JP2898763B2 - Membrane module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane module for liquid filtration capable of removing dissolved gas, and is useful for producing ultrapure water.

[0002]

2. Description of the Related Art In a cleaning process in the production of semiconductors, ultrapure water finally used is produced using a reverse osmosis membrane, a hollow fiber type ultrafiltration membrane, various ion exchange resins, and deaeration equipment. , Number of fine particles, specific resistance, TOC (total organic carbon content),
Strict regulations are made using DO (dissolved oxygen amount), dissolved silica amount, viable cell count and the like as indexes. In particular, recently, in order to further improve the performance of semiconductors, there is a demand for further strengthening of the index for the ultrapure water.

For example, the regulation of TOC elution from ion-exchange resins or the like, which may cause malfunction of semiconductors, has been strengthened.
There is a demand for stricter regulations on DO in piping and use point ultrafiltration hollow fiber membrane modules that may increase the SI contact resistance.

[0004]

Conventionally, DO
Although the pretreatment by the degassing tower is performed in order to reduce the amount of oxygen, dissolution of oxygen from the pretreatment position to the use point becomes a problem under the stricter regulation of DO.
On the other hand, if degassing is performed by the degassing tower immediately before the use point, an increase in fine particles, viable bacteria, and the like removed by the membrane module is unavoidable.

In order to eliminate such absurdity, it is conceivable that the treatment is finally performed with a degassing membrane module. However, a membrane module dedicated to degassing is required in addition to a membrane module for removing fine particles. Complicated maintenance is inevitable. An object of the present invention is to provide a liquid filtration membrane module having a simple configuration capable of removing both fine particles and dissolved gas.

[0006]

According to a first aspect of the present invention, there is provided a membrane module in which a hollow fiber membrane bundle is accommodated in a cylindrical case, an intermediate partition is provided in the case, and an end portion is provided at one end of the hollow fiber membrane bundle. A resin partition is provided, one end of each hollow fiber membrane is opened on the outer surface of the end resin partition, the other end of the hollow fiber membrane is closed, and the inside of the case is divided into two by the intermediate partition. The mouth wall is provided with a mouth portion.

In the membrane module of the second invention, a hollow fiber membrane bundle is housed in a cylindrical case, an intermediate partition is provided in the case, and an end resin partition is provided on both ends of the hollow fiber membrane bundle.
Each end of each hollow fiber membrane is opened on the outer surface of each end resin partition,
An opening is provided on a cylindrical wall of each of the chambers, which is formed by dividing the inside of the case into two by the intermediate partition wall.

[0008]

By making the hollow fiber membrane portion in one room separated by the intermediate partition wall hydrophobic, dissolved gas can be permeated and separated, and by making the hollow fiber membrane portion in the other room hydrophilic, raw water can be removed. Can be filtered.

[0009]

FIG. 1 is an explanatory view showing an embodiment of the first invention. In FIG. 1, reference numeral 1 denotes a cylindrical case. Reference numeral 2 denotes a hollow fiber membrane bundle housed in the cylindrical case 1. Reference numeral 3 denotes an intermediate resin partition wall provided by casting in the case 1, and the inside of the case 1 is divided into two chambers 11 and 12. Reference numerals 111 and 121 denote openings provided in the chambers 11 and 12, respectively. Reference numeral 4 denotes an end resin partition provided by casting on one end of the case 1, and an opening of one end 201 of each hollow fiber membrane is open to the outer surface of the end resin partition 4.

Reference numeral 5 denotes a resin molded body cast at the other end of the hollow fiber membrane.
Is closed. The cap is attached to one end of the case 1 and has a mouth 61. 7 is a cap attached to the other end of the case 1 and has a mouth 71.

According to this membrane module, by making the hollow fiber membrane portion 21 in the chamber 11 hydrophobic and the hollow fiber membrane portion 22 in the chamber 12 hydrophilic, the raw water is filtered while separating the dissolved gas. It is possible to This hydrophobic part 2
1 and the hydrophilic portion 22 are made hydrophilic by making a hydrophobic hollow fiber membrane, for example, a polysulfone hollow fiber membrane, hydrophilic by a surface coating of a moisturizing aqueous solution such as glycerin or polysaccharide.
The inner hollow fiber membrane portion 21 can be obtained by making it hydrophobic with ethanol or the like. The intermediate partition 3 is cast over the boundary between the hydrophobic part 21 and the hydrophilic part 22 of the hollow fiber membrane bundle 2.

When raw water is filtered by the membrane module, the chamber 12 is a raw water chamber, the mouth 71 is an inlet for raw water, and 121 is an outlet for concentrated water. Room 1
1 is a degassing chamber, and the mouth 111 is a degassing gas outlet. The mouth 61 is used as a permeate outlet. In order to filter raw water by the membrane module, the raw water inlet 71
The raw water is supplied to the raw water chamber 12 at a predetermined pressure, and the pressure in the deaeration chamber 11 is reduced. Thus, while the raw water flows in contact with the hydrophilic portion 22 of the hollow fiber membrane 2, the permeable component of the raw water permeates the membrane and the fine particles The passage through the membrane is prevented, and the permeation causes non-permeated water having a high concentration of fine particles, ie, concentrated water, to flow out of the concentrated water outlet 121.

The permeate in the hollow fiber membrane 2 flows toward the open end 201 of the hollow fiber membrane 2, and in the hydrophobic portion 21, the liquid in the permeate flows through the membrane due to the hydrophobic nature of the membrane. Although not passing through, the dissolved oxygen permeates the membrane under a transmembrane pressure difference due to the reduced pressure in the degassing chamber 11 and is discharged from the degassing gas outlet 111 of the degassing chamber 11. Therefore, it is possible to remove dissolved oxygen from the permeate and obtain ultrapure water that can meet the stricter regulations on DO.

FIG. 2 is an explanatory view showing an embodiment of the second invention. In FIG. 2, reference numeral 1 denotes a cylindrical case. Reference numeral 2 denotes a hollow fiber membrane bundle housed in the cylindrical case 1. Reference numeral 3 denotes an intermediate resin partition provided by casting in the case 1, and the inside of the case 1 is divided into two chambers 11 and 120. Reference numerals 61 and 111 denote openings provided in the chambers 11 and 120, respectively.

Reference numeral 4a denotes an end resin partition provided by casting at one end of the case 1. The opening of one end 201 of each hollow fiber membrane is open to the outer surface of the end resin partition 4a. Reference numeral 4b denotes an end resin partition provided by casting on the other end side of the case 1. The opening of the other end 202 of each hollow fiber membrane is connected to the end resin partition 4b.
b is open to the outer surface. Reference numeral 6 denotes a cap attached to one end of the case 1 and has a mouth 121. 7 is a cap attached to the other end of the case 1 and has a mouth 71. According to this membrane module, by making the hollow fiber membrane portion 21 in the chamber 11 hydrophobic and the hollow fiber membrane portion 22 in the chamber 120 hydrophilic, raw water can be filtered while separating dissolved gas. It is.

When raw water is filtered by the above-mentioned membrane module, 71 is a raw water inlet, 121 is a concentrated water outlet, 120 is a permeated water chamber, and 61 is a permeated water outlet. The chamber 11 is a degassing chamber, and the opening 111 is a degassing gas outlet.

In order to treat raw water by the membrane module of this embodiment, raw water is supplied from the raw water inlet 71 into the hollow fiber membrane 2 at a predetermined pressure and the pressure in the degassing chamber 11 is reduced.
Thus, while the raw water passes through the hydrophobic portion 21 of the hollow fiber membrane bundle 2, the dissolved oxygen in the raw water permeates the membrane, reaches the degassing chamber 11, and is discharged from the degas outlet 111. The degassed raw water flows toward one end 201 of the hollow fiber membrane 2, and in the hydrophilic portion 22, the permeable component of the raw water permeates through the hydrophilic membrane portion 22 to remove fine particles by the membrane. Water flows out from the permeated liquid outlet 61 through the permeated water chamber 120. The non-permeate in which the concentration of the fine particles is concentrated by this permeation, that is, the concentrated water flows out of the concentrated water outlet 121.

According to the membrane module of the present invention, the amount of dissolved oxygen in the permeated water can be sufficiently reduced. This can be confirmed from the following comparison between the example and the comparative example.

(Example) In FIG. 1, the hollow fiber membrane portion 21 between the degassing chamber side surface 31 of the intermediate resin partition wall 3 and the case end 21 is made hydrophobic, and the length of the hydrophobic portion is set to 25 cm.
On the other hand, the length of the hydrophilic portion 22 was 75 cm. The inner diameter of the hollow fiber membrane 2 was 0.55 mm, the number of hollow fiber membranes was 600, the inner diameter of the case 1 was 100 mmφ, the length of the case was 100 cm, the thickness of the intermediate partition 3 was 5 cm, and the resin partitions 3, 4 and The sealing molding 5 was cast with an epoxy resin.

According to the product of this embodiment, raw water having a particle number of 60 to 100 per 1 ml (particles having a size of 0.1 μm or more) and a dissolved oxygen amount of 9 to 10 ppb was subjected to filtration treatment (a permeation water amount of a module of 2.7 m ³ / hr · kg / cm ² ), 0-2 / m
l, Ultrapure water having a dissolved oxygen content of 7 to 8 ppb was obtained.

(Comparative Example) The same procedure as in the above example was carried out except that the hollow fiber membrane was not subjected to hydrophobic treatment and the intermediate resin partition was removed. According to this comparative example, the raw water was filtered under the conditions of a permeated water amount of 3.7 m ³ / hrkg / cm ² ,
Although the amount of the fine particles was 0 to 2 / ml, which was not different from that of the example, the amount of dissolved oxygen was 10 to 11 ppb, which was much larger than that of the example.

The present invention can also be used for filtering raw water while degassing dissolved gases other than oxygen. It can also be used for filtering raw water while degassing an organic solvent from a raw liquid containing an organic solvent such as ethanol by means of pervaporation from an organic solvent such as ethanol. In this case, the hollow fiber membrane portion in the degassing chamber is used. May be coated with a thin film having selective permeability to organic solvent vapor.

[0023]

As described above, the membrane module of the present invention has the same structure as described above, and it is possible to remove dissolved gas together with fine particles in one membrane module. , Maintenance and management are easy. In addition, a resin partition may be added to the middle of the case of the ordinary hollow fiber membrane module to make only a part of the hollow fiber membrane bundle hydrophobic, so that the structure of the module is simple.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of the first invention.

FIG. 2 is an explanatory view showing an embodiment of the second invention.

[Explanation of symbols]

 Reference Signs List 1 case 111 mouth part 121 mouth part 2 hollow fiber membrane bundle 201 hollow fiber membrane one end 202 hollow fiber membrane other end 3 intermediate resin partition 4 end partition 4a end partition 4b end partition 5 resin molded body 11 chamber 12 chamber 120 chamber 9

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B01D 63/02 B01D 19/00 C02F 1/20 C02F 1/44

Claims (2)

(57) [Claims] 1. A hollow fiber membrane bundle is accommodated in a cylindrical case,
An intermediate partition is provided in the case, an end resin partition is provided on one end side of the hollow fiber membrane bundle, and one end of each hollow fiber membrane is opened on an outer surface of the end resin partition, and the other hollow fiber membrane is provided. A membrane module, wherein an end is closed, and an opening is provided in a cylindrical wall of each chamber formed by dividing the inside of the case into two by the intermediate partition. 2. A hollow fiber membrane bundle is housed in a cylindrical case,
An intermediate partition is provided in the case, an end resin partition is provided at both ends of the hollow fiber membrane bundle, and each end of each hollow fiber membrane is opened on the outer surface of each end resin partition, and the case is formed by the intermediate partition. A membrane module, wherein an opening is provided in a cylindrical wall of each of the two chambers.