JP3754095B2 - Method and apparatus for applying slurry to tubular honeycomb body - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a slurry application method to a tubular honeycomb body having two end faces facing each other and having a large number of pore-shaped cells communicating between the end faces, particularly the outer peripheral face of the honeycomb body and The present invention relates to a slurry application method and apparatus in which slurry is not applied to an outer peripheral cell.
[0002]
[Prior art]
A catalytic converter used as a purification device for exhaust gas discharged from an engine such as a vehicle is provided with a catalyst carrier, and platinum, rhodium or the like, which is an exhaust gas purification catalyst, is supported on the carrier, and the exhaust gas passing through the carrier is converted into exhaust gas. It is designed to purify contained harmful components.
[0003]
In particular, the monolithic catalyst support is formed into a cylindrical shape having two opposite end faces, and a plurality of fine exhaust gas passages that communicate with each other are formed through the support (hereinafter, “ The exhaust gas discharged from the engine is inserted and installed in the outer cylinder of the catalytic converter so that the exhaust gas discharged from the engine flows into the exhaust gas passage from one end face and flows out from the other end face. Therefore, in this case, the catalyst only needs to be supported on the surface of the exhaust gas passage through which the exhaust gas to be purified passes, and it is not necessary to support the catalyst on the outer peripheral surface of the cylindrical catalyst carrier through which the exhaust gas does not pass.
[0004]
On the other hand, as a method for supporting the purification catalyst on the catalyst carrier, a dispersion layer such as alumina particles adsorbing the catalyst is applied to the catalyst carrier, and then dried and fired to form a catalyst layer on the surface of the catalyst carrier. It is generally done. Therefore, in order to form the catalyst layer only on the surface of the exhaust gas passage in the catalyst carrier having the honeycomb structure as described above, it is necessary to apply the dispersion liquid to each of the pore-shaped passages. It is known that the dispersion liquid is applied to the exhaust gas passage by immersing the catalyst carrier in the dispersion liquid in order to improve work efficiency.
[0005]
However, if the catalyst carrier is simply immersed in the dispersion, the dispersion comes into contact with the entire surface of the catalyst carrier, and as a result, it is unnecessarily applied to the outer peripheral surface of the carrier through which the exhaust gas does not pass. In particular, the purification catalyst contained in the dispersion is an expensive noble metal such as platinum or rhodium as described above. Recently, in addition to the alumina, an expensive zeolite or the like is used as a carrier for adsorbing the catalyst in terms of performance. In view of the material cost of the dispersion, unnecessary application of the dispersion to the outer peripheral surface should be avoided because of the tendency to be used.
[0006]
In addition, as for the application of the dispersion liquid to the exhaust gas passage, it may not be necessary to form a catalyst layer in all of the many exhaust gas passages formed on the catalyst carrier. That is, when the catalyst carrier is inserted and installed in the converter outer cylinder, the carrier is made of a ceramic such as cordierite, while the converter outer cylinder on the side in which the catalyst carrier is made is made of metal. As a result of the different rates, there is a risk that the engagement and support of the catalyst carrier by the converter outer cylinder may become uncertain due to the passage of high-temperature exhaust gas. Further, even if exhaust pulsation occurs, the catalyst carrier may be disengaged and the support may become unstable. And in order to prevent this, as a result of increasing the degree of engagement between the catalyst carrier and a member supporting the carrier such as a set plate, the set plate protrudes to the outer peripheral portion of the end surface of the catalyst carrier. In some cases, the opening of the exhaust gas passage in the outer peripheral portion is shielded, and the exhaust gas does not flow into the shielded exhaust gas passage, that is, the exhaust gas passage in the outer peripheral portion of the catalyst carrier. There is no need to form a layer. Therefore, in this case, for the same reason as avoiding the application of the dispersion liquid to the outer peripheral surface of the catalyst carrier, it is necessary to avoid unnecessary application of the dispersion liquid to the exhaust gas passage of the outer periphery of the catalyst carrier. is there.
[0007]
Various techniques have been proposed for the above problems. For example, as disclosed in Japanese Patent Application Laid-Open No. 62-294445 (hereinafter referred to as “A”), the exhaust gas passage is disposed in a cylindrical device that can be slidably contacted with a monolithic catalyst carrier without gaps. There is known a method (wash coat method) in which the dispersion liquid is applied to the catalyst carrier by inserting the dispersion liquid upward from above the cylindrical device and passing the dispersion liquid through an exhaust gas passage. (See FIG. 3 of the publication). According to this washcoat method, since the outer peripheral surface of the catalyst carrier is in sliding contact with the cylindrical device without any gaps, the poured dispersion does not contact the outer peripheral surface, and only the exhaust gas passage directed in the vertical direction is used. Passing through and contacting the surface of the passage, as a result, the dispersion is applied only to the exhaust gas passage without being applied to the outer peripheral surface.
[0008]
Further, in the gazette, the exhaust gas passage on the outer periphery of the catalyst carrier that is shielded by the set plate (referred to as “retainer” in the gazette) is clogged in advance before this coating step. Is disclosed. According to this, the poured dispersion liquid cannot pass through the exhaust gas passage in the outer peripheral portion where the clogging is performed, and as a result, the exhaust gas does not pass through when installed in the catalytic converter. Application of unnecessary dispersion liquid to the exhaust gas passage is avoided. Similarly, Japanese Patent Application Laid-Open No. 62-294446 (hereinafter referred to as “B”) discloses a method of pre-sealing the exhaust gas passage in the outer peripheral portion, and the dispersion is applied to the exhaust gas passage that does not require a catalyst layer. Is prevented.
[0009]
Japanese Patent Application Laid-Open No. 3-157142 (hereinafter referred to as “C”) discloses that the exhaust gas is sent from below to the inside of the catalyst carrier installed upright, in other words, only into the exhaust gas passage. A technique for applying the dispersion only to the passage is disclosed. This also prevents the dispersion from being applied to the outer peripheral surface of the catalyst carrier, as in the washcoat method.
[0010]
[Problems to be solved by the invention]
However, the wash coating method and the coating method disclosed in C and the clogging method disclosed in A and B have the following disadvantages.
[0011]
First, in the washcoat method, the dispersion is applied to the surface of the exhaust gas passage, and the dispersion is poured from above the catalyst carrier installed in the cylindrical device, and naturally passes through the exhaust gas passage by gravity. Therefore, the contact time between the dispersion and the surface of the exhaust gas passage which is the surface to be coated cannot be adjusted. As a result, for example, when the dispersion is applied to the surface of the exhaust gas passage of the catalyst carrier that is formed of a material that hardly absorbs moisture, the contact time is insufficient and the dispersion is sufficiently applied to the surface to be coated. The problem of not being applied arises.
[0012]
Further, since the dispersion poured from above the catalyst carrier moves downward in the exhaust gas passage due to gravity, it comes into contact with the entire surface of the exhaust passage. Different types of dispersions will be applied. Therefore, it is not possible to meet the demand for coating two types of dispersion liquids separately on the front and rear portions of the exhaust gas passage without extra recoating.
[0013]
In addition, a cylindrical device that can be slidably contacted without gaps and installed in an interior so that the outer peripheral surface of the catalyst carrier is not applied is separately required. Since it is necessary to replace the cylindrical device to be used one by one, the manufacturing cost is also reduced. Furthermore, if there is even a slight gap between the inner surface of the cylindrical device and the outer peripheral surface of the catalyst carrier, the dispersion liquid will permeate and be applied to the outer peripheral surface because of gravity acting from above. Therefore, precise dimensional accuracy is required for both the cylindrical device and the catalyst carrier.
[0014]
On the other hand, in the coating method disclosed in the above publication No. C, since the dispersion liquid is fed from below into the exhaust gas passage of the catalyst carrier installed upright, the above disadvantage does not occur, but the dispersion to the outer peripheral surface of the catalyst carrier is not caused. Only application of the liquid can be avoided, and unnecessary application of the dispersion liquid to the exhaust gas passage around the catalyst carrier cannot be avoided.
[0015]
And in the clogging method disclosed in the above-mentioned A publication and B publication, since the process of clogging the exhaust gas passage in the outer periphery of the catalyst carrier is newly added before the coating process, the length of the production process is long. And the problem of excessive manufacturing equipment arises.
[0016]
Further, when the exhaust gas passage is clogged, the passage no longer functions as a passage, so that the applicable range of the catalyst carrier is narrowed. For example, another kind of dispersion liquid is again passed through the clogged exhaust gas passage. Changes such as application cannot be made. As a result, it is not possible to meet the demand for coating several kinds of dispersion liquids for each exhaust gas passage.
[0017]
Then, according to the clogging method disclosed in the A publication, when clogging the exhaust gas passage at the outer peripheral portion, the outer peripheral portion and the outer peripheral surface of the catalyst carrier are immersed in the dispersion containing the material to be clogged. Therefore, the dispersion liquid excessively attached to the outer peripheral surface must be wiped later, and as a result, the packing material is wasted and is not rational. According to this, the outer peripheral wall of the catalyst carrier is notched from the outer peripheral surface side until reaching the outer peripheral exhaust gas passage, impregnated with ceramic slurry, and then dried and fired to clog the outer peripheral exhaust gas passage. The stuffing process itself is large. In any case, in addition to the catalyst dispersion liquid to be applied, a dispersion liquid or ceramic slurry containing the above-mentioned plugging material must be separately prepared, resulting in excessive production cost.
[0018]
Furthermore, since the exhaust gas passages that can be clogged are limited to the exhaust gas passages that exist on the outer periphery of the catalyst carrier, in other words, the outer peripheral exhaust gas passages are always clogged, so that they are dispersed in the outer peripheral exhaust gas passages. It is impossible to cope with changes such as applying a liquid and not applying a dispersion liquid to an exhaust gas passage existing in the inner core of the carrier.
[0019]
The above problems are not limited to the case where the dispersion of the exhaust gas-purifying catalyst is applied to the catalyst carrier having the honeycomb structure, but to the general cylindrical article (hereinafter referred to as “tubular honeycomb body”) formed into the honeycomb structure. In the case of application of general fluids (hereinafter referred to as “slurry”), the same problem may occur.
[0020]
Therefore, the present invention addresses the above problems in the conventional washcoat method and the coating method disclosed in C and the clogging method disclosed in A and B, and makes the system excessive. In a single step, the outer peripheral surface of the tubular honeycomb body and the cells on the outer peripheral portion (in the tubular honeycomb body, the honeycomb body is passed through the honeycomb body so that the two end faces facing each other are in communication with each other). The slurry is not applied to the surface of a large number of pore-shaped passages (the same applies hereinafter), and the slurry is selectively applied only to the surface of the cell that needs to be applied regardless of the material of the honeycomb body. It is an object of the present invention to provide a slurry coating method and apparatus capable of being coated on the surface.
[0021]
[Means for Solving the Problems]
That is, the invention according to claim 1 of the present application (hereinafter referred to as “first invention”) is a slurry application method to a cylindrical honeycomb body in which a large number of cells communicating two opposite end faces are formed. Then, after the cylindrical honeycomb body is installed so that the cells extend in the vertical direction above the slurry reservoir where the slurry is stored, the liquid level of the slurry in the reservoir is Outer peripheral surface and Regulate it so that it does not rise inside the outer peripheral cell. While dropping a predetermined amount of slurry from the tank higher than the honeycomb body into the slurry reservoir, The honeycomb body is raised to a predetermined height, held at the predetermined height for a predetermined time, and then lowered.
[0022]
The invention according to claim 2 of the present application (hereinafter referred to as “second invention”) is the first invention, wherein one end face of the two end faces of the tubular honeycomb body faces downward, By adhering the outer peripheral part of the end surface and the peripheral part of the hole provided in the lid part of the slurry storage part so that the opening of the cell in the outer peripheral part is shielded, the honeycomb body is placed on the upper part of the storage part. The cells are installed so as to extend in the vertical direction, and the rise of the liquid level inside the cells at the outer peripheral portion of the honeycomb body when the slurry liquid level rises is characterized.
[0023]
The invention according to claim 3 of the present application (hereinafter referred to as “third invention”) is the above-described first invention or second invention, in which the liquid level of the slurry is lowered and then the upper portion of the cylindrical honeycomb body. From the above, air is blown to the honeycomb body.
[0024]
In the invention according to claim 4 of the present application (hereinafter referred to as “fourth invention”), in any one of the first invention to the third invention, the cylindrical honeycomb body is a porous exhaust gas purification catalyst carrier. It is characterized by.
[0025]
The invention according to claim 5 of the present application (hereinafter referred to as “fifth invention”) is characterized in that, in the fourth invention, the slurry is a slurry of an exhaust gas purifying catalyst containing a noble metal.
[0026]
On the other hand, the invention according to claim 6 of the present application (hereinafter referred to as “sixth invention”) is a slurry application device to a cylindrical honeycomb body in which a large number of cells communicating two opposite end faces are formed. A lid for installing the tubular honeycomb body so that the cells extend in the vertical direction is provided above the slurry storage section for storing the slurry, and is in close contact with the outer peripheral portion of the lower end surface of the honeycomb body. A hole having a peripheral portion that shields the opening of the cell in the outer peripheral portion is provided at the honeycomb body installation position of the lid, A tank provided at a position higher than the honeycomb body installed at the honeycomb body installation position of the lid portion and storing a predetermined amount of slurry, and a valve for switching a communication state of the pipe member between the tank and the slurry storage portion A member, and actuating the valve member to bring the pipe member into a communicating state, dropping a predetermined amount of slurry from the tank into the slurry reservoir, A liquid level adjusting means is provided for raising the liquid level of the slurry in the reservoir and allowing the slurry to enter the inside of the honeycomb body installed at the honeycomb body installation position of the lid.
[0027]
The invention according to claim 7 of the present application (hereinafter referred to as “seventh invention”) is in close contact with a predetermined portion of the lower end face of the cylindrical honeycomb body installed at the honeycomb body installation position of the lid in the sixth invention. The slurry introduction preventing member is provided in the hole.
[0028]
The invention according to claim 8 of the present application (hereinafter referred to as “eighth invention”) is the tubular honeycomb body installed at the honeycomb body installation position of the lid in either of the sixth invention or the seventh invention. An air blowing means for blowing air to the honeycomb body from above is provided.
[0029]
The invention according to claim 9 of the present application (hereinafter referred to as “the ninth invention”) is the cylindrical honeycomb body installed at the honeycomb body installation position of the lid portion in any of the sixth to eighth inventions. Supporting means for pressing from above is provided.
[0030]
In the invention according to claim 10 of the present application (hereinafter referred to as “tenth invention”), in any one of the sixth to ninth inventions, the cylindrical honeycomb body is a porous catalyst carrier for exhaust gas purification. It is characterized by.
[0031]
The invention according to claim 11 of the present application (hereinafter referred to as “eleventh invention”) is characterized in that, in the tenth invention, the slurry is a slurry of an exhaust gas purifying catalyst containing a noble metal.
[0032]
[Action]
According to said structure, the following effects are acquired.
[0033]
That is, according to the first aspect of the present invention, after the tubular honeycomb body is installed in the upper part of the slurry storage section where the slurry to be applied is stored so that the cells formed in the honeycomb body extend in the vertical direction, When the liquid level rises, the slurry is introduced into the cell from the cell opening on the lower end face of the honeycomb body, and as a result, the honeycomb body is immersed in the slurry. As a result, the slurry comes into contact with the surface of the cell and is applied to the surface.
[0034]
And when the liquid level of the slurry rises, the liquid level is regulated so as not to rise inside the cells in the outer peripheral part of the honeycomb body, so that the slurry does not come into contact with the surface of the cells in the outer peripheral part. As a result, application of the slurry to the surface of the cell at the outer peripheral portion of the honeycomb body is prevented.
[0035]
In addition, since the slurry liquid level is raised and held for a predetermined time and then lowered, the slurry and cells are used to flow the slurry from above the honeycomb body and let it pass by natural fall as in the conventional washcoat method. The problem that the contact time with the surface cannot be adjusted is solved, and it becomes possible to lengthen the contact time based on the material of the honeycomb body. As a result, the slurry can be applied to the cell surface regardless of the material of the honeycomb body. Can be applied sufficiently.
[0036]
Furthermore, since the rise of the slurry liquid level is set to a predetermined height with respect to the honeycomb body at this time, the problem that the slurry cannot be regulated to be applied over the entire length of the cell as in the conventional wash coat method. And the slurry can be applied only to a predetermined portion of the cell. As a result, not only one type of slurry can be applied over the entire length of the cell, but also the slurry is applied to the middle of the cell length with a predetermined height with respect to the honeycomb body as the middle of the cell length, and then the honeycomb body By applying the other type of slurry to the part that has not been applied yet, the two types of slurry can be applied separately to the front and back of the cell that could not be handled by the conventional washcoat method. It will be possible.
[0037]
In addition, since the honeycomb body is only installed on the upper part of the slurry reservoir, the cylindrical device used in the conventional washcoat method is not required, resulting in an excessive system, pressure on manufacturing costs, and precise dimensional accuracy setting. Is avoided.
[0038]
According to the second aspect of the present invention, the installation of the honeycomb body in the upper portion of the slurry storage portion is directed so that one end surface of the two end surfaces of the honeycomb body faces downward, the outer peripheral portion of the lower end surface and the slurry storage portion. Since it is performed by closely contacting the peripheral edge of the hole provided in the lid, that is, the lid, the cell is placed vertically in the honeycomb body by effectively utilizing the lid that is normally provided when storing the fluid. It can be installed at the upper part of the storage part so as to extend, and at this time, the opening of the cell in the outer peripheral part of the lower end face is shielded by the peripheral part of the hole closely contacting the lower end face, and when the slurry liquid level rises Since the rise of the liquid level inside the cells at the outer peripheral portion of the honeycomb body is restricted, the lid portion is effectively used without using a cylindrical device in the conventional washcoat method. So that the slurry coating into the arm member outer peripheral surface and the cell surface of the outer peripheral portion is prevented.
[0039]
According to the third aspect of the present invention, air is blown onto the honeycomb body from above the honeycomb body after the slurry level is lowered to finish the coating process, so that the honeycomb body that is the object to be coated is moved. Therefore, the slurry application step and the cell clogging prevention step due to the slurry can be continuously performed at the installation position, and the system can be simplified.
[0040]
According to the fourth invention, the cylindrical honeycomb body to be coated is a porous exhaust gas-purifying catalyst carrier, so that the honeycomb body easily absorbs moisture, and as a result, slurry can be applied to the honeycomb body. This makes it easy to reduce the holding time of the raised liquid level and perform sufficient coating.
[0041]
According to the fifth invention, since the slurry to be applied is a slurry of an exhaust gas purifying catalyst containing a noble metal, the effect of preventing excessive application of the slurry to the honeycomb body outer peripheral surface and the outer peripheral cell surface This is remarkable in terms of material cost, and greatly contributes to reduction in manufacturing cost. Further, in combination with the fourth aspect of the invention, a catalyst carrier in which the exhaust gas-purifying catalyst is supported only on a necessary surface can be obtained.
[0042]
On the other hand, according to the sixth aspect of the present invention, the lid for installing the cylindrical honeycomb body so that the cells extend in the vertical direction is provided on the upper portion of the slurry storage section, Since a hole having a peripheral portion that is in close contact with the outer peripheral portion of the lower end face of the honeycomb body and shields the cell opening in the outer peripheral portion is provided, the honeycomb body is installed at the honeycomb body installation position of the lid portion. Thus, the honeycomb body can be installed in the upper part of the slurry reservoir, in other words, above the liquid level of the slurry so that the cells extend in the vertical direction, and the outer peripheral part of the lower end face of the honeycomb body and the above Since the peripheral edge portion of the hole, that is, the lid portion is in close contact with each other, the hole is covered with the honeycomb body, and as a result, the slurry rising up to the lid portion does not leak out from the hole. At this time, since the opening of the cell in the outer peripheral portion of the lower end face is shielded by the peripheral portion, the slurry rising up to the lid portion is not introduced into the cell in the outer peripheral portion of the honeycomb body, and the lid portion is effectively used. By utilizing this, application of slurry to the outer peripheral surface of the honeycomb body and the cell surface of the outer peripheral portion is prevented.
[0043]
And since the liquid level adjustment means for raising the liquid level of the slurry in the slurry reservoir and allowing the slurry to enter the inside of the honeycomb body installed at the installation position, the slurry liquid level is adjusted by the adjustment means. As the liquid level rises, the slurry is introduced into the cell from the cell opening on the lower end face of the honeycomb body, and as a result, the same effect as when the honeycomb body is immersed in the slurry. The slurry comes into contact with the surface of the cell and is applied to the surface.
[0044]
The slurry rising to the lid when the liquid level of the slurry rises is regulated by the lid or the peripheral edge of the hole, and does not leak out from the hole as described above. Since the liquid level of the slurry introduced into the inside core cell of the honeycomb body rises, the liquid level of the slurry on the outer peripheral surface of the honeycomb body and inside the outer peripheral cell As a result, the slurry does not come into contact with the outer peripheral surface of the honeycomb body and the outer peripheral cell surface, and the application of the slurry to these surfaces is prevented.
[0045]
In addition, since the slurry liquid level is raised from below the honeycomb body by the adjusting means, the slurry and the cell surface are placed in order to allow the slurry to flow from above the honeycomb body and pass by natural fall as in the conventional washcoat method. The problem that the contact time cannot be adjusted is solved, and it is possible to adjust the contact time by holding the raised slurry liquid level for a predetermined time, and as a result, the contact time based on the material of the honeycomb body and the like. The slurry can be sufficiently applied to the cell surface regardless of the material of the honeycomb body.
[0046]
Furthermore, by raising the slurry liquid level from below the honeycomb body, the liquid level can be raised to a predetermined height with respect to the honeycomb body, and the slurry can reach the entire length of the cell as in the conventional washcoat method. The problem that it is impossible to regulate the application across the surface is solved, and the slurry can be applied only to a predetermined portion of the cell. As a result, not only one type of slurry can be applied over the entire length of the cell, but also the slurry is applied to the middle of the cell length with a predetermined height with respect to the honeycomb body as the middle of the cell length, and then the honeycomb body By applying the other type of slurry to the part that has not been applied yet, the two types of slurry can be applied separately to the front and back of the cell that could not be handled by the conventional washcoat method. It will be possible.
[0047]
In addition, since the honeycomb body is installed on the lid portion, a cylindrical device used in the conventional washcoat method is not required, and as a result, an excessive system, pressure on manufacturing costs, and setting of precise dimensional accuracy are avoided. The
[0048]
According to the seventh invention, the hole introduction preventing member is provided in the hole, and the blocking member is in close contact with a predetermined portion of the lower end face of the honeycomb body installed at the honeycomb body installation position of the lid portion. The opening of the cell at the site is shielded by the blocking member. As a result, even if the slurry liquid level is raised, the slurry is not introduced into the shielded cell and coating is not performed. It is possible to selectively prevent the slurry from being applied to the surface.
[0049]
Further, since the blocking member does not clog the cell and only shields its opening, the cell in which the application of slurry is restricted still does not lose its function as a passage, and as a result, the slurry is again put in the cell. Can be introduced and applied. Therefore, for example, after applying the slurry once only to the surface of a predetermined cell, by applying a different type of slurry again by reversing the predetermined part shielded by the blocking member, several types of slurry are applied separately for each cell. Is also possible.
[0050]
Furthermore, since the blocking member is only in close contact with a predetermined portion of the lower end face of the honeycomb body in the coating process, the selective coating as described above can be realized in a single coating process, and as a result, the coating process itself is greatly changed. Therefore, the manufacturing process is not excessively increased by adding a process such as clogging the cells.
[0051]
According to the eighth aspect of the invention, since the air blowing means for blowing air to the honeycomb body from above the honeycomb body installed at the installation position is provided, the honeycomb body that is the object to be coated is installed on the lid portion. After the slurry application process is completed, the cell clogging prevention process can be continuously performed at the installation position, and the system can be simplified.
[0052]
According to the ninth aspect of the invention, since the supporting means for pressing the honeycomb body installed at the installation position from above is provided, a pressing force is applied to the honeycomb body installed on the lid portion from above. Even when the slurry liquid level rises from below with respect to the body, the honeycomb body does not move upward along therewith, and the loosening of the close contact between the lower end face and the peripheral edge of the hole does not occur, It will be implemented smoothly.
[0053]
According to the tenth invention, since the honeycomb body that is the object to be coated is a porous exhaust gas purification catalyst carrier, the honeycomb body easily absorbs moisture, and as a result, the slurry can be easily applied to the honeycomb body. Thus, sufficient coating can be performed.
[0054]
According to the eleventh invention, the slurry to be applied is a slurry of an exhaust gas purifying catalyst containing a noble metal. Therefore, the effect of preventing the slurry from being excessively applied to the outer peripheral surface of the honeycomb body and the outer peripheral cell surface is effective. This is remarkable in terms of material cost, and greatly contributes to reduction in manufacturing cost. Further, in combination with the tenth aspect of the invention, a catalyst carrier in which the exhaust gas purifying catalyst is supported only on a necessary surface can be obtained.
[0055]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0056]
The application apparatus in this embodiment is an apparatus for applying a slurry containing an exhaust gas-purifying catalyst to a monolithic catalyst carrier having an elliptical cross section in which a porous material made of cordierite is formed into a honeycomb structure. As shown in FIG. 2, it has a slurry circulation unit 1 that circulates the slurry S to be coated in a certain work routine, and a work work unit 3 on which the catalyst carrier W that is a coating object is installed.
[0057]
Among these, in the slurry circulation unit 1, the slurry S of alumina particles or zeolite particles adsorbed with a predetermined amount of three kinds of precious metal catalysts of platinum, rhodium and palladium, which are adsorbed in a certain ratio, is stirred by a stirrer (not shown). A large agitation tank 10 that is always stocked in a uniform state is provided. Further, another small measuring tank 11 is provided above the stirring tank 10, and a pumping pipe 12 is disposed between the two tanks 10 and 11, and is provided in the middle of the pipe 12. A predetermined amount of the slurry S in the stirring tank 10 is pumped up by a pump for pumping up slurry (not shown) and temporarily stored in the measuring tank 11.
[0058]
A ball valve 14 is provided on the bottom pipe 13 extending vertically downward from the funnel-shaped bottom of the measuring tank 11, and the communication state of the bottom pipe 13 is switched by the air operation. The ball valve 14 is connected with a vertical pipe 15 extending vertically downward, and a bending pipe 16 extending in the vertical downward direction and subsequently curved in a downwardly inclined manner in this order. Yes.
[0059]
Further, above the central portion of the agitation tank 10, a dipping box 18 in which a hollow space constituting the slurry storage unit 17 is formed is placed via a floor plate 19, and a predetermined side wall of the dipping box 18 is provided. In the position, a slurry supply hole 20 is formed through the side wall so as to incline downward toward the storage portion 17, and an end portion of the bending pipe 16 is fitted into the outer opening of the supply hole 20.
[0060]
Further, the lower surface of the dipping box 18 has an inner diameter continuous with the slurry reservoir 17 and hangs over a round hole 22 formed in the top plate 21 of the agitation tank 10 and moves upward in the tank 10. The slurry return pipe 23 is attached to the storage portion 17 between the attachment portion of the return pipe 23 and the inner opening portion of the supply hole 20. A flat butterfly valve 24 formed in the same shape is provided so as to be rotatable about a support shaft 25, and when the butterfly valve 24 is positioned horizontally, a space between the reservoir 17 and the slurry return pipe 23 is provided. The communication state is cut off.
[0061]
Therefore, when the ball valve 14 is operated to bring the bottom tube 13 into communication, the slurry S temporarily stored in the measuring tank 11 passes through the vertical pipe 15, the bending pipe 16 and the supply hole 20, and stores the slurry in the immersion box 18. At this time, the butterfly valve 24 is positioned horizontally, whereby the introduced slurry S can be stored in the storage unit 17, while the butterfly valve 24 is supported on the support shaft. By rotating about 25, the slurry S stored in the storage unit 17 can be returned to the stirring tank 10 described first via the return pipe 23, and pumped out from the stirring tank 10 here. The slurry S thus made is made a round along the circulation unit 1.
[0062]
On the other hand, the work work unit 3 includes a unit bottom plate 30 placed on the upper surface of the immersion box 18, a unit side plate 31 erected on the side of the bottom plate 30, and a unit top plate provided on the side plate 31. A working space 33 surrounded by 32 is provided, and a working device 34 for performing a predetermined work on the catalyst carrier W is suspended from the top plate 32 so as to be driven in the vertical direction. The catalyst carrier W is installed between the working device 34 and the bottom plate 30 with the two end surfaces facing each other in the vertical direction.
[0063]
Among these, a work cradle 35 is fitted in the center of the unit bottom plate 30, and when the bottom plate 30 is placed on the dipping box 18, the upper opening surface of the slurry reservoir 17 is formed by the work cradle 35. A work installation hole 36 formed in the same shape as the cross-sectional shape of the catalyst carrier W to be installed, that is, an ellipse, is provided at a predetermined position of the work cradle 35 so as to cover the storage. The portion 17 and the work space 33 communicate with each other through the installation hole 36. Accordingly, when the amount of the slurry S pumped into the measuring tank 11 is larger than the total volume of the slurry reservoir 17 closed by the butterfly valve 24 and the volume of the supply hole 20 and the bending pipe 16, the reservoir 17 The slurry S led to the leakage from the installation hole 36 to the work space 33.
[0064]
The installation hole 36 is composed of two parts having different sizes as shown in FIG. 3, and the large diameter upper hole 36 a is set to the same size as the outer peripheral surface of the lower end of the catalyst carrier W, When the catalyst carrier W is installed, the outer peripheral surface of the lower end portion is fitted in close contact with the upper hole 36a without any gap, and the lower hole 36b is set smaller than the upper hole 36a. A shelf 37 having a certain width is formed at the boundary between the holes 36 a and 36 b, and a cell shielding packing 38 is provided on the shelf 37.
[0065]
The cell shielding packing 38 is a ring-shaped packing made of a material having good adhesion such as rubber, for example, and the hole 36a is engaged with the shelf 37 when inserted into the upper hole 36a. The catalyst carrier W is in contact with and closely contacts the outer peripheral portion of the lower end surface of the carrier W when the catalyst carrier W is fitted in the upper hole 36a. The exhaust gas passages X1 to X1 opened at the outer peripheral portion of the lower end face of the multiple exhaust gas passages are formed so as to shield the wall.
[0066]
Therefore, when the catalyst carrier W is fitted into the installation hole 36 and the outer peripheral portion of the lower end surface of the carrier W is brought into close contact with the shielding packing 38, the installation hole 36 is blocked by the carrier W. Thus, the communication state between the slurry reservoir 17 and the work space 33 maintained through the installation hole 36 is the exhaust gas passage X in the inner core portion of the catalyst carrier W that is not shielded by the shielding packing 38. ... will be kept only through X.
[0067]
As a result, as described above, when the amount of the slurry S pumped into the measuring tank 11 is large, the slurry S does not leak from the installation hole 36 as shown in FIG. The exhaust gas passages X1 ... X1 are not introduced into the exhaust gas passages X1 ... X1, but instead enter the interior exhaust gas passages X ... X that are not shielded by the shielding packing 38, and fill the interior of the exhaust gas passages X1 ... X1. The slurry S comes into contact with and is applied. Here, the volume of the exhaust gas passages X... X, the volume of the slurry reservoir 17 when the butterfly valve 24 is closed, and the volumes of the supply hole 20, the bending pipe 16 and the vertical pipe 15 are known in advance. By adjusting the amount of the slurry S pumped up to 11, the liquid level of the slurry S entering the exhaust gas passages X... X can be adjusted up and down. It is possible to apply over the entire length, or to apply only to a predetermined portion of the exhaust gas passages X... X as shown in FIG.
[0068]
Further, a cylinder 40 is provided on the unit top plate 32 via a mounting table 39, and a drive rod 41 connected to the cylinder 40 extends downward and is provided on the top plate 32 and the mounting table 39, respectively. A work device 34 is attached to the lower end portion of the work space 33 through the ceiling frame 42 through the hole and reaches the upper part inside the work space 33, and four work pressing rods 43 are attached to the ceiling frame 42. 43 is fixedly attached, and a work pressing plate 44 is attached to the lower ends of these pressing rods 43.
[0069]
A work pressing hole 45 formed in the same elliptical shape as the cross-sectional shape of the catalyst carrier W is provided in the pressing plate 44 at a position facing the workpiece installation hole 36, and the catalyst carrier W is formed in the pressing hole 45. The upper end of each is fitted. As shown in FIG. 3, the pressing hole 45 has a shape that is substantially vertically symmetrical with the workpiece installation hole 36, and the large-diameter lower hole 45 a is set to have substantially the same size as the upper end portion of the catalyst carrier W. In addition, the upper hole 45b is set to be smaller than the lower hole 45a, and a shelf 46 having a certain width is formed at the boundary between both the holes 45a and 45b. The catalyst carrier W is placed in contact with the outer peripheral portion of the upper end surface.
[0070]
Accordingly, the receiving base 35 provided with the work installation hole 36 for fitting the outer peripheral surface of the lower end portion of the catalyst carrier W and the pressing plate 44 provided with the work pressing hole 45 for fitting the upper end portion of the catalyst carrier W are provided. When the two cylinders 35 and 44 come close to each other by the operation of the cylinder 40, the catalyst carrier W is pressed and supported between them, so that the slurry S is supported from below with respect to the carrier W. Even when the liquid level of the catalyst carrier W rises, the carrier W does not float upward and does not cause displacement, and the cell shielding packing 38 and the outer peripheral portion of the lower end surface of the catalyst carrier W are in close contact with each other. The inconvenience of slackening and causing the slurry S to enter the outer peripheral exhaust gas passage X1... X1 or leak into the work space 33 is avoided. The shelf 46 of the pressing hole 45 is formed in a size that does not shield the upper surface opening of the inner core exhaust gas passage X ... X that is not shielded by the shielding packing 38, thereby communicating the exhaust gas passage X ... X. The state is maintained so that entry of the slurry S from the lower surface opening of the exhaust gas passage X ... X is not hindered.
[0071]
Further, the working device 34 is provided with an air blow mechanism for ejecting air downward from above the catalyst carrier W pressed and supported through the work pressing hole 45. The air blow mechanism includes a guide rail 48 attached to a lower portion of the ceiling frame 42 so as to extend in the front-rear direction of the work device 34 by two support members 47, 47, and slides horizontally along the guide rail 48. And a moving member 49 that moves. The mounting plate 50 fixed to the lower surface of the moving member 49 is provided with an air nozzle 52 via two support members 51 and 51, and a position sensor 54 is provided in front of the air nozzle 52 via a mounting plate 53. These members 52 and 54 are integrally moved horizontally in the front-rear direction of the working device 34 by a motor (not shown) provided in the moving member 49.
[0072]
An air supply pipe 55 is connected to one end of the air nozzle 52, and air fed by an air supply device (not shown) is guided into the air nozzle 52 through a supply port 56, and a slit is formed at the bottom of the air nozzle 52. The air outlet 52a is provided close to the work pressing plate 44 and over the long diameter of the work pressing hole 45 so that the air guided into the air nozzle 52 is jetted downward from the air outlet 52a. Has been made.
[0073]
As a result, air can be blown from above the catalyst carrier W pressed and supported by the workpiece pressing plate 44 through the workpiece pressing hole 45 to the entire upper surface of the carrier W. At this time, the air is not shielded by the shielding packing 38. The air passes through the inner core exhaust gas passages X... X in which the communication state is maintained, and clogging of the passages X. Furthermore, since the air blowing can be performed continuously with the slurry S coating process while the catalyst carrier W is pressed and supported, the work process by the apparatus is not complicated.
[0074]
The motor moves the moving member 49 forward or backward based on a signal from the position sensor 54, and the blowout port 52 a moves over the short hole diameter of the work pressing hole 45. The position target of the position sensor 54 is installed so as to do this.
[0075]
The ceiling frame 42 is provided with two guide rods 57 and 57 penetrating the unit top plate 32 and the cylinder mounting table 39 so that the working device 34 driven up and down by the cylinder 40 is not displaced. Yes.
[0076]
In addition to the above-described configuration, the coating apparatus is provided with a control unit that controls the operation of each member in accordance with the flowchart shown in FIG. Next, the control performed by this control unit will be described.
[0077]
First, in step S1, the control unit closes both the ball valve 14 and the butterfly valve 24 to block communication between the bottom pipe 13 of the measuring tank 11 and communication between the slurry reservoir 17 and the return pipe 23. Next, in step S2, after confirming that the catalyst carrier W is installed in the workpiece installation hole 36, the working device 34 is lowered by operating the cylinder 40 in step S3 to press the catalyst carrier W from above. To support. As a result, the catalyst carrier W is fixed between the workpiece cradle 35 and the workpiece pressing plate 44.
[0078]
Next, the control unit sets the required amount (V) of the slurry S to be pumped from the stirring tank 10 to the measuring tank 11 and the contact time (T) between the slurry S and the catalyst carrier W based on the application level in step S4. Here, the application level refers to which part of the exhaust gas passage X... X is applied, in other words, the height of the liquid level of the slurry S that enters the exhaust gas passage X. When the slurry S is applied from the volume of the member over, for example, the entire length of the passage X ... X, the slurry S is necessary so that the liquid level in the passage X ... X rises to the upper surface of the carrier W. The amount (V) is set, and when the slurry S is applied halfway through the passages X... X, the necessary amount (V) of the slurry S is set so that the liquid level of the slurry S rises to that height. Further, the application level includes the degree of application of the slurry S to the surface of the exhaust gas passage X ... X. For example, when applying the slurry S in a relatively large amount, the contact time (T) is set long, When a relatively small amount of slurry S is applied, the contact time (T) is set short. Since the contact time (T) can be adjusted in this way, the slurry S can be sufficiently applied to the surface of the exhaust gas passages X ... X regardless of the material of the catalyst carrier W. Since the catalyst carrier W in this embodiment is made of cordierite, which is a porous material as described above, it is easy to absorb moisture and the slurry S is easily applied, so that the contact time (T) is relatively long. The application amount is selected by adjusting the contact time (T), which is set short.
[0079]
Next, in step S5, the pump is operated to pump the slurry S in the stirring tank 10 to the measuring tank 11, and the amount of the slurry S in the measuring tank 11 thus pumped is the required amount set in step S4. If it becomes (V) (step S6), the operation of the pump is stopped in step S7. Thus, an amount of slurry S having a desired liquid level in the exhaust gas passages X... X is temporarily stored in the measuring tank 11.
[0080]
Next, in step S 8, the ball valve 14 is opened and the bottom pipe 13 of the measuring tank 11 is communicated, whereby the necessary amount (V) of slurry S stored in the tank 11 is guided to the storage unit 17. As a result, the slurry S guided to the storage part 17 is introduced into the inner core part exhaust gas passages X... X that are kept in communication with each other beyond the installation hole 36, and the liquid level rises to a predetermined application level. On the other hand, the slurry S does not leak to the outside of the installation hole 36 in which the outer peripheral surface of the lower end portion of the catalyst carrier W is fitted without a gap, and as a result, the slurry S liquid on the outer peripheral surface of the carrier W The rise of the surface is regulated, and the slurry S is not introduced also into the outer edge exhaust gas passage X1 shielded by the cell shielding packing 38, so that the rise of the liquid level is restricted. Accordingly, the slurry S comes into contact with only the surface of the inner core exhaust gas passages X ... X not shielded by the shielding packing 38, and only the passages X ... X are selectively applied.
[0081]
Further, in step S9 and step S10, the control unit keeps the contact state between the exhaust gas passages X ... X and the slurry S until the contact time (T) set in step S4 elapses, in other words, the liquid level of the slurry S. By maintaining the state in which the height of the slurry S is raised to a predetermined height, adjustment of the desired slurry S coating amount or reliable realization of the slurry S is achieved. And when the said predetermined contact time (T) passes, the butterfly valve 24 is opened by step S11, and the slurry S currently stored by the slurry storage part 17 is returned to the stirring tank 10 via the return pipe 23. FIG. Thereby, the slurry S is removed from the lower surface side opening of the exhaust gas passages X ... X, and the liquid level is lowered.
[0082]
Thus, the coating process by the coating apparatus is completed, and the process of removing clogging due to the residual slurry S in the exhaust gas passages X.
[0083]
That is, after the liquid level of the slurry S is lowered, the air blow mechanism is operated in step S12, and the moving member 49 moves in the front-rear direction for a predetermined number of times along the guide rail 48 (step S13). The operation is stopped (step S14). As a result, the air nozzle 52 sweeps over the entire upper surface of the catalyst carrier W while blowing air downward from the outlet 52a, so that the exhaust gas passage X ... X coated with the slurry S, that is, the passage in the communication state. X ... The air jetted in the X passes from the upper surface to the lower surface of the carrier W, and the clogging in the passage X ... X is removed.
[0084]
Then, by raising the working device 34 in step S15, the pressure support for the catalyst carrier W on which the above work has been performed is released, and the carrier W can be taken out of the work space 33 here, and this control is finished.
[0085]
As a result of the series of operations described above, as shown in FIG. 6, the catalyst carrier W to which the slurry S is not applied is obtained in the exhaust gas passages X1. Instead of the packing 38, for example, as shown in FIG. 7, the inner core exhaust gas passage X ... X not shielded by the shielding packing 38 is shielded, and the shielded outer peripheral exhaust gas passage X1 ... X1 is not shielded. The formed second cell shielding packing 58 is placed on the shelf 37 of the installation hole 36, and the slurry is replaced with another type of slurry S1, and the same operation is performed, as shown in FIG. The catalyst carrier W can be obtained in which the slurry S is coated in the exhaust gas passages X... X and the slurry S1 is separately applied to the exhaust gas passages X1.
[0086]
At this time, it goes without saying that the application modes of the different types of slurries S and S1 can be changed by variously combining the width of the shielding packing 38 and the size of the shielding portion of the second cell shielding packing 58.
[0087]
For example, when a shielding packing 59 as shown in FIG. 9 is used, different types of slurry can be applied separately for each exhaust gas passage on the left and right sides of the catalyst carrier W as shown in FIG.
[0088]
Furthermore, when the rise of the liquid level of the slurry S in the exhaust gas passages X... X is partway through the passages X... X, the slurry S is applied to the rear surface of the passages X. As shown in FIG. 12, a catalyst carrier W that is not used is obtained. Here, the carrier W is turned upside down and installed again, and the slurry is replaced with another type of slurry S1. In one exhaust gas passage X ... X, it is possible to obtain the catalyst carrier W separately applied without the slurry S being applied to the front part and the slurry S1 being applied again to the rear part.
[0090]
【The invention's effect】
As described above, according to the present invention, the slurry is applied only to the cell surface formed in the core of the honeycomb body while reliably preventing the slurry from being applied to the outer peripheral surface of the honeycomb body and the outer peripheral cell surface. Is possible in a single process.
[0091]
In addition, since the slurry liquid level is raised from below the honeycomb body, the contact state between the slurry and the surface to be coated can be adjusted. As a result, the slurry can be sufficiently applied regardless of the material of the honeycomb body. In addition, two types of slurry can be separately applied to the front portion and the rear portion of the cell.
[0092]
Furthermore, since the communication state of a predetermined cell is shielded when the slurry liquid level rises, the slurry can be selectively applied, and several types of slurry can be separately applied to each cell.
[0093]
And since the cells are not clogged, there is no extra process, and the slurry application process and the clogging removal process of the cells are continuously performed at the installation position without moving the honeycomb body. The apparatus can be simplified.
[Brief description of the drawings]
FIG. 1 is a side view showing a coating apparatus in an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA shown in FIG.
FIG. 3 is an enlarged cross-sectional view of a main part of the coating apparatus.
FIG. 4 is an enlarged cross-sectional view of a main part for explaining the operation of the coating apparatus.
FIG. 5 is a flowchart of control performed by a control unit provided in the coating apparatus.
FIG. 6 is an explanatory view showing a coating mode obtained by the coating apparatus.
FIG. 7 is an explanatory view showing an example of a shielding packing provided in the coating apparatus.
FIG. 8 is an explanatory view showing another coating mode obtained by the coating apparatus.
FIG. 9 is an explanatory view showing another example of the shielding packing provided in the coating apparatus.
FIG. 10 is an explanatory view showing another coating mode obtained by the coating apparatus.
FIG. 11 is an explanatory view showing another coating mode obtained by the coating apparatus.
FIG. 12 is an explanatory view showing another coating mode obtained by the coating apparatus.
[Explanation of symbols]
1 Slurry circulation unit
3 Work unit
11 Weighing tank
14 Ball valve
17 Slurry reservoir
18 Immersion box
24 Butterfly valve
35 Work cradle
36 Work hole
38 Shielding packing
44 Work pressing plate

Claims (11)

A method of applying a slurry to a cylindrical honeycomb body in which a large number of cells communicating with two opposite end faces are formed, wherein the cells are vertically moved above the slurry reservoir where slurry is stored. After being installed so as to extend in the direction, the liquid level of the slurry in the storage section is regulated so as not to rise in the outer peripheral surface of the honeycomb body and the cells in the outer peripheral section, and is placed from a tank higher than the honeycomb body. A cylindrical honeycomb, wherein a predetermined amount of slurry is dropped into the slurry storage portion and poured into the slurry body to raise the honeycomb body to a predetermined height, hold at the predetermined height for a predetermined time, and then lower the honeycomb body. A slurry application method to the body. One end face of the two end faces of the tubular honeycomb body is directed downward, and provided at the outer peripheral portion of the end face and the lid portion of the slurry storage portion so as to shield the cell opening at the outer peripheral portion of the lower end face. The honeycomb body is installed so that the cells extend vertically in the upper part of the reservoir, and the cells in the outer periphery of the honeycomb body when the slurry liquid level rises The method for applying a slurry to a tubular honeycomb body according to claim 1, wherein the rise of the liquid level inside is regulated. 3. The tubular honeycomb body according to claim 1, wherein after the liquid level of the slurry is lowered, air is blown onto the honeycomb body from above the tubular honeycomb body. Slurry application method. The method for applying a slurry to a tubular honeycomb body according to any one of claims 1 to 3, wherein the tubular honeycomb body is a porous catalyst support for exhaust gas purification. The slurry application method to the cylindrical honeycomb body according to claim 4, wherein the slurry is a slurry of an exhaust gas purifying catalyst containing a noble metal. A slurry application device for a cylindrical honeycomb body in which a large number of cells communicating with two opposite end faces are formed, and the cells are placed above and below the slurry storage section for storing slurry. A lid portion is provided so as to extend in the direction, and a hole having a peripheral portion that is in close contact with the outer peripheral portion of the lower end face of the honeycomb body and shields the opening of the cell in the outer peripheral portion is installed in the honeycomb body of the lid portion. And a tank provided at a position higher than the honeycomb body installed at the honeycomb body installation position of the lid part and storing a predetermined amount of slurry, and between the tank and the slurry storage part A valve member that switches a communication state of the pipe member, and operates the valve member to bring the pipe member into a communication state so that a predetermined amount of slurry is dropped from the tank to the slurry storage portion and is allowed to flow. The Mukoto, characterized in that the liquid level adjusting means for entering the slurry inside the honeycomb body installed position in the installation honeycomb body raises the liquid level of the slurry in the container portion the cap portion is provided An apparatus for applying slurry to a cylindrical honeycomb body. The cylindrical honeycomb body according to claim 6, wherein a slurry introduction preventing member that is in close contact with a predetermined portion of a lower end face of the cylindrical honeycomb body installed at the honeycomb body installation position of the lid is provided in the hole. Slurry application device. 8. The air blowing means for blowing air to the honeycomb body from above the cylindrical honeycomb body installed at the honeycomb body installation position of the lid portion is provided. The slurry application apparatus to the cylindrical honeycomb body as described in 2. The cylindrical honeycomb body according to any one of claims 6 to 8, further comprising support means for pressing the cylindrical honeycomb body installed at the honeycomb body installation position of the lid portion from above. Slurry application equipment. 10. The apparatus for applying a slurry to a tubular honeycomb body according to claim 6, wherein the tubular honeycomb body is a porous catalyst support for exhaust gas purification. The slurry applying apparatus for a tubular honeycomb body according to claim 10, wherein the slurry is a slurry of an exhaust gas purifying catalyst containing a noble metal.

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