DE2358732B2 - Device for deflecting and reducing the speed of a flowing medium - Google Patents

Description

The invention relates to a device for deflecting and reducing the speed of a flowing medium before entering a catalyst, heat exchanger or the like

In already known designs, the flowing medium, for. B. Exhaust gases, in an exhaust manifold collected and then flows through a catalyst to reduce pollutants, the cross-sectional area of which is larger than the cross-sectional area of the exhaust puff pipe.

An effective catalytic exhaust gas cleaning is known to be dependent on the residence time of the exhaust gases in the Catalyst. Now becomes a catalyst of hot exhaust gases with different velocities unevenly acted upon, the pollutants in the exhaust gases are at a higher speed because of the short residence time chemically only incompletely implemented. The uneven application leads here to considerable temperature differences and thus to high thermal stresses, which can lead to breakage of the catalyst body. Service life and operational reliability are therefore considerably restricted

Further examples are heat exchangers and regenerators, such as those used in the Stirling engine will. The performance and efficiency of the machines depend on a uniform application and flow through these components.

As is known, serve to reduce the flow velocity in closed channels generally diffusers. In vehicle construction, in particular Passenger car construction, they are hardly usable for reasons of space. Also one under the name "Bell diffuser", the well-known limit performance diffuser, cannot be used because of its length.

Even the use of several partial diffusers (multi-diffuser) with a shorter overall length is because of the Thermally and mechanically highly stressed exhaust pipes in internal combustion engines are not possible, because the pulsating, hot exhaust gas flow in the installation and fastening system stimulates vibrations that lead to Cause fatigue fractures.

Various installations in pipelines have become known, which, with a very short overall length, bring about an even loading of the catalytic converter, of which a flat or conical perforated plate placed in front of the catalytic converter is the best known solution is.

Tests have shown that the flowing out of the holes in the perforated plate in the form of individual free jets Gas then needs a calming section until the individual free jets dissolve and have mixed.

However, the inlay of perforated sheets did not provide a satisfactory solution in terms of durability, because the same difficulties arose here as with the use of multi-diffusers.

The small space available for the catalytic converter system in the passenger car requires therefore a practical and optimal new solution.

The invention is therefore based on the object of an effective implementation with structurally simple means to create a sufficiently uniform application and flow through the catalytic converter guaranteed with low pressure loss.

The object is achieved according to the invention in that the medium in the middle of a chamber with approximately round cross-sectional area flows in approximately parallel to a diaphragm that forms a wall of the chamber and those at a distance from a catalyst behind it. Heat exchanger od. The like. Is arranged.

In an advantageous embodiment of the invention, the chamber with the diaphragm is an integral part an inflow line, e.g. B. an exhaust manifold or exhaust manifold.

In another embodiment, the clear width of the chamber between the diaphragm and the outer wall is approximately the same the clear width of the inflow line.

In a further embodiment of the invention, the surface the clear opening of the diaphragm approximately equal to twice the area of the clear width of the inflow line.

Another embodiment of the invention is characterized in that the cross-sectional area of the chamber approximately equal to the cross-sectional area of the catalytic

tors is.

Another advantageous embodiment of the invention is that the clear width between Orifice and catalyst approximately equal to the root of the cross-sectional area of the catalyst minus the The root of the cross-sectional area of the clear opening is the Bende.

For the invention it is also advantageous that the shape of the inlet area from the inflow line is designed pear-shaped in the chamber.

Finally, the embodiment of the invention is also characterized in that the inflow line in the chamber is continued to the edge of the diaphragm.

These embodiments are most favorable for achieving the best possible deflection, loading and flow through to reduce pollutants through effective catalytic exhaust gas cleaning.

In the drawing, the invention is shown, for example, in two embodiments. It shows

1 shows a section of a device according to the invention with a 180 ° deflection,

Fig. 2 is a section along the line H-II in Fig. 1,

F i g. 3 shows a section of a device according to the invention with a 90 ° deflection and

F i g. 4 shows a section along line IV-IV in FIG F i g. 3.

The F i g. 1 and 2 show an inflow line 1 (e.g. exhaust manifold or exhaust gas collection pipe of an internal combustion engine), which opens into a chamber 2, the cross-sectional area of which is designed pear-shaped and which has on one side a cover 3 and then a flange 4 for the connection of a catalytic converter 5.

By means of this embodiment, a deflection of a gas flow by approximately 180 ^{3 is achieved} in a very confined space.

The F i g. 3 and 4 show an inflow line 6 (e.g. exhaust manifold or exhaust gas collection pipe of an internal combustion engine), which opens into a chamber 7 with a pear-shaped cross-sectional area, one on one side Has diaphragm 8 and then at a distance a flange 9 for the connection of a catalytic converter 10.

By means of this embodiment, a gas flow is deflected by approximately 90 °.

Other deflections in the range between 90 and 180 ° are also conceivable.

However, an embodiment is also conceivable in which the chamber, the diaphragm and the subsequent Catalyst have elliptical cross-sectional areas which are matched to one another and which work together produce comparable and good results.

1 sheet of drawings

Claims (8)

Patent claims: 1. Device for deflecting and reducing the speed of a flowing medium before entering a catalytic converter, heat exchanger oddgL, characterized in that the medium flows into the center of a chamber (2, 7) with an approximately round cross-sectional area roughly parallel to a diaphragm (3, 8) that has a wall ίο the chamber (2, 7) and at a distance from a catalyst (5, 10) located behind it, heat exchangers or the like. Is arranged. 2. Device according to claim 1, characterized in that the chamber (2, 7) with a diaphragm (3, 8) integral part of an inflow line (1, 6), 2. B. an exhaust manifold or exhaust manifold is 3. Apparatus according to claim 1 and 2, characterized in that the inside width of the chamber (2, 7) between the diaphragm (3, 8) and the outer wall roughly equal to the clear width of the inflow line (1, 6) is. 4. Device according to claims 1 to 3, characterized in that the surface of the clear The opening of the diaphragm (3, 8) is approximately equal to twice the area of the clear width of the inflow line (1,6) is. 5. Device according to claims 1 to 4, characterized in that the cross-sectional area the chamber (2, 7) is approximately equal to the cross-sectional area of the catalyst (5, IC). 6. Device according to claims 1 to 5, characterized in that the clear width between Orifice (3, 8) and catalyst (5, 10) approximately equal to the root of the cross-sectional area of the Catalyst (5,10) minus the root of the cross-sectional area of the clear opening of the diaphragm (3, 8) is. 7. Device according to claims 1 to 6, characterized in that the shape of the inlet area of the inflow line (1, 6) into the chamber (2,7) is pear-shaped. 8. Device according to claims 1 to 7, characterized in that the inflow line (1,6) is continued in the chamber (2, 7) to the edge of the diaphragm (3, 8).