JPH08294611A - Deodorant filter element - Google Patents

Abstract

PURPOSE: To obtain a unit which has a low pressure loss and can be used for a long period of time by making activated carbon particles granulated carbon, crushed carbon, or spherical carbon and forming aggregates by point-bonding the particles with a binder keeping air between them in activated carbon particle aggregates which are packed into a frame with a honey comb cross section. CONSTITUTION: A cell 1 is a part of the frame of a filter element and is composed of a net 3 which is the wall surface 2 of the cell, and the cell 1 is filled with activated carbon particle aggregates 6 which are molded from activated carbon particles 4 point-bonded with a binder 5. The activated carbon particles 4 are granulated carbon, crushed carbon, or spherical carbon, and the aggregates 6 are molded by point-bonding the particles 4 with the binder 5 keeping air between the particles 4. Since the deodorant filter element is held with a high percentage of voids between the activated carbon particles, the element has a high adsorption capacity and a low pressure loss and is suitable for treating a large volume of gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low pressure loss type deodorizing filter element. More specifically, it is an element using an aggregate formed as a deodorant in a state where spaces between activated carbon particles are held. , No _x, SO _x contained ammonia, acetaldehyde, the removal and road odor of acetic acid gas contained in tobacco smoke, other hydrocarbons, aldehydes, have excellent characteristics in diesel exhaust gas removal, air cleaning filter Used for.

[0002]

2. Description of the Related Art Up to now, a deodorizing element in which a large number of activated carbon particles are filled in a honeycomb frame has been disclosed. For example, Japanese Patent Application No. 63-314474 describes a honeycomb core filled with activated carbon particles as they are. When this filter is used vertically, it is filled with activated carbon particles, and the lower part is densely packed and the upper part is sparse, resulting in a large space and a decrease in the adsorption function as a whole.
Impurities cannot be sufficiently adsorbed / removed only by passing twice. Further, if the activated carbon is packed at a high density, the pressure loss becomes high, the gas treatment amount is reduced, and noise is easily generated, so that a filter having a high adsorption efficiency cannot be obtained.

As an attempt to reduce the pressure loss of the filter unit, there is a filter unit obtained by processing powdered activated carbon into a sheet or pleating a fibrous cloth or knit to increase the adsorption area per volume. Although disclosed, it has a drawback that it cannot be used for a long time because the activated carbon density per filter volume becomes small.

In order to enable long-term use, it is basically necessary to increase the density of the activated carbon filled in the filter unit. The activated carbon used for that purpose is preferably granular, and a filling method that reduces the ventilation resistance of the granular carbon and increases the contact area with air is required.

[0005]

In consideration of various problems of the deodorizing filter unit using the above-mentioned activated carbon,
The filter is suitable for gas treatment with low pressure loss and high air flow, but it aims to develop and provide a filter unit that can be used for a long period of time by increasing the packing density of activated carbon.

[0006]

In order to develop a deodorizing filter suitable for treating a gas with a low pressure loss and a high air flow, the present inventors have developed an activated carbon layer in which a gas in a violent turbulent state has a packing density lowered to some extent. When passing, paying attention to the fact that the contact efficiency between the gas and activated carbon is remarkably increased and the odorous gas removability is improved, so that the deodorization unit is not filled with activated carbon particles at a high density, but many activated carbon particles are present. We examined how to keep it in a state of floating in space. as a result,
Activated carbon particles are not filled into the unit as they are, but a plurality of particles are point-bonded with a binder in a state in which a space is maintained between the particles to form an aggregate. Therefore, the present invention was achieved by finding that a suitable porosity suitable for deodorization is maintained and further examining the structure of the frame for filling these polymers.

That is, it is composed of a frame having a honeycomb cross section, a net attached to the front and rear surfaces thereof, and an activated carbon particle aggregate filled in the inside thereof, and the activated carbon particles are granulated coal, crushed coal or spherical coal, A body is formed by spot-bonding a plurality of particles with a binder while maintaining a space between the particles, and when the aggregate is filled inside the cells of the honeycomb constituting the frame, the activated carbon particles have a high porosity. It is a deodorizing filter element that has low pressure loss and is retained by

Further, in the above-mentioned filter element, the binder is 10 parts by weight or more and 35 parts by weight or less with respect to 100 parts by weight of activated carbon particles, the binder is latex, a hot-melt resin or an adhesive, and a honeycomb-shaped frame The deodorizing filter element whose surface is coated with an emulsion in which activated carbon powder is dispersed is also included in the present invention.

The present invention will be described in detail below.

The deodorizing filter element of the present invention comprises a frame having a honeycomb-shaped cross section, a net attached to the front and rear surfaces of the frame, and an activated carbon particle aggregate filled inside the frame. Since the cross section of the frame is honeycomb-shaped and the net is attached to the front and back surfaces,
The inside of the element is an aggregate of cells having a large number of hexagonal cross sections. Here, the honeycomb shape in cross section is not limited to a regular hexagonal assembly, but may be a distorted hexagonal shape or a shape other than a hexagonal shape such as a triangle or a quadrangle. However, from the viewpoint of the mechanical properties of the frame and the function of uniformly distributing air, a regular hexagonal assembly is preferable.

The material of the frame is not particularly limited, but a plastic molded product is suitable from the viewpoint of moldability and economy, polyethylene or polypropylene is preferable, and the material of the net attached to the front and rear surfaces is also the same, and polyethylene or polypropylene is preferable. preferable.

The size of the cell having a hexagonal cross section is not particularly limited, and can be appropriately selected depending on the use conditions of the filter element and the size of the activated carbon particle aggregate to be filled therein.
When used in home or car air purifiers, the sides of the hexagon and the cell thickness are about 5-10 mm.
It is appropriate that the thickness of the frame is about the same. Also, the mesh of the net can be appropriately selected in consideration of the size of the activated carbon particle aggregate to be filled inside the cell, but when air is circulated, the generation of fine powder due to friction between the aggregates is prevented and the aggregate during use is aggregated. It is preferable to select so that the particles that have fallen out of the body do not leak from the net.

The honeycomb-shaped frame of the filter element of the present invention and the nets attached to the front and rear surfaces thereof can be coated on the surface with an emulsion in which activated carbon powder is dispersed. To coat the emulsion, for example, the frame and net may be dipped in the emulsion, drained, and then dried, or the emulsion may be sprayed and dried. If activated carbon powder is applied to the surface of the frame and net using the emulsion as a binder, the frame and net act as a malodorous adsorbent, and the coating of activated carbon powder causes the inner surface of the cell to become a rough surface, resulting in turbulent air flow. In addition to inducing, it has an effect of inhibiting the activated carbon particle aggregates filled inside and the inner surface of the cell from slipping and stably retaining the aggregates.

A large number of hexagonal-shaped cells constituting the deodorizing filter element of the present invention are filled with activated carbon particle aggregates. The activated carbon as a base material used here usually has a large surface area of several hundred m ² or more per 1 g, and can be widely used as long as it is a carbon material exhibiting high adsorptivity. As the raw material of the activated carbon, a charcoal such as coconut shell or wood or coal is usually used, but any may be used. Further, the activation method may be obtained by steam or carbon dioxide at a high temperature or by any method such as treatment with zinc chloride, phosphoric acid or concentrated sulfuric acid.

The shape of the activated carbon particles used in the present invention must be granulated coal, crushed coal or spherical coal.
In order to keep the gas flow rate high and maintain the deodorizing ability for a long time with low pressure loss, it is necessary to make such a shape having a large adsorption capacity. Granulated coal and spherical coal are prepared by adding 30 to 60 parts of petroleum pitch or coal tar as a binder to 100 parts of carbon material as a binder and activating after kneading and molding according to a conventional method.

Activated carbon is a peculiar material having extremely excellent adsorptivity as a non-polar adsorbent, and exhibits high adsorptivity for almost all gaseous substances. Indoor air in living spaces such as offices and homes usually has a strong cigarette odor, and compositionally contains acetaldehyde, ammonia, lower amines, hydrocarbons, hydrogen sulfide, etc., but adsorbs all of these malodorous substances. Have sex.

The activated carbon particle aggregate filled in the cell of the filter element of the present invention is formed by spot-bonding a plurality of activated carbon particles with a binder in a state in which a space is maintained between the particles. is there. While the particles of granulated coal, crushed coal or spherical coal were stirred, the binder was dropped as small droplets or sprayed with an air blow, and the small droplets were spot-bonded while maintaining a space between the particles. After that, it is obtained by drying.

The number of particles contained in the aggregate can be appropriately selected depending on the size of the particles, but about several particles are suitable. The activated carbon particles packed in one cell do not necessarily have to be made into one aggregate by point-adhesion. Usually, the filling method is easy, so a plurality of aggregates are filled. There is. The inside of the cell of the element of the present invention has a much higher porosity than in the case where the activated carbon particles are not formed into such an aggregate and are poured into the inside of the cell by a conventional method to be filled.

The increase in the porosity between the particles when the filter element of the present invention is packed with the activated carbon particle aggregate is also because the packing specific gravity is reduced to 40 to 80% when packed by the usual method. I understand. Considering the deodorizing property and the pressure loss, the filling specific gravity is preferably 60 to 70% of that in the case of the usual filling method.

The binder used when forming the aggregate from the activated carbon particles is not particularly limited, and those capable of adhering the activated carbon particles can be widely used, but when air is passed through the element, the activated carbon particle aggregate also vibrates to some extent. Therefore, in order to prevent generation of activated carbon powder due to friction between particles, a binder having some elasticity is preferable. For example, latex, hot melt resin or adhesive. In particular, since the air purifier mounted on the vehicle is constantly in a vibrating state during use, the activated carbon particles inside the cell are constantly filled with a high density. For this reason, it is preferable to use a rubber-based adhesive having high elasticity to absorb vibrations and keep the space between particles constant.

Further, the amount of the binder used in the point adhesion of the activated carbon particles is 10 parts by weight or more based on 100 parts by weight of the activated carbon,
It is preferably 35 parts by weight or less. When the amount of the binder used is more than 35 parts by weight, the adhesiveness is hardly improved, and the volume of the activated carbon aggregate is increased by the binder, which increases the air resistance,
Furthermore, since the surface of the activated carbon is covered with the binder, the tendency of a rapid increase in the decrease in the adsorption rate is recognized.
When the amount of the binder used is reduced, the surface of the activated carbon is less coated with the binder and the adsorption rate is increased, but the strength of the aggregate is reduced, and the particles may fall off.

In the filter element of the present invention, since the activated carbon aggregate is filled inside the cell having a relatively small volume, there is an advantage that the activated carbon particles can be fixed in a state where the porosity is high with a relatively small amount of the binder. .

Therefore, when the gas is circulated at a high speed, the adsorption rate is increased by the complicated turbulent flow generated inside due to the influence of the activated carbon aggregate and the wall surface inside the cell, and the activated carbon particles inside the cell are aggregated and Since it is fixed by the wall surface of the cell, fine particles due to friction between particles are hardly generated.

The method for producing the activated carbon particle aggregate to be packed in the filter element of the present invention is, for example, 1 kg of granular activated carbon having a particle size of 6 to 12 Mesh is put into a rolling granulator having a container having a diameter of 30 cm, and the rotation speed is 30 to 60 /. The SBR latex (solid content 70%) discharged by a roller pump is air-blown and sprayed as small droplets onto the activated carbon particles while rotating the container by a minute to maintain a state in which a gap is created between particles. , Particles are point-bonded to form an aggregate of a plurality of particles. After that, it is dried at 120 ° C for 30 minutes and further sieved to obtain an aggregate of 4 to 7 mesh.

When the SBR latex is sprayed while stirring the activated carbon particles, the air blow is adjusted so that the latex droplets become 0.02 to 0.03 g / drop, and one activated carbon particle should contain as many latex droplets as possible. It is preferable that the droplets do not adhere.

Next, a polyethylene mesh of 6 mesh is bonded to one side of the honeycomb frame by hot pressing or the like, and the aggregate obtained above is poured into the cells of the honeycomb from the opposite side to uniformly fill the cells. Further, a 6-mesh polyethylene net is placed on it, heated by a hot press or the like to be adhered, and the activated carbon particle aggregate is enclosed to obtain a filter element.

[0027]

The activated carbon used in the filter element of the present invention is a unique material having extremely excellent adsorptivity as a non-polar adsorbent, and exhibits high adsorptivity for almost all gaseous substances. Indoor air in living spaces such as offices and homes usually has a strong odor of cigarettes and compositionally contains acetaldehyde, ammonia, lower amines, hydrocarbons, hydrogen sulfide, etc. Show.

However, since the ratio of ammonia to the odor of tobacco is relatively high and it is difficult to completely adsorb ammonia with only activated carbon alone, for example, activated carbon is loaded with phosphoric acid or aniline or phosphoric acid and aniline. If used, these odors can be almost completely adsorbed and removed. In particular, when it is mounted on a vehicle and used, by filling these impregnated activated carbons, it is possible to remove the odor and the like of the exhaust gas of diesel vehicles that fill the road.

[0029]

EXAMPLES The present invention will be described in more detail below with reference to examples.

(Example 1) Adjustment of deodorizing filter element 1 kg of pellet type 2 mmφ activated carbon was put in a container of a rolling granulator and SBR latex (solid content 70%) was produced by a roller pump while rotating the container at 30 to 60 rpm. Was dropped to bond the particles of activated carbon to the particles to prepare an aggregate containing several particles. At this time, the latex was dropped in a droplet form, and 10 parts were used for 100 parts by weight of activated carbon. Then the dryer 1
It was dried at 20 ° C. for 30 minutes to obtain an active particle aggregate. Further, it was sieved to make the size of the aggregate uniform, and particles having a particle size of 4 to 7 mesh were obtained. The number of activated carbon particles contained in the aggregate was 2 to 5.

A 8 mesh mesh net was bonded by a hot press to the lower side of a honeycomb-shaped frame having a cross section of 6 mm on a side and having a thickness of 7 mm, and the activated carbon particle aggregate obtained above was uniformly framed. Fill the cells inside. Further, a polyethylene net similar to that on the lower side was bonded to the upper side of the frame by hot pressing to prepare a deodorizing filter element. The frame and net used had been previously coated with an emulsion in which activated carbon powder was dispersed.

The size and properties of the filter element obtained above are shown in Table 1, and the ventilation resistance measured with the filter element standing vertically is shown in Table 2.

Further, in order to show the filling state of the activated carbon particles inside the cell of the filter element, FIG. 1 is a sectional view of the cell. The cell 1 comprises a part of the frame of the filter element and the wall surface 2 of the cell, and a net 3, and the inside of the cell is filled with the activated carbon particle aggregate 6 formed by bonding the activated carbon particles 4 with the binder 5. ing.

[0034]

[Table 1]

[0035]

[Table 2]

(Comparative Examples 1 and 2) For Comparative Examples, the particles used as the raw material of the activated carbon aggregate in Example 1 were filled in the frame as it was in the same manner as in Example 1 so as to fill each cell. To produce a deodorizing filter element. (Comparative Example 1).

Further, the raw material particles of the above-mentioned aggregate were used in Example 1.
A deodorizing filter element was prepared by filling a frame with the same amount as the used amount (Comparative Example 2).

The size and properties of the filter element obtained above are shown in Table 1, and the ventilation resistance measured with the filter element standing vertically is also shown in Table 2.

Further, in order to show the filling state of activated carbon particles inside the cells of the filter elements of Comparative Examples 1 and 2, sectional views of the cells are shown in FIGS. 2 and 3, respectively.
The cell 1 is composed of a part 2 of the frame of the filter element and the wall surface of the cell 2 and a net 3, and the inside of the cell is filled with activated carbon particles 4.

As shown in FIG. 1, the inside of the cell of Example 1 was uniformly filled with activated carbon particle aggregates, but the cell of Comparative Example 2 was filled with the same amount of activated carbon particles. It can be seen that about 1/3 of the upper part of the cell is a space.

Deodorizing Test Using the filter elements of Example 1 and Comparative Examples 1 and 2 obtained as described above, the deodorizing performance was examined as follows.

A filter element having a size of 110 × 110 × 7 mm was installed at a position 4 m from the inlet side of a wind tunnel having a cross-sectional size of 110 × 110 mm and a length of 6 m, a relative humidity of 65% and a temperature of 15%.
℃, gas linear velocity 1 m / sec, flow rate 43.6 m ³ / Hr, toluene
The changes in aeration time and gas concentration at the outlet of the wind tunnel were measured using air containing 2 ppm and air containing SO ₂ 2 ppm.

The results are shown in FIGS. 1 and 2. From these figures, Example 1 has almost the same removal rate of toluene and SO _{2 in} spite of the packing density of activated carbon being lower than Comparative Example 1, and activated carbon particles are suitable as in the cell of Example 1. It can be seen that the adsorptivity is considerably enhanced when it is held with an open space. Since the pressure loss of the element of Example 1 is significantly lower than that of Comparative Example 1 according to Table 2,
It has suitable properties for deodorizing filter elements.

In Comparative Example 2, the amount of activated carbon particles packed was the same as in Example 1, but the adsorptivity was extremely low. It is considered that this is because most of the air passes through that part because there is a space above the cell of the element.

From these results, if the activated carbon particles inside the cell of the element are made to float by holding the voids between the particles in the three-dimensional space as in Example 1, the removal rate is high and the removal rate is high. It can be seen that the filter element of

[0046]

INDUSTRIAL APPLICABILITY The deodorizing filter element of the present invention is filled inside so that the void ratio between activated carbon particles is kept high, and it is suitable for gas treatment with high adsorption and low pressure loss and high air flow. There is. Therefore ammonia contained in cigarette smoke is a major malodorous living space, acetaldehyde, No _x contained in the removal and road odor of acetic acid gas, SO
It excels in removing _x , hydrocarbons and aldehydes, and is suitable for household or vehicle air purifiers.

[Brief description of drawings]

FIG. 1 shows a cross-sectional view of a cell of a deodorizing filter element of the present invention.

FIG. 2 shows a sectional view of a cell of a deodorizing filter element (Comparative Example 1).

FIG. 3 shows a sectional view of a cell of a deodorizing filter element (Comparative Example 2).

FIG. 4 shows the relationship between aeration time and toluene concentration at the outlet of the wind tunnel.

FIG. 5 shows the relationship between the ventilation time and the SO ₂ concentration at the outlet of the wind tunnel.

[Explanation of symbols]

 1 Cell of Deodorizing Filter Element 2 Frame 3 Net 4 Activated Carbon Particles 5 Binder 6 Activated Carbon Particle Aggregate 7 Example 1 8 Comparative Example 1 9 Comparative Example 2

Claims (4)

[Claims] 1. A frame having a honeycomb-shaped cross section, a net attached to the front and rear faces of the frame, and an activated carbon particle aggregate filled inside the frame. The activated carbon particles are granulated coal, crushed coal, or spherical carbon, and aggregates. A body is formed by spot-bonding a plurality of particles with a binder while maintaining a space between the particles, and when the aggregate is filled inside the cells of the honeycomb constituting the frame, the activated carbon particles have a high porosity. Deodorizing filter element with low pressure loss, which is retained by. 2. The deodorizing filter element with low pressure loss according to claim 1, wherein the binder is 10 parts by weight or more and 35 parts by weight or less with respect to 100 parts by weight of activated carbon particles. 3. The deodorizing filter element with low pressure loss according to claim 1, wherein the binder is latex, hot melt resin or adhesive. 4. A honeycomb-shaped frame, a net attached to the front and rear surfaces of the frame, and an activated carbon particle aggregate filled inside the frame, and the honeycomb-shaped frame and the net attached to the front and rear surfaces of the frame have a surface. Is coated with an emulsion in which activated carbon powder is dispersed, the activated carbon particles are granulated coal, crushed coal or spherical carbon, and the aggregate is spot-bonded with a binder in a state in which a space is maintained between the particles. A deodorizing filter element having a low pressure loss, in which activated carbon particles are held in a state of high porosity when the aggregate is filled into the cells of the honeycomb constituting the frame.