JPH0739712A - Active carbon filter - Google Patents

Abstract

PURPOSE:To make an active carbon filter small-sized, with high adsorbability and keep effectively high performance for a long time. CONSTITUTION:A particulate active carbon layer 2 and an active carbon fiber layer 3 are respectively laminated on the upstream side and the downstream side. The particulate active carbon layer 2 is constituted of a particulate active carbon with an outer surface area of smaller than 0.5m<2>/g, a specific surface area of at least 200m<2>/g and an apparent density of 0.1-1g/cc and the active carbon fiber layer 3 is constituted of an active carbon fiber with an outer surface area of at least 0.1m<2>/g a specific surface area of at least 600m<2>/g and an apparent density of at most 0.2g/cc. In addition, it is pref. that the specific surface area of the active carbon fiber is at least 1.2-fold to the specific surface area of the particulate active carbon and the apparent density thereof is smaller than 1/2-fold. It is suitable for a deodorizing apparatus of a printer using a tonner.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an activated carbon filter used for efficiently separating a target component in a fluid. This activated carbon filter mainly separates the target component by adsorption, and can be used especially for removing malodorous gas and harmful gas in the gas. Among them, it is suitable for removing a foul-smelling gas or a harmful gas discharged from an electronic image recording apparatus of a system in which a toner image is thermally fixed on a recording paper, particularly by flash emission fixing.

[0002]

2. Description of the Related Art An activated carbon filter for purifying gas will be described as an example.
Japanese Patent No. 4770 discloses a filter for removing smoke and toner dust contained in the exhaust gas of a printer that fixes a toner image on a recording paper, in which charged fibers and non-charged fibers are laminated, and particles of activated carbon are further added. An air filter in which a deodorizing layer consisting of is laminated is described. In addition, JP-A-60-16
Japanese Patent No. 1712 discloses an activated carbon fiber layer filter for purifying by passing air contaminated with cigarette smoke, floating dust, etc., for air cleaning in which an electret fiber filter layer is laminated on each of the front surface and the rear surface. The filters are listed.

[0003]

The conventional activated carbon filter is not limited to the above-mentioned example, and the main separation layer for removing the target component is composed of either granular activated carbon or fibrous activated carbon. However, granular activated carbon has a large adsorption capacity for a separated substance but a small adsorption capacity per unit time, and fibrous activated carbon has a high adsorption capacity per unit time, but has a property of breaking through in a short period of time. In order to cover these properties, conventionally, it has been dealt with by increasing the filling capacity and the number of times of replacement of activated carbon. However, recently, the number of applications in which the residual allowable amount is extremely small, as seen in the removal of malodorous components, has increased, while the opportunity to attach it to small equipment such as office equipment has increased, and the removal equipment has become more compact and long-term. There is a demand for maintenance-free products, and the above countermeasures are no longer sufficient. In particular, printers that use toner have been required to have a maintenance-free small-sized device in order to remove a bad odor generated during fixing.

The present invention has been completed as a result of research aiming at solving the problems of the prior art and providing an activated carbon filter having a small size, a high removal performance, and a high performance that lasts for a long time. Is.

[0005]

As a means for achieving the above object, the present inventor provides an activated carbon filter comprising a granular activated carbon layer on the upstream side of a treated fluid and an activated carbon fiber layer on the downstream side. . In this activated carbon filter, the granular activated carbon layer has a specific surface area of 200 m ² / g or more and an apparent density of 0.1 to 1 g / cc without an outer surface area exceeding 0.5 m ² / g. Activated carbon is applied to the activated carbon fiber layer with an outer surface area of 0.1 m ² / g or more and a specific surface area of 60.
0 m ² / g or more and an apparent density of 0.2 g / c
It is desirable to use activated carbon fibers that do not exceed c, and that the activated carbon fibers have a specific surface area of 1.2 times or more and an apparent density of less than 1/2 times that of the granular activated carbon. Further, the present invention provides an activated carbon filter in which electret fibers are laminated on the upstream side of a granular activated carbon layer. Then, it is proposed to install these activated carbon filters in the exhaust gas flow path of the printer using toner.

[0006]

Actions and Examples of Embodiments The activated carbon filter of the present invention will be specifically described with reference to examples of embodiments. The activated carbon filter of the present invention is an activated carbon filter in which at least two types of activated carbon having different characteristics are used by dividing them into respective layers, and a granular activated carbon layer is arranged on the upstream side of the treatment fluid and an activated carbon fiber layer is arranged on the downstream side. , And these are laminated. Granular activated carbon is produced by a known production method in which raw materials such as coal, wood and coconut palm are carbonized and then activated and refined.In addition to granular ones, powdered ones, crushed ones and granulated ones Things are included. On the other hand, activated carbon fibers are mainly polyacrylonitrile-based, pitch-based,
A fibrous activated carbon produced by firing and activating fibers such as phenol and cellulose.
Both are easily available in the city. Comparing the granular activated carbon and the activated carbon fiber, the granular activated carbon is generally characterized in that it has a slower adsorption rate but a larger adsorption capacity than the activated carbon fiber. Granular activated carbon has a small adsorption amount per unit time, but finally has a large adsorption amount per unit volume at equilibrium. In the activated carbon filter of the present invention, the granular activated carbon layer has a function of roughly removing the target removal component on the upstream side where the concentration is high, and the activated carbon fiber layer reliably captures the removal component whose concentration is low and small. Has the action of gathering.

The characteristics of the granular activated carbon and activated carbon fibers used in the present invention, the amount used, the ratio used, the flow velocity of the treatment fluid, etc.
It may be determined according to the type and amount of fluid to be treated, the type of substance to be adsorbed and separated, the inlet concentration, the outlet concentration, and the like. Generally, the activated carbon filter of the present invention has an outer surface area of 0.
Specific surface area of 200 m ² / without exceeding 5 m ² / g
It is preferable to use granular activated carbon having an apparent density of 0.1 to 1 g / cc, which is more than g. External surface area of 0.5m ² / g
If it exceeds, the adsorption rate will be too slow and the specific surface area will be 20
If it does not reach 0, the adsorption capacity is too small and the adsorption function does not work effectively. The activated carbon fiber has an outer surface area of 0.1
2.0m ² / g, a specific surface area of 600~3500m ² /
g, those having an apparent density not exceeding 0.2 g / cc are preferable. In the present invention, the specific surface area of the granular activated carbon and the activated carbon fiber is measured according to the BET method, and the outer surface area is a calculated value obtained by modeling and modeling the structure.

Further, the thickness of the activated carbon fiber layer with respect to the thickness of the granular activated carbon layer can be determined as an optimum value depending on the concentration of the removed component in the treatment fluid, the allowable concentration in the discharged fluid and the like. Generally, it is preferable to design so that the granular activated carbon layer and the activated carbon fiber layer break through at the same time, because the capacity of the activated carbon is used as a limit. For example, when the toner is attached to a printer using toner, the granular activated carbon layer has a thickness of 5 to 30 mm and the activated carbon fiber layer has a thickness of 5 to 30 mm.
It is good to set it to about 15 mm.

The activated carbon fiber used in the activated carbon filter of the present invention has a specific surface area of 1.2 times or more and an apparent density of less than 1/2 times that of the granular activated carbon laminated on the same activated carbon filter. Is preferred. Due to this difference, the granular activated carbon of the same volume remarkably exhibits the action of having a large adsorption capacity for the activated carbon fiber, and conversely, the activated carbon fiber can exhibit the action of having a larger adsorption rate than the granular activated carbon.

In the activated carbon filter of the present invention, if electret fibers are laminated on the upstream side of the granular activated carbon, dust adhering to the activated carbon and blocking the micropores and possibly deviating the adsorption function of the activated carbon can be preliminarily obtained. It is preferable since it has the effect of being able to be collected and removed. The electret fibers are polypropylene meltblown non-woven fabrics, spunbonded non-woven fabrics, and film split non-woven fabrics in which electric charges are semipermanently retained by electret processing, and are, for example, JP-A-54-113900 and JP-A-55. -673
No. 13, JP-A-60-168510, JP-A-60-1
It is a fibrous dielectric material having a known charging property described in Japanese Patent No. 68511 and JP-A No. 61-46215.
Electret fibers are easily available in the city (for example, "Tremicron" (registered trademark): manufactured by Toray Industries, Inc.). Further, a lath plate for securing a passage for fluid, a partition plate for filling granular activated carbon, a filter for separating solid matter, and the like can be laminated as required.

Next, a specific shape of the activated carbon filter of the present invention will be described. The activated carbon filter of the present invention is not particularly limited in shape as long as the fluid to be treated is arranged so as to contact the granular activated carbon layer and the activated carbon fiber layer in this order for a predetermined time. If desired, the fluid to be treated is shaped to pass through the electret fiber layer before contacting the granular activated carbon. Examples of the shape include a concentric cylindrical laminated body of these two or three layers and a planar plate-shaped laminated body. The form of stacking both layers is
It is not a requirement that both layers are in close contact with each other, and it is free to insert a partition, an intermediate layer, or a catalyst layer for decomposing the components to be removed.

[0012] Examples of embodiments of the activated carbon filter of the present invention,
A description will be given with reference to the drawings. FIG. 1 is an axial sectional view of an activated carbon filter of the present invention configured by laminating three layers of an electret fiber layer 1, a granular activated carbon layer 2 and an activated carbon fiber layer 3 in a concentric cylindrical shape, and FIG. It is an AA '(diameter direction) sectional view. In this activated carbon filter, the fluid to be treated that has flowed in from the inlet 4 passes through the flow path 6 between the outer cylinder 5 and the electret fiber layer 1, and the electret fiber layer 1, the presser wire mesh 7, the granular activated carbon layer 2, the activated carbon layer. A path from the fiber layer 3 and the supporting wire mesh 8 to the outlet 9 is a fluid passage. 1
0 is an end plate.

FIG. 3 is a schematic explanatory view showing an example in which the activated carbon filter of the present invention is attached to a printer using toner. The gas generated from the flash fixing device 21 contains a decomposed product of an organic component in the toner, for example, a malodorous component such as an amine modified product. The gas containing the malodorous component is sucked into the activated carbon filter 24 of the present invention in which the granular activated carbon layer and the activated carbon fiber layer are laminated by the blower 22 attached to the latter stage of the filter, through the intake duct 23.
The malodorous component in the exhaust gas is adsorbed and removed by the activated carbon filter 24, passes through the exhaust duct 25, and the purified air is released into the atmosphere. Reference numeral 26 is a photosensitive drum, and 27 is a recording paper.

Using the activated carbon filter of the present invention, gas,
It can handle either liquids or mixtures of these,
It is suitable for removing malodorous components and toxic substances from gases, especially gases containing malodorous components and toxic substances.

[0015]

EXAMPLES Next, a performance evaluation test of the activated carbon filter of the present invention was carried out in comparison with a conventional activated carbon filter, and the result was obtained by mounting and using the toner for deodorizing the exhaust of the printer. Will be described.

Example 1 A cylinder having a diameter of 15 mm and a length of 88 mm has a particle size of 24 to 42.
3.49 g of mesh granular activated carbon (GW24 / 42: manufactured by Kuraray Chemical Co., Ltd.) was packed in a thickness of 44 mm, and 0.93 g of activated carbon fiber (FR-15: manufactured by Kuraray Chemical Co., Ltd.) was packed in a thickness of 44 mm. The activated carbon filter of the present invention was used. This filter was compared to a filter in which a cylinder of the same size was filled with 6.98 g of the above-mentioned granular activated carbon to a thickness of 88 mm, and similarly the above-mentioned activated carbon fiber was filled to a volume of 1.89 g and a thickness of 88 mm. The outer surface area of this granular activated carbon is 0.01 m
² / g, the specific surface area was 1100 m ² / g, and the apparent density was 0.45 g / cc. The outer surface area of the activated carbon fiber is 0.56 m ² / g, the specific surface area is 1600 m ² / g,
The apparent density was 0.12 g / cc. 2700p
Air containing pm of benzene was used as process gas, and the temperature of 25 ° C was applied to each of the above-mentioned activated carbon filters.
An accelerated breakthrough test was carried out by passing it at 0 cc / min, that is, a linear velocity of 0.17 m / sec. The benzene concentration in the treated gas before and after passing through activated carbon was measured by gas chromatography, and the measurement results are shown in FIG. 3 with the outlet concentration / inlet concentration as the vertical axis and the treatment time as the horizontal axis. The permissible concentration ratio was 0.4, and the time until reaching this value was defined as the filter life.

As is apparent from FIG. 3, the life of the activated carbon filter of the present invention is about 1.25 times that of the filter using only the granular activated carbon and about 1.5 times that of the filter using only the activated carbon fiber. Was extended to.

Example 2 Outermost diameter 130 mm, innermost diameter 60 mm, height 430 m
In the cylinder of m, the same granular activated carbon used in Example 1 was concentrically formed in the outer layer, and the same fibrous activated carbon used in Example 1 was laminated in the inner layer in layers, the former being upstream, The activated carbon filter of the present invention was manufactured by arranging the latter so as to be located downstream. The granular activated carbon used was about 3500 cc, and the fibrous activated carbon was about 950 cc. Attach this activated carbon filter for deodorizing the exhaust of the printer using toner,
The exhaust was deodorized, and the life until the allowable odor intensity was exceeded was measured (measurement sensor: XP-239: Shin Cosmo Electric Co., Ltd.).
Made). Exhaust air is 25m thick from the outside of the filter.
m of granular activated carbon layer, and then 10 mm thick fibrous activated carbon layer. The displacement of the printer is 1.
The exhaust linear velocity at the central portion in the thickness direction of the activated carbon layer was 5 m ³ / min and 0.19 m / sec.

Then, under the same conditions, the same fibrous activated carbon as described above was filled in all of the above-mentioned activated carbon layers, and a deodorizing test was conducted. Further, similarly, granular activated carbon was filled and a deodorizing test was conducted.

The life of the activated carbon filter of the present invention is about 2.5 as compared with the activated carbon filter using only fibrous activated carbon.
It was double. Further, the activated carbon filter using granular activated carbon could not keep the odor below the allowable limit.

[0021]

Since the activated carbon filter of the present invention has at least two layers of the granular activated carbon layer on the upstream side and the activated carbon fiber layer on the downstream side, the removal component contained in the treatment fluid is
First, it is coarsely removed with a granular activated carbon layer, and then with an activated carbon fiber layer to an allowable concentration. By adopting a combination according to the conditions of the processing fluid, both layers can exert their performance to the limit, so that even if the size is small, high removal performance is maintained for a long time and the filter life is extended. Also,
By stacking the electret fiber layer on the upstream side of the granular activated carbon layer, fine dust such as toner and tars are removed from the processing fluid, so that adverse effects of these substances on the activated carbon layer are avoided, and the above-mentioned effect is obtained. Is not compromised. Since the activated carbon filter of the present invention is small and has a long life,
It is suitable for mounting on a printer or the like that uses toner in order to remove a malodorous component. In addition to this, it can be used for ordinary air purifiers, kitchen air conditioners, etc., and can also be used for removing the musty odor of tap water.

[Brief description of drawings]

FIG. 1 is an axial sectional view of an activated carbon filter of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ (diameter direction) of FIG.

FIG. 3 is a schematic explanatory view showing an example of a printer using the toner of the present invention.

FIG. 4 shows results of accelerated breakthrough tests of Examples and Comparative Examples.

[Explanation of symbols]

1: Electret fiber layer 2: Granular activated carbon layer 3: Activated carbon fiber layer 4: Processing fluid inlet 5: Outer cylinder
6: Flow path 7: Presser wire mesh 8: Support wire mesh 9: Processing fluid outlet
10: End plate 21: Flash fixing device 22: Blower 23:
Intake duct 24: Activated carbon filter 25: Exhaust duct 26:
Photosensitive drum 27: recording paper

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[Procedure amendment]

[Submission date] August 27, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

FIG. 3 is a schematic view showing an example in which the activated carbon filter of the present invention is attached to a printer using toner.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (4)

[Claims] 1. An activated carbon filter comprising a granular activated carbon layer on the upstream side of a treatment fluid and an activated carbon fiber layer on the downstream side. 2. The granular activated carbon layer has an outer surface area of 0.5 m ² /
without exceeding the g, the specific surface area is not more 200 meters ² / g or more, the granular activated carbon in the density of apparent 0.1 to 1 g / cc, the activated carbon fiber layer, the outer surface area of 0.1 m ² /
g or more, the specific surface area is 600 m ² / g or more, and it is composed of activated carbon fibers having an apparent density of not more than 0.2 g / cc, and the activated carbon fibers have a specific surface area of 1 relative to granular activated carbon. The activated carbon filter according to claim 1, wherein the activated carbon filter has a size of 2 times or more and an apparent density of less than 1/2. 3. The electret fiber is laminated further upstream of the granular activated carbon layer.
Or the activated carbon filter described in 2. 4. The toner according to claim 1, wherein the toner is attached to an exhaust gas flow path of the printer.
Activated carbon filter described in.