DE3112796A1 - CHARGED INTERNAL COMBUSTION ENGINE - Google Patents

Description

J 21 P 280

Applicant ; JOHNSON, MATTHEY & CO. LIMITED,

43 Hatton Garden, London, ECIN 8EE, England

Title of the invention : Supercharged internal combustion engine description

The invention relates to reducing the content of smoke and other harmful components, as contained in the exhaust gases of supercharged internal combustion engines.

The exhaust gases from internal combustion engines with internal combustion and turbocharging often contain finely divided particles of hydrocarbons, carbon and other solids that enter the internal combustion engine in the form of smoke leaving.

The exhaust gases from diesel engines, for example, consist of solid particles surrounded by a layer of liquid are made up of tightly chained aggregations in which spherical particles with diameters between 100 and

-1 O
800 10 m connected to each other, from liquid

Sulphates, liquid hydrocarbons and gaseous 30.3.1981 - 2 -

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Hydrocarbons. The solid / liquid particles generally contain carbon particles with adsorbed liquid hydrocarbons, while the tightly chained aggregations generally consist of organic compounds consist of high molecular weight and / or inorganic sulphates.

When an internal combustion engine is started for the first time, white smoke is produced, which can be explained by the condensation of water vapor on the pesticide particles contained in the exhaust gas, which forms a fine mist. Black smoke is produced in diesel engines when the internal combustion engine has warmed up and it contains a relatively high proportion of carbon particles. The blue smoke contains some carbon, but above all a relatively high proportion of gaseous organic compounds such as aldehydes, over 90/2 of the particles forming this smoke have a maximum dimension of less than 1 / u, which is in the range of the inhalable particle size , the remaining 10 $ of the particles forming the smoke have a particle size of less than 4 ax.

The pollutants include hydrocarbons, carbon monoxides and oxides of nitrogen, which are produced by the fuel

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internal combustion engine and further the smoke-forming particles according to the above Executions.

The object of the invention is to reduce the amount of harmful constituents of the exhaust gases from supercharged turbochargers To reduce internal combustion engines with internal combustion.

According to a first aspect of the invention, this object is achieved in that in an internal combustion engine with internal Combustion and turbocharging a chamber with a catalytic converter is provided, with which the pollutants or pollutants the engine exhaust gases are eliminated by catalytic oxidation of the contaminants before the exhaust gases die Leave internal combustion engine.

The turbocharged internal combustion engine is preferably a multi-part substrate in the Associated flow path of the exhaust gases in order to generate turbulence in these.

According to a second aspect of the invention there is provided a method for reducing exhaust gas pollution in turbocharged engines Internal combustion engines

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proposed in which the exhaust gases after leaving the engine cylinder through a chamber with a catalyst are passed, with which the pollutants present in the exhaust gases come into contact, so that at least a part the contaminants are subjected to catalytic oxidation

The catalytic oxidation of carbon particles takes place at around 400 ° C, while the normal combustion temperature of these particles is 700 - 800 ° C. The catalytic oxidation of hydrocarbon ^{particles takes place at about 200 °} C. Since, in the presence of a catalyst, the smoke-forming particles are oxidized in a gas at a temperature that is lower than the usual combustion temperature, there is little or no heating of the exhaust gases from internal combustion engines with internal combustion necessary if the catalytic oxidation of any smoke-forming particles in the gas is desired. Since, for example, the operating temperature of a diesel engine at medium or full power is 400 ° C., no additional heating of the exhaust gases emitted by the engine is necessary before they are passed over the catalytic converter.

In order to offer maximum contact for the exhaust gases, a metallic wire substrate should be arranged accordingly

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be. The wire is preferably flat and it is usually appropriately rolled before an intermediate layer and catalytic Material to be applied. During operation of the internal combustion engine with excess air or oxygen In the combustion chamber, such contact ensures that a substantial part of the contaminants in the above-described Way of catalytic oxidation.

In the following, some embodiments of the present application are referred to as examples of the invention described on the accompanying drawing. Show in the drawing

Fig. 1 shows a first embodiment in which the catalyst chamber is arranged near the outlet openings of the cylinder of an internal combustion engine,

2 shows a second embodiment in which another embodiment of the catalyst chamber is used,
2A shows a third embodiment with yet another catalyst chamber,

3 shows a different means than in the previous embodiments for securing the catalyst carrier against collapsing inward, FIG. H shows an alternative means to the means according to FIG. 3, FIG. 5 shows a fourth embodiment for arrangement near the turbocharger,

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Pig. 6 shows another embodiment for arrangement near

the turbocharger and
7 shows the arrangement of several catalyst chambers.

In the solution according to FIG. 1, a catalyst is arranged in a reaction tube which is arranged essentially centrally in an exhaust gas chamber. An outer wall 1 of the exhaust chamber is provided with openings 7 to 10 which are arranged near and adjacent to the outlet openings of the cylinders of an internal combustion engine. An outlet 12 is arranged near the outlet line 11. The reaction tube 2 is supported in the chamber 1 with struts 5 and 6 and receives the supported catalyst 3. The reaction tube is arranged in such a way that the exhaust gases coming from the cylinders must pass through the reaction tube when they enter the exhaust chamber and come into intensive and continuous contact with the catalyst before they exit the exhaust chamber to reach the exhaust line 11. The flow of exhaust gases through the exhaust chamber is indicated by arrows F ₁ to Fg. The combustion gases pass from the cylinder outlets through the openings 7 to 10 into the exhaust chamber and flow along the reaction tube 2 in order to then pass through the outlet 12 into the exhaust line 11. Above that

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Cross-section of the outlet 12 extends a retaining plate 4 to prevent the catalytic converter 3 slips out of the reaction tube.

The catalyst is applied as a catalytic layer on a catalyst carrier, which in turn is a knitted one Wire mesh is. The catalyst support can be a one-piece block (monolith) or it can be composed of several disc-shaped sections. When building the carrier from individual disks is each disc is provided with an intermediate layer and a catalytic layer, the application of the intermediate layer and the catalytic layer can take place before or after the disks are assembled to form the carrier. In the end Intermediate layer and catalytic layer can also only be applied after the individual panes are inside of the reaction tube have been arranged and connected to one another.

In the solution according to FIG. 2, the outer wall 21 of the catalyst chamber is provided with openings 27 to 30 which are close to and adjacent to the exhaust ports of the cylinders of the internal combustion engine, via a Outlet 32 the connection to the outlet opening 31 is established. The catalyst 23 consists of a carrier, one

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Intermediate layer and a catalytic metal. It is arranged in such a way that the exhaust gas, when entering the catalyst chamber, is forced to pass through the interstices of the catalyst before it leaves the chamber and then enters the exhaust line. The gas enters the catalyst chamber through inlet openings P ₁ J _{1 to F 1,} then the gas flows through the catalyst and then it enters the outlet pipe according to the arrow F ₁ . ^.

In this solution, the support of the catalyst is preferably a knitted wire, and it can be made in one piece as be manufactured as a unit or in individual sections. Is it made of individual sections, for example have the shape of annular tubes, these should be connected to one another before the carrier is in the catalyst chamber is arranged. The supported catalyst is thereby held in the catalyst chamber that its ends Cover disks 25 and 26 are assigned, which are held on the outer walls of the catalyst chamber. To ensure, that the support does not collapse inwardly, is a cylindrical, perforated outlet tube 22 in the catalyst chamber arranged through which the exhaust gases can get into the exhaust pipe 31. The tube 22 can, for example consist of a wire mesh or a perforated tube, the holes of which are round or elongated slots can.

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The alternative arrangement according to FIG. 3 has five rigid rods 100, 200, 300, 400 and 500 at the location of the perforated outlet and support tube in the catalyst chamber, which rods extend in the longitudinal direction of the chamber. The rods are spaced a predetermined distance from one another in the circumferential direction of the chamber and hold the supported catalyst rigidly in place within the catalyst chamber through the use of spacer plates 600. Each plate of each pair of spacer plates 600 connects three of the five rods together, and the two spacer plates of each pair enclose a right angle and so lie on the diameter of the central cylindrical outlet pipe. Two or more pairs of spacer plates can be used, and regardless of their number, they are expediently distributed over the length of the chamber at regular intervals. If such spacer plates are used, they can optionally also be used without the rods, but in which case they extend over the entire length of the catalyst chamber, as is shown in FIG. The spacer plates and the optionally provided rods must consist of a material which up to 800 ⁰ C is oxidatxonsresistent at temperatures.

Another solution is described below with reference to FIG. 2A, with only two for the sake of simplicity

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Outlet openings are shown. The outer wall 100 of the catalyst chamber is provided with openings 101 and 102, which are assigned to the outlet openings of the cylinders of the internal combustion engine and adjoin them. An outlet 103 is opposite the exhaust line of the internal combustion engine. The catalyst 104 includes a supporting substrate, a slurry interlayer, and the catalytic metal. It is arranged so that the exhaust gases from the internal combustion engine must flow through the catalytic converter before they leave the catalytic converter chamber. Spacer plates 105 are used to hold the catalyst in the catalyst chamber. One end of the spacer plates is attached to the chamber wall 100, while the other end of the spacer plates is assigned a disk or plate 108 to ensure that no exhaust gases can leave the catalyst chamber. without having passed through the catalyst. The exhaust gases enter the chamber through the openings 101 and 102 and flow through sleeves 106 and 107 into the interior 110 which is formed by the spacer plates. The exhaust gases then flow continues through the catalyst to the outside and to leave the catalyst chamber through the outlet 103. In FIG. 2A, the flow of the exhaust gases by arrows P _"o to P ₁₀ is illustrated Q.

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The supporting substrate of the catalyst is preferably a knitted wire that comes in four sections or three Units is manufactured. The substrate is composed of sections, for example in the form of annular tubes they are connected to one another before they are inserted into the catalyst chamber.

Another embodiment is described below with reference to Figs. A catalyst chamber has an outer wall 51 with openings 52 and 53. A Catalyst 64 has a support carrier, an intermediate layer and a catalytically active metal. He is so arranged that the exhaust gases pass through the catalytic converter must before they leave the chamber. The carrier is preferably made of knitted wire and it can be in one piece or consist of a number of individual elements, for example in the form of annular tubes and usually bonded together before the carrier is placed in the chamber. Within the The catalyst chamber is held in place by the use of a series of spacer plates 66. One end of the spacer plates 66 is assigned to the chamber wall and at the other end a disc or metal plate is provided to prevent that the exhaust gases leave the chamber without having passed through the catalytic converter.

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The catalyst chamber can be arranged between the turbocharger and the exhaust pipe. The opening 52 can be arranged opposite the outlet of the turbocharger, continuing the outlet, while the opening 53 can be the outlet opening assigned to the exhaust pipe. The flow of the exhaust gas through the catalyst chamber is directed from the outside inwards, as indicated by the arrows P ₁ -. to Fgg is shown (Fig. 5).

The catalyst chamber can also be arranged so that the opening 53 is assigned to the outlet of the turbocharger and continues this outlet, while the opening 52 is assigned to and continues in the exhaust pipe, so that the exhaust gas flow is directed from the inside to the outside, as it is in Fig. 6 by the arrows F ₇₁ to Fog.

If the catalyst chamber is assigned to an internal combustion engine with a large cubic capacity, then according to FIG correspondingly large catalyst chamber several catalysts are arranged. Trained in accordance with the above statements supported catalysts 203-205 are held using spacer plates 206-208. A The end of the spacer plates 212 is assigned to the chamber wall

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and metal disks or plates 209 to 211 are assigned to the other end. The exhaust gas flow through the

Chamber is indicated by arrows F ₂ Ol ^ ^{s P} 246 ^{in Fig} * ^ S ^ekenn ~.

example 1

A 2000 cnr multi-cylinder engine of a commercially available one Motor vehicle powered by a turbo-charged diesel engine j has been modified so that the Results could be demonstrated which can be achieved using the invention. A catalyst chamber according to the above embodiments of Figures 5 and 6 was placed between the outlet of the turbocharger and the exhaust pipe .

The results of a catalyst chamber A were determined by measurements on the exhaust gas coming from the central flow channel the chamber flowed to the outside according to FIG. 6, while for a catalyst chamber B the measurements on the exhaust gas were made, which flowed through the catalyst to the central flow channel according to FIG.

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The catalyst substrate was made from a knitted 310 stainless steel wire 0.254 mm in diameter, which was previously given a flat rectangular cross-section. On this substrate a first layer was slurried \ aluminum oxide, barium oxide and cerium oxide contained, wherein the loading was 0.34 gg ~ wire. The carrier coated with this intermediate layer was impregnated with 5.7% Rh, 94.5 $ Pt, the loading being 918 g cnr. The wire volume used was 2114.6 cm. Measurements were taken after driving 250 miles.

The results were obtained by driving the vehicle through Obtain the LA4 Diesel cycle. The LA4 cycle (Los Angeles cycle) is approved by the Environmental Protection Agency (EPA) of the USA and is a standard test for simulating vehicle operation under the traffic conditions of Los Angeles. It is also a test that is used to determine the effectiveness or other effectiveness of the Demonstrate exhaust gas cleaning unit of a motor vehicle. Hydrocarbons, Carbon monoxide, nitrogen oxides and particulate matter from exhaust emissions are measured in g miles. Basic measurements with regard to the level of impurities in the exhaust gases before they passed through the catalytic converter chamber, carried out.

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TABLE 1

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Max.
percentage
difference Core value Catalytic
A. atorkammer
B. Pests
g mile
percentage
change Min.
percentage
difference 0.4 0.31
22.5 O.32
20th NOX g mile " ¹
percentage
change 1.75 2
-14.3 2.1
-20 CO g mile " ¹
percentage
change 1.25 0.2
84 0.46
63 HCs g mile " ¹
percentage
change 0.2 0.07
65 0.11
45 Back pressure
Nm " ² 13545 22011
-62.5 22688
-67.5 3386 4402
-30 4402
-30

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Example 2

A commercially available vehicle with a turbocharged 2.2 liter diesel engine was equipped with a catalyst chamber which, as shown in FIG. 5, was arranged after the turbocharger. The catalyst material was supported on a substrate of knitted 304 stainless steel wire 0.254 and 0.127 in diameter prior to being formed into flat wire. The knitted material made from the thinner wire was used to produce an inner body, which was surrounded by an outer body made from the knitted material made from the thicker wire. An intermediate layer of aluminum oxide with barium oxide and ceria was assigned to the substrate with a loading of 0.22 pg wire. The catalytic metal used consisted of 7 1/2 QeTn.% Rh, 92 1/2 wt. % Pt with a loading of 0.09 wt./2. The total catalyst volume was 2.6 liters.

When the vehicle was operated in the LA4 cycle, the basic measurements showed a solids content of 0.4 g mile. After this the exhaust gases had been passed through the catalyst chamber, the solids content was 0.19 g mile, which is a Reduction by 52.5 / 5 meant. The maximum back pressure over the entire system was 135 ^ 5 Nm

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Example 3

Using a turbocharged 1.6 bar diesel engine with 14748 cm ⁵ more tests were conducted. At a distance of 1.22 m from the turbocharger, a catalyst chamber with nine catalysts was arranged in rows as shown in FIG. The volume of catalyst used was 213003 cnr. ⁵ The substrate, intermediate layer and catalytic metals were the same as in Example 2.

The engine passed an EPA I98O new vibration cycle test subject to US EPA. The measurements of the solids content in the exhaust gas after the catalyst chamber were carried out every five hours. The results are shown in Table 2.

TABLE 2

Solids in g miles

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Core value after
catalyst
chamber percentage
change 0.0224 O.O745 66.7 O.O782 65 O.O745 66.7 0.1043 53.4 O.O82O 63.4 O.O7O8 68.4 0.0782 65 O.O931 58.4

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The hydrocarbon content in the exhaust gas was reduced from 600 ppm to 12 ppm in the catalyst chamber. The maximum temperature of the exhaust gases passed through the chamber was 388 ^° C. The maximum back pressure of the chamber was 249 Nm " ² .

The examples show the effectiveness of the catalyst chamber according to the invention in removing solids and other contaminants from exhaust gases such as those emitted by internal combustion diesel engines, even if the Chamber is located some distance from the internal combustion engine and operates at a low temperature.

The catalysts used in these internal combustion engines contain as essential to the invention:

a) a subdivided substrate in the flow area of the exhaust gases in order to generate turbulence in them,

b) an intermediate layer of adhering refractory metal oxide on the substrate surface,

c) Ru, Rh, Pd, Ir, Pt, Pe, Co, Ni, V, Cr, Mo, W, Y, Ce, alloys thereof, and intermetallic compounds which contain at least 20 wt.% of one or more of said metals , on the substrate surface or by means of the intermediate layer of refractory metal oxide.

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The refractory metal oxide intermediate layer contains, in the form of its oxides, one or more of Mg, Ca, Sr, Ba, Sc, Y, the lanthanides, Ti, Zr, Hf, Th, Ti, V, Cr, Mn, Co, Ni, B, Al, Si and Sn.

Preferred interlayer materials are Al ₂ O and aluminum oxide hydrates, a stabilizing oxide such as BaO and oxides as promoters for the catalytic activity such as TiOp, ZrOp, HfO ₂ , ThO ₂ , Cr ₂ O ₃ and NiO.

A shape of the catalyst substrate may be a structure made of woven or knitted wire and a a particularly preferred shape is a structure consisting of a woven or knitted wire that is pre-woven or knitting has been rolled into a flat cross-sectional shape. Suitable alloys for the manufacture of the wire are corrosion-resistant and, in particular, oxidation-resistant base metal alloys.

Examples of such base metal alloys are a nickel-chromium alloy with a Ni and Cr addition of more than 20 wt. and an iron alloy with at least one of the following components: chromium 3-40% by weight > aluminum 1-10% by weight, cobalt trace - 5% by weight, nickel trace -72% by weight? and carbon trace -0.5 wt. Such substrates are known per se from DE-OS 24 50 664.

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Other examples of base metal alloys which can meet the severe operating conditions to be expected, are iron-aluminum-chromium alloys having the following ingredients: 0.5-12 wt% Al, 0.1-3.0% Y.. , 0-20 wt.% Cr and the remainder iron. Such alloys are known per se from US Pat. No. 3,027,252.

Alternatively, the base metal alloys can also be less resistant to corrosion, e.g. mild steel, in which case, however a coating covering the substrate made of a correspondingly corrosion-resistant material must be provided, as is the case in GB patent application 7903817 dated 02/02/79 of the same. Applicant is described (published under the number GB 2 012 517 A).

In particular, a wire with a thickness of 0.0254 to 0.508 mm and more should preferably be used for the manufacture of the substrate 0.0254 to 0.305 mm are used.

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Claims (3)

J 21 P 280 Applicant t JOHNSON, MATTHEY & CO. LIMITED, 43 Hatton Garden, London, ECIN 8EE, England Name of the invention : Supercharged internal combustion engine Claims Internal combustion engine charged with a turbocharger with internal combustion, characterized by a Catalyst chamber with a catalyst for removal of dirt or pollutants from the exhaust gases of the internal combustion engine through catalytic ^ Oxidation before the exhaust gases leave the internal combustion engine. 2. Internal combustion engine according to claim 1, characterized in that a multi-part in the flow path of the exhaust gases Substrate is arranged to generate turbulence in the gas flow. 3. Internal combustion engine according to claim 1 or 2, characterized in that the catalyst chamber has the outlet openings is assigned to the internal combustion engine and this continues, with the catalyst chamber still located in front of the turbocharger. 3O.3.198I - 2 - 130066/0685 _ ρ - 4. Internal combustion engine according to claim 1 or 2, characterized characterized in that the catalyst chamber is assigned to and continues the outlets of the turbocharger. 5. Internal combustion engine according to claim 4, characterized in that between the outlets of the turbocharger and a manifold is arranged in the catalyst chamber. 6. Internal combustion engine according to one of claims 1 to 5, characterized in that the catalyst has an annular cross-section and is on a perforated one Outlet pipe is arranged. 7. Internal combustion engine according to one of claims 1 to 5, characterized in that the catalyst on with Is arranged spaced successive support members. 8. Internal combustion engine according to one of claims 1 to "J _3, characterized in that the catalyst chamber encloses a random wire ball, wherein a first layer of heat-resistant metal oxide is slurried on the metal wire and a second layer is deposited thereon which contains the catalytically active metal. J 21 P 280 3/30/1981 - 3 - 130066/0685 9. Internal combustion engine according to claim 8 _}, characterized in that the catalytically active metal is selected from the following group, wherein one or more members of this group can be selected: Ru, Rh, Pd, Ir, Pt, Pe, Co, Ni, V , Cr, Mo, W, Y, Ce, alloys with these metals, as well as intermetallic compounds with at least one of these metals in a proportion of at least 20 wt. ^, The layer with the catalytically active metal directly or via an intermediate layer of heat-resistant metal oxide is applied to the supporting substrate. 10. Internal combustion engine according to claim 8, characterized in that that the refractory metal oxide intermediate layer is one or more oxides of the following Substances contains: Mg, Ca, Sr, Ba, Sc, Y, the lanthanides, Ti, Zr, Hf, Th, Ti, V, Cr, Mn, Co, Ni, B, Al, Si and Sn. 11. Internal combustion engine according to claim Io, characterized in that the intermediate _{layer contains Al 2} O and aluminum oxide hydrates. 12. Internal combustion engine according to claim 11, characterized in that the intermediate layer additionally has a stabilizing one Contains oxide. J 21 P 280 3O.3.198I - 4 - 1 30066/0685 13. Internal combustion engine according to claim 11 or 12, characterized in that the intermediate layer is additionally Contains oxides that accelerate the catalytic activity (promoters). 14. Internal combustion engine according to claim 8, characterized in that the enclosed by the catalyst chamber Wire ball is knitted, woven or pressed from metal wire. 15. Internal combustion engine according to claim 14, characterized in that the metal wire or before knitting Weaving is pressed into a flat cross-section. 16. Internal combustion engine according to one of claims 8 and 14, · characterized in that the wire is made of oxidation-resistant Made of metal. 17. Internal combustion engine according to one of claims 8 and 14, characterized in that the wire consists of an oxidation-resistant base metal alloy. Internal combustion engine according to claim 17, characterized in that that the base metal alloy is a nickel-chromium alloy with a total content of Ni and Cr J 21 P 280 3O.3.198I - 5 - 130066/0685 is from about 20 wt%, and an alloy of iron with at least one of the following additional components:. 3- chromium ¹ wt JO, aluminum 1-10 wt, cobalt trace -5 wt, nickel track -72 wt.?.?.? .? and carbon trace -Ο, 5 wt.?. 19. Internal combustion engine according to claim 17, characterized in that that the base metal alloy is an iron-aluminum-chromium alloy. 20. Internal combustion engine according to claim 19, characterized in that the alloy contains the following components: 0.5-12 wt. Al, 0.1-3.0 wt. Y, 0-20 wt. Cr and the rest iron. 21. Internal combustion engine according to claim 19, characterized in that the alloy contains the following components: 0.5-H weight? Al, 0, r-3.0 wt.? Y, 20.0-95 wt. Cr and the remainder iron. 22. Internal combustion engine according to claim 8 or 14, characterized in that the entire surface of the substrate is coated with the intermediate layer. J 21 P 280 30.3.I98I - 6 - 130066/0685 23 · Internal combustion engine according to claim 8 or 14, characterized characterized in that the thickness of the wire of the supporting substrate is 0.0254-0.508 mm. 24. Internal combustion engine according to claim 23, characterized in that that the wire thickness is 0.0254-0.305 mm. 25. Process for reducing the content of impurities or pollutants in the exhaust gases of turbocharged engines Internal combustion engines, characterized in that the exhaust gases from the engine cylinders are passed through a chamber enclosing a catalytic converter to remove the exhaust gases containing impurities or pollutants in contact with the catalytic converter and at least to slow down partially subject to catalytic combustion. J 21 P 28O
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