JP4392984B2 - Ceramic structure - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a ceramic structure, and in particular, proposes a novel structure of a ceramic structure in which a plurality of through holes are provided in parallel along the longitudinal direction of a ceramic honeycomb structure, a monolith structure, and other members. To do.
[0002]
[Prior art]
In general, a ceramic honeycomb structure in which a plurality of through holes are provided in parallel along the longitudinal direction is used as a filter for purifying exhaust gas for vehicles, exhaust gas from a factory, and the like. In this ceramic structure, the open state of the through-holes on the end surface thereof exhibits a checkered pattern (a state where the adjacent through-holes are in an open-sealed state so as to be different from each other). . That is, only one of the end faces of these through-holes is sealed, and the adjacent through-holes are opened or closed different from each other to form a checkered plug. . Therefore, if one end face of one through hole is open, the other end face is closed. Conversely, a through hole adjacent thereto is closed on one end face and opened on the other end face. Then, when the gas to be treated is introduced from one end face of each of the through holes, the ceramic structure passes through the porous partition wall on the way to the other end, enters the adjacent through hole, and enters the other end face. The treated gas is allowed to flow out of the tank. Note that this ceramic structure is a porous body, and therefore can ventilate each other through the partition walls separating the through holes, and easily enters other through holes in the structure. For this reason, different through holes are circulated on the gas inlet side and the gas outlet side. When exhaust gas is passed through such a ceramic structure, the exhaust gas flowing in from one end face as described above passes through the partition wall toward the outlet, and particulate matter (particulates) in the exhaust gas. ) Is captured and purified by the partition wall. As the exhaust gas is purified, the particulates are collected and accumulated especially on the partition wall on the inlet side, so that clogging gradually occurs and ventilation is hindered. For this reason, the ceramic structure needs to be periodically treated (hereinafter simply referred to as “regeneration”) to remove the particulates accumulated on the partition walls causing clogging by a heating means such as a burner or a heater.
[0003]
However, in the above-mentioned ceramic structure, the inside of the structure is uneven due to uneven heating process, local heat generation due to abnormal combustion of particulates, thermal shock caused by sudden temperature change of exhaust gas, etc. Temperature distribution occurs and thermal stress acts. As a result, the ceramic structure has a problem in that cracks are generated or melted, resulting in breakage and hindering the collection of particulates.
[0004]
On the other hand, as a means for solving the above problem, for example, the ceramic structure is divided into a plurality of ceramic members by a plane perpendicular to the axis or a plane parallel to the axis. There has been proposed a method for reducing the thermal stress acting on the surface (see Japanese Patent Application Laid-Open No. 60-65219). Furthermore, non-adhesive sealant is inserted into the gap between the ceramic members of this split ceramic structure (hereinafter referred to as “split ceramic structure”) to improve the exhaust gas sealing performance. A divided ceramic structure has been proposed (see Japanese Utility Model Publication No. 1-63715).
[0005]
According to each of the above proposals, the split ceramic structure can release the thermal stress as seen in the integrated ceramic structure by adopting the sealing agent. However, since the sealing agent is non-adhesive, the ceramic members cannot be joined firmly. For this reason, the divided ceramic structure according to the above-described prior art requires a binding force to bind the ceramic members and maintain the form as one structure. As means for imparting this restraining force, conventionally, a heat-expandable heat insulating material is provided on the outermost periphery, or a heat-expandable heat insulating material is applied as an internal sealant.
[0006]
However, the non-adhesive sealant and the heat-expandable heat insulating material have low durability against regenerative heat and vibration generated from the internal combustion engine. For this reason, the sealant has a volume shrinkage and a deterioration in strength. However, while the sealing performance is lowered, the heat-expandable heat insulating material also has a problem that the restoring force after volume expansion is drastically reduced. Therefore, the above-mentioned divided ceramic structure loses the force to support a plurality of ceramic members constituting it, and may be decomposed and scattered by the pressure of the exhaust gas. In addition, even if a reinforcing member is provided on the end face on the gas outlet side, it is difficult to prevent deterioration of the sealing agent, and improvement in durability has been desired.
[0007]
In view of such a situation, the inventors firstly used at least inorganic fibers, inorganic binders, organic binders and inorganic particles as a means for overcoming the above-described problems of the prior art. And an elastic material sealing agent in which the inorganic fibers and the inorganic particles that are three-dimensionally crossed are bonded to each other via the inorganic binder and the organic binder (Japanese Patent Laid-Open No. 8-28246). The above non-adhesive sealing agent is mainly composed of inorganic fibers entangled three-dimensionally, and consists of an organic binder for imparting adhesiveness, an inorganic binder for imparting adhesive strength at high temperatures, and In order to give thermal conductivity, inorganic particles such as SiC are added. According to the present invention, it is possible to obtain a sealant having excellent adhesive strength regardless of temperature and excellent thermal conductivity. When a ceramic structure using this sealant is applied to a filter for an exhaust gas purifying apparatus, the regeneration time Shortening, and improving the reproduction efficiency and durability.
[0008]
[Problems to be solved by the invention]
However, although the exhaust gas purifying apparatus has excellent durability under normal use conditions, it is assumed that the exhaust gas purification apparatus is used under more severe conditions, and therefore a ceramic structure that can withstand such cases is invented. It is necessary.
[0009]
The present invention has been made to solve the above-described problems of the prior art, and its main purpose is to improve the durability of the ceramic structure.
[0010]
[Means for Solving the Problems]
As a result of continual research aimed at realizing the above object, the inventors have found an invention having the following contents as a gist. That is, the invention according to claim 1 has a plurality of through-holes arranged in parallel along the longitudinal direction, and each end face of these through-holes is sealed in a checkered pattern, and the gas can be entered. Opening and closing of the side and the exit side are in a reverse relationship, and adjacent ones of these through-holes are bundled together to form an aggregate by binding a plurality of ceramic members that can be vented to each other through a porous partition wall In the ceramic structure, between the ceramic members, From drying and curing a paste-like sealant The ceramic structure is bound, and the sealing agent is composed of an inorganic fiber, an inorganic binder, and an organic binder, and the orientation degree of the inorganic fiber is 70% or more. The degree of orientation here means the degree of directionality of the fiber with respect to the stress direction in one direction.In the present invention, the discharge direction of the sealant discharged from the metering discharge pump as shown in FIG. As a reference (0 °), a fiber whose inclination is within an absolute angle of 20 ° is expressed as a percentage of the number of fibers included in an arbitrary number of fibers.
[0011]
In the present invention, in addition to increasing the discharge speed of the sealing agent, for example, by using a discharge pump equipped with a pore nozzle as shown in FIG. Uniaxially oriented to the inside. When using a nozzle with a large discharge port, install a mesh-like partition plate as shown in Fig. 11 along the discharge direction of the sealant so that it is displaced vertically and horizontally, up to the inside of the thick sealant. The inorganic fiber is uniaxially oriented by applying a shearing force.
[0012]
By doing this, conventionally, the inorganic fibers entangled three-dimensionally cannot suppress the expansion and contraction of the filter in the longitudinal direction, and the thermal stress cannot be released when the filter is used under extremely severe conditions. According to the present invention, there is a possibility that the inorganic fibers are uniaxially oriented along the longitudinal direction, the effect of suppressing expansion and contraction in the same direction is obtained, and the thermal stress applied to the filter can be released.
As a result, by using the inorganic fiber, a ceramic structure having excellent durability even under severe use conditions can be obtained.
[0013]
Therefore, the shape of the discharge port of the adhesive applicator that discharges the sealing agent can be various, but since it can be applied evenly to the bonding surface of the ceramic member, the bonding area is stable and a strong bonding force is obtained, Furthermore, as described above, a flat nozzle as shown in FIG. 6B is desirable in that a high degree of orientation is easily obtained.
[0014]
The opening area of the nozzle of the quantitative discharge pump having the discharge port as described above is desirably 33 mm 2 to 112 mm 2, preferably 39 mm 2 to 84 mm 2, more preferably 42 mm 2 to 52 mm 2. If the opening area is less than 33 mm2, the sealing agent cannot be discharged in a rod shape, and a stable bonding area cannot be secured. On the other hand, if the thickness exceeds 112 mm2, the thickness of the sealing agent is too large, and the supply amount of the sealing agent from the discharge pump cannot catch up, and the sealing agent is cut off in the middle of the paste.
[0015]
The degree of orientation increases as the discharge speed of the sealant paste increases and the aspect ratio (horizontal / vertical ratio) of the nozzle increases.
[0016]
The aspect ratio of the nozzle of the above-mentioned constant discharge pump is 4.3 to 16.1, preferably 8.3 to 13 when the nozzle opening area is 52 mm2. The reason for this is that if it is less than 4.3, the degree of orientation becomes too low, and it becomes impossible to ensure a sufficient adhesion area with respect to the adhesion surface of the ceramic member. On the other hand, if it exceeds 16.1, This is because the adhesive is excessively applied to the adhesive surface, so that the sealing agent protrudes during assembly, and the number of steps for removal increases, resulting in a decrease in productivity.
[0017]
The thickness of the sealing agent is 1.0 mm to 6.0 mm, preferably 1.5 mm to 5.0 mm, and more preferably 2.5 mm to 3.5 mm. The reason for this is that if it is less than 1.0 mm, it will not be possible to absorb the thermal expansion that occurs during regeneration, the filter will crack and the particulates will leak, while if it exceeds 6.0 mm, the thermal conductivity will decrease. This is because the temperature inside the filter cannot be fully raised and the particulates cannot be completely regenerated.
[0018]
In addition, the orientation degree of the inorganic fibers contained in the sealing agent is desirably 70% or more. The reason is that when the degree of orientation is less than 70%, the inorganic fibers are intertwined in three dimensions, so that the expansion and contraction of the filter in the longitudinal direction cannot be suppressed, and the filter is used under severe conditions. This is because there is a possibility that the thermal stress cannot be released and the thermal stress cannot be released as in the case of the integrated ceramic structure.
[0019]
Here, the sealing agent uses at least one fiber selected from silicon carbide fibers as the inorganic fiber, uses at least one colloidal sol selected from silica sol and alumina sol as the inorganic binder, and the organic binder is Desirably, at least one polysaccharide selected from polyvinyl alcohol, methyl cellulose, ethyl cellulose, and carbomethoxy cellulose.
[0020]
Specifically, it is more preferable that the sealing agent has a configuration described below. Of the colloidal sol, the content of the silica sol is 1 to 30 wt%, preferably 1 to 15 wt%, more preferably 5 to 9 wt% in terms of solid content. The reason for this is that if the content is less than 1 wt%, the adhesive strength is reduced, while if it exceeds 30 wt%, the thermal conductivity is reduced.
[0021]
Among the polysaccharides, the content of carboxymethylcellulose is 0.1 to 5.0 wt%, preferably 0.2 to 1.0 wt%, more preferably 0.4 to 0.6 wt% in terms of solid content. This is because when the content is less than 0.1 wt%, migration cannot be suppressed, whereas when the content exceeds 5.0 wt%, the organic binder is burned out due to the high-temperature heat history, and the strength is lowered.
[0022]
The invention according to claim 2 is the ceramic structure according to claim 1, wherein the sealing agent is composed of inorganic fibers, an organic binder, an inorganic binder, and inorganic particles.
[0023]
Here, in the inorganic powder or whisker constituting the sealing agent, the content of silicon carbide powder is 3 to 80 wt%, preferably 10 to 60 wt%, more preferably 20 to 40 wt% in solid content. Is desirable. The reason for this is that if the content is less than 3 wt%, the thermal conductivity decreases, while if it exceeds 80 wt%, the adhesive strength decreases at high temperatures.
[0024]
Of the inorganic powders or whiskers, the silicon carbide powder has a particle size of 0.01 to 100 μm, preferably 0.1 to 15 μm, more preferably 0.1 to 10 μm. The reason for this is that if the particle size exceeds 100 μm, the adhesive strength (strength) and thermal conductivity are reduced, while if it is less than 0.01 μm, the cost is increased.
[0025]
The invention according to claim 3 is the ceramic structure according to claim 1, wherein the inorganic fiber is made of at least one fiber selected from silicon carbide fibers.
[0026]
Of the inorganic fibers, the fiber length of the silicon carbide fiber is preferably 20 to 300 μm, and more preferably 50 to 200 μm. If the fiber length is less than 20 μm, the properties may be close to particles and the adhesive strength may be reduced. On the other hand, if it exceeds 300 μm, it is difficult to uniformly disperse in the adhesive layer, which may cause a decrease in adhesive strength. Moreover, it is preferable that the fiber diameter is 3-15 micrometers. If the fiber diameter is less than 3 μm, the strength of the silicon carbide fiber will be reduced and it will be cut easily, which may lead to a decrease in the adhesive strength. In some cases, the strength may be lowered, and it is difficult to obtain such a thick silicon carbide fiber, resulting in an increase in raw material costs.
[0027]
Further, the content of the silicon carbide fiber is preferably 3 to 80 wt%, more preferably 10 to 70 wt%, and further preferably 40 to 60 wt% in terms of solid content. When the content of silicon carbide fiber is less than 3 wt%, the thermal conductivity is lowered. On the other hand, when it exceeds 80 wt%, the adhesive strength is lowered when the adhesive layer is exposed to a high temperature.
[0028]
[Action]
The feature of the ceramic structure according to claim 1 is to improve the durability of the ceramic structure by setting the orientation degree of the inorganic fibers to 70% or more with respect to the discharge direction of the sealing agent as shown in FIG. It is in the point. In other words, the effect of suppressing the expansion and contraction in the longitudinal direction of the filter can be obtained by increasing the discharge rate of the sealing agent as described above and increasing the orientation degree of the inorganic fiber using a fine nozzle or a mesh-like partition. The thermal stress applied to the filter can be released even under various use conditions.
[0029]
The feature of the sealing agent described in claim 2 is that the thermal conductivity of the ceramic structure can be remarkably improved by adding inorganic particles made of carbide or nitride having excellent heat conduction characteristics. .
[0030]
Therefore, the sealing material containing the inorganic particles is excellent in thermal conductivity. For example, when used in a filter for an exhaust gas purification device, the gap between the plurality of ceramic members is filled, and at the same time, the temperature peak phenomenon occurs during regeneration. It is possible to effectively prevent the ceramic structure from being damaged without incurring any damage. In addition, the occurrence of cracks due to thermal cycling is reduced, and the edge portion on the outer periphery of the filter can be heated in a relatively short time, thereby improving the regeneration efficiency.
[0031]
The feature of the ceramic structure according to claim 3 is that the inorganic fiber has excellent thermal conductivity and elasticity, and by using silicon carbide fiber made of the same material as the ceramic member, the adhesiveness and thermal conductivity of the sealing agent are improved. In addition, the thermal expansion coefficient can be made the same as that of the ceramic member.
[0032]
Therefore, the sealing material can be made of an elastic material having excellent adhesion and strength without using inorganic particles that reduce the adhesion even though it has the effect of increasing the thermal conductivity, and the thermal stress applied to the filter. Can be released. As a result, the ceramic structure in which a plurality of ceramic members are integrally restrained by such a sealing agent has sufficient durability, adhesiveness, and thermal conductivity.
[0033]
In summary, the ceramic structure according to the present invention has adhesiveness and thermal conductivity as well as prevention of cracking due to thermal stress under severe use conditions by suppressing expansion and contraction of the filter. It is characterized by having a sealing agent.
[0034]
Here, as the inorganic fiber, silicon carbide fiber is particularly desirable and acts as an adhesive. This silicon carbide is excellent in adhesiveness, heat resistance and elasticity, and has an effect of increasing thermal conductivity.
[0035]
As the inorganic binder, colloidal sol is desirable, for example, alumina sol and silica sol, but silica sol is particularly desirable and acts as an adhesive (inorganic binder). This silica sol is easy to obtain and is easily converted into SiO2 upon firing, and thus is suitable as an adhesive in a high temperature region.
[0036]
The organic binder is preferably a hydrophilic organic polymer, and more preferably a polysaccharide. Specific examples include polyvinyl alcohol, methylcellulose, ethylcellulose, and carboxymethylcellulose. Carboxymethylcellulose is particularly desirable, contributing to improved workability to ensure fluidity during assembly, and excellent adhesion at room temperature. Indicates.
[0037]
The inorganic particles are preferably carbide or nitride inorganic particles, such as silicon carbide, silicon nitride and boron nitride. These carbides and nitrides have a very high thermal conductivity, and contribute to the improvement of thermal conductivity by interposing on the surface of the ceramic fiber and the surface of the colloidal sol and the inside thereof. For example, the thermal conductivity of silicon carbide is 79.2 W / mk, the thermal conductivity of boron nitride is 56.7 W / mk, whereas the thermal conductivity of alumina is about 33.4 W / mk, especially carbides and nitrides. Is effective in improving the thermal conductivity. Of these inorganic particles made of carbide or nitride, silicon carbide is particularly optimal in terms of heat conduction. That is, silicon carbide has all of adhesiveness, heat resistance, water resistance and thermal conductivity.
[0038]
Hereinafter, an embodiment in which the ceramic structure of the present invention is embodied in a filter for an exhaust gas purifying device attached to a diesel engine will be described in detail with reference to FIGS. FIG. 1 is a view showing an exhaust gas purifying filter 1 using the ceramic structure of the present invention, and FIG. 2 is an enlarged partial sectional view of the filter. In these drawings, the exhaust gas purifying device filter 1 includes eight prismatic ceramic members 2 and four ceramic members 3 with isosceles right angles in cross section, and a sealant made of an elastic material between the members. (Thickness 2.5-3.5 mm) 4 is interposed and bonded together, and is processed into a cylindrical shape by outer peripheral processing. 3 to 5 are views showing the ceramic member 2 constituting the part of the exhaust gas purifying filter 1. In these drawings, through-holes 6 having a substantially square cross section are regularly drilled along the axial direction of a prismatic (33 mm × 33 mm × 254 mm) ceramic member 2. These through holes 6 are separated from each other by a porous partition wall 7 having a thickness of 0.3 mm. One end on either the exhaust gas inflow side or the outflow side of each through hole 6 is sealed in a checkered pattern by a sealing piece 5 made of a porous sintered body. As a result, the cells 8 that are open only on either the inflow side or the outflow side of the ceramic member 2 are formed. The partition wall 7 of the cell 8 may carry an oxidation catalyst made of a platinum group element, other metal elements, oxides thereof, or the like. This is because, if supported, the ignition temperature of the particulates decreases. The ceramic member 3 has the same configuration as the ceramic member 2 except that the cross-sectional shape is a right-angled isosceles triangle. In the case of the ceramic members 2 and 3 constituting the exhaust gas purifying filter 1 of the present embodiment, the average pore diameter is 10 μm, the porosity is 43%, the cell wall thickness is 0.3 mm, and the cell pitch is 1.8 mm. Is set. In the present embodiment, the exhaust gas purifying filter 1 having the configuration as described above is prepared, and the performance of the filter is evaluated.
[0039]
【Example】
The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples.
[0040]
(Example 1)
α-type silicon carbide powder (particle size 5μm) 51.5% by weight and β-type silicon carbide powder 22% by weight are wet mixed, and the resulting mixture is mixed with organic binder (methylcellulose) and water 6.5% by weight and 20% by weight, respectively. It was added and kneaded. Next, a small amount of a plasticizer and a lubricant were added and further kneaded, and the kneaded product was extruded and shaped to obtain a honeycomb-shaped formed shape. Next, this formed shape is dried using a microwave dryer, and then the through hole 6 of the molded body is sealed with a paste for forming a sealing piece 5 made of a porous sintered body, and then dried again. The paste for sealing piece 5 was dried using a machine. The dried body was degreased at 400 ° C. and then fired at 2200 ° C. in an argon atmosphere to obtain porous and honeycomb-like ceramic members 2 and 3.
[0041]
Prior to the bonding process, silicon carbide powder (30 wt% to 50 wt%), resin binder PV-5 (trade name: manufactured by Malvan Co., Ltd.) (40 wt% to 60 wt%), and glycerin as an auxiliary agent Apply a ceramic underlayer consisting of 5 wt% to 10 wt%. The reason for this is that by forming the base layer, it is possible to prevent the sealing agent from permeating into the outer peripheral surface of the ceramic member having fine pores, so that the adhesive can be distributed sufficiently evenly in a relatively short time. It is because it can be made.
[0042]
Ceramic fiber as inorganic fiber (alumina silicate ceramic fiber, shot content 3%, fiber length 0.1-100 μm , Fiber diameter 3 ~ 15μm) 23.3 wt%, silica sol as inorganic binder 7wt% (the equivalent amount of SiO2 in the sol is 30wt%), carboxymethylcellulose 0.5wt% and 39wt% water as organic binder are mixed and kneaded Thus, a sealant having a viscosity of 32 Pa · s was prepared.
[0043]
A metering pump as shown in FIG. 6 (a) having a flat nozzle having an opening area of 52 mm2 and an aspect ratio of 13 as shown in FIG. 6 (b) between the ceramic members 2 and 3. Thus, 37 g was discharged so that the orientation degree of the inorganic fibers was 90%, and as shown in FIG. 9, it was filled so as to have a thickness of 3.0 mm, a width of 26 mm, and a length of 244 mm.
[0044]
In addition, as a measuring method of orientation degree, the sealing agent discharged from the fixed discharge pump was cut | disconnected along the discharge direction, and it image | photographed by SEM about 100 fibers on the cut surface. Moreover, let the center part of a sealing agent be the evaluation object of fiber orientation degree. The reason for this is that when discharging the sealant, the fiber distribution height is high due to the plastic flow of the matrix in the part in contact with the wall of the discharge pump, and conversely the influence is small in the central part. This is because the entire degree of orientation is guaranteed to be higher.
[0045]
Next, the ceramic members 2 and 3 and the sealant 4 are joined and integrated, dried and cured at 50 to 100 ° C. for 1 hour, and cut into a cylindrical shape using a peripheral processing machine (not shown). After processing, a filter 1 as shown in FIG. 1 was created.
[0046]
A layer of a holding sealing body 17 (thickness 4 mm) formed including ceramic fibers was formed on the outer periphery of the filter, and the filter was installed in an exhaust gas purification apparatus as shown in FIG. In addition, an electric heater 21 for heating the filter 1 is provided at a portion on the exhaust gas introduction side of the filter 1, and a temperature sensor 22 is provided in contact with the end face of the filter 1.
[0047]
Connect the inlet pipe 18 of the exhaust gas purification device to the exhaust gas exhaust port of the engine, perform a particulate collection test in which the engine is operated at 3000 rpm, 60 Nm for 12 hours, and use the electric heater 21 after the collection is completed. Then, 20 cycles of a test in which regeneration treatment for burning and removing accumulated particulates was performed for 40 minutes by heating the filter 1 to 600 ° C. were performed.
[0048]
Then, when the joint part of each ceramic member was cut | disconnected in the discharge direction and the cut surface was observed with SEM and the crack was measured, the crack was not discovered.
[0049]
(Example 2)
This example is basically the same as Example 1, except that the degree of orientation of the inorganic fibers contained in the sealant is 40% instead of that in Example 1, and the same conditions as in Example 1 are applied. When cracks were measured by collecting and regenerating curate, many cracks were found.
[0050]
(Example 3)
This example is basically the same as Example 1, except that inorganic particles (silicon carbide powder 30.2 wt%, average particle size 0.3 μm) are added to the sealant, and the orientation degree of inorganic fibers is set to 60%. When cracks were measured by collecting and regenerating particulates under the same conditions as in Example 1, no cracks were found.
[0051]
(Example 4)
This example is basically the same as Example 1, except that the inorganic fibers contained in the sealant are replaced with those in Example 1, silicon carbide fibers (fiber length 50 to 200 μm, fiber diameter 3 to 15 μm) 60 wt%, the orientation degree of the inorganic fibers was 60%, the particulates were collected and regenerated under the same conditions as in Example 1, and cracks were measured. No cracks were found.
[0052]
As is clear from the above results, the filter using the ceramic structure of the present invention can be regenerated by heat cycles generated during operation under severe use conditions and by the uneven deposition of particulates. It was confirmed that the thermal stress can be released even if a temperature difference due to burning of the particulates generated during the process occurs, and that the filter is excellent in durability even under severe use conditions. Moreover, since this ceramic structure is also excellent in thermal conductivity, it is possible to reduce the occurrence of peak temperature in the ceramic member located inside the filter, and to shorten the heating time of the ceramic structure located in the edge portion. As a result, improvement in reproduction efficiency can be realized at the same time.
[0053]
Note that the configuration of the filter 1 to which the ceramic structure of the present invention is applied is not limited to that described in the above embodiment, and can be changed to the following configuration. For example,
The number of combinations of ceramic members does not have to be 12 as in the above embodiment, and can be any number. In this case, it is of course possible to appropriately combine ceramic members having different sizes and shapes. In addition, it is particularly advantageous to adopt a configuration in which a plurality of ceramic members are combined when creating a large exhaust gas purifying filter.
In other words, the filter 1 of the above-described embodiment can be regarded as one large filter being divided into a plurality of pieces along the axial direction. Thus, for example, a modification in which the filter is divided into a donut shape, or is divided perpendicularly to the axial direction can be considered.
Of course, the present invention is not limited to the honeycomb-shaped ceramic members 2 and 3 as shown in the above-described embodiments, and it is of course possible to adopt, for example, a three-dimensional network structure, a foam shape, a noodle shape, or a fiber shape. Of course, materials other than silicon carbide may be selected as the material for the ceramic members 2 and 3.
When the filter 1 is configured, a heater may be provided between the ceramic members 2 and 3. In this case, the heater is not limited to being a metal wire. That is, the heater may be formed by a method such as metal metallization, conductive paste printing, sputtering, or the like.
[0054]
In the present embodiment, the ceramic structure of the present invention has been described as an example of a filter for an exhaust gas purification device attached to a diesel engine. However, the use of the ceramic structure is intended for an exhaust gas purification device of a diesel engine. It is not limited to the filter for use. For example, it can be used as a heat exchanger member, or as a high temperature fluid or high temperature steam filter.
[0055]
【The invention's effect】
As described above, the ceramic structure using the sealant of the present invention is excellent in adhesive strength regardless of use conditions and also in heat conductivity. Even under proper use conditions, not only the durability can be improved, but also the reproduction time can be shortened and the reproduction efficiency can be realized.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an exhaust gas purifying filter using a ceramic structure according to the present invention.
FIG. 2 is a partially enlarged cross-sectional view of a filter for an exhaust gas purifying device using the ceramic structure of the present invention.
FIG. 3 is a perspective view showing a ceramic member of a filter for an exhaust gas purifying apparatus according to the present invention.
4 is a partially broken enlarged cross-sectional view taken along the line AA in FIG.
5 is an enlarged cross-sectional view taken along line BB in FIG.
FIG. 6 is a view of a fixed discharge pump for discharging a sealant and a shape diagram of a nozzle.
FIG. 7 is a diagram showing the inclination of the fiber with respect to the discharge direction of the sealing agent.
FIG. 8 is a diagram in which inorganic fibers are oriented with respect to the discharge direction of the sealing agent.
FIG. 9 is a diagram of an adhesive applicator.
FIG. 10 is a side sectional view of a pore nozzle.
FIG. 11 is a cross-sectional view of a mesh-like partition plate and a nozzle.
FIG. 12 is a cross-sectional view showing an example of an exhaust gas purification device.
[Explanation of symbols]
1 Filter for exhaust gas purifier
2-3 Ceramic parts
4 Sealant
5 Sealing piece
6 Through hole
7 Bulkhead
8 cells
9 exhaust gas
10 rotor
11 drive shaft
12 rods
13 nozzles
14 Metering pump
15 inorganic fiber
16 mesh divider
17 Holding seal body
18 introduction pipe
19 discharge pipe
20 casing
21 Electric heater
22 temperature sensor

Claims (3)

It has a plurality of through-holes arranged in parallel along the longitudinal direction, and each end surface of these through-holes is sealed in a checkered pattern, and the opening and closing of the gas inlet and outlet sides are reversed. In the ceramic structure in which the adjacent ones of these through-holes are made into an aggregate by bundling a plurality of ceramic members that are capable of venting each other through a porous partition wall,
Between each ceramic member is bound by drying and curing a paste-like sealant,
The said sealing agent consists of an inorganic fiber, an organic binder, and an inorganic binder at least, The orientation degree of the said inorganic fiber is 70% or more , The ceramic structure characterized by the above-mentioned .   2. The ceramic structure according to claim 1, wherein the sealing material includes at least an inorganic fiber, an organic binder, an inorganic binder, and inorganic particles. The inorganic fibers, characterized in that it comprises at least silicon carbide fibers, ceramic structure according to claim 1 or 2.

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