JP2019152208A - Holding material for gas treatment device - Google Patents

Abstract

To provide a holding material for gas treatment device of which the holding power is effectively maintained, a gas treatment device and a manufacturing method thereof.SOLUTION: A gas treatment device comprises a treatment structure and a casing accommodating the treatment structure, and a holding material for gas treatment device consists of inorganic fibers disposed between the treatment structure and the casing. In a test of repeating a cycle that the holding material is compressed until its bulk density becomes a predetermined compression-time bulk density, maintained for 10 seconds and the holding material is then opened until its bulk density becomes an open-time bulk density that is smaller than the compression-time bulk density by 12%, the holding material for gas treatment device is characterized in that an open-time bearing of the holding material at a time point when the cycle is repeated 2500 times and the compression-time bulk density satisfies the following relationship. P≥17.10×D-1.62 (P represents the open-time bearing (N/cm) and D represents the compression-time bulk density (g/cm)).SELECTED DRAWING: Figure 3

Description

  The present invention relates to a holding material for a gas processing device, a gas processing device, and a method for manufacturing the same, and more particularly to maintenance of holding power of the holding material.

  A vehicle such as an automobile is provided with a catalytic converter for removing harmful substances such as carbon monoxide, hydrocarbons, and nitrogen oxides contained in exhaust gas. Conventionally, the catalytic converter includes, for example, a catalyst carrier, a metal casing that houses the catalyst carrier, and a mat-like inorganic fiber holding material disposed between the catalyst carrier and the casing. (For example, Patent Document 1).

JP 2007-218221 A

However, conventionally, in the use of a catalytic converter in which heating and cooling are repeated, there has been a problem that the holding power of the holding material decreases with time.
This invention was made in view of the said subject, Comprising: One of the objectives is to provide the holding | maintenance material for gas processing apparatuses, a gas processing apparatus, and its manufacturing method by which holding force is maintained effectively. To do.

In order to solve the above-described problems, a holding member for a gas processing apparatus according to an embodiment of the present invention is as follows.
1. In a gas processing apparatus including a processing structure and a casing that accommodates the processing structure, a holding material made of inorganic fibers disposed between the processing structure and the casing,
The holding material is compressed for 10 seconds until the bulk density reaches a predetermined compression bulk density, and then the holding material has an open bulk density that is 12% smaller than the compression bulk density. In the test of repeating the cycle of releasing until the pressure is reached, the surface pressure at the time of opening of the holding material and the bulk density at the time of compression when the cycle is repeated 2500 times satisfy the following relationship: Retaining material.
P ≧ 17.10 × D−1.62
(P represents the surface pressure at opening (N / cm ² ), and D represents the bulk density at compression (g / cm ³ ).)
2. The holding material for a gas processing device according to 1, wherein the inorganic fibers are alumina fibers composed of 70 wt% to 75 wt% alumina and 30 wt% to 25 wt% silica.
3. The true density of the inorganic fiber is 3.02 g / cm ^{3 to} 3.50 g / cm ³ .
4). The holding | maintenance material for gas processing apparatuses in any one of 1 thru | or 3 characterized by the ratio with respect to the theoretical value of the true density of the said inorganic fiber being 86.9% or more.
5. The holding material for a gas processing apparatus according to any one of 1 to 4, wherein the holding material is a holding material manufactured by a wet method or a dry method.
6). The holding material for a gas processing device according to any one of 1 to 5, wherein the holding material has a wet volume of 750 mL / 5 g or more.
7). A processing structure;
A casing for housing the processing structure;
The holding material according to any one of 1 to 6 disposed between the processing structure and the casing;
A gas treatment device comprising:
8). A processing structure;
A casing for housing the processing structure;
A holding member disposed between the processing structure and the casing;
A method of manufacturing a gas treatment device comprising:
A method for manufacturing a gas processing apparatus, comprising: arranging the holding material according to any one of 1 to 6 between the processing structure and the casing.

  ADVANTAGE OF THE INVENTION According to this invention, the holding | maintenance material for gas processing apparatuses, gas processing apparatus, and its manufacturing method in which holding force is maintained effectively can be provided.

It is explanatory drawing which shows an example of the gas processing apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the cross section which cut | disconnected the gas processing apparatus which concerns on one Embodiment of this invention in the gas distribution direction. It is explanatory drawing which shows the surface pressure at the time of the open after the repeated compression test which the holding material which concerns on one Embodiment of this invention shows. It is explanatory drawing which shows the test apparatus used in the Example which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the result of having measured the surface pressure at the time of the opening | release after repeated compression of the holding material in the Example which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the result of having measured the initial surface pressure of the holding material in the Example which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described. Note that the present invention is not limited to this embodiment.

  FIG. 1 is an explanatory diagram illustrating an example of a gas processing apparatus 1 according to the present embodiment. As shown in FIG. 1, the gas processing apparatus 1 includes a processing structure 20, a casing 30 that houses the processing structure 20, and a holding material 10 that is disposed between the processing structure 20 and the casing 30. And. In FIG. 1, for convenience of explanation, a part of the casing 30 is omitted, and the processing structure 20 and the holding material 10 housed in the casing 30 are exposed.

  FIG. 2 is an explanatory diagram showing an example of a cross section of the gas treatment device 1 cut in the direction indicated by the arrow X. The direction indicated by the arrow X is the direction (gas flow direction) in which the gas to be processed flows through the processing structure 20 of the gas processing apparatus 1.

  The gas processing apparatus 1 is used for processing gas such as gas purification. That is, the gas processing apparatus 1 is used, for example, to remove harmful substances and / or particles contained in the gas.

  Specifically, the gas processing apparatus 1 is, for example, an exhaust gas processing apparatus that purifies exhaust gas. In this case, the gas processing apparatus 1 is provided to remove harmful substances and / or particles contained in exhaust gas discharged from an internal combustion engine (gasoline engine, diesel engine, etc.) in a vehicle such as an automobile.

  That is, the gas processing apparatus 1 is a catalytic converter that is used, for example, to remove harmful substances contained in the exhaust gas of a gasoline engine. The gas processing apparatus 1 is, for example, a DPF (Diesel Particulate Filter) used to remove particles contained in the exhaust gas of a deal engine.

  In the gas processing method using the gas processing apparatus 1, the gas is processed by circulating the gas to be processed inside the processing structure 20 of the gas processing apparatus 1. That is, in the gas processing apparatus 1 shown in FIGS. 1 and 2, a gas such as exhaust gas flows from one end of the casing 30 in the direction indicated by the arrow X, and the gas circulates inside the processing structure 20. The gas purified and purified in the middle flows out of the gas processing apparatus 1 from the other end of the casing 30.

  In addition, at one end and the other end of the gas processing apparatus 1 arranged in a vehicle such as an automobile, a pipe for guiding a gas such as exhaust gas from the upstream side to the gas processing apparatus 1 and the purified gas are processed by the gas processing. Pipes leading from the apparatus 1 to the downstream side are connected to each other.

  The processing structure 20 is a structure having a function of processing a gas. That is, when the gas processing apparatus 1 is a catalytic converter, the processing structure 20 is a catalyst carrier having a catalyst for purifying gas and a carrier for supporting the catalyst. The catalyst is a catalyst for removing harmful substances (carbon monoxide, hydrocarbons, nitrogen oxides, etc.) contained in a gas such as exhaust gas. More specifically, the catalyst is, for example, a metal catalyst such as a noble metal catalyst. The carrier for supporting the catalyst is, for example, a cylindrical molded body (for example, a cylindrical honeycomb-shaped molded body) made of an inorganic material made of ceramics (cordierite or the like).

  Moreover, when the gas processing apparatus 1 is an apparatus for removing particles contained in a gas such as DPF, the processing structure 20 is a structure having a filter for capturing the particles in the gas. . In this case, the processing structure 20 may further include a catalyst or may not include a catalyst.

  The casing 30 is a cylindrical body in which a space capable of accommodating the processing structure 20 is formed. The casing 30 is made of metal, for example. Although the metal which comprises the casing 30 is not specifically limited, For example, it selects from the group which consists of stainless steel, iron, and aluminum.

  The casing 30 may be divided into a plurality of parts, or may be an integral type that is not separable. In the present embodiment, the casing 30 is an integral cylindrical body that is not divided.

  The holding material 10 is used to hold the processing structure 20 in the casing 30. That is, the holding member 10 is disposed in a compressed state in the gap between the processing structure 20 and the casing 30, thereby stably holding the processing structure 20 in the casing 30.

  The holding material 10 has a function of safely holding the processing structure 20 in the casing 30 so as to avoid the processing structure 20 from colliding with the casing 30 and being damaged by vibration or the like in the gas processing apparatus 1. And a function of sealing the gap so that gas that has not yet been purified does not leak downstream from the gap between the processing structure 20 and the casing 30 is required. Moreover, when high temperature (for example, 200-900 degreeC) gas, such as exhaust gas, distribute | circulates in the gas processing apparatus 1, the holding | maintenance material 10 is requested | required to provide heat resistance and heat insulation.

  For this reason, the holding material 10 is a molded body made of inorganic fibers. That is, the holding material 10 contains an inorganic fiber as a main component. Specifically, the holding material 10 includes, for example, 90% by weight or more of inorganic fibers.

  The inorganic fiber constituting the holding material 10 is preferably an inorganic fiber that is not deteriorated or hardly deteriorates in use of the gas treatment device 1, and is composed of 70% by weight to 75% by weight alumina and 30% by weight to 25% by weight silica. Fibers can be used. Preferably, the fiber is composed of 72 wt% to 74 wt% alumina and 28 wt% to 26 wt% silica. Polycrystalline fibers may be used.

The inorganic fiber is, for example, compressed and maintained for 10 seconds until the bulk density of the inorganic fiber holding material 10 becomes 0.5 (g / cm ³ ) when compressed. In the test of repeating the cycle of releasing until the density becomes 0.44 (g / cm ³ ) when the density is 12% smaller than the bulk density at the time of compression, the holding material 10 is released when the cycle is repeated 1000 times. It is preferable that the inorganic fiber has an hourly surface pressure of 8.5 (N / cm ² ) or more. In this case, the holding material 10 may be manufactured by a wet method described later.

Inorganic fibers which can be used in the holding material of the present invention is desirably a true density is high, it is 3.02 g / cm ³ or more, or 3.03 g / cm ³ or more. The upper limit is not limited, 3.50 g / cm ³ or less, 3.30 g / cm ³ or less, 3.10 g / cm ³ or less, 3.08 g / cm ³ or less, 3.07 g / cm ³ or less, or 3.0 It may be 6 g / cm ³ or less.

The true density is preferably 86.9% or more of the theoretical value, more preferably 87.0% or more, or 87.1% or more. The upper limit is not limited, but may be 88.2% or less, 88.0% or less, or 87.9 or less.
When the true density is close to the theoretical value, it means that there are few voids contained in the fiber. The amount of pores can be reduced by changing the firing conditions. The theoretical value of the true density is obtained from the density of each component and its composition ratio when the inorganic fiber is composed of two or more components. Specifically, when the inorganic fiber is made of alumina and silica, the following formula is used.
Theoretical value of true density = (alumina density) x (alumina composition ratio) + (silica density) x (silica composition ratio)

  The holding material 10 may include a binder in addition to the inorganic fibers. The binder is not particularly limited, and an organic binder and / or an inorganic binder is used. That is, for example, the holding material 10 is made of inorganic fibers and may include an organic binder.

  In the holding material, the total of the inorganic fibers and the binder as an optional component can be 95% by weight or more, 98% by weight or more, or 99% by weight or more. Moreover, an inevitable impurity may be included and it is good also as 100 weight%.

  The shape of the holding material 10 is not particularly limited as long as the processing structure 20 can be held in the casing 30. That is, the holding material 10 may be, for example, a plate-like body (film, sheet, blanket, mat, etc.) or a cylindrical body.

  When the holding material 10 is a plate-like body, one end and the other end of the holding material 10 may be formed in a corresponding shape that can be fitted. That is, in the example shown in FIG. 1, one end and the other end of the plate-shaped holding material 10 are respectively formed in a corresponding convex shape and concave shape, and the holding material 10 is wound around the outer peripheral surface of the processing structure 20. In the state, the one end and the other end are fitted.

  Although the method for manufacturing the holding material 10 is not particularly limited, the holding material 10 may be a holding material manufactured by a wet method or a dry method. In the wet method, for example, first, inorganic fibers for forming the holding material 10 and an organic binder (for example, rubber, water-soluble organic polymer compound, thermoplastic resin) in a dehydrating mold having a predetermined shape. And an aqueous slurry containing a thermosetting resin or the like. Next, by performing dehydration molding, an inorganic fiber molded body (wet molded body) having a shape corresponding to the shape of the mold is obtained. Thereafter, the wet molded body is compressed so that the properties such as the bulk density are in a desired range and dried, whereby the holding material 10 which is finally a molded body made of inorganic fibers is obtained.

  Moreover, the holding material 10 is good also as being obtained by baking the molded object after the above-mentioned drying. In this case, the firing temperature is not particularly limited. For example, the firing temperature may be a temperature at which the organic binder contained in the dried molded body disappears.

  Specifically, the firing temperature may be, for example, 300 ° C. or higher, or 500 ° C. or higher. Although the upper limit of the firing temperature is not particularly limited, the firing temperature may be, for example, 900 ° C. or less.

  In the dry method, for example, the holding material 10 that is a molded body made of the inorganic fibers is obtained by needling the collected inorganic fibers. That is, the holding material 10 manufactured by the dry method may be a so-called needle mat.

One characteristic of the present invention is that the holding material 10 is compressed for 10 seconds until the bulk density reaches a predetermined compression bulk density, and then the holding material 10 is moved to its bulk. In a test that repeats the cycle of opening until the density reaches an open bulk density that is 12% smaller than the compressed bulk density (open bulk density that is 0.88 times the compressed bulk density), the cycle is repeated 2500 times. The surface pressure at the time of opening of the holding material 10 and the bulk density at the time of compression satisfy the following relationship: P ≧ 17.10 × D−1.62 (However, in this relationship, P is The surface pressure at the time of opening (N / cm ² ) is represented, and D represents the bulk density at the time of compression (g / cm ³ ).
The predetermined bulk density during compression can be 0.30 g / cm ³ , 0.40 g / cm ³ and / or 0.50 g / cm ³ .

FIG. 3 is an explanatory view showing the relationship between the bulk density during compression and the surface pressure during opening. In FIG. 3, the horizontal axis indicates the bulk density (g / cm ³ ) when the holding material is compressed, and the vertical axis indicates the surface pressure (N / cm ² ) at the time of opening after 2500 repetition compressions. The black triangle marks indicate the contact pressure at the time of opening after the holding material 10 is repeatedly compressed 2500 times in Example 1 described later.

In FIG. 3, a broken line L0 is a straight line obtained by linearly approximating three actually measured values indicated by black triangles. This broken line L0 is expressed as follows when the bulk density during compression is represented by D (g / cm ³ ) and the surface pressure at the time of release after repeated compression 2500 times is represented by P (N / cm ² ): P = 22.42 * D-2.31. Similarly, in FIG. 3, the solid line L1 is expressed as follows: P = 17.10 × D−1.62.

That is, the surface pressure P (N / cm ² ) when the holding material 10 satisfying the above-described relationship (P ≧ 17.10 × D−1.62) after being repeatedly compressed 2500 times is represented by the solid line L1 in FIG. It will be plotted in the area above the solid line L1.

Moreover, in the said repeated compression test, the surface pressure P (N / cm < ² >) at the time of opening after the 2500 compression of the holding material 10 and the bulk density D (g / cm < ³ >) at the time of compression have the following relationship, for example. It may be satisfied: P ≧ 19.54 × D−1.85. A straight line (P = 19.54 × D−1.85) relating to this relationship is plotted between the broken line L0 and the solid line L1 in FIG.

Moreover, in the said repeated compression test, the surface pressure P (N / cm < ² >) at the time of opening after the 2500 compression of the holding material 10 and the bulk density D (g / cm < ³ >) at the time of compression have the following relationship, for example. It may be satisfied: P ≧ 21.98 × D−2.08. Note that a straight line (P = 21.98 × D−2.08) relating to this relationship is between the broken line L0 and the straight line (P = 19.54 × D−1.85) in the previous paragraph in FIG. Is plotted in

Moreover, in the said repeated compression test, the surface pressure P (N / cm < ² >) at the time of opening after the 2500 compression of the holding | maintenance material 10 and the bulk density D (g / cm < ³ >) at the time of compression are the following two, for example The relationship may be satisfied: P ≧ 17.10 × D−1.62 and P ≦ 31.75 × D−3.00. In FIG. 3, the solid line L2 is expressed as follows: P = 31.75 × D−3.00. In FIG. 3, the solid line L2 is illustrated symmetrically with the solid line L1 with respect to the broken line L0.

Moreover, in the said repeated compression test, the surface pressure P (N / cm < ² >) at the time of opening after the 2500 compression of the holding | maintenance material 10 and the bulk density D (g / cm < ³ >) at the time of compression are the following two, for example The relationship may be satisfied: P ≧ 19.54 × D−1.85 and P ≦ 29.31 × D-2.77. The straight line related to the latter relationship (P = 29.31 × D-2.77) is a straight line related to the former relationship (P = 19.54 × D−1.85) with respect to the broken line L0 in FIG. And is shown symmetrically.

Moreover, in the said repeated compression test, the surface pressure P (N / cm < ² >) at the time of opening after the 2500 compression of the holding | maintenance material 10 and the bulk density D (g / cm < ³ >) at the time of compression are the following two, for example The relationship may be satisfied: P ≧ 21.98 × D−2.08 and P ≦ 26.86 × D−2.54. The straight line related to the latter relationship (P = 26.86 × D−2.54) is the straight line related to the former relationship (P = 21.98 × D−2.08) with respect to the broken line L0 in FIG. And is shown symmetrically.

Moreover, in the relationship between the surface pressure P (N / cm ² ) at the time of opening after the above-described holding material 10 is repeatedly compressed 2500 times and the bulk density D (g / cm ³ ) at the time of compression, the bulk density D at the time of compression is For example, it may be 0.25 g / cm ³ or more and 0.55 g / cm ³ or less, may be 0.30 g / cm ³ or more and 0.55 g / cm ³ or less, and may be 0.30 g / cm ^3. cm ³ or more, it may be at 0.50 g / cm ³ or less.

Further, when the holding material 10, which is evaluated as an initial surface pressure in the examples described later, is compressed until the bulk density reaches a predetermined compression bulk density, the surface pressure indicated by the holding material 10 is, for example, When the bulk density during compression is 0.30 g / cm ³ , it is 21 N / cm ² or more, and when the bulk density during compression is 0.35 g / cm ³ , it is 33 N / cm ² or more. If the bulk density is 0.40 g / cm ³ is at 46N / cm ² or more, when compressed at a bulk density of 0.45 g / cm ³ is at 60N / cm ² or more, during compression bulk density When 0.5 is 0.50 g / cm ³ , it may be 73 N / cm ² or more.

The initial surface pressure of the holding material 10 is, for example, 22 N / cm ² or more when the bulk density at compression is 0.30 g / cm ³ , and the bulk density at compression is 0.35 g / cm ³ . In some cases, it is 36 N / cm ² or more, and when the compression bulk density is 0.40 g / cm ³ , it is 53 N / cm ² or more, and when the compression bulk density is 0.45 g / cm ³ in is at 70N / cm ² or more, it is also possible when compressed during bulk density of 0.50 g / cm ³ is 86N / cm ² or more.

In any of the cases described above, the initial surface pressure of the holding material 10 is, for example, 30 N / cm ² or less when the compression bulk density is 0.30 g / cm ³ , and the compression bulk density is When it is 0.35 g / cm ³ , it is 50 N / cm ² or less, and when it is 0.40 g / cm ³ , it is 80 N / cm ² or less. When it is 45 g / cm ³ , it is 110 N / cm ² or less, and when the bulk density upon compression is 0.50 g / cm ³ , it may be 150 N / cm ² or less.

  The wet volume of the holding material 10 is not particularly limited, but may be, for example, 750 mL / 5 g or more, may be 800 mL / 5 g or more, or may be 850 mL / 5 g or more. 900 mL / 5 g or more, or 950 mL / 5 g or more.

  Furthermore, the wet volume of the holding material 10 may be, for example, 1000 mL / 5 g or more, preferably 1050 mL / 5 g or more, and more preferably 1100 mL / 5 g or more.

As described above, the holding material 10 according to the present embodiment can maintain the high holding force even after repeated compression. For this reason, for example, the holding material 10 can be effectively reduced in weight. That is, for example, by reducing the width of the holding material 10 (the length of the gas treatment device 1 in the gas treatment direction) and / or the basis weight (g / m ² ) as compared with the conventional product, the weight is reduced. Can do.

  Specifically, for example, the ratio of the area of the inner surface 11 of the holding material 10 to the area of the outer surface 21 of the processing structure 20 may be 80% or less, or 70% or less. It may be 60% or less.

  In these cases, the lower limit of the ratio of the area of the inner surface 11 of the holding material 10 to the area of the outer surface 21 of the processing structure 20 is within a range in which the holding material 10 plays a desired role in the gas processing apparatus 1. Although not particularly limited, for example, it may be 40% or more.

  The gas processing apparatus 1 includes a processing structure 20, a casing 30 that houses the processing structure 20, and the above-described holding material 10 that is disposed between the processing structure 20 and the casing 30. .

  As described above, the holding material 10 can maintain a high holding force even after repeated compression. Therefore, in the gas processing apparatus 1 including the holding material 10, the holding force of the holding material 10 can be effectively maintained in long-term use with heating and cooling.

  Further, as described above, when the weight of the holding material 10 is reduced by reducing the width of the holding material 10 (the length of the gas processing device 1 in the gas processing direction), for example, the processing structure 20 The ratio of the area of the portion of the outer surface 21 covered with the holding material 10 to the area of the outer surface 21 may be 80% or less, 70% or less, and 60%. It may be the following. Further, the ratio of the area of the portion of the outer surface 21 covered with the holding material 10 to the area of the outer surface 21 of the processing structure 20 may be 40% or more, for example.

  The gas processing apparatus 1 is manufactured by a method including disposing the holding material 10 described above between the processing structure 20 and the casing 30. That is, when the casing 30 is an integral type that is not divided, for example, the holding material 10 is first wound around the outer surface 21 of the processing structure 20, and then the processing structure 20 covered with the holding material 10 is wound. The gas processing apparatus 1 is assembled by inserting it into the casing 30 (so-called stuffing method).

  Further, when the casing 30 can be divided, first, the holding material 10 is wound around the outer surface 21 of the processing structure 20, and then the processing structure 20 covered with the holding material 10 is divided. It sandwiches between a part of the casing 30 and another part, and then the part of the casing 30 and the other part are integrated (so-called clamshell method). This integration is performed, for example, by using a fastening member such as a bolt and a nut and / or welding.

  In the gas processing apparatus 1, as shown in FIGS. 1 and 2, the inner surface 11 of the holding material 10 is in contact with the outer surface 21 of the processing structure 20, and the outer surface 12 of the holding material 10 is In contact with the inner surface 31. Further, in the gas processing apparatus 1, the holding material 10 is disposed between the processing structure 20 and the casing 30 in a compressed state than before being disposed between the processing structure 20 and the casing 30. Is done.

Next, specific examples according to the present embodiment will be described.
Example 1
A holding material 10 made of inorganic fibers was produced by a wet method (dehydration molding method). That is, first, an aqueous slurry was prepared by dispersing 100 parts by mass of inorganic fibers and 3 parts by mass of an organic binder (acrylic resin) in water.
This inorganic fiber was an alumina fiber composed of 73.0% by weight of Al ₂ O ₃ and 27.0% by weight of SiO ₂ , and the measured value of true density was 3.06 g / cm ³ . The measured value of the true density was 87.9% of the theoretical value (3.48 g / cm ³ ).

  Next, the wet slurry was obtained by pouring an aqueous slurry into a dewatering mold having a wire net and performing dewatering molding. Further, the entire wet molded body was dried at 105 ° C. while being compressed so that the thickness thereof was uniform, thereby obtaining a molded body.

The formed body is processed into a disk shape, heated at 700 ° C. for 1 hour and fired to form a disk shape having a diameter of 50.8 mm and a thickness of 10.0 mm, and a bulk density of 0.15 g / An inorganic fiber mat of cm ³ was obtained as the holding material according to Example 1.

Example 2
Examples are as follows, except that the inorganic fiber is composed of 73.0% by weight of Al ₂ O ₃ and 27.0% by weight of SiO ₂ and the true density is 3.03 g / cm ^3. A holding material was produced in the same manner as in Example 1. The measured value of true density of this inorganic fiber was 87.1% of the theoretical value (3.48 g / cm ³ ).

Comparative Example 1
Examples were used except that the inorganic fiber was composed of 96.0% by weight of Al ₂ O ₃ and 4.0% by weight of SiO ₂ and had a measured true density of 3.23 g / cm ^3. A holding material was produced in the same manner as in Example 1. The measured value of true density of this inorganic fiber was 83.2% of the theoretical value (3.88 g / cm ³ ).

Comparative Example 2
Examples are as follows, except that the inorganic fiber is composed of 80.0% by weight of Al ₂ O ₃ and 20.0% by weight of SiO ₂ and has a true density measurement value of 3.07 g / cm ^3. A holding material was produced in the same manner as in Example 1. The measured value of true density of this inorganic fiber was 85.3% of the theoretical value (3.60 g / cm ³ ).

Evaluation Example 1 [Measurement of surface pressure after repeated compression]
Using the test apparatus 40 shown in FIG. 4, the holding material was repeatedly compressed and the surface pressure of the holding material was measured. The test apparatus 40 includes a first jig 41 (a member corresponding to a processing structure such as a catalyst carrier) that is an Inconel (registered trademark) disk (diameter 100 mm, thickness 30 mm), and the first jig 41. And a second jig 42 (a member corresponding to the casing) which is a disk made of Inconel (registered trademark) (diameter: 100 mm, thickness: 30 mm).

  In this test apparatus 40, the holding material manufactured as described above is separated by the distance between the first jig 41 and the second jig 42 (that is, the first jig 41 and the second jig 42). The thickness of the holding material sandwiched between the first jig 41 and the second jig 42 is 10 mm.

  Then, with the holding material sandwiched between the first jig 41 and the second jig, the distance between the first jig 41 and the second jig 42 is repeatedly reduced and increased, so that the holding material is removed. The test of repeated compression and release was started.

That is, first, by reducing the distance between the first jig 41 and the second jig 42 at a speed of 10 mm / min, the holding material has a predetermined bulk density (0.30 g / cm when compressed). ³ , 0.40 g / cm ³ or 0.50 g / cm ³ ). Subsequently, the holding material was maintained for 10 seconds in a compressed state (a state in which the bulk density of the holding material was maintained at the compression bulk density).

Thereafter, by increasing the distance between the first jig 41 and the second jig 42 at a speed of 10 mm / min, the holding material has an open bulk density (12% smaller than the compressed bulk density). Opened bulk densities 0.27 g / cm ³ , 0.36 g / cm ³ and 0.44 g corresponding to the above compressed bulk densities 0.30 g / cm ³ , 0.40 g / cm ³ and 0.50 g / cm ³ , respectively. / Cm ³ ) until the speed reached 10 mm / min. Further, this cycle of compression and release was repeated 2500 times.

And the surface pressure at the time of open | release at the time of repeating the said cycle 2500 times was measured. That is, at the time when the 2500th cycle is completed, the first curing is started from the holding material in the open state sandwiched between the first jig 41 and the second jig (the holding material whose bulk density is the bulk density at the time of opening). The repulsive force per unit area received by the tool 41 was measured as the surface pressure (N / cm ² ) at the time of opening after being repeatedly compressed 2500 times.

In FIG. 5, the result of having measured the surface pressure after repeated compression is shown. In FIG. 5, the horizontal axis indicates the bulk density (g / cm ³ ) when the holding material is compressed, and the vertical axis indicates the surface pressure (N / cm ² ) when released after repeated compression 2500 times.
In FIG. 5, black triangles indicate the results of the holding material according to Example 1, black circles indicate the results of the holding material according to Example 2, and white diamonds indicate the holding material according to Comparative Example 1. The white square marks indicate the results of the holding material according to Comparative Example 2.

As shown in FIG. 5, the holding material according to Examples 1 and 2 was released in any of the cases where the bulk density during compression was 0.30 g / cm ³ , 0.40 g / cm ^3, and 0.50 g / cm ^3. The hourly surface pressure was significantly larger than that of the holding materials according to Comparative Examples 1 and 2.

Further, when the three black triangles shown in FIG. 5 are linearly approximated, the approximate straight line obtained represents the bulk density during compression as D (g / cm ³ ), and the surface pressure during opening after repeated compression 2500 times. When expressed in P (N / cm ² ), it was expressed as follows: P = 24.42 × D-2.31 (R ² = 9.62). This approximate straight line coincides with the broken line L0 shown in FIG. 3 as described above. Further, the surface pressure at the time of opening measured in Comparative Examples 1 and 2 shown in FIG. 5 is plotted below the solid line L1 (P = 17.10 × D−1.62) in FIG.

Evaluation Example 2 [Measurement of initial surface pressure]
As in the case of the surface pressure after repeated compression described above, the initial surface pressure of the holding material was measured using the test apparatus 40 shown in FIG. That is, first, the holding material manufactured as described above was sandwiched between the first jig 41 and the second jig 42 of the test apparatus 40.

Next, with the holding material sandwiched between the first jig 41 and the second jig, the distance between the first jig 41 and the second jig 42 is reduced at a speed of 10 mm / min. The holding material was compressed until its bulk density increased from 0.25 g / cm ³ to 0.50 g / cm ³ .

Then, in the process of compression, the repulsive force per unit area received by the first jig 41 from the holding material whose bulk density is a predetermined bulk density at the time of compression is expressed as an initial surface pressure (N / cm ² ).

FIG. 6 shows the result of measuring the initial surface pressure. In FIG. 6, the horizontal axis represents the bulk density (g / cm ³ ) of the holding material, and the vertical axis represents the initial surface pressure (N / cm ² ).
In FIG. 6, the solid line shows the result of the holding material according to Example 1, the broken line shows the result of the holding material according to Comparative Example 1, and the alternate long and short dash line shows the result of the holding material according to Comparative Example 2.

As shown in FIG. 6, in the wide bulk density range (particularly, the bulk density is in the range of 0.30 g / cm ³ or more and 0.50 g / cm ³ or less), the initial surface pressure of the holding material according to Example 1 is It was significantly larger than that of the holding materials according to Comparative Examples 1 and 2.

That is, in the case of the comparative example the bulk density of the holding member according to 2 ^{0.30g / cm 3, 0.35g / cm} 3, 0.40g / cm 3, 0.45g / cm 3 and 0.50 g / cm ³ the initial surface pressure of the holding member was respectively ^{20N / cm 2, 31N / cm} 2, 42N / cm 2, 54N / cm 2 and 66N / cm ^2.
In contrast, the bulk density of the holding material according to Example 1 is ^{0.30g / cm 3, 0.35g / cm} 3, 0.40g / cm 3, of 0.45 g / cm ³ and 0.50 g / cm ³ the initial surface pressure of the holding member in the case, were respectively ^{23N / cm 2, 39N / cm} 2, 58N / cm 2, 81N / cm 2 and 106N / cm ^2.

Evaluation Example 3 [Measurement of Wet Volume]
The wet volume of the holding material was measured. That is, first, by collecting a part of the holding material (2 g for Examples 1 and 2 and 5 g for Comparative Examples 1 and 2) as a sample and stirring the sample in tap water in a container having a volume of 500 mL The inorganic fibers constituting the sample were dispersed.

  Next, the solution containing the dispersed inorganic fibers was transferred to a 1000 mL graduated cylinder, and tap water was added until the volume of the solution reached 1000 mL while dispersing the inorganic fibers by stirring.

  The inorganic fiber was allowed to settle in 1000 mL of the solution by allowing the graduated cylinder to stand for 30 minutes or more. The scale (mL) of the graduated cylinder corresponding to the position of the upper end surface of the sedimented inorganic fiber mass was read. And the volume (mL) corresponding to the read scale was obtained as a wet volume (mL / 5g) per 5g of holding materials. In addition, about Example 1, 2, since the volume of a solution exceeds 1000 mL when a 5g sample is used, the value obtained using a 2g sample is converted into the value per 5g, and wet volume ( mL / 5 g) was calculated.

  As a result, the wet volume of the holding material according to Example 1 was 1500 mL / 5 g. The wet volume of the holding material according to Example 2 was 1500 mL / 5 g. On the other hand, the wet volume of the holding material according to Comparative Example 1 was 700 mL / 5 g. The wet volume of the holding material according to Comparative Example 2 was 600 mL / 5 g.

  The holding | maintenance material for gas processing apparatuses of this invention can be used for catalytic converters, such as a motor vehicle.

DESCRIPTION OF SYMBOLS 1 Gas processing apparatus 10 Holding material 11 Inner surface of holding material 12 Outer surface of holding material 20 Processing structure 21 Outer surface of processing structure 30 Casing 31 Inner surface of casing 40 Test apparatus 41 First jig 42 Second jig

Claims (8)

In a gas processing apparatus including a processing structure and a casing that accommodates the processing structure, a holding material made of inorganic fibers disposed between the processing structure and the casing,
The holding material is compressed for 10 seconds until the bulk density reaches a predetermined compression bulk density, and then the holding material has an open bulk density that is 12% smaller than the compression bulk density. In the test of repeating the cycle of releasing until the pressure is reached, the surface pressure at the time of opening of the holding material and the bulk density at the time of compression when the cycle is repeated 2500 times satisfy the following relationship: Retaining material.
P ≧ 17.10 × D−1.62
(P represents the surface pressure at opening (N / cm ² ), and D represents the bulk density at compression (g / cm ³ ).) The holding material for a gas processing device according to claim 1, wherein the inorganic fibers are alumina fibers composed of 70 wt% to 75 wt% alumina and 30 wt% to 25 wt% silica. True density of 3.02 g ^/ cm 3 gas processing device for holding material according to claim 1 or 2, characterized in that a ~3.50g / cm ³ of the inorganic fibers. The holding | maintenance material for gas processing apparatuses in any one of Claims 1 thru | or 3 whose ratio with respect to the theoretical value of the true density of the said inorganic fiber is 86.9% or more. The holding material for a gas processing apparatus according to any one of claims 1 to 4, wherein the holding material is a holding material manufactured by a wet method or a dry method. The holding material for a gas processing device according to any one of claims 1 to 5, wherein a wet volume of the holding material is 750 mL / 5 g or more. A processing structure;
A casing for housing the processing structure;
The holding material according to any one of claims 1 to 6, which is disposed between the processing structure and the casing;
A gas treatment device comprising: A processing structure;
A casing for housing the processing structure;
A holding member disposed between the processing structure and the casing;
A method of manufacturing a gas treatment device comprising:
A method for manufacturing a gas processing apparatus, comprising: disposing the holding material according to any one of claims 1 to 6 between the processing structure and the casing.

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