DE102016101191A1 - Apparatus for aftertreatment of exhaust gases - Google Patents

Abstract

An apparatus (1) for the aftertreatment of exhaust gases of an internal combustion engine (2) has an exhaust pipe (3), an exhaust gas purification device (5) which is in a housing (4) connected to the exhaust pipe (3) and having an at least partially curved peripheral wall (16) ), and an injector (6) for injecting an additive into the exhaust pipe (3). The exhaust pipe (3) opens tangentially into the housing (4) of the exhaust gas purification device (5).

Description

The invention relates to a device for the aftertreatment of exhaust gases of an internal combustion engine, with an exhaust pipe and with an exhaust gas purification device, according to the closer defined in the preamble of claim 1. Art. Furthermore, the invention relates to an exhaust gas purification device for purifying exhaust gases of an internal combustion engine having a plurality of spaced apart flat exhaust gas purification elements.

A generic device is from the DE 10 2010 040 808 A1 known. In this case, urea received in a corresponding container is injected into an exhaust gas line and, after passing through a hydrolysis section, arrives at an exhaust gas purification device, in this case a catalyst. The catalyst has a base body, a carrier layer of zirconium oxide, a promoter of tungsten oxide applied to the carrier layer and an active component of palladium applied to the carrier layer.

The DE 10 2012 010 991 A1 describes a method for operating a reducing agent metering of an SCR catalytic converter system of an internal combustion engine. The SCR catalytic converter system has an SCR exhaust gas purification device and an SCR catalytic converter connected downstream thereof and a reducing agent metering device for metering a reducing agent into the exhaust gas flow upstream of the SCR exhaust gas purification device. The reductant dosing is controlled in response to a temperature of the SCR exhaust purifier and the downstream SCR catalyst.

In the DE 10 2013 219 640 A1 is an exhaust gas treatment device having an inlet tube for introducing a combustion exhaust gas, an outlet tube for discharging the combustion exhaust gas, an inner housing connected to the inlet tube and the outlet tube for receiving a particulate filter, a connecting element arranged in a connection region of the inner housing facing the outlet tube for mechanically connecting the particulate filter to the exhaust gas Inner case and arranged upstream of the particulate filter in the inner housing oxidation catalyst for catalyzing an oxidation reaction of the combustion exhaust gas. By means of a counterpressure measuring point provided between the oxidation catalytic converter and the connecting element for measuring a counterpressure exerted by the particle filter during operation of the exhaust gas treatment device, a structurally flexible counterpressure check is made possible.

The DE 10 2014 005 354 A1 describes an apparatus for use in an exhaust pipe connected downstream of a selective catalytic reduction unit. The apparatus includes a fixture for connecting the apparatus to the exhaust conduit downstream of an SCR unit, an outlet connection for connecting the apparatus to the outside, and a mixing structure interfering with the exhaust gas flow in the exhaust conduit connected to the fixture and disposed in the exhaust conduit Outlet connection is connected.

However, the known devices and the exhaust gas purification devices used, which are embodied for example in the form of catalysts, however, have the disadvantage of a partially low efficiency, in particular because the exhaust gas purification device is not flowed through in an optimal manner. Another disadvantage is the need for a hydrolysis track, which requires additional space.

It is therefore an object of the present invention to provide a device for the aftertreatment of exhaust gases, which has a better efficiency than known solutions.

According to the invention, this object is achieved by the features mentioned in claim 1.

As a result of the exhaust pipe opening tangentially into the housing of the exhaust gas purification device according to the invention, the exhaust gas is introduced into the same directly on the curved, in particular cylindrical wall of the housing, whereby the exhaust gas is subjected to a circular or rotational movement. Due to the flow rate of the exhaust gas through the exhaust pipe and the housing of the exhaust gas purification device, this leads to a spiral movement of the exhaust gas through the exhaust gas purification device. This results in a very uniform flow through the exhaust gas purification device with the exhaust gas, whereby all areas of the exhaust gas purification device are subjected to the exhaust gas and this is subjected to a correspondingly effective cleaning. This significantly improves the efficiency of the device according to the invention, whereby a smaller number of exhaust gas purification devices used and thus cost savings can be achieved. For example, this can be dispensed with otherwise required particulate filter.

Furthermore, the device according to the invention achieves a constant temperature balance over the entire length thereof. This additionally improves the efficiency of the device, which also results in a significant reduction in the consumption of the injected Additive results, which may be, for example, a reducing agent

If, in a very advantageous embodiment of the invention, the exhaust gas purification device is arranged in the housing, that in the flow direction of the exhaust gases before the exhaust gas purification device a prechamber is formed, in which the exhaust pipe opens tangentially, the above-described spiral movement of the exhaust gas is already effected in the prechamber , which ensures an even better flow through the exhaust gas purification device.

Another very advantageous embodiment of the invention may consist in that the housing is formed in the region of the antechamber facing away from the exhaust gas purification device is substantially spherical. As a result, on the one hand, the exhaust gas flowing into the housing is subjected to an additional component of movement in the direction of the exhaust gas purification device and, on the other hand, the avoidance of corners and similar areas prevents deposition of pollutant residues on the inside of the housing. The pre-chamber has the further advantage that the injected additive is already vaporized in the pre-chamber, so that an otherwise occurring droplet formation is prevented with the associated crystallization of the additive.

In order to reduce the space requirement of the device according to the invention, it can be provided in a further advantageous embodiment of the invention that the injection device is disposed in front of the exhaust gas purification device dispensing with a hydrolysis path. In particular, by the presence of the pre-chamber and the above-described tangential inflow of the exhaust gas into the same results even without such a hydrolysis good mixing of the additive with the exhaust gas. By dispensing with the hydrolysis path, the exhaust pipe can in principle be designed in any desired manner and, for example, also have bends or the like.

A simple control of the supply of the additive results when a control device, which is connected to at least one NOx sensor and controls the supply of the additive in dependence on the measured NOx value, is provided.

In order to measure different parameters of the untreated exhaust gas, it can be provided that in the flow direction of the exhaust gases in front of the exhaust gas purification device in an exhaust gas-carrying line, a NOx sensor, a temperature sensor and a pressure sensor are arranged.

Furthermore, an advantageous embodiment of the invention may consist in that in the flow direction of the exhaust gases after the exhaust gas purification device in the exhaust pipe, a NOx sensor, a temperature sensor and a pressure sensor are arranged. In particular, in conjunction with the corresponding sensors arranged in the flow direction of the exhaust gases upstream of the exhaust gas purification device, a comparison of the pollutants in the untreated and in the treated exhaust gas results. Thereby, the process of purifying the exhaust gas can be carried out much more effectively.

A further significant improvement of the cleaning effect of the exhaust gas purification device results when the same has a plurality of spaced, exhaust gas cleaning elements having on their respective surface indentations which are introduced into the surface, that are formed by the same protruding from the surface projections which are trimmed to the adjacent exhaust gas purification element.

A further solution of the problem is specified in claim 9.

By protruding from the surface projections a constant distance between the individual surface exhaust gas purification elements of the exhaust gas purification device according to the invention is achieved, resulting in a very uniform and better overall flow through the device according to the invention and thus significantly improves their cleaning effect. According to the projections are formed by passages in the surface of the exhaust gas purification elements, so that on the one hand a material savings is achieved and on the other hand, a flow through the exhaust gas cleaning elements is given by the impressions, since these form recesses in the surface through which the exhaust gas flows. Furthermore, a simple production of the exhaust gas purification device according to the invention can be achieved in this way.

In order to achieve a constant distance from adjacent exhaust-gas cleaning elements, it may further be provided that the projections of two adjacent exhaust-gas cleaning elements are arranged offset to one another. As a result, it is possible to dispense with the otherwise necessary intermediate layers or the like.

Embodiments of the invention are shown in principle with reference to the drawings.

It shows:

1 a very schematic representation of the device according to the invention for the treatment of exhaust gases;

2 a view of the device according to the arrow II 1 ;

3 a very schematic representation of a device according to the invention for the purification of exhaust gases; and

4 a view according to the arrow IV 3 ,

1 shows a device 1 for the aftertreatment of exhaust gases of an internal combustion engine 2 , In the internal combustion engine 2 it is in particular an engine for a ship, a construction machine or a similar large engine. Basically, however, is the use of the device 1 conceivable in motor vehicles. The device 1 indicates one of the internal combustion engine 2 outgoing exhaust pipe 3 into which the exhaust gases of the internal combustion engine 2 be initiated, a housing 4 into which the exhaust pipe 3 opens, one in the housing 4 arranged exhaust gas purification device 5 and an injector 6 for injecting an additive into the exhaust pipe 3 on. The additive used is preferably a reducing agent, in particular a urea-water solution. The exhaust gas purification device 5 is preferably designed as a catalyst, in particular as an SCR catalyst, which has a barrier catalyst serving as the oxidation catalyst section.

By means of the with the injector 6 in the exhaust pipe 3 Injected additive is reduced in a conventional manner, the NOx content in the exhaust gas. The injector 6 is in the flow direction "x" of the exhaust gases immediately in front of the housing 4 and thus before the exhaust gas purification device 5 arranged so that no hydrolysis path is present. Through the injector 6 can also be dispensed with a mixing device. From the presentation of 1 it can be seen that the injection device 6 a container 7 in which the additive is located. In the container 7 an unillustrated level sensor can be arranged. The injection of the additive can be carried out in a conventional manner, wherein the device 1 Furthermore, a control device designed, for example, in the form of a control device 8th which has a NOx sensor 9 is connected, so that it is possible to control the supply amount of the additive as a function of the measured NOx value, so that only the actually required amount of additive is injected. Preferably, however, a higher amount of additive is injected at higher NOx levels.

Next to the NOx sensor 9 are in the flow direction "x" of the exhaust gases before the exhaust gas purification device 5 also a temperature sensor 10 for measuring an exhaust gas temperature and a pressure sensor 11 for measuring a back pressure in the exhaust pipe 3 arranged. Also the temperature sensor 10 and the pressure sensor 11 are with the control device 8th connected, this connection in 1 is not shown for reasons of clarity. It is conceivable in this context, a wireless connection. The control device can control the injection of the additive, for example, so that only when a certain, for example, with the temperature sensor 10 measured temperature of the exhaust gases of the additive is injected. Such a temperature may be, for example, 120 ° C.

In the flow direction "x" of the exhaust gases are also after the exhaust gas purification device 5 in one the exhaust pipe 3 continuing, belonging to the same, exhaust-carrying line 12 another NOx sensor 13 , another temperature sensor 14 and another pressure sensor 15 arranged. Also the NOx sensor 13 , the temperature sensor 14 and the pressure sensor 15 are with the control device 8th connected in a manner not shown. As a result, differential measurements of said parameters are possible, which are used to control the injection of the additive by means of the control device 8th can be used.

The control device 8th can be connected via an interface, not shown, with a special, tailored to the particular application diagnostic device, for example, the control device 8th read out or in any other way communicate with it. The control device 8th This can have its own IP address with access to an on-board Internet system.

The control device 8th is preferably not connected to an engine control unit, not shown, so that no complex and complex application of different maps of the two control units is required. This reduces an otherwise existing error rate by parallel calculations of two control units.

In 2 it can be seen that the housing 4 is substantially cylindrical, ie an at least partially curved peripheral wall 16 having. Also an oval cross section of the housing 4 is conceivable. From the presentation of 2 also shows that the exhaust pipe 3 tangentially into the housing 4 the exhaust gas purification device 5 opens, resulting in a direction indicated by the arrow "A" rotational movement or a centrifugal movement into the housing 4 incoming Exhaust gases results. Together with the basic flow direction "x" of the exhaust gases within the exhaust pipe 3 This leads to a spiral movement of the exhaust gases through the housing 4 and thus also by the exhaust gas purification device 5 , As a result, the exhaust gas purification device 5 subjected to the exhaust gases over their entire cross-section.

Furthermore, turn in 1 recognizable that the exhaust gas purification device 5 with a certain distance from the area of the housing 4 into the exhaust pipe 3 opens, is arranged. As a result, in the flow direction "x" of the exhaust gases in front of the exhaust gas purification device 5 an antechamber 17 formed, in which the exhaust pipe 3 as described above opens tangentially. In 1 is also apparent that the housing 4 in the exhaust purification device 5 remote area of the antechamber 17 is substantially spherical or at least in this area has a curvature. In the antechamber 17 Due to the rotational movement of the exhaust gas, a good mixing of the injected additive with the exhaust gas takes place and the exhaust gas is additionally in the direction of the exhaust gas purification device 5 emotional.

Furthermore, a bypass line 18 provided, via which the exhaust gas purification device 5 is bypassable. The bypass line 18 is by means of a storage or control flap 19 locked. The control flap 19 For example, via the control device 8th be controlled, if necessary, for example, when exceeding a certain exhaust gas temperature and / or a certain exhaust backpressure the bypass line 18 for the exhaust gases to open or close.

In the 3 and 4 is the exhaust gas purification device 5 shown in more detail. It can be seen that these are spaced apart, spaced exhaust gas purification elements 20 having. The exhaust gas purification elements 20 have on their surface respective punched or impressions 21 on, so in the surface of the emission control elements 20 are introduced, thereby protruding from the surface protrusions 22 as well as recesses 23 formed in the surface. The projections 22 are the adjacent exhaust gas purification element 20 dressed and serve as a spacer between the exhaust gas purification elements 20 , So can adjacent exhaust purification element 20 abut each other and yet their surfaces have a certain distance from each other. As well as in 3 it can be seen, are the impressions 21 which the projections 22 and the recesses 23 form, so executed, that the projections 22 in both directions away from the surface of the emission control elements 20 extend.

Through the recesses 23 the exhaust gas can flow and thus passes from a gap between two exhaust gas purification elements 20 in an adjacent space. In this way, there is a very good flow through the exhaust gas purification device 5 , The arrangement of the projections 22 on the surface of the emission control elements 20 is in 4 illustrated by way of example and in a very schematic manner. It can be seen that the projections 22 two adjacently arranged exhaust gas purification elements 20 offset from one another. In known manner, the exhaust gas purification elements 20 be helical or helical rolled up or wound up into a round cylinder. In this case, means may be provided with which it is possible to ensure that the offset of the projections 22 two adjacently arranged exhaust gas purification elements 20 is complied with.

For example, the height of a projection 22 2 mm and the distance between two adjacent protrusions 22 each other 20 mm.

The exhaust gas purification elements 20 For example, they may be made of stainless steel and optionally provided with a suitable coating, which may preferably comprise vanadium and tungsten. This will reduce the cost of the waste gas purifier 5 significantly reduced. Alternatively, however, the use of a base body made of ceramic with a corresponding honeycomb structure is conceivable.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010040808 A1 [0002]
• DE 102012010991 A1 [0003]
• DE 102013219640 A1 [0004]
• DE 102014005354 A1 [0005]

Claims (10)

Contraption ( 1 ) for the aftertreatment of exhaust gases of an internal combustion engine ( 2 ), with an exhaust pipe ( 3 ), with an exhaust gas purification device ( 5 ) in one with the exhaust pipe ( 3 ), an at least partially curved peripheral wall ( 16 ) housing ( 4 ) is arranged, and with an injection device ( 6 ) for injecting an additive into the exhaust pipe ( 3 ), characterized in that the exhaust pipe ( 3 ) tangentially into the housing ( 4 ) of the exhaust gas purification device ( 5 ) opens. Apparatus according to claim 1, characterized in that the exhaust gas cleaning device ( 5 ) in the housing ( 4 ) is arranged such that in the flow direction (x) of the exhaust gases before the exhaust gas purification device ( 5 ) an antechamber ( 17 ) is formed, in which the exhaust pipe ( 3 ) opens tangentially. Device according to claim 2, characterized in that the housing ( 4 ) in which the exhaust gas purification device ( 5 ) facing away from the antechamber ( 17 ) is substantially spherical. Apparatus according to claim 1, 2 or 3, characterized in that the injection device ( 6 ) waiving a hydrolysis route immediately before the exhaust gas purification device ( 5 ) is arranged. Device according to one of claims 1 to 4, characterized by a control device ( 8th ), which at least with a NOx sensor ( 9 ) and controls the feed of the additive in dependence on the measured NOx value. Device according to one of claims 1 to 5, characterized in that in the flow direction (x) of the exhaust gases in front of the exhaust gas purification device ( 5 ) in the exhaust pipe ( 3 ) a NOx sensor ( 9 ), a temperature sensor ( 10 ) and a pressure sensor ( 11 ) are arranged. Device according to one of claims 1 to 6, characterized in that in the flow direction (x) of the exhaust gases after the exhaust gas cleaning device ( 5 ) in an exhaust-carrying line ( 12 ) a NOx sensor ( 13 ), a temperature sensor ( 14 ) and a pressure sensor ( 15 ) are arranged. Device according to one of claims 1 to 7, characterized in that the exhaust gas cleaning device ( 5 ) a plurality of spaced-apart, exhaust gas cleaning elements ( 20 ), which on its respective surface impressions ( 21 ), which are introduced into the surface in such a way that by the same projecting from the surface projections ( 22 ), which the adjacent exhaust gas purification element ( 20 ) and recesses ( 23 ) are formed in the surface. Exhaust gas purification device ( 5 ) for the purification of exhaust gases of an internal combustion engine ( 2 ) with a plurality of spaced-apart exhaust gas purification elements ( 20 ), characterized in that the exhaust gas purification elements ( 20 ) on their respective surface impressions ( 21 ), which are introduced into the surface in such a way that by the same projecting from the surface projections ( 22 ), which the adjacent exhaust gas purification element ( 20 ) and recesses ( 23 ) are formed in the surface. Exhaust gas purification device according to claim 9, characterized in that the projections ( 22 ) of two adjacently disposed exhaust gas purification elements ( 20 ) are offset from one another.

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