JP4666452B2 - Compressed activated carbon block - Google Patents

Description

  The present invention relates to a water purifier filter applied to the purification of tap water.

The structure of a conventional compressed activated carbon block is shown in FIG. This conventional block 10 uses pulverized coal 11 whose particle size is uniformized to about 250 μm by sieving. After completely mixing polyethylene 12 as a binder, it is pressure-formed into a hollow cylinder at about 200 ° C.

The block 10 thus molded is used as a water purification filter having pores 13 having a diameter of about 10 μm. In this compressed activated carbon block, fine particles having a size larger than the pore diameter, for example, foreign matters mixed in tap water such as floating organic components, microorganisms, iron rust, gravel, etc. can be physically captured by a sieving effect.
Furthermore, by utilizing the adsorption performance of activated carbon, free chlorine components such as hypochlorous acid and soluble organic substances such as organochlorine compounds such as carcinogenic trihalomethanes, 2-methylisoborneol and other molds. Remove odorous and agrochemical ingredients.
In recent years, it has been assumed that a small amount of soluble lead is contained, and the activated carbon is 20-30%.
Often used in combination with other cation exchange resins.

The crushed charcoal used for the activated carbon block uses carbonaceous raw materials such as charcoal, coconut shell charcoal, and coal, and is 700 to 1 in a gas mixture such as water vapor, carbon dioxide, and air.
After firing at 000 ° C, it is crushed and manufactured through washing and drying. The crushed coal produced through the above process is subjected to a sieving operation in order to make the particle size distribution uniform.
The particle size of the crushed coal used for the activated carbon block is 10-60 mesh,
When the finest 60 mesh crushed coal is employed, the particle size is 0.25 mm or less. Fig. 3 shows an enlarged view of crushed coal. Innumerable pores 15 for adsorbing the free chlorine component and soluble organic matter are formed on a flat crushing surface 14 of crushed coal.
FIG. 4 shows a pore distribution diagram of the compressed activated carbon block. The compressed activated carbon block has a wide pore diameter ranging from 1 × 10 ⁻² to 1 × 10 ² μm, but 10 μm.
The distribution has a large occupation rate in the vicinity of m.

In Patent Document 1, activated carbon in which ultrafine powder activated carbon having a particle size of 30 μm or less is mixed with 35 to 200 μm base activated carbon is pressure-molded using a ceramic binder,
A technique for producing a fired activated carbon block filter having a main pore distribution between 10 ^{−1 and} 8 μm by firing and capturing the bacteria and viruses is described.
JP 2003-55051 A

The conventional compressed activated carbon block has the following problems.
(1) Micro-animals such as protozoa and arthropods whose body shape is 10 μm or more can be completely removed, but bacteria of 1 μm or less, for example, E. coli having a body diameter of 0.5 to 1 μm, and 0.
It was impossible to capture 5-0.8 μm Pseudomonas aeruginosa and 0.01-0.2 μm virus.
(2) Although it has a pore diameter of 10 μm or less, the pore distribution is biased in the vicinity of 10 μm, and the surface of the crushed coal used as a raw material is extremely flat.
Since the filtration performance of this compressed activated carbon block depends only on the 10 μm sieving effect due to the pores near the surface, the trapping capacity of foreign matter is poor and it has the disadvantage of causing clogging in a short period of time.

In addition, when the calcined activated carbon block filter having the fine pore diameter described in Patent Document 1 is used, if the amount of the binder is decreased with respect to the blended amount of the ultrafine activated carbon, the ultrafine powder activated carbon is removed or blocked. Since chipping of the filter occurs, it is necessary to increase the additive rate of the binder in order to ensure the strength of the fired activated carbon block filter taking practical aspects into consideration.
An increase in the binder addition rate means a decrease in the amount of activated carbon, which leads to a decrease in the adsorption capacity for organochlorine compounds, musty odor components, agricultural chemicals, etc., resulting in a decrease in the expected life of the filter for water purifiers. It was.
Furthermore, the calcined activated carbon block filter is composed of a binder and activated carbon after pressure molding.
It contains 0wt% of moisture, and this moisture is humidified and dried by heating before baking, which causes a large volume change (shrinkage) in the binder and causes a large variation in the pore distribution described above. .

The main object of the present invention is to provide a compressed activated carbon block that solves the above-mentioned problems and stably supplies tap water free from contamination by microorganisms and organic substances.

In order to solve the above-mentioned problems, the compressed activated carbon block of the present invention is 10 to 100.
Pulverized coal with a particle size range of μm is granulated under humidified conditions with clay mainly composed of SiO ₂ and Al ₂ O ₃ and calcined to produce granulated coal with a main particle size distribution around 50 to 200 μm Then, the granulated coal is mixed with polyethylene as a binder, and heated and pressed into a hollow cylindrical shape.

In the compressed activated carbon block of the present invention, the raw crushed coal is 100 μm or more and 1
A crushed charcoal with a uniform particle size is obtained by sieving in two steps of 0 μm or less.
This crushed charcoal is granulated with clay. Further, by performing the sieving operation again after firing the particles, granulated coal having a uniform particle size distribution with very little variation around 50 to 200 μm can be generated.
The granulated coal has a structure in which a large number of protrusions are formed on the surface of the granulated coal, the crushed coal being randomly scattered on a spherical and flat clay surface. After complete mixing of granular charcoal and polyethylene binder, press molding into a hollow cylindrical shape under heating conditions.

In the compressed activated carbon block according to the present invention, granulated coal having an initial particle size distribution after firing can be used, and since the binder is completely melted and penetrated and joined to polyethylene, the particle size of the binder is used. Does not affect the pore distribution after molding. Furthermore, the additive rate of the binder can be kept low, and a long-life water filter with an increased granulated coal content can be provided.

In addition, since the protrusions of crushed coal protrude everywhere inside the pores, the pore diameter is 1 ×
Can provide a wide and smooth pore distribution of 10 ^{−3 to} 10 μm, and 0.1 μm
Many fine pores of m or less can be provided.
Therefore, according to the compressed activated carbon block of the present invention, it is a matter of course that protozoa and arthropods exceeding 10 μm are small animals such as Escherichia coli and 0.5 to 1 μm in diameter.
High capture performance can be exhibited even for bacteria such as ~ 0.8 μm of Pseudomonas aeruginosa and viruses of 0.01 to 0.2 μm.

Furthermore, pore distribution of said compressed activated carbon block, 1 × ¹⁰ no bias was pronounced in the range of -3 10 .mu.m, the ^{1 × 10 -3 ~1 × 10 -1} μm occupancy of minute regions of the By increasing the size, it is possible to increase the pore utilization rate for capturing foreign substances of various sizes, so that it is possible to realize a compressed activated carbon block having a high capacity for capturing foreign substances and a long filtration life.

Hereinafter, an embodiment embodied in the present invention will be described with reference to the drawings. As shown in FIG. 1, the compressed activated carbon block 1 of the present invention comprises a polyethylene 4 having a granulated coal 2 as a binder.
The crushed coal 3 scattered on the surface of the granulated coal 2 protrudes everywhere inside the pores 5 formed by the gaps of the granulated coal 2.
The crushed charcoal 3 is produced through the process of calcination, crushing, washing and drying using carbonaceous materials such as charcoal, coconut husk charcoal, coal, etc., as in the above-mentioned prior art. By making these two steps, the particle size is made uniform.
In addition, in order to make the mixing work performed in the next process more efficient and uniform, moisture is added to the crushed charcoal 3 having the above-mentioned particle size and moistened. At this time, when excessive moisture is given, the crushed charcoal 3 aggregates and uniform mixing is not performed.
It is desirable to adjust the humidity to about 50 wt%.

Furthermore, a clay powder mainly composed of SiO ₂ and Al ₂ O ₃ is screened.
The particle size is adjusted to 200 μm or less. Even if extremely fine clay powder of 50 μm or less is mixed, it is not a problem because it is absorbed by large particles in the granulation process described later.

The crushed charcoal 3 and the clay powder after humidity conditioning are mixed in a mixture ratio of 2: 1 to 4: 1 to produce a mixed powder and put into a granulator. The granulator is provided with a supply port for moisture necessary for conditioning the mixed powder and granulation in the upper part and a rotating plate in the lower part.
The mixed powder forms spherical particles by repeatedly colliding with the protrusions while rolling on a rotating flat plate, and the crushed coal 3 having a small particle size is collected on the surface of the particles to generate granulated coal.
In the granulation process, it is necessary to add water to prevent the formed particles from being pulverized and to promote the collection of crushed coal 3 and to prevent the crushed coal 3 from falling.
It is desirable to supply about t% of moisture.

In addition, this granulated coal is fired at a high temperature of about 1000 ° C. and then subjected to a sieving operation again, so that the granulated coal has a main particle size distribution around 50 to 200 μm and a uniform particle size with very little variation. 2 is generated.

FIG. 5 shows an enlarged view of the granulated coal 2 after firing. As described above, the surface of the granulated coal 2 has a shape in which the crushed coal 3 is randomly scattered.
The clay 6 used for granulation suppresses the dispersion of the particle size distribution due to volume reduction after firing,
In addition, considering the application to water purifiers, the organic matter content and iron content are low.
It is desirable to select raw materials that do not contain harmful substances such as lead and arsenic.

Polyethylene 4 containing 70 to 80 wt% of the granulated coal 2 and 30 to 2
As a 0 wt% blend, after mixing well, it is heated to about 200 ° C. or higher, which is the melting temperature of polyethylene 4, and pressed to form a hollow cylinder. The pores 5 formed in the compressed activated carbon block 1 manufactured in this way have the shape and size of the apertures remarkably changed from the outer surface toward the inside due to the presence of the protrusions 3a of the crushed coal 3. ing.
The change in the pore diameter will be described based on the pore distribution diagram (FIG. 6). 1 × 10 ⁻³ to 10
For pores with a wide pore size of μm and relatively large pores of 1 × 10 ⁻¹ μm or more, a smooth distribution is given. For micropores of less than 1 × 10 ⁻¹ μm, the former Although it tends to decrease in comparison, it has a wide and high occupation rate.

Therefore, according to the compressed activated carbon block of this embodiment, the following effects can be expected.
(1) Using granulated charcoal after firing with uniform particle size distribution, and the binder is completely melted,
Since polyethylene that penetrates and joins is used, the particle size of the binder does not affect the pore distribution after molding, and it is a wide and smooth surface between 1 × 10 ^{−3 and} 10 μm. A compressed activated carbon block having a pore distribution can be provided.
In addition, since the binder addition rate can be kept low and the blending rate of granulated coal can be increased, long-term water purification performance is ensured for organic substances such as free chlorine, organic chlorine compounds, mold odor components, and agricultural chemical components. it can.
(2) Since it has a wide and smooth pore distribution of 1 × 10 ^{−3 to} 10 μm and a high occupation rate of micropores of less than 1 × 10 ⁻¹ μm, the body diameter is 10 μm.
1 × 10 ⁻¹ μm order bacteria and 1 × 10 ⁻²
High capture performance can be demonstrated even for viruses of μm order.
(3) Realize a compressed activated carbon block with a long filtration life by improving the pore utilization rate and increasing the trapping capacity of the foreign matter because the pores that perform the filtration function differ depending on the size of the foreign matter. Can do.

In this compressed activated carbon block, clay containing abundant SiO ₂ and Al ₂ O ₃ is used as a granulated material for crushed coal. Since SiO ₂ and Al ₂ O ₃ are raw materials for zeolites used as cation exchangers and have the property of removing harmful heavy metal ions such as lead and chromium in water, there is no need to add a cation exchange resin. Lead ion removal performance can be ensured.

It is the schematic which shows one Embodiment of the compression activated carbon block which concerns on this invention. It is the schematic which shows the conventional compressed activated carbon block. It is an enlarged view of crushed charcoal. It is a figure which shows an example of the pore distribution in the conventional compressed activated carbon block. It is an enlarged view of the granulated coal of the compressed activated carbon block which concerns on this invention. It is a figure which shows an example of the pore distribution of the compressed activated carbon block which concerns on this invention.

Explanation of symbols

1 Compressed activated carbon block 2 Granulated coal 3 Crushed coal 3a Protrusion 4 Polyethylene 5 Pore 6 Clay

Claims (2)

A water purifier filter for removing organic substances, heavy metal ions and bacteria in tap water, comprising crushed charcoal for forming protrusions on the surface and clay particles mainly composed of SiO ₂ and Al ₂ O ₃ Compressed activated carbon block characterized by comprising granulated charcoal that is fired, solidified by adding a binder, and having pores having a wide and smooth distribution between 1 × 10 ^{−3 and} 10 μm . It is granulated under humidified conditions with crushed coal having a particle size range of 10 to 100 μm and clay mainly composed of SiO ₂ and Al ₂ O _3. 2. The method for producing a compressed activated carbon block according to claim 1, wherein granulated coal having a particle size distribution is produced, and the granulated coal is heated and pressed into a hollow cylindrical shape using polyethylene as a binder.

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