JPH05329312A - Water treatment material - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a filter medium for filtering contaminants of a polluted solvent, which is easy to handle and has good filtration efficiency with little skinning phenomenon even when reused by backwashing. [Structure] A sliver composed of crimped fibers having a fiber length of 30 to 200 mm is molded into a rod-shaped continuous fiber body, and a point-bonded portion is formed between the fiber molded bodies, which is cut into a specific shape. [Effect] By forming a filter body with crimped fibers, the air permeability is high, the fiber packing density is high, and
By backwashing, a high-performance filter body having no thinning phenomenon was obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter material for liquid treatment for filtering suspended matters or suspensions existing in a liquid such as sewage, and particularly, it has high filtration efficiency and is repeatedly washed by backwashing and reused. The present invention relates to a filter material that does not cause thinning even when the above steps are performed.

[0002]

2. Description of the Related Art Conventionally, filter papers, filter cloths, wire meshes, sands, ceramics, etc. have been used as filter media. Liquid filtration using filter papers, filter cloths, wire meshes, etc., is a suspended matter in the liquid to be filtered. And suspensions adhere to the surfaces of these filter media and cause clogging, and the filtration flow rate decreases with time, resulting in poor filtration efficiency.
Further, in the internal filtration of a liquid using a deposited layer of particulate matter such as sand and ceramics, although the filtration flow rate does not decrease much, the filtration rate is slow and the filtration accuracy is limited, resulting in poor transparency of the filtrate. There is. In addition, there is a problem that the cleaning efficiency at the time of backwashing the filter medium is poor, and the backwashing causes the filter medium to become finer particles, which reduces the amount of the filter medium.

Therefore, for example, as disclosed in Japanese Patent Publication No. 62-11637, natural fibers are used as a liquid filter medium,
Non-crimped organic fibers such as recycled fibers and synthetic fibers, and non-crimped inorganic fibers such as glass fibers and metal fibers are appropriately selected as necessary, and the non-crimped fibers are entangled with each other by an appropriate method. The method of using is shown.

In Japanese Patent Publication No. 62-55885, a filtration is carried out by using a filter material composed of an elliptic spherical fiber entangled with non-crimped organic fibers having a fiber length of 5 to 50 mm and a maximum diameter of 5 to 100 mm. The device is shown.

[0005]

However, these fiber lumps have a entangled structure due to the entanglement of non-crimped fibers, and these fiber lumps are used as filter media in JP-B-62-55885. When a filter medium layer is constituted by a filtering device as seen in Japanese Patent Laid-Open Publication No. 2000-242242 and a solvent containing suspended matter is filtered, the filter medium layer is clogged with trapped suspended matter and the filtration performance starts to decrease, and the filtration is stopped. It is necessary to carry out washing, that is, backwashing. However, since these fibers do not have single fibers joined to each other and are non-crimped fibers, the entanglement between fibers is weak, so Fray between fibers is likely to occur when backwashing with, and if repeatedly used,
There is an inconvenience that the fibrous mass becomes thin, the filtering effect is lowered, and the separated single fibers are mixed in the filtered water. In addition, since the fiber lumps produced by such a method do not have a homogeneous fiber filling structure up to the inside, there are voids inside, and when the solvent is filtered, suspended matter remains attached to these voids. It is difficult to sufficiently wash the remaining filter medium. Further, this method for producing a fiber lump is difficult to continuously produce, and there is a problem that the productivity of the filter medium is low, and thus the size of the fiber lump obtained due to the length and thickness of the single fiber is likely to vary widely.

[0006] Further, if a fiber mass is formed by the method using a non-crimped fiber having a fineness of 10 denier or less, only a rod-shaped fiber mass can be formed, so that the handleability as a filter medium is poor and the crimped fiber is used. When a fiber lump is formed by the method, a certain fiber can be obtained only as a string-shaped or large-lump entangled fiber, and it cannot be said that the fiber is suitable as a filter medium.

[0007]

The present invention has been made against the above background, and an object thereof is high filtration performance, excellent shape retention, dimensional stability and durability, and It is to provide a water treatment material that can be continuously manufactured at low cost.

The water treatment material of the present invention has a fiber length of 30 to 200 mm.
The crimped organic fibers can be formed into a sliver shape, forming point-bonding points between the aligned fibers, forming a rod-shaped body, and then cutting into a length of 3 to 50 mm. It is preferable to use a hot melt type adhesive as the adhesive used for forming the point adhesion points between the fibers, and its form can be a particulate form, a fibrous form, or the like. When melt type fibers are used, they are mixed and spun into fiber bundles in advance, but the fibers themselves used in the present invention are those having hot melt characteristics. In addition, in order to generate spot adhesion points in the rod-shaped fiber bundle, it is also possible to effectively use a method of supporting a granular adhesive or a plasticizer in the fiber bundle in addition to the method of using the heat-fusible fiber described above. it can. When the water treatment material of the present invention is filled in a filtration device, the length of the water treatment material is approximately the same as the diameter of the water treatment material, and the anisotropy during filling is small, which causes abnormalities in the filtration device. It is preferable because it can be filled without forming voids.

Further, it is preferable that the diameter of the water treatment material of the present invention, which is a continuous rod-shaped molded product, is 3 mm or more and 50 mm or less. A water treatment material with a diameter of less than 3 mm is likely to cause fiber loss in the back washing process, while a water treatment material with a diameter of more than 50 mm is likely to cause an abnormal void when the water treatment material is packed in the filtration device.
The filter layer once having an abnormal void is difficult to fill the gap sufficiently even by the compression, so that the filtering performance is deteriorated and the molding becomes difficult.

Since the water treatment material of the present invention partially joins the fibers inside the bundle of crimped fibers, it has uniform voids inside and easily shrinks the voids by compression. The filtration effect can be improved, and it can be easily restored to its original shape when it is in a non-compressed state, and the fibers do not fall off during back washing. The production of this rod-shaped molded body can utilize a part of the usual spinning process.The card web is sprayed with an adhesive and a plasticizer, preheated by dry heat in a card sliver state, and the solvent is melted if necessary. It can be manufactured by supplying it to the surface of the bonded fiber, passing it through a cylindrical heating element, compressing it, and cooling it to continuously mold it, molding it into a fiber rod-shaped body, and then cutting it.

When a solution is filtered using the water treatment material of the present invention, this water treatment material is put into a filtration device, and both sides thereof are sandwiched by perforated plates, and in a downflow filtration device, the upper perforated plate is placed. By the method of moving the water treatment material below the filtering device to compress the water treatment material, and in the upflow filtration device, by moving the lower porous plate above the filtration device and compressing the deposited layer of the water treatment material. It is possible to obtain a filtration layer having a high fiber density.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0013]

[Example 1] Two card-sliver core-sheath fusion-bonded fibers having a crimped fineness of 2 denier with a medium-density polyethylene sheath and a PP core and a fiber length of 51 mm and a weight of 5.4 g per 1 m After pre-heating by passing through a cylindrical heater that is heated to 140 ° C with a length of 5 cm and 110 ° C air jet is blown, It was passed through a small cylindrical heater having a thickness of 8 mm and a length of 3 cm to be compressed and air-cooled in a state where the fused fibers were partially bonded to obtain a rod-shaped continuous molded body having a diameter of 8 mm. The production rate of this continuous rod-shaped molded product was 50 cm / min. This rod-shaped molded body was cut into a length of 1 cm to prepare a chip-shaped filtering material, which was used as a test product A. The weight per chip product is 0.
It was 11g. This test product A was put into a cylindrical filter with a diameter of 5 cm at a height of 80 cm, compressed with a perforated plate to a height of 55 cm from the top, and water containing 11.3 ppm of iron rust was poured from above, and the flow rate was 30 m / hour. 500 ml of filtered water filtered by downward flow
Was filtered with a 0.45 μm Millipore filter, the filtrate was dried and then weighed, and the solid content removal rate was measured. The results are shown in Tables 1 and 2. In addition, 100 pieces of this test product A were placed in a cylindrical container having a diameter of 6 cm and containing 1.5 liters of water, and air was introduced from the lower side while water was sufficiently permeated into the inside of the filter, and bubbling was performed for 24 hours. The dropout property of the monofilament was evaluated by observing the dropout.

[0014]

[Example 2] Just before forming a card sliver with an acrylic conjugate fiber having a latent crimp and a fineness of 3 denier and a fiber length of 64 mm, a urethane resin for adhesion processing was sprayed so as to have a weight ratio of 25%. Using the dry heat type heating device used in Example 1, a continuous fiber bundle was formed, and this bundle was cut to make a chip-shaped filter medium having a diameter of about 8 mm, a length of 1 cm and a weight of 0.097 g. Had made. A latent crimp was developed when the card sliver was heated, and a water treatment material with high elasticity was produced. This test product B was operated in the same manner as test product A, and the results of evaluation of filtration performance and single fiber drop-off property are shown in Table 1.
And shown in Table 2.

[0015]

[Comparative example] Single fiber denier 18 denier and elliptical cross section, fibers with average fiber length of 15 mm were treated with vortex flow to obtain a non-crimped polyester fiber mass with an average sphere diameter of 17 mm and a weight of 0.2 g / piece. As a water treatment material, this was used as a test product C, and the results of evaluating the filtration performance in the same manner as the test product A are shown in Tables 1 and 2.

[Table 1]

[Table 1]

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 1, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

[Example 2] Immediately before forming a card sliver with an acrylic conjugate fiber having a latent crimp and a fineness of 3 denier and a fiber length of 64 mm, a urethane resin for adhesion processing was sprayed so as to have a weight ratio of 7.5 %. Then, using the dry heat type heating device used in Example 1, a continuous fiber bundle is formed, and this bundle is cut to have a diameter of about 8 mm, a length of 1 cm, and a weight of 0.
A test product B was prepared by making 097 g of a filter material in the form of chips. A latent crimp was developed when the card sliver was heated, and a water treatment material with high elasticity was produced. The test product B was operated in the same manner as the test product A, and the results of evaluating the filtration performance and the single fiber drop-off property are shown in Tables 1 and 2.

[Procedure amendment]

[Submission date] June 15, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

Further, it is preferable that the diameter of the water treatment material of the present invention, which is a continuous rod-shaped molded body, is 1.5 mm or more and 50 mm or less. A water treatment material having a diameter of less than 1.5 mm and a length of less than 3 mm easily causes fibers to fall off during the back washing process, while a water treatment material having a diameter of more than 50 mm causes abnormal voids when the water treatment material is packed in the filtration device. Is likely to occur, and it is difficult to sufficiently fill the gap in the filtration layer that once has an abnormal void even by the compression thereof, so that the filtering performance deteriorates and the molding becomes difficult. On the other hand, the water treatment material of the present invention can be uniformly filled in the filtration device due to its shape, and since the cross-linking point in the filtration material is also appropriate, there is no loss of fibers during backwashing with filtration, and the filtration efficiency is improved. It can be good.

Claims (1)

[Claims] 1. A rod-shaped fiber bundle obtained by aligning crimped organic fibers having a fiber length of 30 to 200 mm and forming a large number of point adhesion points between the aligned fibers is cut into a length of 3 to 50 mm. Water treatment material.