JP2002136816A - Coating method of honeycomb filter and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating method of a honeycomb filter capable of simply providing a coating layer having uniform thickness on a honeycomb structure being a porous substrate. SOLUTION: One or more dried porous substrates 12 are erected so that the flow path is in the vertical direction, and a slurry of ceramic particles is force-charged from the downward of the porous substrates 12 and the moisture in the slurry is penetrated from the pores of the porous substrates 12, and then the porous substrates 12 are rotated 180 deg. in the vertical direction and subsequently air is injected into the porous substrates 12 in the same direction as the forcible feeding direction, and the moisture in the slurry is forcibly discharged from the pores of the porous substrates 12, thus the coating layers are formed on the surfaces of the porous substrates 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for coating a honeycomb filter and a coating apparatus used for the method.

[0002]

2. Description of the Related Art Conventionally, dust filters have been mainly made of bag filters using paper, fiber, or polymer resin. In recent years, however, environmental measures such as pollution prevention, product recovery from high-temperature gas, and clean high-temperature energy have been developed. Markets for collecting dust in a temperature range of 250 ° C. or higher where polymer materials cannot be used for recovery have increased.

Under such circumstances, ceramics have excellent heat resistance and corrosion resistance, and have favorable characteristics as a filter material in a high-temperature, corrosive gas atmosphere. Examples of the ceramic filter using this ceramic as a material include a tubular filter and a filter having a shape called a candle type in which one side is a closed tubular shape. It is used in a wide variety of fields such as the chemical, electric power, steel, and industrial waste treatment industries for the purpose of collecting products from wastewater and removing dust from exhaust gas for environmental measures.

As shown in FIG. 2, in such a honeycomb filter for dust collection, the ends of a large number of flow passages 1 of the honeycomb are reversely connected to the upstream side B and the downstream side C by a plugging portion 2 for each cell. It has a sealed structure, and the high-temperature gas entering from the upstream side B passes through the porous partition wall 3 and passes through the hole on the downstream side C. At this time, dust in the high-temperature gas passes through the inside of the partition wall. It has a mechanism of being trapped in the pores.

[0005] In such a general honeycomb filter, in order to achieve a small pressure loss while increasing the trapping efficiency, the surface of a porous substrate having a honeycomb structure having a relatively large average pore diameter is usually provided. And a filter layer having an average pore diameter smaller than that of the porous substrate.

As a method of coating a porous substrate for forming such a filter layer, conventionally, one end of a porous substrate having pores saturated with a liquid is decompressed and ceramic particles are contained from the other end. A dynamic pressure vacuum method for supplying a slurry (Japanese Patent Application Laid-Open No. 61-238315), an airflow coating in which a powder composed of ceramic particles is adhered to the surface of a porous substrate in an airflow, and then moisture is imparted and absorbed. (Japanese Patent Application Laid-Open No. Hei 10-249124), a slurry injection / discharge method in which a slurry containing ceramic particles is brought into contact with and held on the surface of a porous substrate, and then discharged. Dipping method of dipping,
The ceramic particles adhere to the surface of the honeycomb structure by supplying the slurry composed of the ceramic particle powder to each cell of the honeycomb structure, which is a porous base material, and removing the moisture in the slurry by permeating the inside of the porous material. A slurry direct filtration method and the like are known.

[0007]

However, it is difficult to apply the dynamic pressure vacuum method to a porous base material having a complicated shape such as a honeycomb structure. It is necessary, which is not preferable in terms of production efficiency and production cost.

In the airflow coating method, since the ceramic particles are aggregated and adhere to the porous substrate, the average pore diameter of the coating layer becomes large, and it is difficult to realize high trapping efficiency. There is a problem that the rate of increase in pressure loss increases due to the occurrence of clogging.

[0009] Further, in the slurry injection / discharge method and the dipping method, it is difficult to control the coat thickness, and therefore, there has been a problem that the capture efficiency and the degree of pressure loss between filters vary.

[0010] On the other hand, in the slurry direct filtration method, if it is attempted to form a coat layer using ceramic particles having a small average particle size, the ceramic particles penetrate into the pores of the porous substrate, and the porous substrate is coated with the porous substrate. There is a problem that a mixed layer of both having a dense structure is formed between the layers, and the pressure loss increases.

In addition, in these honeycomb filter coating methods, due to the problems that each has,
At present, there is no coater capable of automatically controlling its implementation and having practicality such as mass production.

[0012] Therefore, there has been no honeycomb filter coating method and apparatus used to solve the above-mentioned problems and to consider the manufacturing cost, and development of such a technique has been awaited.

The present invention has been made in view of such problems of the related art, and an object of the present invention is to form a coating layer having a uniform thickness on a honeycomb structure as a porous substrate. A method for coating a honeycomb filter which can be easily provided, and having the above-mentioned features, there is no variation in the coating layer thickness between porous substrates, and it can contribute to a reduction in honeycomb filter manufacturing cost. It is an object of the present invention to provide a honeycomb filter coating device that can be used.

[0014]

Means for Solving the Problems According to the present invention, ceramic particles constituting the porous substrate are provided on the surface of the porous substrate having a honeycomb structure composed of a large number of flow passages surrounded by partition walls. A method for coating a honeycomb filter, comprising providing one or more coat layers made of ceramic particles having an average particle diameter different from the above, wherein one or a plurality of the dried porous base materials are vertically And the slurry of ceramic particles is press-fitted from below the porous substrate to allow moisture in the slurry to pass through the pores of the porous substrate. Is rotated up and down by 180 °, and then air is injected into the porous substrate in the same direction as that of the slurry, so that moisture in the slurry permeates through the pores of the porous substrate. And forced discharge Ri, coating method of the honeycomb filter, which comprises forming a coating layer on the surface of the porous substrate is provided.

Furthermore, in the present invention, the concentration of the slurry of the ceramic particles is preferably 0.5 to 2.0% by weight, and the supply amount of the slurry of the ceramic particles is 3 to 6 times the total volume of the coated cells. It is preferred that

On the other hand, according to the present invention, a rotating shaft that is arranged horizontally and is rotatable at least 180 °, a frame that is arranged in parallel with the rotating shaft, and a rotating shaft and the frame Driving means, one or a plurality of porous substrate upper fixing means disposed on the upper side inside the frame, and one or more porous substrate lower fixing means disposed on the lower side inside the frame. A coating apparatus for a honeycomb filter, comprising: a slurry supply port provided in the porous substrate lower fixing means; and a slurry supply means connected to the slurry supply port.

Further, in the present invention, the porous substrate upper fixing means comprises: an air cylinder having a movable range in the vertical direction; a rod-shaped fixture interlocked with the air cylinder; It is preferable to provide a pressing plate having an elastic body, and it is preferable that the distal end portion of the rod-shaped fixing tool in contact with the pressing plate is spherical.

In the present invention, it is preferable that a seal packing is incorporated in the porous base material lower fixing means, and the angle between the surface where the seal packing contacts the porous base material and the horizontal plane is 30 to Preferably it is 60 °.

In the present invention, the slurry supply means preferably includes a slurry pipe and an air pipe connected to a slurry supply port, a slurry tank, and a slurry supply pump. Preferably has a sensor for sensing the liquid level of the slurry in the slurry tank, and a control device linked to the sensor and the slurry supply pump.

Further, in the present invention, one slurry supply means is preferably connected to one slurry supply port, and a mesh member is preferably provided above the slurry supply port.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and is within the scope of the present invention. It should be understood that design changes, improvements, etc. may be made as appropriate based on the knowledge of

FIG. 1 is a schematic configuration diagram showing one embodiment of an apparatus for performing a method for coating a honeycomb filter according to the present invention. In the coating device 5 of the honeycomb filter, a horizontally arranged rotating shaft 6 and a frame 7 are arranged in parallel with the rotating shaft 6. This frame 7
One or a plurality of porous base member upper fixing means 8 are provided above the inside. This porous substrate upper fixing means 8
Is composed of an air cylinder 9 having a movable range in the vertical direction, a rod-shaped fixture 10 interlocked with the air cylinder 9, and a holding plate 11 in contact with the rod-shaped fixture 10 on the upper surface,
One or a plurality of porous substrates 12 are provided upright.

One or a plurality of porous substrate lower fixing means 13 are provided below the inside of the frame 7, and a slurry pipe 14 is provided in the porous substrate lower fixing means 13.
And the air pipe 15 are connected. In addition, 16 is a motor, 17 is a rotary bearing, 18 is a support, and 19 is a pedestal.

In the honeycomb filter coating device 5 having the above-described structure, the dried porous base material 12 having one or more honeycomb structures is fixed to the lower fixing means 13 so that the flow passage thereof is in a vertical direction. And fixed at an appropriate pressure by an air cylinder 9 constituting the upper fixing means 8. In addition, as shown in FIG.
When the fixing member 2 is fixed, the pressing plate 11 is configured such that a gap 20 is formed between the pressing plate 11 and the porous substrate 12 that constitute the porous substrate upper fixing means 8. Further, as described later, the porous substrate lower fixing means 13 has a seal packing therein, and the porous substrate 12
It is configured to seal between the lower base and the lower base that constitutes the porous substrate lower fixing means 13. Further, as shown in FIG. 2, the porous base material 12 is configured such that the end portions of a large number of flow passages 1 are sealed on the upstream side B and the downstream side C by a plugging portion 2 for each square. It has the structure which was done. Also, "dry" here
"" Means that the material is dried to a constant weight by using a dryer at an appropriate temperature and time.

Next, a slurry of ceramic particles having a predetermined concentration is press-fitted from below the porous base material 12 by applying an appropriate pressure through the slurry pipe 14. Here, the ceramic particles in the pressed slurry are mixed with the porous substrate 1
A layer is formed on the partition wall surface without passing through the pores of No. 2. On the other hand, the water in the slurry permeates through the pores of the porous substrate 12. The water that has passed through the pores of the porous base material 12 gradually moves upwards of the porous base material 12, and the gap 2 shown in FIG.
Flows out of zero.

After confirming that a predetermined amount of the slurry has been injected, the injection of the slurry is stopped. Next, the rotating shaft 6 is rotated by the motor 16 to rotate the frame 7 by 180 ° together with the porous substrate 12 fixed inside the frame 7, so that the frame 7 passes through the pores of the porous substrate 12 and The water accumulated in the flow passage is discharged downward. In addition, a container or the like for receiving outflow and discharged water may be provided below the porous substrate 12 as necessary. Next, air is applied to the porous substrate 12 by applying an appropriate pressure in the same direction as the slurry injection direction through the air pipe 15, and water in the slurry is forced from the pores of the porous substrate 12. Discharge by letting it pass through.

In the case where the above-described coating method is applied to a porous substrate that has not been dried, there is a possibility that a problem may occur in that a thick coating layer is formed on the side opposite to the slurry injection side. Therefore, in the present invention, since a dried porous substrate is used, a coat layer having a uniform thickness as a whole can be formed on the surface of the porous substrate.

Further, when the slurry is press-fitted from above the porous substrate, there is a possibility that a problem that the coat layer below the porous substrate is formed thickly may occur.
Therefore, the coating method of the present invention employs a method in which the porous substrate is erected so that the flow path thereof is vertical, and the slurry is press-fitted from below. Having a coating layer can be formed on the surface of the porous substrate.

Further, in the present invention, when the water in the flow passage is discharged, the porous substrate is rotated by 180 ° to be inverted, and an appropriate pressure is applied in the same direction as the slurry injection direction. Air is injected and water is forcibly permeated through pores of the porous substrate and discharged. Therefore,
The time required for the coating can be greatly reduced, and the number of treatments per unit time can be increased.

In the method for coating a honeycomb filter according to the present invention, the slurry concentration of the ceramic particles used for coating is preferably 0.5 to 2.0% by weight, and more preferably 0.8 to 1.5% by weight. %, More preferably 1.0 to 1.3% by weight. From the viewpoint of the balance between the sedimentability of the slurry and the adhesion of the particles to the porous substrate, it is preferable to be within the above numerical range.

In the method for coating a honeycomb filter according to the present invention, the volume of the slurry of ceramic particles used for coating is 3 to 6 times the total volume of the coated cells.
Preferably, the ratio is 3.5 times, more preferably 3.5 times and 5.5 times, particularly preferably 4 times and 5 times. If it is less than 3 times, a difference in film thickness occurs between the upper and lower portions of the cell, and if it is more than 6 times, the balance between the thickness and the concentration of the coat layer and the amount of slurry necessary for forming the coat layer become large. This is because there is a disadvantage that the work becomes difficult.

Note that two or more coat layers can be provided as needed. The formation of the second and subsequent coat layers may be performed in the same manner as described above, after firing the first coat layer to form a filter layer.

As shown in FIG. 1, the coating apparatus 5 of the present invention has a structure in which the porous substrate 12 is fixed in the frame 7, so that the entire apparatus is stable and the porous substrate 12 Can be securely fixed and held. Accordingly, the rotation of the rotating shaft 6 causes the porous substrate 12 to rotate.
The stable operability can be ensured even when the handset is inverted. The driving means for rotating the rotating shaft 6 is shown in FIG.
It is not limited to the electric motor 16 as shown in FIG. 1, but any means that can rotate the rotating shaft 6 provided with the frame 7, the porous base material 12, and the like at least 180 ° can be used without any problem. it can.

FIG. 3 is a schematic configuration diagram showing an embodiment of the upper fixing means. In this upper fixing means, an appropriate pressure is applied to the porous base material 12 downward by the air cylinder 9 having a movable range in the vertical direction, and the pressing plate 11 and the elastic body 22 are passed through the tip 21 of the rod-shaped fixing tool 10. Has been fixed through.

FIG. 4 is a schematic view showing a corner portion of a honeycomb structure which is a porous base material, and FIG. 5 is a plan view showing a state where a holding plate is viewed from below. The porous substrate 12 used here has a structure in which the ends of the flow passages 1 are sealed by plugging portions 2 for each cell. At this time, the flow passages forming the corners of the porous substrate have a structure in which both the upstream side and the downstream side are sealed to ensure strength. Therefore, in the present invention, as shown in FIG. 3, it is preferable that four elastic bodies 22 are provided at four corners of the lower surface of the holding plate 11 and the surface in contact with the porous substrate 12. This prevents the porous substrate 12 from being chipped or damaged by the fixing pressure of the air cylinder 9, and the porous substrate 12 falls off even when the porous substrate 12 is rotated together with the frame 7. Therefore, it is possible to surely fix the apparatus without performing the operation.

FIG. 4 shows a state in which four elastic bodies 22 are provided at four corners on the lower surface of the holding plate 11 and in contact with the porous base material 12. The present invention is not limited to this, and any condition may be used as long as an elastic body is provided between the plugging portion 2 and the holding plate 11 without closing the flow passage 1. With such a configuration, the above-described effect is exhibited.

Further, as shown in FIG. 3, in the present invention, it is preferable that the distal end portion 21 of the rod-shaped fixture 10 in contact with the holding plate 11 is spherical. That is, since the rod-shaped fixture 10 and the holding plate 11 are in contact with each other at a point, the fixing pressure generated from the air cylinder 9 can be evenly distributed on the holding plate 11, and the fixing pressure is biased. This prevents the porous substrate 12 from being chipped or damaged due to this, and also has an effect that the porous substrate 12 can be securely fixed.

FIG. 6 is a schematic configuration diagram showing one embodiment of the lower fixing means.
The lower support 31 is provided with a slurry supply port 32 provided therein, and the slurry supply port 32 is provided inside the lower support 31 and is fixed above the slurry supply port 32. A state in which the mesh member 33 is incorporated below the honeycomb filter 12 is shown. As described above, in the present invention, it is preferable that the seal packing 30 is incorporated in the porous substrate lower part fixing means 13, and further,
A surface where the seal packing 30 is in contact with the porous substrate 12;
That is, the angle θ between the upper surface of the seal packing 30 and the horizontal plane is preferably 30 to 60 °.

In the present invention, since the porous base material 12 is fixed to the lower support 31 via the seal packing 30, when the slurry is pressed from below the porous base material 12, the lower support 31 There is no gap between the substrate and the porous substrate 12, and therefore, the coating method of the present invention can be carried out without causing a problem such as leakage of slurry. Further, the porous substrate 12 may be erected and fixed by a fixing pressure that does not cause leakage of the slurry, and it is possible to prevent the porous substrate 12 from being damaged due to an excessive fixing pressure.

FIG. 7 is a schematic configuration diagram showing another example of the lower fixing means.
It is configured to be erected on the lower receiving base 31 via the “0”. At this time, when no angle is provided on the upper surface of the seal packing 30, that is, when the seal packing 30 is parallel to the horizontal plane,
The outermost circumference and the flow passage 1 near the outermost circumference may be blocked. Therefore, there is a possibility that a problem may occur that the slurry cannot be pressed into the flow passage.
In the present invention, the seal packing 30 has an angle θ of 30 degrees between a surface contacting the porous substrate 12 and a horizontal plane.
Preferably, it is で 60 °. In this case, the seal packing 30 is in contact with the outer peripheral portion of the porous base material 12, and the outermost periphery and the flow passages 1 near the outermost periphery are not blocked, and the slurry is pressed into all the flow passages 1. Becomes possible.

FIG. 8 is a schematic configuration diagram showing one embodiment of the slurry supply means. As described above, the slurry supply means 35 constituting the apparatus for performing the method for coating the honeycomb filter according to the present invention includes the slurry tank 36 for storing the slurry of the ceramic particles, the slurry pipe 14 communicating therewith, A slurry pipe 14 is connected to a slurry supply port (not shown) and is inscribed in the lower fixing means 13. The air pipe 15 is connected to the slurry pipe 1 via a switching valve 38.
4, and it is not necessary to provide a new supply port for supplying air in addition to the slurry supply port in the lower fixing means 13, and the air is supplied only by operating the switching valve 38. It is a configuration that can be sent to By configuring the apparatus for performing the method of coating the honeycomb filter by combining the above slurry supply means,
It is possible to stably and reliably carry out the method of coating the honeycomb filter. Further, the honeycomb filter coating device according to the present invention has such a simple configuration, and thus has an effect of reducing the manufacturing cost of the honeycomb filter and the like.

As shown in FIG. 8, in the present invention, the slurry tank 36 is
Sensor for detecting the level of slurry in the metal (metal piece 40)
And a control device (proximity switch 41) interlocked with the sensor and the slurry supply pump 37. This makes it possible to automatically control the adjustment of the amount of slurry for carrying out the method for coating a honeycomb filter according to the present invention, and has an effect of reducing the manufacturing cost of the honeycomb filter.

The sensor is not limited to the metal piece 40 as shown in FIG. 8, but may be any mechanism capable of sensing the liquid level of the slurry. The present invention is not limited to this, and any mechanism that can appropriately control the supply of the slurry in conjunction with the sensor can be used without any problem, and the above-described effects can be obtained.

Further, in the present invention, it is preferable that one slurry supply means is connected to one slurry supply port. In the case where the coating method is performed by connecting a plurality of porous substrates to one supply unit,
There is a possibility that it is difficult to supply an even amount of slurry due to a slight difference in porosity, aeration differential pressure, and the like between the porous substrates. Therefore, as described above, by connecting one slurry supply means to one slurry supply port, the above problem can be effectively solved, and a honeycomb filter having no variation in quality can be manufactured. It is possible.

In the present invention, as shown in FIG. 6, a mesh member 33 is preferably provided above the slurry supply port 32. When the slurry flowing out from the slurry supply port 32 is directly injected into the porous base material 12, there occurs a problem that the slurry is harder to be injected into the outer flow path than the inner flow path. There may be a difference in the thickness of the coat layer between inside and outside. Therefore, as described above, the mesh member 33 is provided above the slurry supply port 32, and by applying an appropriate pressure to the slurry to be press-fitted, the slurry can be press-fitted without any difference between the inner and outer flow passages. As a result, it is possible to manufacture a honeycomb filter having no variation in quality such as the thickness of the coat layer.

[0046]

As described above, according to the method for coating a honeycomb filter of the present invention, a slurry of ceramic particles is pressed into a honeycomb structure as a dried porous substrate by a predetermined method, and In order to discharge the permeated water, it is possible to easily provide a coating layer having a uniform thickness on the honeycomb filter. Further, according to the honeycomb filter coating device of the present invention,
Due to the predetermined configuration, there is no variation in the coating layer thickness between the honeycomb filters,
Further, since a plurality of porous substrates can be treated at the same time, it is possible to contribute to a reduction in manufacturing cost of the honeycomb filter.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an apparatus for performing a honeycomb filter coating method according to the present invention.

FIG. 2 is a partial cross-sectional view illustrating a honeycomb filter.

FIG. 3 is a schematic configuration diagram showing one embodiment of an upper fixing means.

FIG. 4 is a schematic configuration diagram showing a corner portion of a honeycomb structure which is a porous base material.

FIG. 5 is a plan view showing a state in which the holding plate is viewed from below.

FIG. 6 is a schematic configuration diagram showing one embodiment of a porous substrate lower part fixing means.

FIG. 7 is a schematic configuration diagram showing another example of the porous substrate lower part fixing means.

FIG. 8 is a schematic configuration diagram showing one embodiment of a slurry supply unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flow path, 2 ... Sealing part, 3 ... Partition wall, 5 ... Coating device, 6 ... Rotating shaft, 7 ... Frame, 8 ... Porous base material upper fixing means, 9 ... Air cylinder, 10 ... Rod fixing tool, 11 ...
Pressing plate, 12: porous substrate, 13: porous substrate lower fixing means, 14: slurry piping, 15: air piping, 16 ...
Motor, 17: rotating bearing, 18: support, 19: pedestal,
DESCRIPTION OF SYMBOLS 20 ... gap part, 21 ... front-end | tip part, 22 ... elastic body, 23 ... partition, 24 ... outer peripheral part, 30 ... seal packing, 31 ... lower support, 32 ... slurry supply port, 33 ... mesh member, 35 ...
Slurry supply means, 36 ... Slurry tank, 37 ... Slurry supply pump, 38 ... Switching valve, 40 ... Metal piece, 41 ...
Proximity switch, 42 ... pillar, 43 ... pedestal, 44 ... trappet.

Claims (12)

[Claims] 1. A porous substrate having a honeycomb structure composed of a large number of flow passages surrounded by partition walls, comprising ceramic particles having an average particle diameter different from that of the ceramic particles constituting the porous substrate. A method for coating a honeycomb filter provided with one or two or more coat layers, wherein one or a plurality of the dried porous base materials are erected such that the flow passages are in the vertical direction, After pressurizing a slurry of ceramic particles from below the substrate and allowing moisture in the slurry to pass through the pores of the porous substrate, the porous substrate is rotated 180 ° up and down, Air is injected into the porous substrate in the same direction as the slurry injection direction, and water in the slurry is permeated through pores of the porous substrate and forcibly discharged, thereby forming the porous substrate. Coat layer on the surface of A method for coating a honeycomb filter, comprising: 2. The method for coating a honeycomb filter according to claim 1, wherein the concentration of the slurry of the ceramic particles is 0.5 to 2.0% by weight. 3. The method for coating a honeycomb filter according to claim 1, wherein the supply amount of the slurry of the ceramic particles is 3 to 6 times the total volume of the coated cells. 4. The apparatus according to claim 1, which is arranged horizontally and has at least one
A rotating shaft rotatable by 80 °, a frame disposed in parallel with the rotating shaft, a driving means for rotating the rotating shaft and the frame, and one or more disposed inside and above the frame A porous substrate upper fixing means, one or a plurality of porous substrate lower fixing means disposed below the inside of the frame, and a slurry supply port provided in the porous substrate lower fixing means. And a slurry supply means connected to the slurry supply port. 5. An air cylinder having a movable range in a vertical direction, a rod-shaped fixture interlocked with the air cylinder, an upper surface in contact with the rod-shaped fixture, and an elastic body on a lower surface. The coating device for a honeycomb filter according to claim 4, further comprising a pressing plate having the pressing plate. 6. The coating device for a honeycomb filter according to claim 5, wherein a tip portion of the rod-shaped fixing member in contact with the pressing plate has a spherical surface. 7. The coating device for a honeycomb filter according to claim 4, wherein a seal packing is incorporated in the porous substrate lower part fixing means. 8. An angle between a surface of the seal packing in contact with the porous substrate and a horizontal surface is 30 to 60 °.
A coating device for the honeycomb filter according to the above. 9. The honeycomb filter according to claim 4, wherein the slurry supply means includes a slurry pipe and an air pipe connected to the slurry supply port, a slurry tank, and a slurry supply pump. Coating equipment. 10. The honeycomb filter coating apparatus according to claim 9, further comprising: a sensor for sensing the liquid level of the slurry in the slurry tank, and a control device interlocked with the sensor and the slurry supply pump. 11. The coating device for a honeycomb filter according to claim 4, wherein one slurry supply means is connected to one slurry supply port. 12. The coating device for a honeycomb filter according to claim 4, further comprising a mesh member provided above the slurry supply port.