JPH029875Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spiral type membrane separation device that uses a selectively permeable membrane to perform membrane separation treatment, particularly of high-temperature fluids.

In general, in a spiral membrane separation device, the open end of a membrane envelope made of a selectively permeable membrane sandwiching a permeate channel material is communicated with a permeate collection pipe, and the membrane envelope and the raw solution channel material are used to collect the permeate. It consists of a spiral wound around a water pipe.

As an example of the structure of a conventional spiral membrane separation device, as shown in FIG. 1, both sides of a porous sheet-like permeate channel material 11 are sandwiched between selective permeation membranes 12, and the three sides are adhesive-sealed. A membrane envelope is formed with the remaining side open to form a seal portion 13, and the open end of the membrane envelope is communicated with a permeate collection pipe 14 having a plurality of small holes. For example, it is known that a net-like plastic sheet material 15 for the raw solution flow path is wound around the permeate collection pipe 14 so that the material 15 for the raw solution flow path is disposed between adjacent membrane envelopes. There is.

When treating a high-temperature fluid using a membrane separation device configured in this manner, the allowable temperature limit of the device is limited by the allowable temperature limit of the selectively permeable membrane and other constituent materials. However, even if the temperature is below the above-mentioned heat resistance temperature, thermal expansion of the equipment constituent materials occurs during equipment operation, and the difference in thermal expansion coefficients causes the material for the raw solution flow path to be pressed against the permeable membrane surface, damaging the membrane. The drawback was that the separation performance deteriorated.

The present invention has been made to solve the drawbacks of the prior art, and the open end of a membrane envelope made of a selectively permeable membrane sandwiching a permeate channel material is communicated with a permeate collection pipe. In a spiral type membrane separation device in which a membrane envelope and a material for the raw solution flow path are wound in a spiral around the permeate collection pipe, the material for the raw solution flow path is placed between adjacent membrane envelopes at both ends of the membrane separation device. The present invention relates to a spiral type membrane separation device characterized in that it is provided with.

Hereinafter, an example of the present invention will be explained based on the drawings.

In FIG. 2, both sides of a porous sheet-shaped permeate channel material 1 are sandwiched between selectively permeable membranes 2, three sides of which are adhesively sealed to form a sealing part 3, and the remaining side is left open. There is.

The open end of the membrane envelope constructed in this way communicates with the permeate collection pipe 4 having a plurality of small holes, and the membrane envelope and the raw solution channel material 5 of the net-like plastic sheet are connected to the permeate collection pipe 4. is wound around the membrane so that it is disposed between adjacent membrane envelopes at both ends of the device.

In the present invention, the stock solution flow path material 5 is arranged between adjacent membrane envelopes at both ends of the membrane separator to provide a gap between the membrane envelopes that allows the stock solution flow path to be maintained, and as much as possible between the membrane envelopes. This is to prevent the presence of the stock solution channel material 5. For example, as shown in FIG. 2, it is preferable to arrange stock solution channel materials 5 having a width of about 2 to 4 cm near the sealing portion 3 of the membrane envelope, that is, at both ends of the membrane separation device. With this configuration, the membrane surface that the undiluted solution flow path material 5 is in contact with does not have a separation function, so even if the undiluted solution flow path material 5 is pressed against the membrane surface, the separation performance of the entire device will deteriorate. Never.

According to the present invention, the material for the raw solution flow path is disposed between adjacent membrane envelopes at both ends of the membrane separation device, preferably only at the adhesive seals at both ends. It is possible to avoid pressing the membrane against the surface as much as possible, and to obtain a highly safe spiral type membrane separation device without damaging the membrane surface. Furthermore, there are also advantages in that pressure loss in the stock solution flow path can be reduced and separation efficiency is good.

Although a single-plane spiral in which a set of materials is wound around a permeated liquid collection pipe has been described above, the present invention can of course be similarly applied to a bi-plane spiral.

Next, the present invention will be specifically explained with reference to Examples.
In the examples, the removal rate is a value defined by the following equation.

Removal rate (%) = (1 - salt concentration in permeate solution / salt concentration in stock solution) x 100 Example A composite reverse osmosis membrane having a thin film formed on a polysulfone porous membrane, a polyester nonwoven fabric treated with melamine As shown in Figure 2, spiral type membrane separation with a diameter of 2 inches and a length of 30 cm was carried out using a permeate flow path material made of PVC, a permeate collection pipe made of vinyl chloride, and a raw solution flow path material of a polypropylene net with a width of 3 cm. Got the device.

Using the above apparatus, a 0.5% sodium chloride solution was subjected to reverse osmosis treatment under the conditions of a pressure of 42 Kg/cm ² , an outlet flow rate of 5/min, and a temperature of 60°C.

As a result, the initial performance (after 3 hours) of the device was a permeate volume of 0.30 m ³ /day (calculated at 25°C) and a removal rate of 99.46%. Furthermore, even after 1000 hours of continuous operation, the amount of permeated water was 0.31 m ³ /day (calculated at 25°C), and the removal rate was 99.46%, and the removal rate remained stable with no decrease observed.

Comparative Example A spiral type membrane separator having a diameter of 2 inches and a length of 30 cm as shown in FIG. 1 was obtained in the same manner as in the example except that the material for the raw solution flow path was disposed over the entire surface between adjacent membrane envelopes.

As a result of reverse osmosis treatment using the above device in the same manner as in the example, the initial performance (after 3 hours) of the device was a permeate volume of 0.25 m ³ /day (calculated at 25°C) and a removal rate of 99.46%. After 250 hours, the amount of permeated liquid was 0.45m ³ /day (25℃
(converted), the removal rate was 97.80%, and the removal rate was decreasing.

[Brief explanation of the drawing]

FIG. 1 is a partially expanded explanatory view showing an example of a conventional spiral type membrane separation device, and FIG. 2 is a partially expanded explanatory view showing an example of the spiral type membrane separation device of the present invention. 1...Permeate flow path material, 2...Selective permeation membrane,
4...Permeated liquid collection pipe, 5...Material for raw solution flow path.

Claims (1)

[Scope of utility model registration request] The open end of a membrane envelope made of a selectively permeable membrane sandwiching the permeate flow path material is communicated with the permeate collection pipe, and the membrane envelope and the raw solution flow path material are arranged in a spiral shape around the permeate collection pipe. 1. A spiral type membrane separation device formed by winding, characterized in that the above-mentioned stock solution flow path material is disposed between adjacent membrane envelopes at both ends of the membrane separation device.