JPH04305202A - Water separating filter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter capable of adsorbing and removing finely dispersed water in a liquid.

0002

[Prior Art] From a dispersion system consisting of two phase-separated liquids,
Techniques for separating dispersed microdroplets are industrially important and desired in many fields. For example, removal of micro droplets of water dispersed in cutting oils, lubricating oils, organic solvents, removal of micro droplets of oil dispersed in industrial wastewater, removal of micro droplets of oil dispersed in expensive heating media such as dichlorodifluoromethane. This includes microdroplet separation, etc. Several types of methods for separating these microdroplets are known. Examples include a coalescer method using glass fibers or organic fibers, and an adsorption method using a water-absorbing resin. In either case, when the filtration rate is high, there is a drawback that the capture rate for microparticles of 0.1 to 2 μm is poor. Further, in the case of the coalescer method, there is a problem that the apparatus is large and complicated. The reason for this is that in the coalescer method, when the filtration rate is high, the separation accuracy decreases. In addition, in the adsorption method, if the pore size of the filter is large, 0.
Water particles of 1 to 2 μm cannot be removed sufficiently because they do not come into sufficient contact with the filter and pass through it. In order to solve this problem, increasing the fabric weight or increasing the density to decrease the filter pore diameter results in disadvantages such as increased pressure loss and shortened service life. As a result of intensive research into ways to solve these drawbacks, the inventors of the present invention found that by combining a water-absorbing filter with an element that causes grain coarsening, it is possible to remove moisture from fine particles that could not be removed with conventional water-absorbing filters. We have now invented a water separation filter that removes up to 100% of water, has low pressure loss, and has a long lifespan.

0003

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks of the conventional technology, and to obtain a high filtration rate, a high capture rate, and a low pressure drop from a dispersion containing phase-separated microparticles. The object of the present invention is to provide a filter that removes water particles.

0004

[Means for Solving the Problems] The water separation filter of the present invention is composed of a coarsening element and a water-absorbing sheet. The present invention will be described below with reference to the drawings. A typical example of a structure in which the water separation filter of the present invention is made into a cartridge is shown in FIG. In FIG. 1, a cylindrical perforated plate is inserted into a pleated cylindrical water separation filter sheet. An upper cap 4 and a lower cap 5 are attached to both upper and lower end surfaces of the filter, respectively, and the upper end 2 and lower end 3 of the filter are both sealed with epoxy resin. The water adsorption filter cartridge has a housing 6. The housing is preferably a cylindrical perforated plate. The housing and internal cylindrical perforated plate are made of metals such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, ABS resin, epoxy resin, iron, aluminum, and stainless steel such as SUS304. can be mentioned. The fluid to be treated passes from the outside through the perforated plate of the housing and enters the water separating filter sheet. The water separation filter sheet has multiple layers. The layers include a first layer to a fourth layer. The first layer is the outermost layer and has a layer of non-woven fabric or mesh for reinforcement and as a pre-filter to remove large dirt particles. A coarse-grained sheet is placed in the second layer so as to be in contact with the first layer. This layer traps small water particles, turns them into coarse particles, and discharges them to the rear. A water-absorbing sheet is placed as the third layer to adsorb and remove water particles. As the fourth layer, a sheet of nonwoven fabric or the like is placed to prevent water from draining from the water absorbent sheet. After passing through a water separation filter,
The processing liquid flows through a circular perforated plate in the inner cylinder. Regarding the direction of filtration in the cartridge, it is possible to flow the processing liquid from both directions: from the out to the in, and from the in to the out. In this case, the order of stacking the filters is as above for out to in, and the first one for in to out.
The layers are the innermost layer and the fourth layer is the outermost layer.

[0005] The coarse graining referred to in the present invention is usually from 0.1 μm to
This refers to the phenomenon in which a minute droplet with a diameter of 50 μm becomes a droplet with a diameter of 0.1 μm or more. In the present invention, the coarse-grained sheet refers to a sheet that has the function of coarsening minute droplets in the treatment liquid by allowing the treatment liquid to pass through it, and includes fibrous sheets, glass fibers, etc. Although there are sheets, metal sheets, etc., fibrous sheets are particularly desirable.

The type of fiber constituting the fibrous sheet is not limited in any way, but examples include polyethylene terephthalate, polyethylene terephthalate adipate, and polyethylene terephthalate isophthalate. , polyethylene sebacate, polyethylene terephthalate
Fibers of polyester copolymers such as dodecanedioate and polybutylene terephthalate, polyhexamethylene adipamide, polyhexamethylene sebamide, polyhexamethylene hexamide, polycapramide, polyoctamide, polynonamide, polydecamide, polytetramid Polyamide fibers such as polyamide/imide fibers, aromatic polyamide fibers, polyester ether fibers such as polyparaoxybenzoate, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polytetrafluoroethylene, etc. Examples include fibers of halogen-containing polymers, fibers of polyolefins such as polypropylene and polyethylene, various acrylic fibers and polyvinyl alcohol fibers, recycled cellulose, and acetate.

Fibrous sheets include nonwoven fabrics, woven fabrics, knitted fabrics, and
Although any form may be used, a nonwoven fabric is preferable in consideration of its performance as a filter. Examples of the nonwoven fabric include those obtained by a melt spinning method such as a spunbond method, a flash spinning method, and a melt blowing method, a dry method such as a dip bonding method and a needle punch method, and a wet method such as a papermaking method.

The form of the fibrous sheet is not limited in any way, and can be used in any form such as a flat membrane, cylindrical, tubular, spiral, bellows, etc. However, from the viewpoint of processing efficiency, is preferably used in a bellows-like form. The glass fiber sheet preferably has a filter paper-like form manufactured by a paper making method or the like.

[0009] The metal sheet is preferably in the form of a mesh-like woven fabric or knitted fabric. The material is not limited in any way, but stainless steel is preferred from the viewpoint of corrosivity. Preferably, the single fiber diameter is 0.5 to 5 μm. When the single fiber diameter exceeds 5 .mu.m, finely dispersed water droplets (5 .mu.m or less) tend to pass through the coarse-grained sheet, resulting in a decrease in separation accuracy. 0.5μ
If it is less than m, the pressure loss of the filter increases and the filter
Performance tends to decrease. More preferably, the single fiber diameter is in the range of 1 μm to 3 μm.

[0010] Furthermore, in order to improve the efficiency of separating and removing fine water particles, coarse grained sheets may be overlapped. Although the number of stacked sheets is not limited in any way, it is practically about 1 to 8 sheets. It is also possible to use a reinforcing material such as a wire gauze or a mesh-like sheet for the purpose of reinforcing the coarse-grained sheet of the present invention. Furthermore, it is also possible to overlay a pre-filter such as a fibrous sheet non-woven fabric. In order to collect dust and the like in the target liquid, it is also possible to place a dust-collecting material as a pre-filter before processing with the fibrous sheet. For example, the pre-filter may be a membrane-like, paper-like, non-woven fabric-like, cotton-like, thread-like dust collecting material, or the like.

Materials constituting the water absorbent sheet include acrylic resins and fibers containing carboxyl groups, partially carboxyalkylated cellulose resins and fibers such as carboxymethyl or carboxyethyl, and carboxyalkylated cellulose resins and fibers. There is starch. Moreover, those in which part or all of these are substituted with alkali metal ions such as sodium, potassium, lithium, or ammonium ions are preferable because they have higher water absorption.

If necessary, other fiber materials such as synthetic fibers such as polyethylene, polypropylene, acrylic fibers, polyester fibers, and polyamide fibers, recycled cellulose fibers such as rayon and cuprarayon, cotton, U-
It is also possible to blend, twist, twist, weave, and knit with natural fibers such as rubber.

The form of the sheet may be nonwoven fabric, woven fabric, knitted fabric, etc., but from the viewpoint of water retention, a web with a loose structure can be needle punched, water woven, etc.
Punched nonwoven fabrics are preferred. Saturated absorbent sheet
It is also possible to place an auxiliary filter after the water-absorbing sheet to prevent the flow of water and the discharge of water. Examples of such filters include water-repellent nonwoven fabric sheets and paper filters.

[0014]

EXAMPLES The present invention will be explained in detail based on Examples, but these are not intended to limit the scope of the present invention. The measurement method and evaluation method used in the present invention are described below. 1) Measurement method A filter was attached to a stainless steel filter holder (filtration area 12.6 cm2), and a constant amount of the target liquid (20°C) prepared under the following conditions was delivered at a rate of 155 cc/min. The separation accuracy was tested. The target liquid was prepared by adding 3 cc of water to kerosene 101 and stirring the mixture. Finely disperse for 1 minute using an ultrasonic cleaner. The dissolved water concentration in kerosene was 300 ppm. 2) Water concentration measurement (ppm) Karl Fisher, Kyoto Electronics Co., Ltd. - Water concentration meter MKC-3P3) Evaluation method a) Measure the free water concentration after passing through the filter. (Measure the dissolved water concentration after passing through the filter, and subtract the dissolved water concentration in the oil (blank) at 20°C.)
10 ppm or less b) Pressure loss (accumulated flow rate 51 hours) 1.0 kg/cm2
Below, those within the above range were marked as ○, and the rest were marked as ×.

[0015]

[Example 1] Single fiber diameter 1.7 by melt blowing method
A nonwoven fabric made of polyethylene terephthalate having a weight of 80 g/m2 and a thickness of 0.1 mm was obtained. Next, this nonwoven fabric was subjected to a hydrophilic treatment under the following conditions to obtain a fibrous sheet. Processing conditions: Processing agent SR-1000 (Takamatsu Yushi (
(Water absorption processing agent manufactured by Co., Ltd.) Concentration: 4% by weight Solution drying Heat treatment at 100°C for 3 minutes Pad dry cure method at 170°C for 1 minute Single fiber fineness consisting of 75.4% by weight of acrylonitrile and 24.6% by weight of sodium acrylate 3d fiber copolymer was used. Next, this fiber was cut to 76 mm, passed through a card, and needle punched to obtain a nonwoven fabric with a basis weight of 80 g/m2. This was made into three layers and used as a water absorbent sheet. A fibrous sheet was used as a coarsening element, and a water-absorbing sheet was laminated thereon to be used as a water separation filter.

[0016]

[Examples 2 to 5] Single fiber diameter 0 by melt blowing method
．． Four types of polyethylene terephthalate nonwoven fabrics having different fiber diameters of 5 to 5 μm were obtained. Thereafter, a fibrous sheet and a water absorbent sheet were obtained in the same manner as in Example 1, and tested as a water separation filter.

[0017]

Example 6 A fibrous sheet was obtained in the same manner as in Example 1. A carboxymethyl starch sheet was used as the water-absorbing filter. Fabric weight 270g/m2, thickness 0
．． It was 3 mm.

[0018]

Example 7 A Teflon-coated 440-mesh stainless steel mesh was used as a coarsening element, and the water-absorbent sheets used in Example 1 were laminated to form a water separation filter.

[0019]

[Comparative Example 1] A similar test was conducted on a commercially available water adsorption filter. The filter is composed of three layers: the first layer is a pre-filter for removing dust and is made of cellulose with a single fiber diameter of 20 μm, and the second layer is carboxymethyl starch that adsorbs water. The third layer is an auxiliary filter and is the same as the first layer.

Table 1 shows the measurement results and evaluation results. It can be seen that the filter of the present invention has a much higher water removal efficiency than the filter of the comparative example.

[0021]

[Table 1]

[0022]

[Example 8] Inner diameter 35mm, outer diameter 70mm, height 250mm
A cylindrical adsorption filter cartridge of mm was manufactured. The housing, internal cylindrical perforated plate, and upper and lower caps are made of SUS
304 was used. It was manufactured so that the flow direction of the processing liquid was out-in. The filter medium has four layers: the first layer is an ester spunbond nonwoven fabric (fabric weight 50 g/m2) as a pre-filter, the second layer is the fibrous sheet used in Example 1 as a coarsening element, and the third layer is a In the water absorbent sheet used in Example 1, an ester spunbond nonwoven fabric (fabric weight: 30 g/m2) was used for the fourth layer. Stack these 25
Pleats were processed with a width of 0 mm. The height of the pleated mountain is 1
0mm, number of pleats is 55, total filtration area is 0.27m
It is 2. The pleating machine used was one manufactured by Toyo Koki Co., Ltd. The ends of the filter media were joined by heat sealing, and the upper and lower caps were sealed with epoxy resin to produce a filter cartridge.

Next, a test was conducted to remove water from turbine oil. The free water concentration in the oil was 100 ppm, and the treatment flow rate was 1.7 l/min. As a result, the free water concentration after passing through the filter was 1 ppm, and the pressure loss was 0.02 kg/cm.
It was 2.

[0024]

[Comparative Example 2] A cartridge was manufactured in the same manner as in Example 8. However, the second layer fibrous sheet was not attached. The test method was also carried out in the same manner as in Example 8. the result,
The free water concentration after passing through the filter was 43 ppm, and the pressure loss was 0.017 kg/cm2.

[0025]

[Comparative Example 3] A cartridge was manufactured in the same manner as in Example 8. However, it was created without attaching the second layer of water absorbent sheet. The test method was also carried out in the same manner as in Example 8. As a result, the free water concentration after passing through the filter was 15 ppm, and the pressure loss was 0.02 kg/cm2. However, in this case, a device having a separation mechanism after passing through the filter is required, resulting in a very large and complicated device.

[0026]

[Effects of the Invention] The water adsorption filter of the present invention has a high capturing efficiency of minute water droplets, and has the effect of reducing pressure loss during filtration.

[Brief explanation of drawings]

FIG. 1 is a front view of a cartridge formed by molding the water adsorption filter of the present invention.

FIG. 2 is a side view of a cartridge formed by molding the water adsorption filter of the present invention.

[Explanation of symbols]

1 Water separation filter 2 Seal part on the upper end surface 3 Seal part on the lower end surface 4 Upper cap 5 Lower cap 6 Housing 7 Cylindrical perforated plate

Claims (1)

[Claims] 1. A water separation filter characterized in that a coarse-grained sheet and a water-absorbing sheet are laminated.