JPH11682A - Biological carrier for fluidized bed and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new biological carrier suitable for the waste water treatment by utilizing a fluidized bed. SOLUTION: A fluidized bed biological carrier is formed into the cylindrical shape by a network knitted sheet piece 2. Yarns constituting the knitted sheet piece 2 contain a material of bulky properties and a material of rigidity for retaining the cylindrical shape. The knitted sheet piece 2 is formed into the rectangular shape, and strip sections 5 in which yarns are disposed more thickly than other sections are formed on its side ends. The shapes of the sheet and the strip sections 5 are retained by heat-treating the knitted sheet piece 2. The knitted sheet piece 2 is wound into the cylindrical shape, and the strip sections 5 are disposed on the ends of a cylinder thus formed, and one end and the other end along the length direction of the strip sections of the rectangular knitted sheet piece 2 are overlapped each other in the peripheral direction of the cylinder and hot glued thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biological carrier for a fluidized bed and a method for producing the same.

[0002]

2. Description of the Related Art As equipment for wastewater treatment, there is known an equipment in which a carrier is disposed inside a treatment layer, the carrier is immersed in water to be treated, and treatment is performed by microorganisms attached to the surface. Have been. And BO at the time of wastewater treatment
For the purpose of improving the capacity per unit volume of the carrier at the time of D removal or nitrification treatment, a fluidized bed using a fluid carrier has been increasingly used.

[0003] The biological carrier for the fluidized bed flows together with a water stream generated by aeration air for supplying oxygen into the treatment tank, and microorganisms adhering to the surface of the carrier move into the BOD in the wastewater.
A predetermined treatment is carried out by oxidatively decomposing the components or oxidizing ammonia nitrogen to nitrate nitrogen by nitrifying bacteria on the surface.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel biological carrier for a fluidized bed suitable for such a treatment by a fluidized bed and a method for producing the same.

[0005]

In order to achieve this object, the present invention relates to a biological support for a fluidized bed formed of a mesh-like woven sheet in a cylindrical shape, wherein the yarn constituting the woven sheet is bulky. And a rigid material for maintaining the cylindrical shape.

[0006] With such a structure, a space for supporting microorganisms is secured because the mesh is formed of a mesh-shaped woven sheet, and a cylindrical shape is used for a fluidized bed. The required performance as a carrier is maintained. In addition, since a rigid material for maintaining a cylindrical shape is included, the shape of the carrier is reliably maintained, and further, since a material having bulkiness is included, the surface area of the carrier is large and high performance fluidization is performed. It becomes a biological carrier for floors.

Further, the present invention is to form a mesh-like woven sheet using a yarn containing a bulky material and a stiff material for maintaining its shape, and to form the mesh sheet in the warp direction or the weft direction in the woven sheet. At certain distances along
Form a belt-like part where threads are arranged more densely than other parts,
Next, the formed woven sheet is subjected to a heat treatment so that the form of the sheet and the band-shaped portion is maintained. Thereafter, each central portion of each band-shaped portion and a position at a fixed distance along the length direction of the band-shaped portion. Cutting the sheet in each case to form a rectangular woven sheet piece; and
The rectangular woven sheet piece is wound into a cylindrical shape, and the band portion is disposed at the end of the cylinder. One end and the other end of the rectangular woven sheet piece along the length direction of the band portion are provided. The parts are overlapped with each other in the circumferential direction of the cylinder and are thermally bonded.

As described above, by cutting a large mesh-shaped woven sheet and winding the woven sheet piece obtained by this cutting into a cylindrical shape, a cylindrical flow formed by the mesh-shaped woven sheet is obtained. A biological carrier for the floor is obtained. At this time, one end and the other end of the rectangular woven sheet piece are overlapped with each other in the circumferential direction of the cylinder and thermally bonded,
Since the thread is densely arranged at the end of the cylinder and the band-like portion whose shape is maintained by the heat treatment is arranged, a biological carrier for a fluidized bed in which the cylindrical shape is firmly held is obtained.

[0009]

FIG. 1 shows a biological carrier 1 for a fluidized bed according to the invention. The biological carrier 1 for a fluidized bed is formed by winding a rectangular mesh-shaped woven sheet piece 2 into a cylindrical shape. Specifically, for example, the diameter and length of the cylinder can each be about 50 mm. Numeral 3 denotes a constituent thread of the mesh-shaped woven sheet piece 2. At one position in the circumferential direction of the cylinder, a thermal bonding portion 4 is formed. At the thermal bonding portion 4, one end and the other end of the rectangular woven sheet piece 2 are overlapped and thermally bonded to each other. . Band-shaped portions 5 are formed at both ends of the cylinder. In the belt-like portion 5, the yarns are densely arranged along the axial direction of the cylinder as compared with the other portions, and are subjected to a heat treatment to be held in a plate shape.

FIG. 2 shows a constituent material for the constituent yarns 3 of the woven sheet piece 2. As shown in FIG. 1A, the constituent yarn 3 comprises a rigid material 6 for holding the cylindrical shape of the carrier 1 and a bulky material 7 for supporting microorganisms. Material 8 that prevents mesh misalignment
In this configuration, a plurality of materials 6 having rigidity and a plurality of materials 7 having bulkiness are arranged side by side, and then bundled by entanglement of misalignment preventing material 8. FIG. 2B shows a thread 9 for forming the band-like portion 5 on the end face of the cylinder. The thread 9 can be formed from the same material as the misalignment preventing material 8.

The rigid material 6 is preferably formed of a polypropylene monofilament, an ester monofilament or the like. Material 7 with bulkiness
Is preferably formed of a processed polypropylene yarn, an acrylic high bulky yarn, or a blended or blended yarn thereof. Further, the yarn 9 for forming the misalignment preventing material 8 and the belt-shaped portion 5 is preferably formed of an ester heat fusion hardening yarn, a polyethylene heat fusion yarn, or the like. In addition, since it constitutes the biological carrier for a fluidized bed, it is necessary that all the materials have excellent chemical resistance. In addition, by appropriately selecting each material or adjusting the bulk height of the material having bulkiness, the specific gravity of the finally obtained carrier is suitable for use in a fluidized bed for biological treatment. Things.

Then, the yarn 3 is formed as shown in FIG. 2, and a sheet is formed by knitting as shown in FIG. 3, and then heat treatment is performed to fuse the misalignment preventing material. The contact portions of the yarns 3 in the mesh structures 1 and 3 are fused and fixed to each other, thereby preventing misalignment. Further, the thermal fusion of the thread 9 fixes the belt-shaped portion 5, that is, the edges at both ends of the cylinder, beautifully and strongly.

It is preferable that the mesh-shaped knitted woven sheet piece 2 configured as described above has a fiber diameter of the constituent yarn 3 of 3 to 10 mm and a mesh of about 4 to 25 mm. By using a relatively coarse mesh having such a size, sludge can be connected and attached at the time of wastewater treatment. In particular, as shown in FIG. 2A, a plurality of materials 6 having rigidity and a plurality of materials 7 having bulkiness are arranged side by side and bundled by the misalignment preventing material 8, so that a large fiber as described above is obtained. It is possible to form a thread 3 having a diameter. In addition, by forming the warp and the weft in a plain weave shape, that is, by forming the warp and the weft alternately in the vertical position at the contact portion between the yarns, a strong mesh structure can be obtained. It is.

As described above, if the knitted woven sheet piece 2 is wound into a cylindrical shape, and one end and the other end of the knitted woven sheet piece 2 are overlapped with each other at one location in the circumferential direction, the heat bonding portion 4 is formed. The desired carrier is obtained. At this time, if, for example, an ultrasonic fusion treatment in a pressurized state is performed as the thermal bonding treatment, the yarns 3 constituting the overlapping portion are thermally fused to each other,
The heat bonding portion 4 can be formed firmly, and a bonding strength that can sufficiently withstand long-term use as a carrier can be achieved.

Next, a detailed method for producing the above carrier will be described. First, using the above-mentioned material, a wide knitted fabric is made as shown in FIG. The region 11 where the yarns are arranged more densely than the portion is formed. This region 11 is formed so as to have a width twice as large as the band-shaped portion 5 of the carrier 1, and when the diameter and the length of the cylinder of the carrier 1 are each about 50 mm as described above,
The width of the region 11 is set to about several mm.

Next, the obtained knitted fabric is subjected to a dry heat treatment,
The misalignment preventing material 8 formed of the heat-sealing yarn is converted into resin to maintain the form of the woven sheet, thereby preventing misalignment of the mesh of the sheet. At the same time, the thread 9 constituting the region 11 is also resinified, and the shape of the region 11, that is, the shape of the band portion 5 is held in a plate shape. When using each of the above materials, the temperature of the dry heat treatment is preferably about 140 to 160 ° C.

Thereafter, as shown in FIG. 5, a plurality of metal blade dies 12 are arranged side by side by using a punch metal dies 12 having dimensions corresponding to the axial length and circumferential length of the cylinder of the carrier 1. The end of each metal blade mold 12 is located in the region 1 of the woven sheet.
The knitted sheet is cut so as to be positioned at the center of the knitted sheet 1. Thereby, a plurality of woven sheet pieces 2 can be obtained efficiently and economically.

Further, the obtained knitted woven sheet piece 2 is wound into a cylindrical shape, and one end and the other end of the sheet piece 2 are overlapped in a certain range in the circumferential direction, and as shown in FIG. The part is ultrasonically heat-sealed. When forming into a cylindrical shape, it is also possible to apply sewing machine sewing or the like instead of the above-mentioned heat fusion, but when used as a carrier for a fluidized bed, friction may cause wear on the sewing thread. It is not suitable for a product used for a long period of time because the cylindrical shape is easily broken due to the occurrence of yarn fraying.

In the above, a plurality of raw materials 6 having rigidity and a plurality of raw materials 7 having bulkiness are juxtaposed as the yarns 3 constituting the woven sheet piece 2 as shown in FIG. In the above description, the misalignment preventing material 8 is entangled and bundled. Alternatively, the yarn 3A having the configuration shown in FIG. 6 may be used. That is, as shown in FIG. 6, the yarn 3A can be constituted by a so-called mossy structure in which rigid materials are arranged on both sides of a plurality of bulky materials 7 arranged singly or in parallel. . FIG. 7 is an enlarged view of a main part of the knitted and woven sheet piece 2 formed by the yarn 3A.

If a knitted woven sheet is formed using the yarn 3A having such a mocha structure and subjected to a dry heat treatment, the rigid material 6 and the bulky material 7 can be obtained without using the misalignment preventing material. With only this, a beautiful and orderly mesh-like sheet can be obtained.

[0021]

【Example】

(Example 1) Two 900D /-polypropylene monofilaments as a rigid material and a 1 / 6S acrylic high bulky / heat-fusible ester blended yarn (50/50 blend ratio) 2 as a bulky material Using a book,
A single 1/16'S heat-sealing ester yarn as a misalignment preventing material was entangled and bundled to produce a conjugate yarn having a configuration as shown in FIG. 2 (a). In addition, 2/16'S heat-fused ester yarn was used as the belt-shaped portion.

The conjugated yarns having the above construction were arranged as warp and weft at intervals of 5 mm. Also, every 60 mm, 20 yarns of the band-like portion having the above-mentioned configuration were arranged over a distance of 10 mm to form a portion having a high density only in the warp direction. Using these, a net-like knitted sheet was formed with a plain weave structure.

Next, the base fabric, that is, the sheet thus obtained was subjected to dry heat treatment at 140 to 160 ° C. At this time, the processing is performed at a speed of 30 m per minute while firmly pressing the ears of the sheet with a pin using a setting machine having a set zone of 30 m length, so that the sheet is bulky and rigid. In the region where the yarns were densely arranged in order to form a woven sheet, a knitted sheet having a nearly plate-like finish was obtained.

The woven sheet was punched by a punching die having a predetermined size to obtain a rectangular woven sheet piece. On both sides of the sheet piece, a band-shaped portion was formed in a state of being distributed by 5 mm. Then, this knitted woven sheet piece is processed into a cylindrical shape, and one end and the other end in the length direction are overlapped with each other by 10 mm and heat-sealed by an ultrasonic welder machine to obtain a final piece having a diameter of 60 mm and a length of 60 mm. A typical cylindrical biological fluid bed carrier was obtained. Its overall specific gravity was 1.08. (Example 2) Three polypropylenes are used between two polypropylene monofilaments using a 900D polypropylene monofilament as a rigid material and an 800D polypropylene split yarn (defibrated yarn) as a bulky material. By arranging the split yarns, a sheet having a so-called mosaic texture as shown in FIGS. 6 and 7 was produced. In addition, 2/1
6S heat fusible ester yarn was used in a plain weave design.

That is, as in the first embodiment, the number of
mm at intervals of 60 mm.
By arranging 20 pieces over 0 mm, a mesh-like sheet was produced. Then, dry heat treatment is performed under the same conditions as in Example 1, punching and cutting are performed with a metal blade mold, and the ends are heat-sealed with an ultrasonic welder machine to form a cylindrical shape having a diameter of 60 mm and a length of 60 mm. Was obtained. Its specific gravity is 0.
97.

The obtained carrier was formed of a sheet having a beautiful and orderly network structure based on the above-mentioned mocha texture. Further, it was excellent in bulkiness, rigid, and had no misalignment. In addition, the carrier has excellent durability and a rational structure that does not require other materials.

[0027]

As described above, according to the present invention, in a biological carrier for a fluidized bed formed in a cylindrical shape from a mesh-shaped woven sheet, the yarn constituting the woven sheet is made of a material having bulkiness. Since it is made to include a material having rigidity for holding the cylindrical form, since it is formed of a mesh-shaped woven sheet, a space for supporting microorganisms can be secured, and the cylindrical shape Since it is formed, required performance as a carrier for a fluidized bed can be maintained. In addition, to include a rigid material to maintain the cylindrical shape, it can reliably hold the cylindrical shape as a carrier,
In addition, the surface area of the carrier is large due to the inclusion of a bulky material, so that a high-performance biological carrier for a fluidized bed can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a biological carrier for a fluidized bed according to an embodiment of the present invention.

FIG. 2 is a diagram showing constituent fibers of the carrier of FIG.

FIG. 3 is a view showing a main part of a mesh-shaped woven sheet constituted by the fibers of FIG. 2 for forming the carrier of FIG. 1;

FIG. 4 is a view showing a wider range than that of FIG. 3 for the same woven sheet.

FIG. 5 is a view showing a method for cutting the knitted sheet of FIG. 4;

FIG. 6 is a view showing another example of the constituent fibers of the carrier.

FIG. 7 is a view showing a main part of a mesh-shaped woven sheet constituted by the fibers of FIG. 6;

[Explanation of symbols]

 2 Woven sheet piece 3 Constituent fiber 4 Heat bonding part 5 Strip part

Claims (10)

[Claims] 1. A biological carrier for a fluidized bed formed in a cylindrical shape from a mesh-like woven sheet, wherein the yarn constituting the woven sheet is formed of a bulky material and the cylindrical form. A biological material for a fluidized bed, comprising: a material having rigidity for holding. 2. The biological carrier for a fluidized bed according to claim 1, wherein the yarn constituting the knitted sheet further contains a material having a property of preventing mesh misalignment. 3. The biological carrier for a fluidized bed according to claim 1, wherein the form of the woven sheet is maintained by heat treatment. 4. The biological carrier for a fluidized bed according to claim 2, wherein the material having the property of preventing misalignment of the mesh is made of a hot-melt fiber material. 5. A fiber material having rigidity for maintaining a cylindrical shape is arranged on both sides of a plurality of bulky fiber materials in which a yarn constituting a knitted sheet is arranged singly or in parallel. 2. The configuration according to claim 1, wherein
A biological carrier for a fluidized bed according to the above. 6. A yarn constituting a knitted woven sheet is provided with a bulky fiber material and a rigid fiber material for maintaining a cylindrical shape. 3. The biological carrier for a fluidized bed according to claim 2, wherein the fiber material has an entangled structure. 7. A rectangular woven sheet piece is wound in a cylindrical shape, and one end and the other end of the rectangular woven sheet piece constituting one location in the circumferential direction of the cylinder are overlapped with each other. The biological carrier for a fluidized bed according to any one of claims 1 to 6, which is thermally bonded. 8. At both ends of the cylinder, the yarns are arranged more densely along the axial direction of the cylinder than at other parts,
The biological carrier for a fluidized bed according to any one of claims 1 to 7, wherein a portion where the yarns are densely arranged is maintained in a shape by heat treatment. 9. A mesh-shaped woven sheet is formed by using a yarn containing a bulky material and a rigid material for maintaining a shape, and a constant amount of the knitted sheet along a warp direction or a weft direction is provided. For each distance, a band-like portion in which the yarns are arranged more densely than the other portions is formed, and then the formed woven sheet is subjected to a heat treatment to retain the shape of the sheet and the band-like portion. The sheet is cut at each central portion of the band portion and at each position at a fixed distance along the length direction of the band portion to form a rectangular woven sheet piece, and the rectangular woven sheet A piece is wound into a cylindrical shape, and the band-shaped portion is arranged at the end of the cylinder, and one end and the other end of the rectangular knitted sheet piece along the length direction of the band-shaped portion of the cylinder are attached to the cylinder. A method for producing a biological carrier for a fluidized bed, wherein the biological carriers are superimposed on each other in a circumferential direction and thermally bonded. 10. A mesh-like woven sheet is formed by using a yarn including a material having a bulkiness and a material having a rigidity for maintaining a form, and a material having a property of preventing mesh misalignment. The method for producing a biological carrier for a fluidized bed according to claim 9, wherein: