JP2002283329A - Manufacturing method of honeycomb formed body and drying equipment thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a honeycomb formed body and drying equipment thereof which are capable of drying the honeycomb formed body having a cell wall thickness of 0.125 mm or below, without causing a defect such as a crack or a wrinkle in the outer peripheral skin part. SOLUTION: On the occasion of drying the excluded honeycomb formed body 1 of clay, in the method of manufacturing the ceramic honeycomb formed body 1 having a large number of cells 10 provided by arranging cell walls 11 of a thickness of 0.125 mm or below in the shape of a honeycomb, the honeycomb formed body 1 is exposed to a high-humidity atmosphere having a humidity of 70% or above and also irradiated with a microwave having the frequency of 1000-10000 MHz.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a honeycomb formed body, and more particularly to a drying step and a drying apparatus for the same.

[0002]

2. Description of the Related Art In manufacturing a honeycomb formed body made of ceramic, a honeycomb formed body made of clay is extruded and formed.
After being dried, it is fired. As a method for drying a honeycomb formed body, for example, as disclosed in JP-A-63-166745, a method using a high frequency generated by passing a current between electrodes disposed above and below the honeycomb formed body is used. It has been known. This method is intended to uniformly heat the inside and outside of the honeycomb formed body and to prevent the occurrence of defects such as cracks and wrinkles in the outer peripheral skin portion caused by a difference in shrinkage caused by a difference in drying speed.

[0003]

The above-mentioned drying method uses a cell wall thickness of 0.30 to 0.15 mm and a peripheral skin thickness of 0.3 to 0.1 mm, which has been generally used as a catalyst carrier of an exhaust gas purifying apparatus for automobiles. This is effective for a honeycomb formed body of about 1.0 mm. However, the cell wall thickness, which has been developed in response to recent needs for improving exhaust gas purification performance, is 0.1%.
In a thin-walled product having a thickness of 25 mm or less and a thickness of the outer skin portion of 0.5 mm or less, the strength of the cell wall itself and the strength of the outer skin portion itself are lower than those in the related art. Therefore, in this thin-walled product, it has become difficult to take sufficient measures against the occurrence of defects in the outer skin portion by the conventional method using high frequency.

The present invention has been made in view of the above-mentioned conventional problems, and is intended to dry a honeycomb formed body having a cell wall thickness of 0.125 mm or less without causing defects such as cracks and wrinkles in an outer peripheral skin portion. It is an object of the present invention to provide a method for manufacturing a honeycomb formed body and a drying apparatus which can perform the method.

[0005]

The invention according to claim 1 has a thickness of 0.125.
In a method of manufacturing a ceramic honeycomb formed body provided with a large number of cells by arranging cell walls of not more than 1 mm in a honeycomb shape, dielectric loss is reduced to about 0.1 mm when the extruded clayey honeycomb formed body is dried. The honeycomb formed body placed on a transfer tray made of porous ceramics having a porosity of 10% or less and a cross-sectional area ratio of open area of 50% or more is exposed to a high-humidity atmosphere of 70% or more. A method for manufacturing a honeycomb formed body, which comprises irradiating a microwave having a frequency of 1,000 to 10,000 MHz.

In the manufacturing method of the present invention, as described above, the honeycomb formed body is heated in a high humidity atmosphere having a humidity of 70% or more. Accordingly, it is possible to prevent rapid drying such that the outer peripheral surface of the honeycomb formed body is deformed, and to maintain the outer peripheral surface at an appropriate humidity. This gives
The difference in drying speed between the outer peripheral surface and the inside can be reduced. Therefore, even when the cell wall thickness is as thin as 0.125 mm or less and the outer skin portion is relatively thin,
The difference in shrinkage due to the difference in drying speed between the inside and outside of the honeycomb formed body can be reduced. Therefore, cracks in the outer skin,
Defects such as wrinkles can be prevented. The higher the humidity of the high humidity atmosphere is, the more preferable it is.
Alternatively, it may be in a supersaturated state.

In the present invention, the microwave is used as the heating means. Thereby, heating in the high humidity atmosphere can be realized. That is, in the case of the conventional high-frequency heating, it is necessary to arrange an electrode near the honeycomb formed body. If these electrodes are placed in a high humidity atmosphere, discharge or dielectric breakdown may occur between the electrodes, and equipment failure due to electrode damage may occur.

On the other hand, the microwave can be guided through the waveguide, and there is no need to provide an electrode near the object to be heated. Therefore, the microwave can easily reach the honeycomb formed body even in the high-humidity atmosphere and can heat it. Thus, in the present invention,
Due to the combination of microwave heating and high humidity atmosphere, even if the cell wall thickness is as thin as 0.125 mm and the outer skin is relatively thin, sufficient cracking and wrinkling of the outer skin during drying can be achieved. Can be prevented. By improving the quality at the time of drying, the honeycomb formed body as a fired product obtained through the subsequent firing step can be made to have excellent quality.

Further, in the present invention, the drying is performed by:
The above-described honeycomb formed body is placed on a carrier tray made of porous ceramics having a dielectric loss of 0.1 or less, a porosity of 10% or more, and a cross-sectional opening area ratio of 50% or more. As a method of supporting the honeycomb formed body at the time of drying, it is of course possible to use a tray made of general ceramics in addition to the method using the above-mentioned transfer tray made of the specific ceramics. However, by using a transfer tray made of the above specific ceramics,
During the drying of the honeycomb formed body, it is possible to suppress the occurrence of problems at the contact surface between the honeycomb formed body and a member supporting the honeycomb formed body.

[0010] That is, in the above-mentioned clay-based honeycomb molded body, components may be eluted when in contact with a water film. Therefore, if moisture from a high-humidity atmosphere or moisture evaporated from the honeycomb formed body stagnates in a contact portion with another member supporting the honeycomb formed body, there is a possibility that components of the honeycomb formed body may be eluted in the contact portion. . On the other hand, by mounting the honeycomb formed body on a transfer tray made of porous ceramics having a porosity of 10% or more and a cross-sectional opening area ratio of 50% or more, the transfer tray and the honeycomb formed body are separated. Even if the water stays in the vicinity of the contact portion, the water can be prevented from staying by the drainage action through the pores of the transport tray. If the porosity is less than 10% or the cross-sectional area ratio is less than 50%, the drainage function may not be sufficiently obtained.

When the other member supporting the honeycomb formed body has a property of a large dielectric loss, the other member is also heated by the microwave for heating the honeycomb formed body. In this case, due to direct heat transfer from the heated other member, the honeycomb formed body at the contact portion may be locally heated at a high speed to cause deformation or the like. On the other hand, as described above, by placing the honeycomb formed body on the transfer tray having a dielectric loss of 0.1 or less,
Heating of the transfer tray can be avoided, and the above-described problems can be prevented.

Next, as in the second aspect of the present invention, it is preferable that the honeycomb formed body is placed with one of the open end faces of the cell in contact with the upper surface of the transport tray. The mounting direction of the honeycomb formed body on the transport tray can be any direction. However, especially when one of the open end surfaces of the cells is brought into contact with the upper surface of the transport tray as described above, the communication between the pores of the transport tray and the cells of the honeycomb formed body can be ensured.

Preferably, the transport tray is made of urea resin foam.
In this case, it is possible to easily obtain an excellent transport tray having the above-mentioned dielectric loss characteristics, porosity, and cross-sectional opening area ratio in the above-described preferred ranges.

In drying the above-mentioned honeycomb formed body as in the invention of claim 4, each honeycomb formed body is arranged so as to have a certain interval between adjacent honeycomb formed bodies. And dried. In this case, the microwave applied to each honeycomb formed body can be made more uniform, and the occurrence of drying unevenness can be suppressed. Therefore, troubles that may occur during drying can be more sufficiently prevented.

In drying the honeycomb formed body, it is preferable to change the microwave irradiation conditions according to the number of the honeycomb formed body. In this case, regardless of the number of the honeycomb formed bodies in the drying tank, each of the honeycomb formed bodies can be uniformly irradiated with the microwave. Therefore, troubles that may occur during drying can be more sufficiently prevented.

Next, the invention according to claim 6 has a thickness of 0.125.
a honeycomb drying apparatus for drying an extruded clay-like honeycomb molded body in producing a ceramic honeycomb molded body provided with a large number of cells by arranging cell walls of not more than 1 mm in a honeycomb shape; A drying tank for storing the molded body, a humidifying device for setting the inside of the drying tank to a high humidity atmosphere having a humidity of 70% or more, and a microwave generator for supplying microwaves in a frequency range of 1000 to 10000 MHz into the drying tank. And a conveying device for continuously feeding and discharging a plurality of honeycomb formed bodies into and from the drying tank.

By using the drying apparatus of the present invention, drying in the above-described manufacturing method can be easily realized, and a honeycomb formed body having excellent quality can be manufactured. That is, a honeycomb formed body to be dried is placed in the drying tank, and the humidity in the drying tank is increased to 70% or more by the humidifier to form a high humidity atmosphere. And
By introducing microwaves from the microwave generator, the honeycomb formed body can be microwave-heated. Thereby, the honeycomb formed body can be dried without generating cracks and wrinkles in the outer peripheral skin portion.

Further, in the present invention, the above-mentioned conveying device for continuously feeding and discharging the plurality of honeycomb formed bodies into and from the drying tank is provided. Therefore, the honeycomb formed body can be continuously dried. Therefore, according to the drying device, the honeycomb formed body can be dried very efficiently while preventing the outer peripheral skin portion of the honeycomb formed body from cracking and wrinkling.

According to a seventh aspect of the present invention, the drying tank has openings for feeding and discharging a plurality of honeycomb formed bodies to and from the drying tank continuously. Preferably, the section has a shut-off means for preventing the high-humidity air in the drying tank from mixing with the outside air. In this case, a uniform and high humidity atmosphere can be formed in the drying tank. In addition, since high-humidity air in the drying tank can be prevented from flowing out,
A desired high humidity atmosphere can be formed by a small-scale humidifier or the like.

According to the present invention, the shut-off means cuts off the high-humidity atmosphere in the drying tank from the outside atmosphere by forming a flow of air which shuts off the opening. It is preferable that it is comprised as follows. In this case, the above-described effects can be obtained with a small-sized and simple equipment configuration.

According to a ninth aspect of the present invention, the drying device is configured to change the microwave irradiation conditions according to the number of honeycomb formed bodies in the drying tank. Is preferred. In this case, even if the number of honeycomb formed bodies in the drying tank varies, the amount of microwaves applied to each honeycomb formed body can be made uniform.

According to a tenth aspect of the present invention, the transport device adjusts the supply of the honeycomb formed bodies so that the honeycomb formed bodies fed into the drying tank are arranged at equal intervals. It is preferable to have an accumulator function. Here, the accumulator function is a function of adjusting a variation in the supply amount of the honeycomb formed body supplied to the transfer device and feeding the honeycomb formed body to the drying tank at regular intervals. According to the accumulator function, the honeycomb formed bodies can be conveyed in the drying tank in a state where they are arranged at equal intervals, regardless of the supply state of the honeycomb formed bodies to the transfer device.

Preferably, the drying apparatus has a plurality of inlets for introducing the microwave. By irradiating the microwaves from a plurality of inlets, variations in the microwave density in the drying tank can be suppressed. Therefore, drying unevenness can be suppressed, and the operation and effect of the present invention can be further enhanced.

According to a twelfth aspect of the present invention, the drying device includes a first inlet provided near an opening through which the honeycomb formed body is fed into the drying tank; A second inlet provided in the vicinity of an opening for sending out from the drying tank; the first inlet irradiates the microwave toward the opening on the sending side; It is preferable that the second inlet is configured to irradiate the microwave toward the opening on the sending side.
By irradiating microwaves from opposite directions along the transport direction, it is possible to further suppress the variation in the microwave density between the sending side and the sending side of the drying tank.

According to a thirteenth aspect of the present invention, the drying device further comprises a first inlet provided above an opening through which the honeycomb formed body is fed into the drying tank; A second inlet provided on the lower side, wherein the first inlet and the second inlet are connected to the microwave toward an opening for sending out the honeycomb formed body from the drying tank. Is preferably configured to be irradiated. As described above, by arranging the microwave introduction port, the variation in the microwave density in the vertical direction of the drying tank can be further suppressed.

According to a fourteenth aspect of the present invention, the drying apparatus has a first inlet provided at an upper part of the drying tank and a second inlet provided at a lower part of the drying tank. The first inlet irradiates the microwave toward a lower portion of the drying tank, and the second inlet irradiates the microwave toward an upper portion of the drying tank. Is preferred. By irradiating the microwaves from opposite directions along the vertical direction, the variation in the microwave density between the upper side and the lower side of the drying tank can be further suppressed.

According to a fifteenth aspect of the present invention, the drying device comprises a first inlet port and a second inlet port provided on both sides of the inside of the drying tank opposite to each other with the transfer device interposed therebetween. And the first inlet is configured to irradiate the microwave toward the opposite side, and the second inlet is configured to irradiate the microwave toward the opposite side. Is preferred. The microwave density is further suppressed on both sides of the drying tank with the transfer device interposed therebetween by irradiating microwaves from the opposite direction along a direction perpendicular to the transfer direction and horizontal to the ground. be able to.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A method for manufacturing a honeycomb formed body and a drying apparatus according to an embodiment of the present invention will be described with reference to FIGS. In this example, as shown in FIG. 2, a method for manufacturing a ceramic honeycomb formed body 1 in which a plurality of cells 10 are provided by arranging cell walls 11 having a thickness t1 of 0.125 mm or less in a honeycomb shape. As shown in the figure, the honeycomb formed body 1 of this example has a rectangular cell 10 and a cylindrical outer skin portion 12 having a thickness t2 of 0.5 mm or less. The cell shape and overall shape can be changed according to the application.

In the method of the present embodiment, when drying the extruded clay-like honeycomb formed body 1, the honeycomb formed body 1 is exposed to a high humidity atmosphere having a humidity of 70% or more and a micro-frequency of 1000 to 10,000 MHz is used. Irradiate waves. The details are described below.

In manufacturing the honeycomb formed body 1 of this example, first, 5 parts by weight of an organic binder and 15 parts by weight of water were added to 100 parts by weight of a ceramic raw material powder mainly serving as cordierite. And kneaded to produce a clay-like ceramic raw material. Next, the ceramic raw material was extruded from a honeycomb mold using an extruder (not shown) and cut into a predetermined length to form a clay-like honeycomb molded body 1. Examples of the extruder include a plunger type and an auger type. In this example, the slit width of the cell wall of the honeycomb mold was set to 0.115 mm, and the slit width of the outer peripheral skin was set to 0.3 mm.

Next, the thin-walled honeycomb formed body 1 obtained by the extrusion molding was dried using a drying device 3 shown in FIG. As shown in the figure, the drying device 3 includes a drying tank 30 for storing the honeycomb formed body 1, a humidifying device 32 for making the inside of the drying tank 30 a high humidity atmosphere having a humidity of 70% or more,
A microwave generator 34 for supplying microwaves in a frequency range of 1000 to 10000 MHz into the drying tank 30;

The drying tank 30 has a size capable of accommodating a plurality of honeycomb formed bodies transported by the transport device 4 described later. Waveguides 340 extending from the four microwave generators 34 are connected to and open at the four corners of the one side wall 303 at the front, rear, upper and lower sides. This opening is the microwave introduction port 341.

Two steam pipes 320 extending from a boiler as the humidifier 32 and connected are opened at two locations before and after the side wall 303. This opening is the steam inlet 321. The steam introduced from the steam inlet 321 is high-temperature steam sent from the boiler as described above, and its temperature is 80 ° C. or higher.

Further, the drying device 3 of the present embodiment has a transporting device 4 for transporting the honeycomb formed body, and the plurality of honeycomb formed bodies 1 are continuously fed into the drying tank 30 to be transported. It is a continuous device configured to be able to send. Specifically, the drying tank 30 has an entrance 301 therein.
The belt conveyor 41 is provided so as to connect the outlet section 302 with the belt conveyor 41. A roller conveyor 42 is provided outside the outlet side of the drying tank 30.

The transport device 4 including the belt conveyor 41 and the roller conveyor 42 is configured to transport the transport tray 5 on which the honeycomb formed body 1 is placed. In this example, the transport tray 5 has a dielectric loss of 0.
1 or less, porosity is 10% or more, cross-sectional opening area ratio is 50%
The above porous ceramics, in this example, those made of cordierite were used. This material is made of urea resin,
It can be changed to something else. Further, on the transport tray 5, one of the open end surfaces (101) of the cells 10 of the honeycomb formed body 1 was placed in contact with the upper surface 51 of the transport tray 5. Thereby, each honeycomb formed body 1
The cell 10 is oriented vertically and communicates with the pores of the transport tray 5.

A hot air generator 36 is provided outside the drying tank 30 and below the roller conveyor 42. The hot air generator 36 is provided with the roller conveyor 42.
It is configured to blow hot air of 120 ° C. upward from below the transport tray 5 moving upward. This temperature is a temperature at which the binder contained in the honeycomb formed body 1 does not burn.

In drying the honeycomb molded body 1 extruded as described above using the drying apparatus 3 having such a configuration, first, as shown in FIG. 1, each honeycomb molded body cut to a predetermined length is formed. The body 1 is placed on the transport tray 5 and sequentially placed on the belt conveyor 41. Thereby, each honeycomb formed body 1 is sequentially fed into the drying tank 30.

Each of the honeycomb formed bodies 1 sent into the drying tank 30 is moved into the entrance 3 by the movement of the belt conveyor 41.
It is dried while moving from the 01 side to the outlet section 302 side. Here, the inside of the drying tank 30 has a high humidity atmosphere of 70% or more (80% or more in this example) and a temperature of 80 ° C. or more due to the high-temperature steam introduced from the humidifier 32. Microwaves emitted from the microwave generator 34 are introduced. Therefore, drying tank 3
The honeycomb formed body 1 in 0 is rapidly dried while preventing the outer skin portion 12 from cracking or wrinkling.

That is, since the drying tank 30 has a high-temperature and high-humidity atmosphere as described above, when the honeycomb formed body 1 is heated, rapid drying such that the outer peripheral surface is deformed is prevented, and the Humidity is maintained. Therefore, the difference in drying speed between the outer peripheral surface and the inside can be reduced.
Therefore, even with the honeycomb formed body 1 of the present example having a thin cell wall thickness of 0.125 mm or less, a difference in shrinkage due to a difference in drying speed between inside and outside can be reduced. Therefore, defects such as cracks and wrinkles of the outer peripheral skin portion 12 can be prevented.

In this embodiment, the microwave is used as the heating means. The microwave can be easily introduced through the waveguide 70 even when the inside of the drying tank 30 has the high humidity atmosphere as described above. for that reason,
Dielectric heating of the honeycomb formed body 1 can be easily performed without taking a complicated equipment configuration. As described above, in this example, the combination of the microwave heating and the high-humidity atmosphere makes it possible to obtain a thin product having a cell wall thickness of 0.125 mm or less and an outer skin portion of 0.3 mm or less.
The occurrence of cracks and wrinkles in the outer skin portion 12 during drying can be sufficiently prevented.

Further, in this embodiment, after drying by microwaves in a high humidity atmosphere in the drying tank 30, hot air generated from the hot air generator 36 passes through the cell 10 to the honeycomb formed body 1. Guess. That is, in this example, the honeycomb formed body 1 is dried by a combination of microwave heating in a high humidity atmosphere and heating by hot air. Specifically, the water content of the honeycomb formed body before drying is 10 to 20%.
% Is dried by microwave heating in the high humidity atmosphere described above until the moisture content is still 5%.
% By using hot air.

Thus, it is possible to easily control the microwave heating in the high humidity atmosphere, and it is possible to prevent the binder component of the honeycomb molded body from being burned out due to the excessive heating of the microwave heating. . Then, accurate and complete drying can be realized by hot air at a temperature at which there is no risk of excessive heating.

Further, the drying device 4 of the present embodiment has the transport device 4 as described above, and has a configuration capable of continuous operation.
Therefore, the drying step can be performed very efficiently. Further, as described above, the transport tray 5 of this embodiment is made of a specific ceramic such as porous cordierite having a dielectric loss of 0.1 or less, a porosity of 10% or more, and a sectional opening area ratio of 50% or more. I have. Therefore, at the time of drying by the microwave, it is possible to prevent the retention of water and the temperature of the transport tray 5 from being raised. Further, at the time of heating with hot air, the supply of hot air through the pores causes the cells 10 to be heated.
Hot air can easily pass through the inside.

Embodiment 2 In this embodiment, the humidity is changed by changing the amount of high-temperature steam introduced into the drying tank 30 by using the drying apparatus 3 of Embodiment 1 and the correlation between the humidity and the quality of the outer skin portion. An experiment was performed. Conditions other than the humidity were the same as those in the first embodiment.

FIG. 3 shows the experimental results. In the figure, the horizontal axis indicates the humidity in the drying tank 30 and the vertical axis indicates the crack / wrinkle defect rate of the outer skin portion. In each experiment, 20 honeycomb formed bodies were processed, and those having even slight cracks and wrinkles were regarded as defective products, and the ratio of the number was calculated as a defective rate. As is known from the figure, it was found that the effect of preventing cracks and wrinkles was exhibited by increasing the humidity above 50%, and that the cracks and wrinkles could be almost completely prevented at 70% or more.

Embodiment 3 In this embodiment, the porosity of the transport tray 5 in Embodiment 1 is changed, and the humidity in the drying tank 30 is changed in the same manner as described above, thereby preventing the problem caused by the accumulation of moisture during drying. An experiment to determine the presence or absence was performed. Conditions other than the porosity of the transport tray 5 and the humidity in the drying tank 30 were the same as those in the first embodiment.

FIG. 4 shows the experimental results. In the figure, the porosity of the transport tray is plotted on the horizontal axis, and the humidity of the drying tank 30 is plotted on the vertical axis. The treatment under each condition was performed once, and X was plotted when there was any elution of the cell wall or outer skin portion, and O was plotted when there was no elution. As can be seen from the figure, the elution becomes easier as the humidity becomes higher. However, at least when the humidity is 70%, the elution can be prevented by setting the porosity of the transfer tray to 10% or more. Also, it can be seen that even when the humidity is 100%, elution can be prevented by setting the porosity of the transport tray to at least 25% or more.

Fourth Embodiment In this embodiment, as described in the first embodiment, when the honeycomb formed body is dried, the honeycomb formed body is fed into a drying tank using a transfer device having an accumulator function. This is an example.

This embodiment is carried out by using a drying device 3 as shown in FIG. Based on the drying device 3 of the first embodiment, the drying device 3 causes the transport device 4 to hold the accumulator 43 serving as the accumulator function and the honeycomb formed body 1 on the accumulator 43. A stopper 45 is added. Further, the drying device is the same as the drying device 30 of the first embodiment.
Based on the above, an air generator 35 for forming an air curtain at the opening of the drying tank 30 is added.

Here, the air curtain is a plane formed in parallel with an opening formed by an opening communicating with the outside in order to prevent the atmosphere inside and outside the drying tank from being mixed. Air flow. The accumulator 43 includes a plurality of cylindrical rollers 44. Each cylindrical roller 44 is mounted so that its axial direction is horizontal to the ground and perpendicular to the transport direction. The accumulator 43 has such a cylindrical roller 44,
They are arranged in a line in the transport direction. further,
Each cylindrical roller 44 is connected by a motor (not shown), and is configured to rotate in the direction of arrow R as shown in FIG.

Then, the accumulator 43 is
The honeycomb formed body 1 is transported by the frictional force generated between the outer peripheral surface of the rotating cylindrical roller 44 and the transport tray 5. Here, a smooth surface is formed on the outer peripheral surface of the cylindrical roller 44, and the honeycomb formed body 1 is configured to be easily retained on the accumulation conveyor 43.

In this embodiment, the stopper 45 switches the state of the honeycomb formed body 1 between the transport state and the stationary state. As shown in FIG. 5, the stopper 45 is connected to the drying tank 30.
Is configured to protrude upward near the entrance portion 301 and hit the side surface of the transport tray 5.

The air generator 35 is provided with an air pipe 350
And an air outlet 351.
Are disposed near the openings of the inlet 301 and the outlet 302 of the drying tank 30. Further, the air ejection port 351 is configured to blow air in a diagonal direction of the opening to form an airflow parallel to an opening surface formed by the opening.

In this example, the honeycomb formed body 1 was dried by using the drying device 3 configured as described above. The honeycomb formed body 1 carried into the drying device 3
Are placed on the transport tray 5 and transported by the accumulator 43. When the sheet is conveyed to the vicinity of the entrance 301 of the drying tank 30, the transfer tray 5
Contacts the stopper 23 and stops. Thereafter, when the honeycomb formed bodies 1 are successively carried into the drying device 3, the honeycomb formed bodies 1 are sequentially stopped on the accumulation conveyor 43. Then, the stopped honeycomb formed body 1 forms a matrix on the accumulator 24.

Then, after a certain number of the honeycomb formed bodies 1 are stopped on the accumulation conveyor 43, the feeding of the honeycomb formed bodies 1 into the drying tank 30 is started. First, after operating one of the honeycomb formed bodies 1 by operating the stopper 23, the stopper 23 is returned to the original position and the remaining honeycomb formed body 1 is stopped again. After a predetermined interval has elapsed, a series of steps of unloading one honeycomb molded body 1 as described above is repeatedly performed. Here, the predetermined interval was determined according to the interval that each honeycomb formed body 1 should make on the accumulator 24.

As described above, according to the present embodiment, the accumulator function separates the honeycomb molded body 1 from the supply timing of supplying the honeycomb molded body 1 to the drying device 3 and separates the honeycomb molded body 1 at regular intervals. It can be sent to the drying tank 30. Therefore, in the drying tank 30, the honeycomb formed bodies 1 can be always arranged at equal intervals.

In this embodiment, an air curtain is installed at the opening of the drying tank 30. Therefore, it is possible to prevent the high humidity atmosphere in the drying tank 30 from being mixed with the external atmosphere while facilitating the feeding and sending of the honeycomb formed body 1 to the drying tank 30. Therefore,
A uniform high humidity atmosphere can be accurately maintained in the drying tank 30.

As described above, according to this embodiment, the drying tank 3
In the uniform high-humidity atmosphere kept within 0, the honeycomb molded body 1 can be uniformly irradiated with the microwave. For this reason, in the honeycomb formed body 1 that is dried using the drying device 3, the occurrence of drying unevenness can be further suppressed. Therefore, in the honeycomb formed body 1 having a thin cell wall or the like, cracking and wrinkling of the outer peripheral skin portion 12 during drying can be more sufficiently prevented. Other configurations and functions and effects
This is the same as the first embodiment.

Fifth Embodiment This embodiment is an example in which the microwave output value of the drying device 3 is adjusted in accordance with the number of the honeycomb formed bodies 1 in the drying tank 30 in the first embodiment. Therefore,
An appropriate microwave output value of the drying device 3 was examined. As a result, as shown in FIG. 6, it was found that it was appropriate to set the microwave output value according to the number of honeycomb formed bodies 1 in the dry layer 30. Therefore, in this example, when the honeycomb formed body 1 is dried using the drying device 3,
The microwave output was adjusted according to the number of the honeycomb formed bodies 1 in the drying tank 30, as shown in FIG.

According to the present embodiment, even when the number of the honeycomb formed bodies 1 in the drying tank 30 fluctuates, the microwave applied to each honeycomb formed body 1 can be made uniform. Therefore, it is possible to effectively suppress the variation in the degree of drying that occurs for each honeycomb formed body 1. Therefore, in the honeycomb formed body 1 having a thin cell wall or the like, cracking and wrinkling of the outer peripheral skin portion 12 during drying can be more sufficiently prevented. Other configurations and operational effects are the same as those of the first embodiment.

Embodiment 6 This embodiment is an example in which the drying apparatus in Embodiment 1 is used in which the variation in the microwave density in the drying tank 30 is suppressed. As shown in FIG. 7, the drying device 3 of the present example is based on the drying device 3 of the first embodiment, and the arrangement of the microwave device including the microwave generator, the waveguide, and the microwave inlet is changed. Things.

The drying device 3 is provided with the honeycomb formed body 1
A first introduction port 344 provided near the opening 381 for feeding the honeycomb formed article 1 into the drying tank 30, and a second introduction port provided near the opening 382 for sending the honeycomb formed body 1 from the drying tank 30. Port 347. Then, the first inlet 344 irradiates the microwave toward the opening 382 on the sending side, and the second inlet 347 irradiates the microwave toward the opening 381 on the sending side. It is configured as follows.

In this example, the honeycomb formed body 1 was dried using the drying apparatus 3 configured as described above. In the drying tank 30, the dispersion of the microwave density is suppressed between the sending side and the sending side of the drying tank. Therefore, the honeycomb formed body 1 is
While being conveyed in the drying tank 30, it is uniformly irradiated with microwaves. Therefore, according to this example, the drying of the honeycomb formed body 1 proceeds at a constant speed, and the trouble at the time of the drying can be prevented. Other configurations and operational effects are the same as those of the first embodiment.

Seventh Embodiment This embodiment is an example in which the drying apparatus which suppresses the variation of the microwave density in the drying tank 30 in the first embodiment is used. As shown in FIG. 8, the drying device 3 of the present example is based on the drying device 3 of the first embodiment, and the arrangement of the microwave device including the microwave generator, the waveguide, and the microwave inlet is changed. Things.

The drying device 3 is provided with the honeycomb formed body 1
It has a first inlet 344 provided above the opening 381 for feeding the water into the drying tank 30, and a second inlet 347 provided below the opening 381. The first inlet 344 and the first inlet 347 are configured to irradiate the microwave toward the opening 382 for sending the honeycomb formed body 1 from the drying tank 30.

In this example, the honeycomb formed body 1 was dried using the drying device 3 configured as described above. In the drying tank 30, unevenness in the density of the microwave irradiated in the transport direction is suppressed above and below the drying tank. Therefore, the microwave can be uniformly irradiated on the upper and lower sides of the outer peripheral surface of the honeycomb formed body 1. Therefore, according to this example, the upper part and the lower part of the honeycomb formed body 1
Similarly, the drying proceeds, and the trouble at the time of the drying can be prevented. Other configurations and operational effects are the same as those of the first embodiment.

Eighth Embodiment This embodiment is an example in which the drying apparatus in which the variation of the microwave density in the drying tank 30 is suppressed in the first embodiment is used. As shown in FIG. 9, the drying device 3 of the present example is based on the drying device 3 of the first embodiment, and the arrangement of the microwave device including the microwave generator, the waveguide, and the microwave inlet is changed. Things.

The drying device 3 has a first inlet 344 provided above the drying tank 30 and a second inlet 347 provided below the drying tank 30. The first inlet 344 irradiates the microwave toward the lower part of the drying tank 30, and the second inlet 347 irradiates the microwave toward the upper part of the drying tank 30. It is configured.

In this example, the honeycomb formed body 1 was dried by using the drying apparatus 3 configured as described above. In the drying tank 30, the unevenness in the density of the microwave irradiated in the vertical direction is suppressed on the upper and lower sides of the drying tank. Therefore, the microwaves can be evenly applied to both end faces of the honeycomb formed body 1. Therefore, according to the present example, the drying proceeds in the same manner in the upper portion and the lower portion of the honeycomb formed body 1, and the trouble at the time of the drying can be prevented. Other configurations and operational effects are the same as those of the first embodiment.

Embodiment 9 This embodiment is an example in which the drying apparatus in Embodiment 1 in which the variation in the microwave density in the drying tank 30 is suppressed is used. As shown in FIG. 10, the drying device 3 of the present example is based on the drying device 3 of the first embodiment, and the arrangement of the microwave device including the microwave generator, the waveguide, and the microwave inlet is changed. Things.

The drying device 3 has a first inlet 344 provided on the side surface 303 of the drying tank 30 and a second inlet 347 provided on the side 304 opposite to the side 303. The first inlet 344 is connected to the side surface 3.
The microwave is irradiated toward the side 04, and the second inlet 347 is configured to emit the microwave toward the side surface 303.

In this example, the honeycomb formed body 1 was dried using the drying device 3 configured as described above. In the drying tank 30, the dispersion of the microwave density is suppressed on both sides of the drying tank with the transfer device interposed therebetween. Therefore, microwaves can be uniformly irradiated on both sides of the honeycomb formed body 1 in the transport direction. Therefore, according to the present embodiment, drying proceeds in the same manner on both sides of the honeycomb formed body 1, and the trouble at the time of the drying can be prevented. Other configurations and operational effects are the same as those of the first embodiment.

It is also conceivable to arrange the microwave inlet in the drying tank by combining all or a part of the sixth to ninth embodiments. In this case, the volume, length,
It is preferable to appropriately select the combination of the arrangement of the microwave introduction ports according to the height, the number of the honeycomb formed bodies simultaneously fed into the drying tank, and the like. The variation in the microwave density in the drying tank can be further suppressed, and the effect of the present example can be further enhanced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a drying device according to a first embodiment.

FIG. 2A is a perspective view of a honeycomb formed body according to the first embodiment, and FIG. 2B is an explanatory view showing a cell wall thickness.

FIG. 3 is an explanatory diagram showing a relationship between the humidity in a tank and a crack / wrinkle defective rate in a second embodiment.

FIG. 4 is an explanatory diagram showing a relationship between humidity in a transport tray and a tank and elution of a honeycomb formed body in a third embodiment.

FIG. 5 is an explanatory diagram illustrating a configuration of a drying device according to a fourth embodiment.

FIG. 6 is a graph showing a relationship between an appropriate number of honeycomb formed bodies and an appropriate microwave output in the drying apparatus according to the fifth embodiment.

FIG. 7 is an explanatory side view showing an arrangement of microwave introduction ports in a drying apparatus according to a sixth embodiment.

FIG. 8 is an explanatory diagram showing a side view of an arrangement of microwave introduction ports in a drying apparatus according to a seventh embodiment.

FIG. 9 is an explanatory side view showing an arrangement of microwave introduction ports in the drying apparatus according to the eighth embodiment.

FIG. 10 is an explanatory top view showing an arrangement of microwave introduction ports in a drying apparatus according to Embodiment 9;

[Explanation of symbols]

 1. . . 9. honeycomb formed body, . . Cell, 11. . . 11. cell walls, . . Outer skin part, 3,6. . . Drying device, 30, 60. . . Drying tank, 32, 62. . . Humidifier, 320, 620. . . Steam piping, 321,621. . . Steam inlet, 34, 64. . . Microwave generator, 340, 640. . . Waveguide, 341, 641. . . Microwave inlet, 36, 66. . . Hot air generator, 4. . . Transfer device, 41. . . Belt conveyor, 42. . . Roller conveyor, 5. . . Transport tray,

Continued on the front page (72) Inventor Hiromi Kato 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (Reference) 3L113 AA02 AC13 AC27 AC36 AC67 BA01 DA24 4G055 AA08 AB03 AC10 BA12

Claims (15)

[Claims] 1. A method for manufacturing a ceramic honeycomb formed body having a large number of cells by arranging cell walls having a thickness of 0.125 mm or less in a honeycomb shape, comprising the steps of: Upon drying, the dielectric loss is 0.1 or less, the porosity is 10% or more, and the sectional opening area ratio is 5
The honeycomb formed body placed on a transfer tray made of 0% or more porous ceramics is exposed to a high humidity atmosphere having a humidity of 70% or more, and a frequency of 1000 to 10000.
A method for manufacturing a honeycomb formed body, which comprises irradiating a microwave in a MHz region. 2. The method for manufacturing a honeycomb formed body according to claim 1, wherein the honeycomb formed body is placed with one of the open end surfaces of the cells in contact with the upper surface of the transport tray. 3. The method for manufacturing a honeycomb formed body according to claim 1, wherein the transfer tray is formed of a urea resin foam. 4. The method according to claim 1, wherein:
In drying the above-mentioned honeycomb formed body, each honeycomb formed body is arranged and dried so as to have a certain interval between adjacent honeycomb formed bodies, and is dried. . 5. The method according to claim 1, wherein:
A method for manufacturing a honeycomb formed body, characterized in that, when drying the honeycomb formed body, the microwave irradiation conditions are changed according to the number of the honeycomb formed body. 6. A method of manufacturing a ceramic honeycomb formed body having a plurality of cells by arranging cell walls having a thickness of 0.125 mm or less in a honeycomb shape, drying an extruded clay-based honeycomb formed body. A drying tank for storing the honeycomb formed article, a humidifying apparatus for setting the inside of the drying tank to a high humidity atmosphere having a humidity of 70% or more,
A honeycomb, comprising: a microwave generator for supplying microwaves in the range of 000 to 10000 MHz into the drying tank; Drying device for moldings. 7. The drying tank according to claim 6, wherein the drying tank has openings for feeding and discharging a plurality of honeycomb formed bodies to and from the drying tank in a continuous manner. An apparatus for drying a honeycomb formed body, comprising: a shut-off means for preventing high-humidity air in a drying tank from mixing with outside air. 8. The device according to claim 7, wherein the blocking means forms a flow of air for blocking the opening.
An apparatus for drying a honeycomb formed body, wherein the apparatus is configured to shut off a high humidity atmosphere in the drying tank and an external atmosphere. 9. The method according to claim 7, wherein:
The drying device for a honeycomb formed article, wherein the drying device is configured to change the irradiation condition of the microwave according to the number of the honeycomb formed articles in the drying tank. 10. The honeycomb molded body according to any one of claims 7 to 9, wherein the conveying device is configured to dispose the honeycomb molded bodies sent into the drying tank at equal intervals. An apparatus for drying a honeycomb formed body, which has an accumulator function for adjusting supply. 11. The drying apparatus for a honeycomb formed body according to claim 7, wherein the drying apparatus has a plurality of inlets for introducing the microwave. 12. The drying apparatus according to claim 11, wherein the drying device comprises: a first inlet provided near an opening for feeding the honeycomb formed body into the drying tank; A second inlet provided in the vicinity of an opening for sending out, the first inlet irradiating the microwave toward the opening on the sending side, and irradiating the second inlet with the second inlet.
An apparatus for drying a honeycomb formed body, wherein the inlet is configured to irradiate the microwave toward the opening on the inlet side. 13. The drying device according to claim 11, wherein the drying device includes a first inlet provided above an opening through which the honeycomb formed body is fed into the drying tank, and a drying device provided below the opening. A first inlet and a second inlet for irradiating the microwave toward an opening for sending out the honeycomb formed body from the drying tank. An apparatus for drying a formed honeycomb article, comprising: 14. The drying device according to claim 11, wherein the drying device has a first inlet provided at an upper part of the drying tank and a second inlet provided at a lower part of the drying tank. The inlet is configured to irradiate the microwave toward a lower part of the drying tank, and the second inlet is configured to irradiate the microwave toward an upper part of the drying tank. Drying device for honeycomb formed body. 15. The drying device according to claim 11, wherein the drying device has a first inlet and a second inlet provided on both sides of the inside of the drying tank opposite to each other with the transfer device interposed therebetween. The first inlet is configured to irradiate the microwave toward the opposite side surface, and the second inlet is configured to irradiate the microwave toward the opposite side surface. A drying device for honeycomb formed bodies.