JPH043248B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a liquid separation method, and more particularly, the present invention relates to a liquid separation method, and more specifically, the present invention relates to a method for separating a liquid, and more particularly, the present invention relates to a method for separating a liquid, and more particularly, to prevent a temperature drop of a liquid to be treated in a pervaporation membrane module, and to prevent the permeation of an organic liquid through a pervaporation membrane module. This invention relates to a liquid separation method with improved performance.

[Prior art]

The conventional pervaporation membrane module 1 has, for example, a third
It has a structure as shown in the figure.

That is, the pervaporative membrane 13 is laminated on the plate 15 via the gasket 14, and the porous plate 12 and the wire mesh 11 are further laminated on the pervaporative membrane 13.

The organic liquid to be treated is then transferred to the plate 15.
The component is supplied between the membrane 13 and the membrane 13 from the direction of the arrow A, permeates the membrane 13, and vaporizes, passing through the perforated plate 12 and the wire mesh 11 and being discharged in the direction of the arrow B.

Incidentally, the amount of permeation through the membrane 13 is proportional to the temperature of the supplied liquid to be treated, and generally, the higher the temperature of the liquid to be treated, the higher the temperature of the liquid to be treated.
The amount of permeation increases.

However, the components in the liquid to be treated permeate the membrane,
During vaporization, the secondary side of the membrane is kept under reduced pressure, so the latent heat of vaporization is absorbed, and as permeation and vaporization progress, the temperature of the liquid to be treated decreases and the amount of permeation through the membrane decreases.

Therefore, the conventional module requires a large membrane area, making it impossible to avoid increasing the size of the device.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned conventional drawbacks, and provides a liquid separation method that can prevent the temperature of the liquid to be treated from decreasing by a simple method and improve the separation performance of the membrane. The purpose is to

[Structure of the invention]

The liquid separation method of the present invention that achieves the above object is a liquid separation method in which a liquid to be treated is separated by a pervaporation membrane into a permeable component and a non-permeable component of the pervaporation membrane. The supply space for the liquid to be treated is divided into at least two by partition plates provided at intervals, the liquid to be treated is supplied to the space far from the pervaporation membrane, and then this liquid is passed through the pervaporation membrane. The present invention is characterized in that the liquid to be treated flows in a space that is in contact with the pervaporation membrane and is far from the pervaporation membrane, and is caused to flow countercurrently through the partition plate.

The present invention will be explained below based on a first embodiment shown in FIG.

In the liquid separation method of the present invention, the liquid supply space to be treated divided by the pervaporation membrane 5 is divided by the partition plate 3.

That is, the frame body 2 is provided with a partition plate 3 and a bottom plate 4, and a space P far from the pervaporation membrane 5 is formed between them.

Further, a pervaporation film 5 is stretched over the frame 2' on the partition plate 3 with a gasket 6 in between, at a distance from the partition plate 3.

The materials used for the frames 2, 2' are usually metal materials such as stainless steel and carbon scale, and plastic materials such as polysulfone and polyethylene.

Further, the shapes of the partition plate 3 and the bottom plate 4 are not particularly limited, but a rectangular or square shape is preferable in consideration of ease of manufacturing the module.

The material of the membrane 5 is not particularly limited either, and can be appropriately selected from, for example, a polyvinyl alcohol membrane, a silicone rubber membrane, etc., depending on the intended use of the module 1.

Furthermore, in the present invention, porous materials are laminated on the membrane 5, respectively.

As the porous material, a material such as a perforated plate, nonwoven fabric, or wire mesh is used that prevents damage to the membrane 5 due to the secondary side of the membrane 5 being maintained at reduced pressure, and does not impede the passage of permeation and vaporized components. be done.

Further, such a porous material may be laminated in one layer on the membrane 5, or as shown in the figure, a porous plate 7 is laminated on the membrane 5, and then a wire mesh 8 is further laminated on the porous plate 7. You can also do that.

Furthermore, in the present invention, the frame 2 of the space P is provided with at least one liquid supply port 9, and the partition plate 3 is provided with at least one liquid passage port 10. Processed liquid passage port 1
Although the position of 0 is not particularly limited, it is preferable to provide it on the partition plate 3 near the frame body facing the liquid supply port 9 to be treated.

In other words, it is preferable that the liquid to be processed passage port 10 is located at the farthest possible distance from the liquid to be processed supply port 9.

Furthermore, in the present invention, the frame 2' on the partition plate 3
, preferably at a position close to the liquid to be treated supply port 9,
At least one treated liquid outlet 11 is provided.

In this first embodiment, the pervaporation membrane 5
are stretched on the partition plate 3 at intervals through the gasket 6, but the present invention is not limited to this, and the gasket 6 may not be provided.

Such a module 1 may be used alone, or a plurality of modules may be used in a stacked manner.

FIG. 2 shows a second embodiment of the present invention, in which the first
While the embodiment is of an asymmetric type, this second embodiment is of a symmetric type.

In other words, the frame pair 2'' on the lower plate 4 also has the lower plate 4.
A pervaporation membrane 5' is stretched through a gasket 6' at a distance from the membrane, and a porous plate 7' and a wire mesh 8' are laminated on this membrane.

The lower plate 4 is provided with at least one liquid passage port 10', and the frame 2' is further provided with at least one liquid discharge port 11'.

Next, the function of the module of the present invention is converted into a second one.
This will be explained based on the diagram. For example, assume that a liquid to be processed heated to 110° C. is supplied from the liquid to be processed supply port 9 . Then, this liquid to be treated flows through the space P in the frame body 2 in the direction of the arrow Q, for example, at 95° C., from the liquid to be treated passage port 10 to the partition plate 3, the bottom plate 4 which also functions as a partition plate, the membrane 5, 5' and flows in the direction of arrow S.

Heat exchange then takes place between the flow indicated by arrow Q and the flow indicated by arrow S through the partition plate 3 and the lower surface plate 4.

On the other hand, in the flow indicated by arrow S, components in the liquid to be treated permeate through the membrane 5 and are separated by vaporization.
The temperature decreases in the flow of arrow S due to latent heat of vaporization.

However, as described above, heat exchange between the streams indicated by arrows Q and S prevents the temperature of the stream S from decreasing, and the temperature of the stream S is maintained at 95°C, for example, and the discharge port 1
It is discharged from 1.

On the other hand, the components that have permeated the membrane 5 and vaporized are stored in a condenser (not shown), for example, on the secondary side of the membrane 5.
It is cooled, condensed, and extracted as a separated component.

〔Effect of the invention〕

As described above, according to the present invention, the supply space for the liquid to be treated is divided into at least two spaces by the partition plate, the liquid to be treated is supplied to the space far from the pervaporation membrane, and then the liquid to be treated is supplied to the space far from the pervaporation membrane. Since the liquid to be treated flows in a space far from the pervaporation membrane while being in contact with the pervaporation membrane, the liquid to be treated flows countercurrently through the partition plate, so that the liquid to be treated at a higher temperature is supplied to the space far from the pervaporation membrane. It is possible to prevent a drop in the temperature of the liquid to be treated that flows while in contact with the pervaporation membrane by heat exchange between the liquid itself and the liquid to be treated that flows while in contact with the pervaporation membrane. Therefore, the amount of permeation through the pervaporation membrane can be maintained at a high level.

Furthermore, in the present invention, as described above, the amount of permeation through the pervaporation membrane can be maintained at a high level by heat exchange using the heat amount of the liquid to be treated, and no heat source such as a heat medium is required. I don't.

That is, only the inlet and outlet of the liquid to be treated are required, and the structure of the apparatus can be simplified.

Therefore, it is not only easy to operate, but also reduces operating costs and makes the device more compact.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the liquid separation method of the present invention, FIG. 2 is a schematic diagram showing the second embodiment, and FIG. 3 is a schematic diagram of a conventional liquid separation method. 1... Pervaporation membrane module, 2, 2', 2''...
... Frame body, 3 ... Partition plate, 4 ... Bottom plate, 5, 5'
...Permeable vaporization membrane, 7,7'...Perforated plate, 8,8'...
...wire mesh, 9...processed liquid supply port, 10, 10'...
...To-be-treated liquid passage port, 11, 11'... To-be-treated liquid outlet.

Claims (1)

[Claims] 1 In a liquid separation method in which a liquid to be treated is separated by a pervaporation membrane into a permeable component and a non-permeable component of the pervaporation membrane, the pervaporation membrane is separated by partition plates provided at intervals. The processing liquid supply space is divided into at least two parts, the liquid to be treated is supplied to the space farthest from the pervaporation membrane, and the liquid is then supplied to the space far from the pervaporation membrane while being in contact with the pervaporation membrane. A method for separating a liquid, the method comprising causing countercurrent flow to the flowing liquid to be treated through the partition plate.