JP6726520B2 - Activated carbon molding and water purification cartridge - Google Patents

Description

The present invention relates to an activated carbon molded body and a water purification cartridge.

Conventionally, tap water purified by a water purifier has been used as drinking water. In a general water purifier, an activated carbon molded body is incorporated as a filter medium inside a water purification cartridge. The activated carbon molded body incorporated in the water purification cartridge adsorbs and removes odorous substances such as free residual chlorine in tap water and organic compounds such as trihalomethane.

By the way, in order to improve the filtration performance of the water purifier, it is necessary to improve the filtration performance of the activated carbon molded body incorporated inside. In order to improve the filtration performance of the activated carbon molded body, it is effective to increase the surface area per unit volume to increase the adsorption rate, and a method such as blending pulverized coal having a small particle size can be considered. Here, when pulverized coal is simply blended, the gap between the activated carbon particles is narrowed, and it becomes difficult for water to flow in the water purifier, resulting in a decrease in filtration performance. Therefore, for example, an activated carbon molded body containing a particulate activated carbon in which the content of particles having a particle diameter of 10 μm or less is 2% by volume or less has been proposed (see, for example, Patent Document 1).

JP, 2015-112518, A

However, it cannot be said that the activated carbon molded body of Patent Document 1 has sufficient filtration performance, and further improvement in filtration performance has been demanded.

The present invention has been made in view of the above, and an object thereof is to provide an activated carbon molded body having a higher filtration performance than conventional ones.

In order to achieve the above object, the present invention provides a particulate activated carbon (for example, the particulate activated carbon 10 described later) and a porous material (for example, diatomaceous earth 13 described later) having continuous pores in which adjacent pores communicate with each other. Which is an activated carbon molded body (for example, activated carbon molded body 1 to be described later), which has an integrated volume of pulverized coal (for example, pulverized coal 12 to be described later) having a particle diameter of 10 μm from a side having a smaller particle diameter of the particulate activated carbon. There is provided an activated carbon molded product having a ratio of 2 to 20% and a content of the porous material with respect to the particulate activated carbon of 1 to 40% by mass.

The porous material is preferably diatomaceous earth.

The diatomaceous earth preferably has a large median particle diameter D ₅₀ of the center particle diameter D ₅₀ of the granular activated carbon.

The present invention also provides a water purification cartridge including the activated carbon molded body.

According to the present invention, it is possible to provide an activated carbon molded body and a water purification cartridge having higher filtration performance than ever before.

It is a figure which shows typically the structure of the activated carbon molded object which concerns on one Embodiment of this invention. It is a figure which shows typically the structure of the conventional activated carbon molded body. It is a figure which shows typically the activated carbon molded object which mix|blended the pulverized coal with the conventional activated carbon molded object. 7 is an SEM image of the activated carbon molded body of Example 6. 3 is an SEM image of an activated carbon molded body of Comparative Example 1.

An embodiment of the present invention will be described below with reference to the drawings. The present invention is not limited to the embodiments below.

The activated carbon molded body according to the present embodiment is used, for example, in a water purification cartridge of a water purifier for purifying water to be treated such as tap water. The activated carbon molded body according to the present embodiment adsorbs and removes the removal target contained in the water to be treated. Examples of the object to be removed include odor substances such as free residual chlorine contained in tap water and organic compounds such as trihalomethane.

FIG. 1 is a diagram schematically showing the structure of an activated carbon molded body 1 according to this embodiment.
As shown in FIG. 1, the activated carbon molded body 1 according to the present embodiment is configured to include particulate activated carbon 10 and diatomaceous earth 13. The activated carbon molded body 1 according to the present embodiment is molded into a cylindrical shape, for example, by suction filtration molding using a slurry containing at least these particulate activated carbon 10 and diatomaceous earth 13, as described later.

As the particulate activated carbon 10, activated carbon obtained from any starting material can be used. Specifically, after coconut shell, coal, phenol resin, etc. are carbonized at a high temperature and then activated, activated carbon can be used. Activation is a reaction for developing fine pores of a carbonaceous raw material to change it into a porous state, and is performed using a gas such as carbon dioxide or water vapor or a chemical. Most of such particulate activated carbon is composed of carbon, and a part thereof is a compound of carbon and oxygen or hydrogen.

The particulate activated carbon 10 according to the present embodiment has an integrated volume ratio of 2 to 20% from the smaller particle diameter side to the particle diameter 10 μm. That is, in the particle size distribution curve, the cumulative volume ratio from the small particle size side to the particle size of 10 μm is 2 to 20%.
If the cumulative volume ratio of 10 μm particle diameter is less than 2%, the ability of pulverized coal to filter free residual chlorine and the like cannot be improved. Further, when the cumulative volume ratio of the 10 μm particle diameter exceeds 20%, the reduction of the filtration flow rate cannot be suppressed even by the addition of diatomaceous earth described later. The more preferable integrated volume ratio of 10 μm particle diameter is 10 to 20%.

In the present embodiment, among the activated carbon particles forming the particulate activated carbon 10, the activated carbon particles having a particle diameter of 10 μm or less are called pulverized coal 12, and the activated carbon particles having a particle diameter of more than 10 μm are simply called activated carbon particles 11. As shown in FIG. 1, the pulverized coal 12 is dispersed in the particulate activated carbon 10, and the pulverized coal 12 is present between the activated carbon particles 11.

The above-mentioned particle diameter is a value measured by a laser diffraction method, and the above-mentioned particle diameter distribution curve means a particle diameter distribution curve obtained by measurement by a laser diffraction method. Specifically, it can be measured using, for example, a laser diffraction/scattering particle size distribution measuring device “Microtrac MT3300EXII” manufactured by Microtrac Bell Co., Ltd.

The particulate activated carbon 10 according to the present embodiment preferably has a central particle diameter D ₅₀ of 40 to 100 μm. When the central particle diameter D ₅₀ of the particulate activated carbon 10 is within the above range, the removal target adsorption amount per unit mass of the particulate activated carbon 10 is improved.

The central particle diameter D ₅₀ of the particulate activated carbon 10 means the value of 50% diameter in the volume-based integrated fraction in the particle diameter distribution curve obtained by the measurement by the laser diffraction method described above. The central particle diameter D ₅₀ can be measured by the above-described measuring device.

Here, FIG. 2 is a diagram schematically showing the structure of a conventional activated carbon molded body 1A. Further, FIG. 3 is a diagram schematically showing an activated carbon molded body 1B in which pulverized coal 12 is mixed with a conventional activated carbon molded body 1A. 1 to 3, W represents water flowing into each activated carbon molded body.

In the conventional activated carbon molded body 1A shown in FIG. 2, that is, the activated carbon molded body 1A which is composed of only the activated carbon particles 11 and does not contain the pulverized coal 12, the water W flows without being clogged. Therefore, although there is no problem with the filtration flow rate, the ability to filter free residual chlorine and the like is low because it does not contain pulverized coal 12.

On the other hand, in the conventional activated carbon molded body 1B shown in FIG. 3, that is, the activated carbon molded body 1B containing the activated carbon particles 11 and the pulverized coal 12, the particles between the activated carbon particles 11 are narrowed due to the blending of the pulverized coal 12. As a result, the water W cannot pass through the activated carbon molded body 1B due to clogging, and the effect of improving the free residual chlorine filtration capability that the pulverized coal 12 originally has cannot be obtained.

On the other hand, in the activated carbon molded body 1 according to the present embodiment, as shown in FIG. 1, diatomaceous earth 13 is blended in addition to the pulverized coal 12. The diatomaceous earth 13 is a porous material having pores 14 having a larger pore diameter than the pores of the activated carbon particles 11 described above. The pores 14 formed in the diatomaceous earth 13 are continuous pores. That is, the diatomaceous earth 13 has continuous pores in which adjacent pores communicate with each other. Therefore, as shown in FIG. 1, the narrowing of the gap between the activated carbon particles 11 due to the blending of the pulverized coal 12 is suppressed by the blending of the diatomaceous earth 13. Further, the clogging is suppressed and the flow of the water W is not hindered, and the reduction of the filtration flow rate is suppressed, and as a result, the filtration performance is improved.

The content rate of the diatomaceous earth 13 with respect to the above-mentioned particulate activated carbon is 1 to 40 mass %. When the content of the diatomaceous earth 13 is less than 1% by mass, it is not possible to suppress the decrease in the filtration flow rate due to the addition of the pulverized coal 12. On the other hand, when the content rate of the diatomaceous earth 13 exceeds 40 mass %, the content rate of the pulverized coal 12 in the activated carbon molded body 1 decreases, so that the filtration performance such as the free residual chlorine filtration capacity cannot be improved.

The diatomaceous earth 13 preferably has a central particle diameter D ₅₀ larger than the central particle diameter D _{50 of the} particulate activated carbon 10. As a result, it is possible to further suppress the narrowing of the gap between the activated carbon particles due to the addition of the pulverized coal 12, and it is possible to further suppress the decrease in the filtration flow rate. In addition, since the diatomaceous earth 13 has the continuous pores 14 larger than the pores of the activated carbon particles as described above, water can pass through the pores 14 in the diatomaceous earth 13 and the filtration flow rate can be improved. ..

Specifically, the central particle diameter D ₅₀ of the diatomaceous earth 13 is preferably 92 to 203 μm. As a result, the above-mentioned effect is surely obtained. The more preferable central particle diameter D ₅₀ of the diatomaceous earth 13 is 117 to 151 μm.
The center particle diameter D ₅₀ of the diatomaceous earth 13 is synonymous with median particle diameter D ₅₀ of the granular activated carbon 10 above, can be measured using the same measuring device.

Further, the activated carbon molded body 1 according to the present embodiment preferably contains fibers. A fibril fiber is preferably used as the fiber. Any fiber can be used as the fibril fiber as long as the particulate activated carbon 10 can be entangled to maintain the shape. Specific examples include acrylic fibers, polyethylene fibers, and cellulose fibers.

Further, the activated carbon molded body 1 according to this embodiment may include other particles and the like within a range that does not impair the effects of this embodiment. For example, the activated carbon molded body 1 may further include particles having ion exchange performance for the purpose of removing ionic components that cannot be completely removed by the particulate activated carbon 10. Specifically, it may contain particles of zeolite, titanium silicate, ion exchange resin, or the like. This makes it possible to remove soluble lead, arsenic, hardness components, etc. from water.

The activated carbon molded body 1 according to the present embodiment is manufactured by, for example, conventionally known suction filtration molding. Specifically, first, a slurry containing particulate activated carbon 10 (activated carbon particles 11 and pulverized coal 12), which is a raw material of the activated carbon molded body 1, diatomaceous earth 13 and water, and optionally fibers and the like is prepared. Next, the activated carbon molded body 1 according to the present embodiment is obtained by conventionally known suction filtration molding using the prepared slurry.

The water purification cartridge according to this embodiment is used in a water purifier for purifying water to be treated such as tap water, and is not particularly limited as long as it includes the above-mentioned activated carbon molded body 1 as a filter medium. In addition to the above-mentioned ceramic filter as a supporting member of the activated carbon molded body 1 or a filtration filter such as a hollow fiber membrane, a nonwoven fabric for protecting the surface of the activated carbon molded body 1 may be included.

According to this embodiment, the following effects are exhibited.
In the present embodiment, in the activated carbon molded body 1 containing the particulate activated carbon 10 and the diatomaceous earth 13, the cumulative volume ratio of the pulverized coal 12 from the side having a smaller particle diameter of the particulate activated carbon 10 to the particle diameter 10 μm is 2 to 20. %. Moreover, the content rate of the diatomaceous earth 13 with respect to the particulate activated carbon 10 was set to 1 to 40 mass %.
Thereby, the pulverized coal 12 can be blended to improve the filtration performance such as free residual chlorine filtration capacity. At the same time, by mixing the diatomaceous earth 13, it is possible to suppress the narrowing of the gaps between the activated carbon particles 11 due to the mixing of the pulverized coal 12, and it is possible to suppress the reduction in the filtration flow rate. Therefore, according to this embodiment, it is possible to obtain the activated carbon molded body 1 having higher filtration performance than the conventional one.

Further, in the present embodiment, as the diatomaceous earth 13, one having a central particle diameter D ₅₀ larger than the central particle diameter D _{50 of the} particulate activated carbon 10 was blended. Thereby, the above-mentioned effect is further enhanced.

Further, in the present embodiment, the water purification cartridge is configured to include the above-mentioned activated carbon molded body 1. As a result, a water purification cartridge having a higher filtration performance than before can be obtained.

The present invention is not limited to the above-described embodiment, and modifications and improvements within a range in which the object of the present invention can be achieved are included in the present invention.
For example, in the above-described embodiment, the activated carbon molded body 1 is configured to include the diatomaceous earth 13, but the present invention is not limited to this. Instead of the diatomaceous earth 13, the activated carbon molded body 1 may be configured to include a porous material such as the diatomaceous earth 13 having continuous pores in which adjacent pores communicate with each other.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[Examples 1 to 22 and Comparative Examples 1 to 5]
According to the manufacturing method described in the above embodiment, the activated carbon molded bodies of Examples 1 to 22 and Comparative Examples 1 to 5 having the formulations shown in Table 1 were prepared. The central particle size of the particulate activated carbon was adjusted by blending activated carbons having different particle sizes. In addition, the 10 μm cumulative volume% and the central particle diameter of the particulate activated carbon and the central particle diameter of the diatomaceous earth are measured using a laser diffraction/scattering particle diameter distribution measuring device “Microtrac MT3300EXII” manufactured by Microtrac Bell Co., Ltd. did.

[Evaluation]
For each activated carbon molded body produced in Examples 1 to 22 and Comparative Examples 1 to 5, surface enlargement observation using SEM was performed. As a representative, SEM images of Example 6 and Comparative Example 1 are shown in FIGS. 4 and 5.

The activated carbon moldings produced in Examples 1 to 22 and Comparative Examples 1 to 5 were evaluated for their ability to filter free residual chlorine. The free residual chlorine filtration capacity was evaluated according to the method based on JIS S3201. The results are shown in Table 1.

For each activated carbon molded body produced in Examples 1 to 22 and Comparative Examples 1 to 5, the filtration flow rate was evaluated. Regarding the filtration flow rate, each activated carbon molded body was put in a cylindrical special case having an outer diameter of 25 mm, an inner diameter of 8 mm, and a length of 90 mm, and then water having a water pressure of 0.05 MPa was circulated for evaluation. The results are shown in Table 1.

As shown in FIG. 4, in the activated carbon molded body of Example 6, it was confirmed that the blended pulverized coal and diatomaceous earth were present in the activated carbon molded body. This is clear when compared with the activated carbon molded body of Comparative Example 1 shown in FIG. 5, which contains neither pulverized coal nor diatomaceous earth. Similar results were obtained in the other examples.

As shown in Table 1, according to the activated carbon molded body of the present example in which the integrated volume ratio of pulverized coal is 2 to 20%, and the content ratio of diatomaceous earth to the particulate activated carbon is 1 to 40% by mass. It was confirmed that the free residual chlorine filtration capacity was higher than that of the activated carbon molding of Comparative Example 1 containing neither charcoal nor diatomaceous earth. At the same time, it was also confirmed that the activated carbon molded body of this example has a higher filtration flow rate than the activated carbon molded body of Comparative Example 2 containing only pulverized coal and not containing diatomaceous earth. Therefore, according to this example, it was confirmed that a higher filtration performance than the conventional one was obtained.

1 Activated Carbon Molded Body 10 Particulate Activated Carbon 11 Activated Carbon Particles 12 Fine Coal 13 Diatomaceous Earth

Claims (3)

A particulate activated carbon, a porous material made of diatomaceous earth having continuous pores in which adjacent pores communicate with each other, an activated carbon molded body,
The cumulative volume ratio of the pulverized coal from the smaller particle size side of the particulate activated carbon to the particle size of 10 μm is 2 to 20%,
An activated carbon molded product, wherein the content of the porous material in the particulate activated carbon is 1 to 40% by mass. The activated carbon molded body according to claim 1 , wherein the diatomaceous earth has a central particle diameter D50 larger than the central particle diameter D50 of the particulate activated carbon. Purification cartridge containing activated carbon molded article according to claim 1 or 2.