DE1244477B - Catalytic converter muffler - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

FOIn

German class: 46 c6 - 6/01

Number: 1244 477

File number: A 503131 a / 46 c6

Filing date: September 21, 1965

Opened on: July 13, 1967

The invention relates to a catalytic converter muffler with two in a cylindrical housing in the longitudinal direction, concentrically arranged one inside the other, between the perforated tubes enclosing the catalyst mass, of which the inner tube is connected at one end to the inlet port and closed at the other end, while the outer tube is spaced from the housing jacket at least on a part of the circumference, whereby a chamber is formed which is connected to the outlet port.

Such a catalytic converter muffler is used to remove the toxic and harmful to health To oxidize components of the hydrocarbon-containing combustion gases of internal combustion engines.

The monitoring of automobile exhaust gases has become increasingly important in recent years Has become a problem, especially in densely populated city centers. The reason for this is that the exhaust gases, the combustion of hydrocarbon fuels, such as. B. gasoline, diesel fuel and the like, in internal combustion engines, mixtures of carbon monoxide, various saturated ones and unsaturated hydrocarbons, oxides of nitrogen and other components that contain are both toxic and the preconditions for a condition commonly referred to as "smog" designated. The mechanism of smog formation has been studied very carefully and it is now known that the smog from the photochemical interaction of oxides of nitrogen, reactive Hydrocarbons and sunlight result. The effects of smog are among other things vaporous mist, a high concentration of oxidant in the atmosphere, mainly Ozone, eye irritation, damage to plants and the like.

A catalytic converter muffler is a device that has been designed to remove the harmful constituents to eliminate vehicle exhaust fumes. Such devices are generally in the exhaust pipe an internal combustion engine instead of an ordinary muffler. Through the The effect of the catalytic converters contained in these devices is an oxidation of the exhaust gases achieved so that the gases emerging from the muffler are less harmful and toxic components contain.

It is known that a radial arrangement of the catalyst bed causes the exhaust gases in the catalyst bed be evenly distributed. With this catalytic converter muffler

Applicant:

American Cyanamid Company,

Wayne, N. J. (V. St. A.)

Representative:

Dr. I. M. Maas

and Dr. W. G. Pfeiffer, patent attorneys,

Munich 23, Ungererstr. 25th

Named as inventor:
William Beveridge Innes,
Upland, Calif. (V. St. A.)

Claimed priority:
V. St. v. America September 22, 1964
(398 308)

However, if the catalyst is used for a long time, bubbles appear in the catalyst filling. In the US Pat. No. 3,094,394 a device is described in order to prevent a through-flow in the radial direction To keep the catalyst bed under constant pressure, so that the formation of cavities in the catalyst filling is prevented. Despite considerable advantages of the catalytic muffler after this one Patent has the relocation of the exhaust from a horizontal position when an automobile for example sways back and forth on an uneven surface or when going up or downhill, result in the formation of cavities on the surface of the catalyst filling. These cavities allow a shorter path for the exhaust as it goes up through the bed and through the perforations in the sleeve, which represents the boundaries of the catalyst bed, flow. The shorter way for the exhaust gases has a greater velocity of the gases on these short cuts especially at high speeds Speed of the internal combustion engine result. The locally higher speed causes a shift of the catalyst particles and possibly a vigorous shaking as well as even one Displacement of the catalyst from one section of the filling to another. This repression

709 610/423

1 244 447

3 4

or shifting the catalyst has many very points; the inner tube is at one end with

adverse effects. connected to the inlet port and at the other end

In the first place, it causes abrasion, closed, while the outer tube shrinks and premature wear of the housing shell on at least part of the circumference of the catalyst particles. Secondly, there are also comfortable driving conditions under the catalytic converter which is connected to the outlet connection.
Filling formed channels result in that considerable covers are provided to flow the ends of the lent quantities of the exhaust gases through the catalyst bed tube and the first zone at the outlet end, without covering the catalytic oxidation of the device. These covers are subject to. These channels are formed as a result of, for example, a plate which forms the ends of the natural flow direction of the exhaust gases through the pipe in the center and the first zone and the generally fixed system more easily with the inlet pipe and the catalyst filling in vertical directions. Third comes a lock that is delimited by the first zone. A large part of the catalytic converter does not natively contact the exhaust gases in either one or both covers, and the contact time is generally rigidly fixed in a manner as it is in uniform. The overall result of this damaging US Pat. No. 3,094,394 is described, whereby influences are an uneconomical use and a cover that closes the inlet pipe serves as an early exhaustion of the catalytic converter as well as a relief valve when the catalytic converter leads to low conversion of the toxic and harmful is heated above a certain undesirable level. Components of the exhaust gases to be less harmful 20 This cover then enables the combustion products and gases to be discharged directly through the facility

In the above-mentioned USA. Patent is one without it being with the catalyst filling in Device described in which a spring or contact come and oxidize. Likewise, how Similar devices are used to one described in U.S. Patent 3,094,394 Apply pressure to the catalyst filling and then the cover that removes the catalyst filling to close the formation of voids or bubbles which is located in the first zone. The coil springs are made of a heat-exchangeable to be easily used up catalyst made of resistant steel alloy and preferred to replace.

wise in a fireproof wool or other The essential characteristic of the object of this

embedded in stable heat-resistant material. This invention is a closed, preformed, upper

Heat-resistant materials are necessary around the segment section extending in the longitudinal direction

correct functioning of these coil springs or the outer cylindrical tube that holds the catalytic converter

the other elastic devices to guarantee filling, which around the cylindrical, in

Afford. These refractory materials are arranged in a very longitudinal direction extending inner tube

costly and difficult to manufacture and wear, therefore, is externally limited. With the object after the

half of the very high cost of the U.S. catalytic patent mentioned is the cylindrical

Converter of this type. outer tube perforated on the entire circumference.

The invention aims at a catalytic converter The closing of the upper section of the cylinder muffler, In the even more effective of the catalytic sleeve, replacement particles can be used in various ways than follow in the known arrangement. For example, the perforation in the is made use of and in which an optimal um- corresponding area of the outer tube is easy Conversion of toxic and harmful ingredients. In another embodiment, allocate A completely perforated tube is first made of the hydrocarbon combustion gases will hold. and then a metal foil or a curved heat-

The construction of the catalytic muffler 45 solid metal part on or under the perforated top

should be simple and easy in the exhaust line segment section of the pipe, fitted with a snug fit,

to be attached to an internal combustion engine. The area of the tube that is closed can

The displacement of the catalyst particles should be determined by the radian measure. Suitable

catalyst muffler according to the invention a mini arc dimensions are from about 20 to 120 ° and preferably

mum, so that the catalyst losses as a result of 50 wise from about 40 to 100 °,

Abrasion, Abrasion and Premature Consumption The catalyst mufflers after this refreshment

can be significantly reduced. Finally, a manure will be described as cylindrical pots

The purpose of a catalytic converter muffler, which is not made of metal and preferably symmetrically designed, is them

spring made of a heat-resistant alloy, but can also have an elliptical cross-section.

to enclose the catalyst filling. In the erfrn- 55 wise.

proper catalyst muffler should the local- On the basis of the figures, the invention is exemplified

Liche speed of the exhaust gases explained in more detail in the entire way.

Catalyst filling must be the same. Likewise, a good F i g. 1 shows a vertical longitudinal section through

noise dampening effect can be obtained. a catalyst exhaust pot according to this invention;

These objects are achieved in that 60 F i g. 2 shows a section along line 2-2 in FIG

The invention measured the outer tube along its Fig. 1;

upper segment a closed wall on- F i g. 3 shows a section through a known one

shows. This measure according to the invention is applied to the catalyst muffler of the same general con

an ICatalyst muffler applied, which is in struc- ture, but in which the invention

a cylindrical housing in the longitudinal direction, and 65 element is absent;

although concentrically one inside the other, two pipes with between F i g. 4 shows a cross section through a preferred

between the catalyst particles for the Oxydierimg supplied embodiment of the catalyst muffler

of the exhaust gases from hydrocarbon combustion according to this invention.

1 244

In Fig. 1 is one embodiment of a catalyst exhaust plug illustrated according to this invention. The catalytic converter muffler has a cylindrical shape Housing 1®, which is preferably made of a highly heat-resistant steel, on. In general steels or metals, preferably light metals, the temperatures in the range up to Withstand 750 ° C. This cylindrical housing encloses itself in the longitudinal direction extending cylindrical outer tube 11 with perforations 12 in the lower part. The upper segment section 13 is closed. This tube surrounds an inner one that also extends in the longitudinal direction cylindrical tube 14, which is arranged in the middle of the outer tube and an inlet end IS that at the exhaust manifold of a car can be connected, as well as an outlet end (not shown) which can be closed with a cap (not shown). This cap can be tight or attached to a suitable heat-fusible element at a predetermined Overheating temperature melts so that the cap is opened when the pressure of the non-oxidized Exhaust gases exceeds a certain value. The longitudinally extending cylindrical inner tube has perforations 16 over approximately its entire surface as far as it is located inside the tube 11. The perforations of the two tubes can be designed in various ways, i. h., it metal grids or metal sheets that are perforated to the required extent can be used. The tubes delimit a first hollow cylindrical zone 17 between their cylindrical surfaces, in which the Kaialysatorfüll is included. Define the cylindrical housing and the outer tube with its surfaces a second hollow cylindrical zone 19 which carries the catalytically oxidized exhaust gases to the outlet end 20 of the muffler leads. Supports, such as shown at 21 and 22, can be used for the Bracket of the ring cap 23 may be provided. These supports can be resiliently attached to a To enable displacement of the cap and replacement of the catalyst filling. Annular end plates 24 and 25 for the first and second zones are at the inlet end of the inner tube 14 intended. A closure ring 26 forms a closure plate for the catalyst muffler on the other side.

Any of a variety of catalysts suitable for this purpose can be used, such as e.g. B. an iron oxide-chromium oxide catalyst, which consists of 85 to 97% Fe ₂ O ₃ and 0.5 to about 15% Cr ₂ O ₃ .

During operation, the hydrocarbon-containing combustion gases enter the catalytic converter muffler through the inlet pipe 14 and flow in the radial direction into the catalyst filling, which through the first zone 17 is limited. Since the upper portion 13 of the outer tube 11 is closed, the normally preferred flow path of the exhaust gases in the catalyst mass bypassing the closed Section deflected to the adjacent lower parts of the catalyst filling. During the time, in which the hydrocarbon-containing combustion gases flow through the catalyst bed, the toxic and noxious constituents of these gases essentially as they pass through the catalyst particles oxidized. After the catalytic conversion, the oxidized gases flow in the second Zone 19 continues in its natural direction and out of this zone through outlet 20 into the atmosphere or into a suitable conduit through which they are discharged into the atmosphere.

F i g. Fig. 2 shows a cross section along the line 2-2 in Fig. 1, the concentric arrangement of the cylindrical housing and the outer tube 11 and the exhaust gas inlet pipe 14 and in particular the closed upper segment section 13 of the tube 11 can be seen. It can be seen that the Exhaust gas flow is deflected through the closed upper part of the tube 11, so that the normally preferential channeling of the exhaust gases through the upper part of the catalyst filling, which the above-mentioned Shifting the catalyst bed has the consequence is prevented.

F i g. 3 shows, in a section similar to FIG. 2, a cross section through a known one cylindrical catalytic converter muffler with the same concentric arrangement of the elements, but with the closed upper part of the tube 11 is missing. It can be seen from FIG. 3 it can be seen that with not closed upper part, the exhaust gases prefer their flow path through this upper part of the Search for catalyst filling and thereby cause a displacement of the catalyst particles, which to channel formation and poor utilization of the catalyst particles.

In Fig. 4 is shown in a cross section an embodiment according to the invention in which the Housing 10 has an elliptical cross section and is arranged at points 27 and 28 close to tube 11 or is even connected to it, for example, by welding. It can also be made from this figure the longitudinally extending cylindrical tube 14 can be seen, which is a closed one upper part 29, whereby the flow of exhaust gases even more from the upper Area of the catalyst filling, which is covered by the closed section 13, deflected will. This closed part 29 of the inner tube can thereby be formed during the manufacture of this tube v / ground that a metal grid or a perforated metal sheet is rolled up in a cylindrical shape and the edges overlap and are welded together. It is emphasized that the elliptical shape of the housing in FIG. 4 the space requirement of the catalytic converter muffler in vertical direction Direction diminished. This is very important since the construction of modern automobiles with low-lying Center of gravity require a muffler that is as flat as possible.

The use of the improved catalyst muffler of this invention avoids im essentially the displacement of the catalyst particles and the formation of channels through the exhaust gases, which in flow in the vertical direction through the upper part of the catalyst filling. The advantages of the invention Measures are a longer life of the catalyst, a greater uniformity of the The exhaust gases flow through the catalyst particles and a better and more complete oxidation of the combustion gases containing hydrocarbons. In addition, the covered upper section serves of the catalyst bed as a reserve for the replacement of exhausted catalyst particles in the lower ones Sections of the filling and isolates the

side of the motor vehicle, which is adjacent to the muffler, against the heat in the reaction space.

Claims (3)

Patent claims: 1. Catalytic converter muffler with two in a cylindrical housing in the longitudinal direction, and although concentrically arranged one inside the other, enclosing the catalyst mass between them perforated tubes, of which the inner tube is connected at one end to the inlet port and is closed at the other end, while the outer tube to the housing jacket at least spaced on part of the circumference, thereby forming a chamber which is connected to the Outlet nozzle is connected, characterized in that that the outer tube (11) has a closed wall along its upper segment (13). 2. catalyst muffler according to claim 1, characterized in that the closed upper segment (13) of the outer tube (11) extends over an arc of 20 ° to 120 °, preferably from 40 ° to 100 °. 3. catalyst muffler according to claim 2, characterized in that the inner one Tube (14) has a closed wall on its upper segment (29). Considered publications: German Patent No. 675 355;
U.S. Patent No. 3,094,394. 1 sheet of drawings 709 610/423 7.67 © Bundesdruckerei Berlin