MXPA99007580A - Method for covering the flow channels of a monolithic catalyst holding body with a dispersion of revestimie - Google Patents

Abstract

The present invention relates to a method for coating the flow channels of a monolithic catalyst carrier body having a cylindrical shape with a coating dispersion, wherein the carrier body has two front faces which are connected to each other by channels of flow arranged parallel to the cylinder axis, by means of the vertical orientation of the cylinder axis of the bearing body, the application of a predetermined amount of the coating dispersion from a storage tank on the upper front face of the carrier body and the aspiration of the dispersion through the flow channels, the elimination of the excessive coating dispersion out of the flow channels by means of blow-off of the flow channels, the recovery of the excessive dispersion towards the deposit of storage and fixing of the coating by dispersion by means of a calcination n. The method is characterized by the fact that the coating dispersion is aspirated with a flow rate of 0.1 to 1 m / s through the flow channels, and that after finishing the aspiration the dispersion and excessive coating is eliminated. outside the flow channels by means of the application of a suction impulse from below, in which the suction air is sucked with a flow velocity between 40 and 1 m / s through the flow channels and is separated the excessive coating dispersion that is carried with the air stream outwards, from the air current within a time less than 100 ms, after the exit of the carrier body of catalyzed

Description

METHOD FOR COATING THE FLOW CHANNELS OF A MONOLITHIC CATALYST CONCERNING BODY WITH A COATING DISPERSION Field of the Invention The present invention relates to a method for the re-stretching of the flow channels of a monolithic catalyst carrier body having a cylindrical shape with a coating dispersion.

Background of the Invention The monolithic catalyst carrier bodies are used in large quantities for the manufacture of catalysts for automobile exhaust gases. They have a cylindrical shape and are penetrated by a multitude of flow channels for the exhaust gases of the internal combustion engines, which are arranged parallel to the cylinder axis. Such bearing bodies are very often also referred to as honeycombed bodies.

Ref: 031064 The shape of the cross section of the bearing bodies of the catalyst depends on the assembly requirements in the car. Very often the catalyst carrier bodies are used with a circular cross section, an elliptical cross section or a triangular cross section. The flow channels frequently have a square cross section and are distributed in a very narrow grid over the entire cross section of the catalyst carrier bodies. According to the case of application, the density of channels or cells, respectively, is varying in t r e 10 and 120 cm "2. Catalyst bearing bodies with cell densities up to 250 cm- 'and more are in development.

For the purification of exhaust gas from automobiles, the catalyst carrier bodies obtained by extrusion of ceramic masses are used. As an alternative to the aforementioned, corrugated or rolled metal sheet catalyst support bodies are available. For the purification of automobile exhaust gases for people, the catalyst carrier bodies with a cell density of 62 cm 2 are still used today. The cross-sectional dimensions of the flow channels are in this case of 1.27 x 1.27 mm 2. The wall thicknesses of such catalyst support bodies are between 0.1 and 0.2 mm.

For the conversion of the pollutants contained in automobile exhaust gases, such as carbon monoxide, hydrocarbons, and nitrogen oxides, into harmless compounds, platinum group metals very finely distributed are used in most cases, those that can be changed in their catalytic effect by means of combinations with non-noble metals. These catalytically active components must be precipitated on the catalyst bodies. However, it is not possible to guarantee the required finer distribution of the catalytically active components by means of precipitation of these components on the geometrical surfaces of the catalyst bodies. This applies in the same way to the non-porous metallic catalyst bodies as for the porous ceramic catalyst bodies. A surface large enough for the catalytically active components can only be made available by coating a carrier layer of high-surface fine particle materials.

Description of the invention An object of the present invention is a method for coating such a carrier layer on the inner surfaces of the flow channels of the monolithic catalyst carrier bodies having a honeycomb shape. Within the scope of the present invention, the carrier layer for the catalytically active components is referred to as a dispersion coating. The dispersion coating consists of high-surface fine particle materials, and the same is produced under the use of a so-called coating dispersion. The coating dispersion is a separation by gravity in a suspension of the fine particle materials in many cases in water.

Various methods for precipitation of the coating dispersion on the catalyst body are known from the state of the art. After the coating process, the catalyst bodies are dried and then calcined to solidify the dispersion coating. The ally active ac components are then introduced into the coating dispersion by impregnation with solutions in many aqueous cases of the precursor compounds of the catalytically active components. Alternatively to the above-mentioned, the catalytically active components can already be added to the coating dispersion itself. In this case, a subsequent impregnation of the coating dispersion already completed with the catalytically active components is not necessary.

Patent GB 1 515 733 describes a reversing method for ceramic catalyst bodies. The porous catalyst bodies are inserted stationary, ie with vertically oriented flow channels, in a pressure resistant coating chamber, and they are degassed by applying a negative pressure of 0.84 bar (63.5 cm) (25 inches) of mercury column). The coating dispersion is then filled through the upper front face of the catalyst body into the dispersion chamber, and pressed through the application of an overpressure into the pores of the catalyst body. After the reduction of the overpressure and the opening of the discharge valve at the bottom of the dispersion chamber, the excess coating dispersion flows out of the flow channels of the catalyst body. Finally, the flow channels that were eventually blocked by the coating dispersion are released by blowing with pressurized air from above. The cycle time of this dispersion method lasts less than 1.5 to 2 minutes.

US Patent 4,208,454 describes also a method for the dispersion of porous ceramic catalyst bodies. The catalyst bodies to be coated are placed with their lower front face - over the opening of a precipitation vessel, in which the pressure is reduced with respect to atmospheric pressure by means of a high volume fan by 12.7 to 40.7 cm (5 to 16 inches) of water column. This negative pressure remains constant throughout the dispersion time. A predetermined volume of the coating dispersion is distributed over the upper front face of the catalyst body, and the same is sucked uniformly through the flow channels into the precipitation vessel. The aspiration process is maintained for at least 30 seconds. After the first 5 seconds, the amount of complete coating is drawn through the catalyst body. During the remaining time, the air flowing through the flow channels takes care of opening the flow channels that eventually were blocked by the coating dispersion. The amount of coating remaining on the catalyst body can be influenced by the duration of the total suction time and by the value of the negative pressure. The axial uniformity of the coating on the catalyst body can be improved, because the catalyst body is turned after half the suction time and aspirated in the opposite direction. With this method, coating dispersions with a solids content of 3 CL to 45% as well as a viscosity between 60 and 3000 cps can be prepared. The preferred solids content is 37% by weight and the preferred viscosity is 400 cps. The reproducibility of the reversal amount is indicated in this method with + 5%.

EP 0 157 651 Bl also describes a method for coating bodies of ceramic catalyst with a predetermined amount of a coating dispersion. For this purpose, a pre-weighed amount of the coating dispersion is filled into a wide open container and the catalyst body with its lower front face is immersed in the dispersion. The dispersion is then aspirated by applying a slight negative pressure to the upper front face into the flow channels of the catalyst body. To improve the axial uniformity of the coating, it is also recommended in this method to carry out the coating process in two stages. In the first stage, only about 50 to 85% of the total coating amount is filled into the container, and it is sucked into the catalyst body, then the catalyst body is turned over and the amount of coating is aspirated. remaining in the opposite direction in the catalyst body. This method of coating does not require any separate step for opening flow channels eventually blocked. Cycle duration - from this method of just under 1 minute. With this method, coating dispersions having a solids content between 35 and 52% can be prepared as well as those having viscosities between 15 and 300 cps.

The patent US 5,182,140 describes a method for the coating of ceramic and metal catalytic body. In this, the coating dispersion is pumped from below into the vertically standing catalyst bodies until the dispersion reaches a height completely above the upper front face of the catalyst body. The excess coating dispersion is then removed by the application of pressurized air on the upper front face of the catalyst body from the body. At the same time, the flow channels that were eventually blocked are blown free. According to example 1 of this patent, the filling level of the coating dispersion is adjusted 2 cm above the upper front face of the catalyst body. The pressurized air for the ejection of the excess coating dispersion from the flow channels is subsequently applied in two pressure stages. During the first 2 seconds after filling the catalyst body, the coating dispersion is charged with a pressurized air of 3.7 bar. This high pressure is sufficient to completely expel the excess coating dispersion for the 2 seconds that are available from the flow channels. Then the pressure of pressurized air is reduced to 0.37 bar and this pressure is charged twice for 0.5 seconds on the catalyst body. With this method, coating dispersions having a specific density of between 1 and 2 g / ml and having a viscosity between 100 and 500 cps can be prepared.

German patent 40 40 150 C2 also describes a method for the uniform coating of a honeycomb body made of cerimica or metal. For this purpose, the alveolate body is entered into an immersion chamber and the same is filled from below with the coating dispersion. The alveolate body is then emptied again by means of blowing or aspiration. The honeycomb body is then removed from the immersion chamber and released in a separate arrangement of excessive dispersion by means of blowing or suction to avoid blocked flow channels. With this method, coating dispersions having a solids content between 48 and 64% by weight and having viscosities between 50 and more than 100 cps can be prepared.

The methods described are suitable both for the coating of ceramic bearing bodies and metal bearing bodies. In the case of metal bearing bodies, it is known from DE 4233404"C2, WO 92/14549 and EP 07758808 Aligning, as an alternative to the coating of the completed bearing bodies, the metal strips before assembling the carrying body in a strip coating arrangement.

The purification of internal combustion engines is subject to constantly increasing legal requirements with respect to the conversion of pollutants. In order to meet these requirements, catalyst bearing bodies with densities of increasingly high cells are developed. However, most of the catalyst bearing bodies produced still have cell densities of only 62 cm-2. A small part of load-bearing bodies is manufactured and with a cell density of 124 cm "2. This is mainly about bearing bodies made of metal strips.

Under development are the loadbearing bodies with densities of cells greater than 186 cm "2. In addition, attempts are being made to improve the conversion of pollutants by means of start catalysts that are mounted near the engine in the exhaust gas conduit upstream of the catalytic converter. This is true of small volume catalysts which can also have a high density of cells.These catalysts can also be used advantageously for the purification of motorcycle exhaust gases.

The coating methods described for the catalyst carrier bodies are only insufficiently suitable for the coating of small-volume catalyst carrier bodies. This is particularly true for the coating of small volume catalyst bodies with a high cell density. The durations of the cycle that can be achieved with known methods are too small for an economic coating. With these methods, only the bearing bodies can be well coated with small cell densities. The control of the viscosities of the coating dispersion partly requires a high stress, since it is extracted from the coating dispersions by means of a long contact with the air streams used for the release of the flow channels. a part of significant humidity, which must be permanently completed in order to guarantee the reproducibility of the coating.

On the other hand, the manufacture of small volume catalysts from previously coated metal strips leads to losses of active coating material by closing flow channels during assembly of the catalysts. These losses can be, in unfavorable cases, up to 10%. Furthermore, it is a feature of this method of procedure that acute angled spaces are formed at the contact points of adjacent strips that have an unfavorable effect on the access of the exhaust gases to the catalytic coating., And can therefore reduce the activity catalytic of the catalyst.

Therefore, it is an object of the present invention to make available a new coating method for ceramic and metallic catalyst bodies having a honeycomb shape, which is characterized by cycle times of less than 10 seconds and which allows to coat supporting bodies with a cell density greater than 180 cm "2.

This objective is solved by means of a method for coating the flow channels of a monolithic catalyst carrier body having a cylindrical shape with a coating dispersion, in which the carrier body has two front faces which are connected to each other by flow channels arranged parallel to the cylinder axis. The coating is effected by the vertical orientation of the cylinder axis of the carrier body, the application of a predetermined amount of the coating dispersion from a storage tank on the upper front face of the carrier body and the aspiration of the dispersion through the flow channels, the elimination of the excessive coating dispersion out of the flow channels by means of blow-off of the flow channels, the recovery of excessive dispersion towards the storage tank and the fixing of the coating by dispersion by means of a calcination.

The method is characterized by the fact that the coating dispersion is aspirated with a flow rate of 0.1 to 1 m / s through the flow channels, and that after finishing the aspiration the excess coating dispersion is eliminated. out of the flow channels by means of the application of a suction pulse from below, in which the suction air is sucked with a flow velocity between 40 and 1 m / s through the flow channels and is separated the excessive coating dispersion that is carried with the air stream outward, from the air stream within a time less than 100 ms. after the exit of the catalyst carrier body.

In this way, according to the present invention, the coating of the flow channels is carried out in two stages. In the first stage a predetermined amount of the coating dispersion is applied on the upper front face of the catalyst carrier body and by means of the application of a negative pressure to the lower front face which sucks the same through the flow channels with a flow velocity of 0.1 to 1 m / s. Preferably the predetermined amount of the coating dispersion is provided so that it corresponds to 0.5 to 2 free volume of the flow channels. The flow rate is advantageously chosen so that the aspiration process must be completed after less than one second.

The second stage of the method immediately follows this first stage, in which the flow channels of the excess coating dispersion are released by means of the application of a suction pulse. Under an aspiration pulse is meant in the present invention a process in which a large amount of air is first transported through the flow channels. However, during the course of the suction pulse, the quantity transported is continuously reduced.

Such a suction pulse can be carried out in such a way that the lower front face of the carrier body is connected to a large container of negative pressure, which has as a consequence that the initial velocity of the suction air inside the flow channels is very high, and it is reduced continuously during the course of the suction since the negative pressure in the negative pressure vessel is reduced due to the suction air carried. According to the present invention, the initial velocity of the suction air must be between 5 and 40 m / s. Towards the end of the suction process, the flow rate is reduced to a minimum of approximately 1 m / s.

During the first method step, the lower front face of the catalyst carrier body is also connected to the negative pressure vessel for suction of the coating dispersion through the flow channels. By means of a suitable spraying, however, care must be taken to maintain the flow rates according to the present invention of the coating dispersion within the flow channels.

An essential aspect of the present invention is the early separation of the excessive coating dispersion carried with the suction air out of the flow channels, from the suction air. In this way, the extraction of liquid from the coating dispersion by means of the suction air must be reduced and the recovery of the excessive coating dispersion towards the storage tank facilitated. Without this measure it would permanently increase the solids content of the coating dispersion within the storage tank, and therefore, a reproducible coating of the catalyst carrier bodies would be complicated.

For the further description of the present invention, Figures 1 and 2 are shown.

Figure 1 shows a device for carrying out the whole present; and Figure 2 shows the filling of acute angle spaces of a metal catalyst body by means of a precoating.

The device shown in Figure 1 is schematically suitable for carrying out the method according to the present invention. With the number 1 the carrier body to be coated is called. Above the carrier body 1, the storage tank 3 is arranged with the coating dispersion 4. The storage tank 3 has a lower opening 5 for filling the flow channels of the carrier body 1 with the coating dispersion 4. The cross section of the opening 5 corresponds to the cross-sectional shape of the carrier body to be coated 1, however it is slightly smaller than the cross section of the catalyst carrier body 1 to allow the support of the supporting body edge 1 on the seal 2 and therefore to prevent the coating dispersion output 4 between the storage tank 3 and the support body 1 during the filling process. For the application of the predetermined amount of the coating dispersion 4 on the upper front face of the supporting body 1, the storage tank 3 is provided with a filling valve 6.

The supporting body 1 is supported with its lower front face on the edge of the opening 8 in the cover plate 9 of the suction chamber 7. The opening 8 also has the same cross-sectional shape as the supporting body 1, however, it is slightly smaller than the cross-section of the supporting body 1 for, with the aid of the seal 2 ', hermetically sealing the outer edge of the supporting body 1. In the suction chamber 7, a beaker 10 is arranged. below the opening 8 for the collection of the excessive coating dispersion. The upper edge of the beaker 10 is designated with the number 11. The beaker 10 is equipped at its bottom with a vacuum valve 12. Opening the valve from time to time can be pumped back the excess coating dispersion. 4 'which is accumulated in the beaker 10 through pipe conduits by a pump 14 into the storage tank 3. The suction chamber 7 is connected via a conduit 16 of large cross section with a negative pressure vessel. 18. The connection can be released or interrupted with the suction valve 17. The suction chamber 7 is further connected via another conduit 20 and a sputtering valve 21 with the negative pressure vessel 18. The negative pressure vessel 18 it is evacuated by means of a fan 19 to a pressure between 100 and 850 mbar absolute pressure. The volume of the negative pressure vessel corresponds to approximately 500 to 1000 times the volume of the catalyst carrier body to be coated 1.

The storage tank 3 in Figure 1 can be moved in the vertical direction. For filling the flow channels with the coating dispersion, the storage tank 3 with its seal 2 is lowered onto the upper edge of the catalyst carrier body. In this way an intimate connection between both is produced. After finishing the filling process, the filling valve 6 is closed again and the storage tank 3 is lifted. To allow this movement, the recovery conduit 13 is provided in Figure 1 with a sliding sleeve 15. As an alternative , a flexible hose connection can also be provided for this purpose.

The seals 2 and 2 'can be, for example, inflatable rubber seals that are inserted in the carrier body. When inflating the rubber seals an intimate connection is made between the seals and the lateral surface of the bearing body 1.

In Figure 1 an alternative embodiment of the gaskets in the form of a flat gasket is shown. This embodiment is particularly suitable for load-bearing bodies whose surfaces protrude in the form of a raised edge above the actual front surface of the catalyst body 1. In this case the gasket can be easily made by the fact that the edges of the body are pressed. of catalyst 1 on the flat joints.

The coating method according to the present invention is particularly suitable for small volume catalysts with high densities of cells greater than 180 cm 2 and with lengths up to 10 cm and diameters of less than 10 cm. out in the following stages: 1. Close the suction valve 17; 2. Place the supporting body on the gasket 2 'of the suction chamber and lower the storage tank with its gasket 2 on the upper edge of the supporting body; 3. Open the filling valve 6 for a period of less than one second and flood the upper front face of the carrier body 1 with a predetermined amount of coating dispersion (hereinafter also referred to as the filling quantity); 4. Aspirate the coating dispersion through the flow channels of the bearing body during the opening time of the filling valve with a flow velocity between 0.1 and 1 m / s, in which negative pressure occurs which is necessary for this purpose, in the lower front face of the supporting body by means of the throttle valve 21; Close the filling valve 6 and disconnect the connection between the supporting body and the storage tank in order to allow free air to enter the upper front face of the supporting body; Apply a suction pulse to the lower front face of the carrier body by opening the suction valve 17 in order to eliminate excessive coating dispersion from the flow channels by means of a suction release with an amount of air corresponding to 100 and 1000 times the free volume of the flow channels and with a decreasing flow rate between 40 and 1 m / s; Close the suction valve and remove the coated carrier body, dry and calcine from the coating in a drying oven; Periodically open the vacuum valve 12 for the recovery of the coating dispersion 4 'which accumulates in the precipitation vessel by means of the pump 14 towards the storage tank 3.

Thus, according to the present invention, the carrier body to be coated is first filled by suctioning the coating dispersion into the flow channels. The amount of the coating dispersion (filling quantity) which is used in this process is advantageously between 0.5 times and twice the free volume of the flow channels. The suction through the flow channels is carried out with a flow velocity of the ispersion within the flow channels between 0.1 and 1 m / s. The necessary opening time of the filling valve can be easily calculated from the filling quantity, the length of the catalyst body and the flow rate. This time is less than a second.

The necessary flow rate can be adjusted by means of the pressure in the negative pressure vessel and the regulation of the regulating valve 21. Advantageously, the throttling valve 21 remains open during the entire coating process.

After the closing of the filling valve, the connection between the storage tank and the catalyst body is released, for example, by raising the storage tank, and therefore a free access of air to the face is established. upper front of the catalyst body. At the same time, the suction valve 17 is opened, which establishes a connection with a large cross section with the negative pressure vessel. In this way, an aspiration pulse is applied to the lower front face of the catalyst body, which ensures that the excessive coating dispersion is eliminated out of the flow channels and that any blocked flow channels are released by suction. The force of the suction pulse depends on the pressure inside the negative pressure vessel. The pressure must have an absolute maximum of 850 mbar in order to generate a sufficient suction pulse with initial air flow velocities within the flow channels between 5 and 40 m / s.

Good coating results are obtained, according to experience, with an aspiration pulse with which an amount corresponding between 100 and 1000 times to the free volume of the flow channels is aspirated within a time which, in general, is significantly less than 5 seconds through the flow channels. During this time the flow rate is reduced due to the pressure inside the negative pressure vessel from its maximum initial value to a minimum of approximately between 1 and 5 m / s.

After aspiration of the excess coating dispersion the catalyst body can be removed from the coating device, and then dried in an oven and calcined.

The entire coating process is completed from the insertion of the catalyst body into the coating device until it is removed in less than 10 seconds.

An essential characteristic of the method according to the present invention is, in addition to the application of the suction pulse, the early separation of the excess coating dispersion from the air flow for the aspiration release of the catalyst body. According to the present invention, it must pass between the outlet of the coating dispersion outwardly from the lower front face of the catalyst body and the separation from the air flow, a period of time less than 100 ms, preferably less than 10 seconds. ms These periods of time are reached in the coating device described according to FIG. 1 on account of the fact that in the suction chamber a precipitation vessel 10 is arranged which, with its upper edge 11, is brought closer to a distance less than 5 cm towards the lower front face of the catalyst body.

Thus, the suction pulse is essentially applied through the annular passage between the upper edge 11 of the precipitation vessel 10 and the cover plate 9 of the suction chamber to the lower front face of the catalyst body. After passing through the catalyst body, the air flow undergoes a deviation of about 90 °. Due to their inertia, the aspirated drops of the coating dispersion do not follow this deviation, but accumulate on the lower part of the precipitation vessel. Thanks to this construction of the suction chamber and the precipitation vessel, the liquid surface of the dispersion accumulated in the precipitation vessel is no longer in contact with the air flow.

Therefore, the air flow can not continue the concentration of the coating dispersion, as is the case, for example, in the arrangement of US Patent 4,208,454. In this arrangement the liquid surface of the coating dispersion is exposed during the entire time of aspiration of 30 seconds to the air flow, which results in a loss of strong liquid, and therefore, leads to the need for air conditioning. the excessive coating dispersion, before it can be transported back to the storage tank.

According to the method according to the present invention this conditioning can be suppressed without this having a negative effect on the reproducibility of the coatings.

By means of a pre-coating of the bearing bodies made of metal strips with a dispersion or free solution of noble metals of low viscosity having a high surface tension and a subsequent drying, the acute angled spaces can be filled in the connecting places of the metal strips, as shown in Figure 2. In this way they can be shortened during a subsequent coating with a dispersion in which the catalytically active noble metal is fixed on the solid elements of the dispersion, the diffusion paths for the conversion of pollutants. With which you can both save noble metal and increase the catalytic activity of the catalyst Figure 2 shows schematically a partial view of a catalyst carrier body made of flat metal strips 30 and corrugated 31 alternately stacked. The wedges of acute angles at the contact points of the corrugated and flat metal strips can be filled by means of a coating with a noble metal-free dispersion 32.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (5)

Claims

1. A method for coating the flow channels of a monolithic catalyst carrier body having a cylindrical shape with a coating dispersion, wherein the carrier body has two front faces which are connected to each other by flow channels arranged in a manner parallel to the cylinder axis, by means of the vertical orientation of the cylinder axis of the supporting body, the application of a predetermined quantity of the coating dispersion from a storage tank on the upper front face of the supporting body and the aspiration of the dispersion through the flow channels, the elimination of the excessive coating dispersion out of the flow channels by means of blow-off of the flow channels, the re-ection of the excessive dispersion towards the storage tank and fixing the dispersion by means of a calcination, characterized in that it is the coating dispersion is aspirated with a flow rate of 0.1 to 1 m / s through the flow channels, and that after finishing the suction the excess coating dispersion is removed out of the flow channels by means of the application of a suction impulse from below, in which the suction air is sucked with a flow velocity between 40 and 1 m / s through the flow channels and the excess coating dispersion that is carried with the air flow outward, from the air stream within a time less than 100 ms after the exit of the catalyst carrier body.

2. The method according to the rei indication 1, characterized in that the predetermined amount of the coating dispersion is provided so that it corresponds to 0.5 to 2 times of the free volume of the flow channels.

3. The method according to claim 2, characterized in that the amount of air for the suction release of the flow channels corresponds to 100 to 1000 times the free volume of the flow channels.

4. The method according to claim 1, characterized in that a coating dispersion which already contains catalytically active noble metals is used. ~ -

5. The method according to claim 1, characterized in that a precoating according to the same method with a noble metal-free coating dispersion is carried out prior to the application of the coating dispersion containing noble metals. . Summary of the Invention The present invention relates to a method for coating the flow channels of a monolithic catalyst carrier body having a cylindrical shape with a coating dispersion, wherein the carrier body has two front faces which are connected to each other by flow channels arranged parallel to the cylinder axis, by means of the vertical orientation of the cylinder axis of the supporting body, the application of a predetermined amount of the coating dispersion from a storage tank on the upper front face of the supporting body and the aspiration of the dispersion through the flow channels, the elimination of the excessive coating dispersion out of the flow channels by means of blow-off of the flow channels, the recovery of the excessive dispersion towards the deposit of storage and fixing of the coating by dispersion by means of a calcination n. The method is characterized by the fact that the coating dispersion is aspirated with a flow rate of 0.1 to 1 m / s through the flow channels, and that after finishing the aspiration the dispersion and excessive coating is eliminated. outside the flow channels by means of the application of a suction impulse from below, in which the suction air is sucked with a flow velocity between 40 and 1 m / s through the flow channels and is separated the excessive coating dispersion that is carried with the air stream outward, from the air stream within a time less than 100 ms. after the exit of the catalyst carrier body.