DE1088764B - Catalytic exhaust gas cleaner for internal combustion engines - Google Patents

Description

The regulation of the temperature of the catalytic converter is more catalytic! Exhaust gas cleaning from internal combustion engines a difficult problem. Each catalytic converter has a very specific one, depending on the material used Temperature or a temperature range in which it has a maximum effect. In to the effect is considerably reduced at low temperatures. When the temperature rises enough and the catalyst is fully effective, the heat generated is that of the incoming exhaust gases and from which arises from the catalytic reaction, often too great. In general, the heat becomes so great that the system becomes inoperable, or at least at least so large that expensive, highly heat-resistant materials for the catalyst container and expensive and bulky Isolations will be required. In order to work and to be effective, the catalysts must be kept at a temperature between 315 and 815 ° C and are at temperatures between 482 and 593 ° C are most effective.

It has been found that the most favorable operating temperature is maintained and the catalyst in one practically usable temperature range is maintained when according to the invention in the catalyst chamber a filled with a gas or a liquid metal piston is arranged with an expandable Dose that controls the variable throttle valve is connected. This allows the maximum effect can be set.

The device according to the invention is explained in more detail with reference to the drawings.

Fig. 1 is a partially sectioned side view of a catalytic exhaust gas purifier;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

The system consists of an exhaust pipe 2 coming from the machine, not shown, a catalyst chamber 4 and an exhaust pipe 6 leading from this into the open. The chamber 4 has a sheet metal wall 8 with welded sheet metal partitions 10 and 12, which are provided with holes for the passage of the exhaust gases are. In the inner chamber part 16 there is an oxidation catalyst. The exhaust gases must therefore flow from the exhaust pipe 2 via the partition 12 through the catalytic converter space 16 in order to flow out of the chamber part 18 to the exhaust pipe 6. Contact with the catalytic converter completely oxidizes the hydrocarbons and other organic compounds so that the harmless exhaust gases escape into the open.

In addition to the connection of the exhaust pipe 2 with the catalyst chamber 4, an inlet pipe 20 is connected, by which in a known manner the air required for the catalytic oxidation through the

Catalytic exhaust gas cleaner
for internal combustion engines

Applicant:

General Motors Corporation,
Detroit, me. (V. St. A.)

. Representative: Dipl.-Ing. E. Vorwerk
and Dipl.-Ing. K. Walter, patent attorneys,
Berlin-Charlottenburg 9, Bolivarallee 9

Claimed priority:
V. St. v. America April 18, 1958

George Joseph Nebel, Grosse Pointe, Mich.

(V. St. A.),
has been named as the inventor

Effect of a venturi 22 is sucked in from the open air. The inlet line 20 contains a variable throttle point 23 (FIG. 2), which consists of a metal screen 24 welded into the tube, the opening of which can be regulated by a closure plate 26. The closure plate 26, which can be pivoted about a screw 30 in front of the opening of the diaphragm 24, protrudes through a slot 28 to the outside. The regulated throttle point 23, together with the Venturi tube 22 through which the exhaust gases flow, thus determines the amount of air that is supplied to the exhaust gases. The end plate 26 is connected via a handlebar 32, an angle lever 34 and a handlebar 36 to a tight, expandable can 40 which is attached to the outer wall 8, in which a gas or liquid-filled, embedded in the catalyst Metal piston 38 opens. The gas or liquid, e.g. B. mercury, or a wax that expands when heated expands when the piston 38 is heated and moves the can 40 upwards. The can can be pressed or otherwise manufactured and have relatively strong resilient walls made of rubber or metal so that ₍ it normally contracts. This effect can also be achieved by a light spring inside the can or in the course of the linkage the actuated end plate 26 is moved in the direction of the closed position.

009 590/205

The expandable can, the linkage and the closure plate are set so that the desired temperature is maintained in the catalyst chamber will. The mode of operation is as follows: If the catalyst is cold, the can 40 is contracted, and the closing plate 26 effects a maximum throttling of the inflowing through the inlet line 20 Air. So there is relatively little cooling air introduced into the exhaust gas flow, so that the catalytic converter is heated up fairly quickly by the heat of the exhaust gas. If the catalyst reaches the desired Temperature, about 538 ° C, the can 40 expands and moves the end plate via the linkage 26., so that this opens the throttle point and more cooling air can flow to the exhaust gases. It will reached an equilibrium state in which the catalyst at the desired temperature or in the desired temperature range is maintained.

The device should preferably operate in a temperature range between 315 and 815 ° C and generate a sufficiently large mechanical actuating force to adjust the closure plate 26 without reinforcement to be able to. The throttling of the incoming air is advantageous because of its simple structure and has only low frictional resistance, so that only a small amount of force is required for actuation.

Claims (1)

PATENT CLAIM: Catalytic exhaust gas purifier for automobiles with a chamber containing an oxidation catalyst, the exhaust gases via a line, one Venturi nozzle and one air inlet line which can be regulated by a variable throttle valve contains, supplied and from which they are removed via a line after cleaning, thereby characterized in that in the catalyst chamber (4) a filled with a gas or a liquid Metal piston (38) is arranged with an expandable can (40), which the changeable Throttle valve (23) controls, is connected. Considered publications:
German patent specifications No. 470 389, 563 757,
284 1 * sheet of drawings © 009 590/205 8.60