSE:To obtain an apparatus having a simple structure and a high concn. speed, by a method wherein a porous membrane is also mounted at the position of a conventional cooling surface and the steam generated from a solution supplied is absorbed without being condensed, by an absorbing liquid, which flows through a place where conventional cooling water flows. CONSTITUTION:This apparatus consists of three chambers, that is, a first chamber 10 through which a solution 13 supplied flows, a third chamber 12 through which a vapor absorbing liquid flows and a second chamber 11 in which generated steam moves and the respective chambers are partitioned by porous membranes 2, 2' each having a property previous to gas but impervious to a liquid. The solvent vapor of the solution supplied is generated on the porous membrane 2 contacting with the first chamber 10, and the generated vapor is moved to the second chamber 11 to be allowed to pass through the porous membrane 2' contacting with the third chamber 12 and absorbed by a vapor absorbing liquid 14 to concentrate the above mentioned solution supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a concentrating device for liquid solutions, and more particularly to a concentrating device that is effective for concentrating various aqueous solutions using a medium-low temperature heat source.

[Conventional technology]

Conventionally, as a method for concentrating an aqueous solution using a porous membrane that does not allow liquid to pass through but allows gas to pass through, there is a concentration (separation/distillation) device used in seawater desalination devices and the like.

As shown in FIG. 2, this type of conventional concentrating device has a first chamber 24 through which a feed aqueous solution 27 flows, a third chamber 26 through which cooling water 28 flows, and a permeate liquid 29 by condensing permeate vapor. It consists of three chambers, a second chamber 25 for taking out, and the first chamber 24 and the second chamber 25 are partitioned by a porous membrane 22, and the second chamber 25 and the third chamber 26 are partitioned by a cooling surface 23. It is being In this conventional system, a feed aqueous solution 27 enters the first chamber 24 .

The vapor evaporates on the membrane surface of the porous membrane 22 and
The vapor that has passed through 6 moves inside the second chamber 25, is cooled and condensed on the cooling surface 23, and is taken out of the system as a permeated liquid 29. Therefore, the steam moves using the pressure difference between the water vapor pressure of the supplied aqueous solution and the water vapor pressure on the cooling surface 23 as a driving force.

The feed aqueous solution 27 is therefore concentrated.

[Problem that the invention seeks to solve]

In a hydraulic device, not only is the device required to have many inputs and outputs such as a supply aqueous solution outlet, a cooling water outlet, and a permeate outlet, but also the porous membrane 22 and the cooling surface 23 are installed in parallel. However, a structure must be adopted to secure three chambers, which has the drawback of making the device structure extremely complicated. In addition, the concentration rate of the aqueous solution, that is, the permeation rate, is
It is known that the concentration rate is inversely proportional to the distance between the porous membrane 22 and the cooling surface 23, and as the distance between the porous membrane 22 and the cooling surface 23 becomes smaller, the concentration rate increases. The permeated liquid 29 fills the inside of the second chamber 25, and the heat of the supplied aqueous solution 27 is transferred to the cooling water 28 in the form of thermal conduction, resulting in a large heat loss.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a concentrating device that has a simple structure and a high concentration rate.

[Means for solving problems]

In order to achieve the above object, the present invention has the following configuration.

In other words, the supplied solution flows through the first chamber in contact with the porous membrane as before, but a porous membrane is also installed at the position of the conventional cooling surface, so that the vapor generated from the supplied solution is not condensed and is passed through the conventional cooling process. The water will be absorbed by the absorbing liquid flowing in the place where it was flowing.

[Effect]

For this reason, the structure of the device is simpler than the conventional type because there is no permeated water outlet, and at the same time, since only steam exists in the second chamber where steam used to condense, heat loss due to permeated water occurs. Things will go away. Furthermore, by keeping the second chamber under reduced pressure, it is possible to significantly reduce the resistance to vapor movement, which not only increases the concentration rate but also creates a heat insulation effect, allowing for a higher-performance concentrator. Become.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIG. 1 and FIGS. 3 to 3.
This will be explained in detail using figures. FIG. 1 is a conceptual diagram of a concentrator according to the present invention, FIG. 3 is a system diagram of a concentrator according to the present invention, and FIG. 4 is a front view of an example of a concentrator according to the present invention.
FIG. 5 shows a sectional view taken along line A-A' in FIG.

As shown in FIG.
1st room where 3 flows 10. Third chamber 12 through which vapor absorption liquid flows
It consists of three chambers, including a second chamber 11 through which generated steam moves, and each chamber is partitioned by a porous membrane 2 that allows gas to pass through but not liquid. The concentration method in this device is such that solvent vapor of the supplied solution is generated on the porous membrane 2 in contact with the first chamber 10, and the generated vapor moves within the second chamber.
The vapor absorbing liquid 1 passes through the porous membrane 2' in contact with the third chamber 12.
Absorbed by 4. At this time, the movement of solvent vapor is as follows: feed solution 1
This occurs using the difference between the vapor pressure of the absorption liquid 14 and the vapor pressure of the absorption liquid 14 as a driving force. In other words, the movement of steam within the second chamber occurs as the steam diffuses in the air. Therefore, if the air (non-condensable gas) in the second chamber 11 is removed by extraction 15 and the second chamber 11 is filled only with steam, the movement of the vapor is no longer due to diffusion, so the amount of movementゎThe concentration rate increases significantly.

FIG. 3 is an example of a system diagram of a concentrator according to the present invention. On the concentrator, a flat porous membrane 2゜2' is placed in the first chamber 10. 2nd room 11. It has a laminated structure so that a third chamber 12 is formed. On both sides of the first chamber 10 through which the supply solution flows, there is a second chamber 11, which is a space in which the generated vapor moves, and adjacent thereto, there is a third chamber 12, through which an absorption liquid that absorbs the moving vapor flows. They are made of a structure in which a plurality of credit unions are laminated.

The feed solution 13 is heated by the heater 5 in the feed solution tank 3 and reaches a predetermined temperature, and then is sent onto the concentrator by the feed solution pump 7. The feed solution 13 fed into the first chamber 10 above the a-condenser flows in contact with the porous membrane 2. Similarly, the vapor absorption liquid 14 is supplied to the cooler 6 in the absorption liquid tank 4.
After being cooled down to a predetermined temperature, the vapor absorption liquid pump 7
' is sent onto the concentrator. The vapor absorption liquid 14 sent into the third chamber 12 above the concentrator also flows while contacting the porous holes ff[2' which are in contact with the third chamber 12. The second chamber 11 into which the steam moves can be maintained under reduced pressure by extracting air 15. The vapor generated from the supply solution 13 on the surface of the porous membrane 2 passes through the second chamber 11 and is absorbed by the absorption liquid 14 . still.

For this vapor absorption liquid, for example, for absorption of water vapor,
Hygroscopic aqueous solutions (lithium bromide, calcium chloride,
(aqueous solutions of salts such as) can be used. It is also possible to absorb water depending on the conditions. Furthermore, as porous membrane materials that allow gas to pass through but not liquids, hydrophobic materials such as polytetrafluoroethylene (PTFE) and polypropylene (PP) (with a critical surface tension value of 35
dyne/a! 1 or less) can be used.

FIG. 4 shows an example of a concentrating device using a tube-shaped membrane, whereas FIG. 3 has a stacked structure of flat membranes. Further, FIG. 5 is a sectional view taken along the line AA' in FIG. 4. This concentration device 400 has a cylindrical container 401 and a tube-shaped porous I! 1402゜402' and tube plate 4 on both ends.
05, 405' is built in, and the tube plates 405, 405' are connected to the cylindrical container 401 and sealed. Further, both ends of the cylindrical container 401 are sealed by side lids 411, 411' so that four ice chambers 412 to 415 can be formed. A bleed hole 409 is connected to the cylindrical container 401, and a supply solution inlet 408 and an absorption liquid inlet 407 are connected to the side lid 411.
A supply solution outlet 403 and an absorption liquid outlet 404 are connected to the side surface 'M411'.

The feed solution is fed into the water chamber 4 through the feed solution inlet 408.
12 and connected to the tube sheet 405
Enter the first chamber formed inside 02. The solution concentrated in the first chamber is collected in the water chamber 413 and then the feed solution outlet 40
It is discharged from 3.

Similarly, the absorption liquid also enters the water chamber 414 from the absorption liquid population 407 and enters the third chamber formed within the tubular membrane 402'. The absorption liquid that has absorbed steam in the third chamber is collected in the water chamber 415 and then discharged from the absorption liquid outlet 404. A second chamber 40 formed outside the tubular membrane 402, 402'
6 can bleed air through the bleed hole 409. In this embodiment, it is also possible to reverse the flow of the supply solution and absorption solution.

As described above, the embodiment according to the present invention has a simpler structure and can achieve a higher concentration rate than the conventional apparatus.

FIG. 6 shows another embodiment of the invention. In this A-ray device 617, a supply solution 627 is supplied to the first chamber 60.
The generated steam passes through the porous membrane 605 into the second chamber 625, is cooled and condensed on the condensing surface 623, becomes permeated water 629, and is released outside the system. Be it.

The cooling liquid 628' cools the condensing surface 623 while being cooled by the cooler 631 in the third chamber 626.

FIG. 7 also shows one of the concentrating devices according to the present invention, and has a structure having a porous membrane 705' that allows gas to pass through but not liquid, in place of the condensing surface in FIG. 6. In this device, vapor generated from the feed solution 727 through the porous membrane 705 is transferred to the absorbing liquid 728' through the porous membrane 705.
Absorbed via 5'. Therefore, in this device, the generated vapor is not taken out as a permeated liquid, so the number of liquid outlets is reduced by one.

Also in this device, since the absorption liquid 728' is cooled as needed by the cooler 731 in the third chamber 709, the supply solution 728'
7 and the absorption liquid 728' are no longer required to flow in large quantities.

FIG. 8 is a systemization of the conceptual diagram shown in FIG. 7. The concentrating device 701 includes a porous membrane 705 and a heating plate 70.
6. It shows a laminated structure in which cooling plates 706' are stacked, and from the left side of the device, from the side wall 709, the heating fluid flow path 707
, heating plate 706, first chamber 708, porous membrane 705, second
Chamber 71o, porous membrane 705', third chamber 709. Cooling plate 7
06'.

cooling fluid flow path 711, cooling plate 706', third chamber 709,
It has a structure in which several layers of units such as a porous membrane 705', a second chamber 710, a porous membrane 705, a first chamber 708, a heating plate 706, and a heated fluid channel 707 are laminated. A feed solution 727 to be concentrated is sent to the a-condensation device 701 by a feed solution pump 704 . The feed solution 727 fed into the concentrator 70 flows against a porous membrane 705 on one side and a heating plate 706 heated by a heating fluid 714 on the other side, and the generated vapor passes through the porous membrane 705. Move to the second room 710. The heat used for evaporation is also replenished by heating plate 706 which is heated by heating fluid 714. Further, an absorption liquid 728' that absorbs evaporated vapor is sent from an absorption liquid tank 703 to a concentrator 701 by a pump 704. Concentrator 70
The absorption liquid 728' sent into the process flows in contact with a cooling plate 706' which is cooled by a porous membrane 705 on one side and a cooling fluid 712 on the other side, and moves to a second chamber 710. The vapor is absorbed through the porous membrane 705'.

The latent heat obtained at this time is transferred to the cooling fluid 7-12 through the cooling plate 706' on the opposite side, so that the temperature of the absorbing liquid 728' is always constant. As the vapor absorbing liquid, for example, a hygroscopic aqueous solution (aqueous solution of salts such as lithium bromide, calcium chloride, etc.) can be used for absorbing water vapor. It is also possible to absorb water depending on the conditions. Furthermore, as a porous membrane material that allows gas to pass through but not liquid, hydrophobic materials such as polytetrafluoroethylene (PTFE) and polypropylene (PP) (with a critical surface tension value of 35 dyne/
am or less) can be used. Furthermore, in one device, changing the flow locations of the heating fluid and the cooling fluid causes vapor transfer from the absorption liquid to the feed solution, making it possible for the device to perform concentration and dilution operations.

Incidentally, in the above embodiment, since the movement of vapor occurs due to diffusion of vapor in the air in the second chamber, the concentration rate is further increased when the air in the second chamber is extracted and operated under reduced pressure.

As described above, it can be seen from the embodiments of the present invention that the apparatus is more compact and more economical than the conventional apparatus.

〔Effect of the invention〕

According to the concentrator according to the present invention, the structure is simplified because there is one less liquid outlet than the conventional type, and at the same time, heat loss can be reduced because there is no condensation in the steam moving part. Furthermore, by bleeding the vapor transfer portion, the diffusion resistance can be reduced, making it possible to increase the vapor transfer rate, that is, the concentration rate.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a concentrator according to the present invention, FIG. 2 is a conceptual diagram of a conventional concentrator, FIG. 3 is a system diagram of a concentrator according to the present invention, and FIG. 4 is a concentrator according to the present invention. A front view of an example of the device, and FIG. 5 is a sectional view taken along line AA' in FIG.
FIG. 6 and FIG. 7 are conceptual diagrams of the concentrating device according to the present invention, and FIG.
The figure is a system diagram of a concentrator according to the present invention. Yo...Concentrator, 2.2'...Porous membrane, 13...
- Supply solution, 14... vapor absorption liquid, 402, 402'
...Tube-shaped porous membrane.

Claims (1)

[Claims] 1. A first region through which a solution to be concentrated flows, a second region through which a solution that absorbs solvent vapor emitted from the solution to be concentrated flows, and a third region connecting the above two regions. , a device in which each region is partitioned by a porous membrane that does not allow liquid to pass through, but allows gas to pass through. A concentrating device characterized in that a solution flowing through a first region is concentrated by absorbing the solution into a solution flowing through a second region. 2. A concentrating device characterized in that the third region according to claim 1 is operated under reduced pressure.