JPH0751565A - Molded adsorbent and its manufacture - Google Patents

Abstract

PURPOSE:To improve the passage of fluid without enlarging the cross section of an adsorbent. CONSTITUTION:The cross section across the passage of fluid in the molded adsorbent 1 is made to be a multilayered structure of concentric circles 2. In the method for manufacturing the molded adsorbent in which a wet molded article is formed by laminating a aggregated material such as active carbon on the surface of a mold by a suction molding method and the wet molded article is dried, the aggregated material is laminated at the water passing position of the mold surface from the position which is to be the outside of the cross section across the fluid passing direction as a molded adsorbent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded adsorbent used for adsorbing and removing coloring substances, odorous components and other harmful substances contained in a gas phase or a liquid phase, and a method for producing the same. The present invention relates to a molded adsorbent used in a water purifier or the like for adsorbing and removing chlorine and the like in tap water and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a molding adsorbent of this type has a molding die immersed in an aqueous slurry (hereinafter, also simply referred to as a slurry) containing activated carbon and a fibrous binder (binder), and sucks the slurry. Then, by filtering at the water passage portion of the molding die, which has a large number of fine water passage holes, activated carbon, a binder or the like is aggregated with respect to the water passage portion. It was manufactured by stacking the aggregates to form a wet compact, and drying the compact. More specifically, for example, in the case of a shaped adsorbent mainly composed of fibrous activated carbon, 10 to 25% by weight of a heat-meltable fibrous synthetic resin is mixed as a binder with respect to the total weight thereof. Prepared as a uniform aqueous slurry, a mold is dipped in this liquid, a predetermined amount of solid content is laminated on the mold surface by a suction method, taken out from the liquid, and dehydrated for wet (wet) molding After that, this is taken out from the molding die, heated to a predetermined temperature in a state of being loaded in a drying die (form), and the binder is heat-melted to bond and dry the activated carbons.

When the shaped adsorbent is, for example, for a water purifier and has a columnar shape, it is formed by a forming die 81 shown in FIG. That is, in this molding die 81, a flange 83 is provided around the upper end surface of a cylindrical molding die main body 82, and a water passage plate (strainer) 85 having a large number of water passage holes 84 is attached thereon, and A fine mesh wire netting 86 is attached on it, and is fixed via an annular plate 87 and bolts 88, and a cylindrical mold 89 is placed on the metal net 86 inside the annular plate 87 and fitted. It will be. Then, as shown in FIG.
1 is immersed in a predetermined aqueous slurry S while suctioning (vacuuming) under the condition that the end of the pipe P connected to the lower end of the main body 82 is connected to a suction pump (not shown).
Innumerable aggregates (solid content) are filtered and laminated with 6, and the thickness is changed from a disk to a cylinder to form a cylindrical molded body.

[0004]

By the way, the molded body thus molded has a structure in which the agglomerates are stacked in layers on the metal wire 86 side of the mold surface by the suction action in one direction during molding. Therefore, the composition has a large number of layers in which relatively dense dense layers formed of aggregates and relatively coarse dense layers between the dense layers are alternately repeated (Fig. 11 and 12). In other words, it has a structure in which circular papers having a fine composition and circular papers having a coarse composition are alternately stacked. Therefore,
When a shaped adsorbent obtained by drying this is used in, for example, a water purifier, the passage direction of water is along the axis of the cylinder, as indicated by the arrow in FIG. It passes through the molded adsorbent 91 while penetrating a large number of dense layers (films). Therefore, there was a problem that the resistance was remarkably large, and as a result, it was difficult to secure a desired water flow rate (water flow rate per unit time). Moreover, since it has a structure in which the cylinders are layered in the height direction, they have a good cushioning property in that direction, and thus are easily crushed. Therefore, the higher the pressure of water, the more the water tends to be compressed, and the more dense the tissue becomes. Inviting and reducing water permeability. That is, in the structure of the molded adsorbent 91, the water-passing performance or the water purification treatment rate is low, and there has been a demand for improvement for some time.

Further, when it is used as a shaped adsorbent, adsorption of foreign matters (clogging of activated carbon structure) progresses and the water passage cross-sectional area decreases, so that it is necessary to set a large initial water passage amount. Therefore, in order to increase the water-passing capacity, it is necessary to use a molded adsorbent having an extremely large cross-sectional area, which leads to an increase in the size of the water purifier itself and a significant increase in the cost of the molded adsorbent. The present invention has been devised to solve the above-mentioned problems of the prior art, and provides a molded adsorbent having good fluid passage performance and a method for producing the same, without increasing the passage cross-sectional area. To aim.

[0006]

In order to achieve the above object, the present invention provides a shaped adsorbent formed by containing activated carbon and a fibrous binder, which allows a fluid such as liquid or gas to pass therethrough. The structure of the cross-section with respect to the direction is such that it has a number of substantially concentric annular layers. here,
With the naked eye, it is said that it is composed of many layers of approximately concentric rings.
Synopsis It means that multiple layers or streaks appear like the annual rings of a tree. And as the suitable manufacturing method, there are the following. That is, the mold is immersed in an aqueous slurry containing activated carbon and a fibrous binder, the aqueous slurry is sucked, and the mold surface of the mold has a water passage portion having a large number of water passage holes. By forming a wet compact by laminating an aggregate formed by aggregating activated carbon, a binder, etc. on the water-passing portion by filtration, and drying the compact, the adsorbent is formed. In the method for producing a molded adsorbent for obtaining the molded adsorbent, in forming the molded body, a cross-section with respect to a direction in which a fluid such as a liquid or a gas is passed as the molded adsorbent, the agglomerate with respect to a water passage portion of the mold surface. It is laminated from the part which will be the outer side of.

[0007]

The shaped adsorbent according to the present invention has the above-described structure, and when the fluid is passed, it can be passed in the direction along the layer without passing through the dense layer unlike the conventional one. it can. That is, since it is possible to selectively pass along the coarse and dense layer, the passage resistance is correspondingly reduced, and a large flow rate can be passed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention and manufacturing methods thereof will be described in detail with reference to FIGS. The shaped adsorbent 1 of this example is a water purifier in which activated carbon is a mixture of granular activated carbon and fibrous activated carbon, and an antibacterial material is added as an additive, and the columnar shape (diameter 40 mm, height 50)
mm), and the cross-section forms a layer having a substantially concentric annular shape, and activated carbon, a binder, and the like form an annular layer, which is formed like a tree ring.

The molding adsorbent 1 of this example is manufactured with a slurry prepared as described below. First, the molding die used in this example will be described. FIG. 2 shows a molding die 3 used in the manufacture of the molding adsorbent 1 of this example, and the molding die body 4 has a stepped cylindrical shape with an enlarged upper portion, and the enlarged upper end surface thereof. A flange 5 is provided around the circular plate 8, and a circular plate 8 is attached to the flange 5 via a circular plate 6 and bolts 7. However, near the outer periphery of the circular plate 8, a large number of through holes 9, 9 are provided at substantially equal angular intervals on the substantially same periphery. On the other hand, inside the annular plate 6 and on the upper surface of the circular plate 8, a large-diameter outer cylinder 10 and a small-diameter inner cylinder 11 concentric with the outer cylinder 10.
The cylindrical mold 12 made of is seated. However, the upper surface thereof is closed to form a ring-shaped space 13 inside. Further, a large number of water passage holes 14 are formed in the inner cylinder 11, and a wire mesh 15 of a fine mesh is stretched inside thereof to form a water passage portion, which forms an outer peripheral surface of a molded body to be molded. It's a face. A lid 16 is fitted on the upper surface of the cylindrical mold 12 so as to cover the upper end opening of the inner cylinder 11. However, a circular small hole 17 is formed in the center of the lid 16.
Is installed throughout. In this way, when suction is performed from the lower end portion (suction port) 4a of the molding die body 4, the cylindrical die 12 and the lid 1
6 is sucked to the mold body 4 side, and in FIG.
As indicated by the arrow, the slurry enters the columnar molding space 18 in the inner cylinder 11 through the small holes 17 of the lid 16 and expands, and cross-sections toward the wire net 15 and the water passage hole 14 of the inner cylinder 11. In the radial (radial) direction, is diffused and sucked, reaches the space 13 between the outer cylinder 10 and the inner cylinder 11, and is discharged from the lower end portion 4 a of the molding die body 4. Innumerable aggregates such as solids in the slurry are filtered and stacked on the wire net 15.

Next, the aqueous slurry used in this example will be described, and its composition is as follows. That is, in the aqueous slurry of this example, 100 parts by weight of granular activated carbon, fibrous activated carbon and antibacterial material mixed at a ratio of 45:45:10 (wt%) were used as a binder. It is obtained by adding 5% by weight of acrylic fiber. The granular activated carbon is coconut shell type activated carbon mainly composed of micropores, having a grain size of 0.18 to 0.36 mm and a specific surface area of 1550 m @ 2 / g or more.
In addition, the fibrous activated carbon is a coal pitch type in this example, the fiber thickness is 10 μm to 15 μm, and the specific surface area is 15 μm.
It is more than 00 m 2 / g and has a length of about 0.5 mm. The antibacterial material is antibacterial zeolite (powder) in which antibacterial metal ions are added to zeolite. Acrylic fiber is 3 denier, 3
The mm-cut product is prepared into a fine dendritic structure in which the fibers are sufficiently fibrillated by a refiner and a beater to easily entangle fibers, and the activated carbon and the antibacterial material in the slurry are easily aggregated.

Then, a suction pipe (not shown) is connected to the lower end portion 4a of the molding die body 4, and the molding die 3 is immersed in the aqueous slurry in the molding tank in the same manner as shown in FIG. Is immersed and suction is applied, the aqueous slurry enters the molding space 18 in the inner cylinder from the small hole 17 of the lid 16, and is sucked in a radial direction toward the wire net 15 at once.
Filtered. Then, the agglomerates in the slurry adhere to the entire surface of the wire mesh (mold surface) 15 to form a layer (film). This layer is the part that will form the outer side of the cross section of the obtained molded adsorbent, and on top of that, the agglomerates are further laminated inward, and finally the axial line portion. Is filled with to form a columnar shape. Thus, after a lapse of a predetermined time (after several tens of seconds), the inner cylinder 11 is filled with the solid content so as to form a structure just like a tree ring. After that,
The mold 3 is pulled up from the slurry, and the lid 16 and the cylindrical mold 12 are pulled up.
Remove the mold, take out the wet molded body,
By passing through a predetermined drying step, it is possible to obtain a desired adsorption molded body 1 having a structure (laminated structure) forming a number of substantially concentric annular layers 2 and 2 shown in FIGS. 3 and 4 (see FIG. 1). ). In this example, the lid 1 which is the entrance of the slurry of the molding die 3 is used.
The small holes 17 of No. 6 are narrowed down, and as soon as the slurry enters the mold, the slurry diffuses in the radial direction at once, so that it is possible to obtain a large number of extremely homogeneous concentric annular layers (annular rings).

Next, the molded adsorbent 1 thus obtained.
The water-passing performance was compared with that of a conventional laminated structure of the same size manufactured from the same slurry. However, the comparison is obtained by this example, when a water purifier is connected to a faucet set to a constant water supply rate of 10 L / min, and a molded adsorbent (comparative example) manufactured by a conventional manufacturing method is loaded. The difference in the initial amount of water supplied from the water purifier (faucet) was confirmed when the molded adsorbent was loaded. As a result, although the initial water supply amount was reduced to 3 to 3.5 L / min by the conventional manufacturing method, it was 5 to 5.5 L / min when the molded adsorbent of this example was used. The decrease could be suppressed to an extremely small level. That is, in this example,
It was possible to secure a flow rate of approximately 1.5 to 2 times that of the conventional one. It is considered that this is because the particles pass through the dense layers in a direction along the layers 2 and 2 without being allowed to pass through the dense layers. Furthermore, in the above, after passing 3000 L of water through the water purifier (molding adsorbent), that is, after measuring the water flow rate per unit time after use for a predetermined period, compare it with the initial water supply rate. It looked like this: That is, the conventional manufacturing method,
It was 1.5 to 1.7 L / min, whereas that of the manufacturing method of this example was 3.5 to 4 L / min. Therefore, it is understood that the life of the present example can be remarkably extended. The chlorine concentration of the treated water showed almost no change. As can be seen from these results, it can be seen that the molded adsorbent according to the present example retains remarkably high water-passing performance without causing a decrease in its adsorption performance as in the conventional one.

In the above-mentioned embodiment, the molded adsorbent is dried and used as it is as the molded adsorbent. However, as shown in FIG. 4, the molded adsorbent 1 obtained above has its axis line. Center (axis) in vertical section including
The part had a V or U shape. Therefore, it is considered that the water flow resistance in the central part is somewhat inferior to that in the outside. Although there is a decrease in raw material yield, if a longer product is manufactured and the lower end is cut, the cross section becomes a so-called annual ring shape, and further improvement in water flow performance is expected.

The molded adsorbent 21 shown in FIGS. 5 and 6 is
Although it also has a columnar shape, the structure of the transverse section has a number of layers of substantially concentric rings 22, 22, while the layers 22, 22 are entirely V or U in the longitudinal section including the axis. It has a letter-like shape, that is, a stacked state in which large and small cups are stacked. This is a wire mesh of a fine mesh in which a large number of water passage holes are provided on the die surface (the portion corresponding to the bottom surface 23 of the adsorbent body 21) of the circular plate 8 of the die 3 shown in FIG. 2 in the previous example. It is the one that is aspirated and molded with the attached. That is, by forming agglomerates not only on the outer peripheral surface of the shaped adsorbent 21 which forms the outer side of the cross section with respect to the direction in which the fluid passes but also from the portion which will form the bottom surface 23 of the shaped adsorbent 21. It was done. The results of the same comparative test as the previous example are as follows. The initial water supply from the water purifier is
In this example, it is 4.8 to 5.2 L / min, and 30
The amount of water supplied after passing 00 L of water was 3.4 to 3.8 L / min. That is, in each case, it is about 3 to 5 than the previous example.
%, Which is significantly better than the conventional one. In this example, since there are many parts where the agglomerate is started to be laminated, the time required for molding the molded body can be reduced,
Therefore, the production efficiency can be improved although the performance is slightly lowered. In addition, the cause of the deterioration in performance is the bottom surface 2
This is considered to be due to the formation of layers along the cross-section at a position closer to 3. Similar to the previous example, the performance can be improved by manufacturing a longer product and cutting the lower end.

The shaped adsorbent 31 shown in FIG. 7 has the same structure as the two adsorbents shown in FIG. 1 (FIG. 4) joined together at their lower end surfaces. That is, the one shown in FIG. 1 is the molding die 3 shown in FIG. 2, and one lid 16 in which a small hole 17 which is a slurry inlet is covered on the upper portion of the cylindrical die 12
However, in this example, it is obtained by molding a molded body with the molding die 33 shown in FIG. The molding die 33 used in this example will be described, but the differences from the molding die 3 in FIG. 2 will be mainly described. That is, the molding die 33 includes a concentric inner cylinder 41 and an outer cylinder 40.
A cylindrical mold 42 having both ends closed is used as a mold main body, and a ring-shaped space 43 is formed therein. A large number of water passage holes 44, 44 are provided in the inner cylinder 41. ,
Further, a fine mesh wire net 45 is stretched inside thereof to form a mold surface that forms the outer peripheral surface of the molded body to be molded. On the other hand, on the outside of the outer cylinder 40, a suitable number of suction ports 33a are projectingly opened at equal angular intervals.
A is connected to the suction pump via a pipe (not shown). Then, on both upper and lower end surfaces of the cylindrical mold 42, a lid 46, which covers the upper and lower end openings of the inner cylinder 41,
46 is fitted. However, in the center of each lid 46,
A circular small hole 47 is provided therethrough.

However, in the same manner as in the previous example, this molding die 3
When 3 is immersed in the slurry and suction-molded, the slurry expands into the cylindrical molding space 48 from the small holes 47, 47 of the upper and lower lids 46, 46, as shown by the arrow in FIG. The wire mesh 45 and the water passage 44 of the inner cylinder 41 are diffused and sucked in the radial direction in the cross section, reach the space 43, are discharged from the suction port 33a, and the aggregates are filtered and laminated in the wire mesh 45. , A molded body is formed. Also in this structure, the structure of the cross-section has a number of layers of substantially concentric rings, but as shown in FIG. 7, it has a substantially symmetrical shape with respect to the axial direction, so that it becomes a more homogeneous structure. However, the initial water supply from the water purifier is 5 to 5.5 L / min.
In addition, the amount of water supply after passing 3000 L of water is 3.6-
It was 4.1 L / min, which was equivalent to that according to the first embodiment.

The type and particle size of activated carbon forming the composition of the shaped adsorbent of the present invention and the mixing ratio (blending ratio) thereof may be appropriately determined depending on the application of the shaped adsorbent. However, when the particles are used so as to be suitable for suction molding, the particle size is preferably 0.18 to 0.36 mm. Further, in the preceding example, the binder was fibrillated acrylic fiber, but it is needless to say that it is not limited to this as long as it is fibrous. With or without fibrillation, synthetic resin such as aramid fiber,
Alternatively, pulp, hemp, etc. can also be used. In addition,
Acrylic fibers containing a substance such as sodium acrylate as a sticky substance (gelatin etc.) have a high strength because they have a binding force due to sticking or adhesion in addition to the entanglement of fibers during drying. If the fibers are fibrillated, the activated carbon can be joined by the entanglement of the fibers, so that the strength can be improved without heat fusion. It should be noted that, depending on the use of the molded adsorbent, a yield improver, a paper strength enhancer, and a coagulant may be added to the aqueous slurry, or a fibrous substance (material) for enhancing water permeability is mixed. You may.

The molded adsorbent according to the present invention is an adsorbent (filter) for a water purifier used for deodorizing and decolorizing drinking water and removing chlorine components, an adsorbent for an air purifier, a solvent in a chemical factory, etc. It can be applied to various applications such as an adsorbent used for the recovery of The shaped adsorbent can be embodied not only as a columnar shape, but also as a polygonal prism shape or a taper shape that is close to these.

[0019]

As is apparent from the above description, the molded adsorbent according to the present invention has a structure in which the fluid does not pass through the dense layer of the structure of the molded adsorbent as in the conventional case, and the tissue is Since the fluid can be passed in the direction along the dense layer, the passage resistance is small, and thus a large flow rate can be passed per unit time.
As a result, it is possible to reduce the size and extend the life of the molded adsorbent. Further, according to the method for manufacturing a molded adsorbent according to the present invention, a molded adsorbent having a small fluid passage resistance and a long life can be efficiently manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an embodiment in which a molded adsorbent according to the present invention is embodied.

FIG. 2 is a central vertical cross-sectional view of a molding die used for manufacturing the molding adsorbent shown in FIG.

FIG. 3 is a conceptual diagram for explaining a cross section of the molded adsorbent shown in FIG.

FIG. 4 is a conceptual diagram for explaining a vertical cross section of the molded adsorbent shown in FIG.

FIG. 5 is a conceptual diagram for explaining a vertical cross section of another embodiment in which the molded adsorbent according to the present invention is embodied.

6 is a conceptual diagram for explaining a cross section taken along the line AA in FIG.

FIG. 7 is a conceptual diagram for explaining a vertical cross section of still another embodiment in which the molded adsorbent according to the present invention is embodied.

8 is a central vertical cross-sectional view of a molding die used to manufacture the molding adsorbent shown in FIG.

FIG. 9 is a central vertical cross-sectional view of a molding die used for manufacturing a conventional molding adsorbent.

FIG. 10 is a schematic cross-sectional view for explaining a state in which the molding die shown in FIG. 9 is immersed in an aqueous slurry and suction-molded.

FIG. 11 is a perspective view showing the appearance of a conventional molded adsorbent.

12 is a conceptual diagram for explaining a vertical cross section of the shaped adsorbent shown in FIG.

[Explanation of symbols]

 1,21,31 Molded adsorbent 2,22,32 Layer of cross section of molded adsorbent 3,33 Mold 15,45 Wire mesh (water passage part) S Aqueous slurry

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01J 20/20 C 7202-4G C02F 1/28 D

Claims (2)

[Claims] 1. In a shaped adsorbent formed by including activated carbon and a fibrous binder, a structure having a cross section in the direction of passage of a fluid such as a liquid or a gas has a large number of substantially concentric annular layers. A shaped adsorbent characterized by being formed. 2. A mold is immersed in an aqueous slurry containing activated carbon and a fibrous binder, and the aqueous slurry is sucked,
By filtering at a water passage portion having a large number of water passage holes on the mold surface of the molding die, an aggregate formed by aggregating activated carbon or a binder is laminated on the water passage portion. In the method for producing a molded adsorbent, which comprises molding a molded body in a wet state and drying the molded body to obtain a molded adsorbent, in molding the molded body, the above-mentioned method is applied to the water passage portion of the mold surface. A method for producing a shaped adsorbent, which comprises laminating aggregates from a portion that is to be an outer side of a cross section with respect to a direction in which a fluid such as a liquid or a gas passes as the shaped adsorbent.