JPH01119305A - Liquid separation apparatus - Google Patents

Abstract

PURPOSE:To reduce the number of washing times of a separation membrane module, by providing a contamination removing module having a hydrophylic membrane surface to the front stage of the separation membrane module. CONSTITUTION:A contamination removing module 6 having a hydrophilic membrane surface composed of polysulfone or the like and formed into an arbitrary shape is mounted to the front stage of a separation membrane module 5. A membrane having separation function may not be necessarily used in the contamination removing module. The water to be treated passing through a sand filter 1 and a cartridge filter 4 is sent to the contamination removing module 6 to be allowed to flow along the membrane surface thereof and the contaminant in the water to be treated is allowed to sediment on the membrane surface. The transmitted water and concd. water of the contamination removing module 6 are met to be supplied to the separation membrane module 5 through a pump 32.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid separation device that prevents contamination within a separation membrane module for liquid separation.

[Prior Art] FIG. 4 is a schematic diagram showing an example of a conventional liquid separation device.

In the figure, raw water, such as well water or river water, is supplied to a sand filter 1 with a suitable flocculant added thereto. The water that has passed through the sand filter 1 is then stored in a water storage tank 2.

The water in the water storage tank 2 is sucked up by a pump 3, passes through a cartridge filter 4, and is further pumped into a high-pressure pump 3. Normally, the separation membrane module 5 is pressurized with water and supplied to the separation membrane module 5 such as a reverse osmosis membrane (RO) module. / Porous layer / Separation membrane layer It has a structure in which about six elements, each of which is a spirally wound separation membrane layer, are connected in the axial direction, and these elements are enclosed in a container.

[Problems to be Solved by the Invention] As described above, the separation membrane module 5 has a structure in which a plurality of elements are connected in the axial direction. A large amount of dirt components such as iron oxide remaining in the membrane deposits on the surface of the separation membrane of the element in the first stage of the separation membrane module 5, and as a result,
The pressure loss of the separation membrane module 5 increases, and the amount of permeated water tends to decrease.Therefore, in conventional devices, although the elements in the second and subsequent stages of the separation membrane module 5 are relatively less contaminated, Since the first stage element is easily contaminated, the entire separation membrane module 5 must be frequently cleaned, which is very troublesome.

Normally, when cleaning the separation membrane module 5, the dirt deposited on the separation membrane surface is dissolved or decomposed using pickling or a surfactant to drain it out. It tends to adhere to the elements of the separation membrane module 5, making it difficult to clean the entire separation membrane module 5. Also, if the number of cleanings increases, the surface of the separation membrane will be damaged, and the life of the separation membrane module 5 will be shortened. There is also a problem.

The present invention was made to solve these problems, and an object of the present invention is to provide a liquid separation device that can reduce the number of times a separation membrane module is washed.

[Means for Solving the Problems] In order to solve these problems, the present invention takes the following measures.

That is, the liquid separation device according to the present invention has the above-mentioned N'W! J. module comprises a separate dirt removal module, said dirt removal module:
The membrane module has a hydrophilic membrane surface, and is characterized in that treated water flowing along at least the membrane surface is supplied to the separation membrane module.

The form of the separation membrane module is not particularly limited, and may be any form such as a spiral module, a flat membrane module, or a hollow fiber module.
Examples include reverse osmosis membranes (RO) and ultrafiltration membranes (UF).

The dirt removal module is a membrane module that is provided separately from the separation membrane module and has a hydrophilic membrane surface. The form of the dirt removal module may be any form such as a spiral module, a flat membrane module, or a hollow fiber module.

Examples of the membrane having a hydrophilic membrane surface include polysulfone and cellulose acetate. However, membranes with hydrophobic surfaces, such as Teflon or polysulfone coated with silicone to make them hydrophobic, are not suitable as membranes for dirt removal modules.

This is because even if treated water is allowed to flow along such a hydrophobic membrane surface, dirt in the treated water is unlikely to be deposited on the membrane surface.

Since the dirt removal module causes the dirt in the treated water to be deposited on the membrane surface by flowing the treated water along the membrane surface, it is not necessarily necessary to use a membrane with a separation function. A separation membrane module can be used as a dirt removal module. in this case,
Along with permeated water, treated water (concentrated water) is supplied to the next stage separation membrane module.

Separation membrane modules that can be used as dirt removal modules are not particularly limited in the type of membrane function, but because they are not intended for separation by permeation of treated water, expensive separation membrane modules such as reverse osmosis membranes are not recommended. There is no need to use 0 For example, relatively inexpensive separation membrane modules such as microfiltration membranes (MF) and ultrafiltration membranes (UF), or ordinary separation membrane modules because there are some scratches on the surface of the separation membrane. Separation membranes that cannot be used as membranes can also be used as membranes in fouling removal modules.

Further, as explained in connection with the conventional device, since the first stage portion of the separation membrane module is particularly prone to dirt, one or two elements constituting the dirt removal module are sufficient.

[Example] Examples of the present invention will be described below.

FIG. 1 is a schematic diagram of a liquid separation device according to an embodiment of the present invention.

In this figure, the parts indicated by the same reference numerals as those in FIG. 4 are the same constituent parts, so the description thereof will be omitted here.

Reference numeral 6 is a dirt removal module, and in this embodiment, a spiral module using an ultrafiltration membrane is used. The permeated water and concentrated water of the dirt removal module 6 are combined and supplied to the separation membrane module 5 via the pump 38. Note that the permeated water outflow pipe of the dirt removal module 6 is
Pump 3. to create a pressure differential within the module. is provided.

FIG. 2 is an explanatory diagram showing a dirt removal mechanism in the dirt removal module 6 of the liquid separator shown in FIG. 1. In the figure, 7 represents an ultrafiltration membrane, 8 represents a treated water (concentrated water) flow path, and 9 represents a permeated water flow path. When the treated water passes through the treated water channel 8, dirt 10 contained in the treated water is deposited on the separation membrane surface of the ultrafiltration membrane 7. on the other hand,
A pump 3. is connected between the treated water channel 8 and the permeated water channel 9. Therefore, a pressure difference is generated, and the permeated water passes through the ultrafiltration membrane 7 from the treated water flow path 8 to the permeated water flow path 9. In this way, due to the pressure difference between the treated water flow path 8 and the permeated water flow path 9, the dirt 10 contained in the treated water is deposited on the separation membrane surface of the ultrafiltration membrane 7 more efficiently than when no pressure difference is applied. .

FIG. 3 is a schematic diagram of another embodiment of the present invention.

The feature of this embodiment is that two dirt removal modules 69, 6□ are arranged in parallel in the treated water pipe, and each dirt removal module 61, 6! Switch valve 11. ~t1
The reason is that the dirt removal module can be switched by s, and either one of the dirt removal modules can be used selectively. According to this embodiment, for example, while one dirt removal module 6 is being cleaned, the operating efficiency of the apparatus using the other dirt removal module 6 can be increased.

[Effects of the Invention] As is clear from the above description, the liquid separation device according to the present invention includes a dirt removal module provided with a hydrophilic membrane surface upstream of the separation membrane module, and a dirt removal module provided with a hydrophilic membrane surface at least along the membrane surface. The treated water that has been distributed is sent to the next stage! Since the water is supplied to the III module, most of the dirt contained in the treated water is removed in the dirt removal module, reducing the dirt on the separation membrane module and reducing the frequency of cleaning the separation membrane module. .

On the other hand, according to the present invention, although the frequency of cleaning the separation membrane module is reduced, it is necessary to clean the dirt removal module, but the dirt removal module is smaller because the number of elements is smaller than that of the separation membrane module. , the separation membrane module can be cleaned more easily than when cleaning the separation membrane module.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a liquid separation device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a dirt removal mechanism in the dirt removal module 6 of the liquid separation device shown in FIG. FIG. 3 is a schematic diagram of a liquid separation device according to another embodiment of the present invention, and FIG. 4 is a schematic diagram of a conventional liquid separation device. 1...Sand filter 2...Water tank 3, ~3. ... Pump 4 ... Cartridge filter 5 ... Separation membrane module 6.6. ．． 6. ... Dirt removal module 7... Ultrafiltration membrane 8... Treated water channel 9... Permeated water channel 10... Dirt 11, ~11. ...Switching valve applicant: Azuma Shi Co., Ltd. Company agent: Patent attorney: Tsutomu Sugitani

Claims (3)

[Claims] (1) A dirt removal module separate from the separation membrane module is provided upstream of the separation membrane module, and the dirt removal module is a membrane module having a hydrophilic membrane surface, at least along the membrane surface. A liquid separation device characterized in that distributed treated water is supplied to the separation membrane module. (2) In claim 1, the membrane with a hydrophilic membrane surface in the dirt removal module is a liquid separation functional membrane, and the treated water (concentrated water) that flows along this membrane surface is A liquid separation device that supplies permeated water that has passed through a membrane to a separation membrane module. (3) In claim 1 or 2, the dirt removal module is comprised of a plurality of dirt removal modules arranged in parallel in a treated water pipe, and the pipes connected to each module are switchable. A liquid separation device consisting of: