EXHAUST PURIFICATION APPARATUS FOR AN ENGINE

• US 20100107612A1
• Filed: 04/22/2008
• Published: 05/06/2010
• Est. Priority Date: 05/01/2007
• Status: Active Grant

• Current Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Original Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Inventors: Yamazaki, Satoshi, Takeda, Yoshinaka, Saito, Shinichi, Hiranuma, Satoshi, Fujita, Hiroaki
• Granted Patent: US 8,359,838 B2
• Time in Patent Office: Days
• US Class Current: 60/295
• CPC Class Codes: B01D 2251/2067 Urea
• CPC Class Codes: B01D 53/90 Injecting reactants
• CPC Class Codes: B01D 53/9431 Processes characterised by a specific device
• CPC Class Codes: B01D 53/9477 with catalysts positioned on separate bricks, e.g. exhaust systems
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 13/08 Other arrangements or adaptations of exhaust conduits pipes, joints or supports therefor in general F16L; collecting or removing exhaust gases of vehicle engines in workshops B08B15/00, on highways E01C1/005
• CPC Class Codes: F01N 2470/02 Tubes being perforated
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 3/0253 adding fuel to exhaust gases
• CPC Class Codes: F01N 3/035 with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/106 Auxiliary oxidation catalysts
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 3/24 characterised by constructional aspects of converting apparatus filtering in combination with catalytic reactors F01N3/035
• CPC Class Codes: F01N 3/2882 Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices combined with absorbents or adsorbents only F01N3/0814; combined with particulate filters F01N3/035
• CPC Class Codes: F01N 3/2892 Exhaust flow directors or the like, e.g. upstream of catalytic device
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An exhaust purification apparatus for an engine has a first casing (17) that is interposed in an exhaust path (13); a second casing (23) that is set downstream of the first casing (17) and contains an exhaust purification device (24); a connecting pipe (22, 41, 51) that connects the first casing and the second casing (23) to each other and includes an insertion portion that is inserted in the first casing (17); and an injection nozzle (27, 52) that has a tip end inserted in the connecting pipe (22, 41, 51) and injects an auxiliary agent from the tip end. The insertion portion of the connecting pipe (22, 41, 51) is provided with a plurality of through-holes (22a, 41a, 41b, 51a) connecting the inside and the outside of the connecting pipe (22, 41, 51), so that the exhaust gas contained in the first casing (17) is introduced into the connecting pipe (22, 41, 51) through the through-holes and guided towards the second casing (23).

Claims

1. An exhaust purification apparatus for an engine comprising:

a first casing that is interposed in an exhaust passage of the engine;

a second casing that is interposed in the exhaust passage on a downstream side of the first casing and contains an exhaust purification device;

a connecting pipe that connects the first and second casings to each other and includes an insertion portion that is inserted in the first casing, the connecting pipe being provided in the insertion portion with a plurality of through-holes connecting the inside and outside of the connecting pipe, thus introducing exhaust gas within the first casing into the connecting pipe through the through-holes, and guiding the exhaust gas towards the second casing; and

an injection nozzle that has a tip end inserted in the connecting pipe and injects an auxiliary agent required for the exhaust purification device from the tip end.

2. The exhaust purification apparatus for an engine according to claim 1, wherein:

the first casing has a substantially cylindrical shape;

the second casing is placed on a lateral side with regard to a central axis of the first casing; and

the connecting pipe is disposed so that an upstream-side portion thereof extends from one portion of a lateral face of the first casing through to another portion of the lateral face, and the through-holes are formed in the insertion portion that is located inside the first casing.

3. The exhaust purification apparatus for an engine according to claim 2, wherein:

the connecting pipe is provided with the through-holes so that diameters of the through-holes located downstream as seen in an exhaust flow direction in the first casing are larger than those of the through-holes located upstream.

4. The exhaust purification apparatus for an engine according to claim 2, wherein:

the through-holes having virtually the same diameter are substantially uniformly arranged in the insertion portion of the connecting pipe.

5. The exhaust purification apparatus for an engine according to claim 1, wherein:

the connecting pipe is provided with the through-holes so that total opening area of the through-holes is larger than passage-sectional area of the connecting pipe.

6. The exhaust purification apparatus for an engine according to claim 1, wherein:

the injection nozzle injects the auxiliary agent from the upstream side as considered in the exhaust flow direction towards the downstream side along a central axis of the connecting pipe.

7. The exhaust purification apparatus for an engine according to claim 1, wherein:

the first casing has a substantially cylindrical shape;

the second casing is placed in a direction of a central axis of the first casing;

one end of the connecting pipe is connected to the second casing and extends from the second casing towards the first casing, so that a portion located on a side of the other end of the connecting pipe is inserted into the first casing through an end portion of the first casing, which is located on a side of the second casing; and

the injection nozzle injects the auxiliary agent from a side of the end of the connecting pipe, which is located within the first casing.

8. The exhaust purification apparatus for an engine according to claim 1, wherein:

the injection nozzle injects a urea aqueous solution as the auxiliary agent; and

the exhaust purification device is a selective reduction type NOx catalyst for reducing NOx contained in exhaust gas by using ammonia produced from the urea aqueous solution that is injected from the injection nozzle.

9. The exhaust purification apparatus for an engine according to claim 1, wherein:

the injection nozzle injects fuel as the auxiliary agent; and

the exhaust purification device is a pre-stage oxidation catalyst for forcibly regenerating a diesel particulate filter that is set downstream thereof, by causing an oxidation reaction of the fuel injected from the injection nozzle and increasing exhaust temperature.

10. The exhaust purification apparatus for an engine according to claim 1, wherein:

the injection nozzle injects fuel as the auxiliary agent; and

the exhaust purification device is a pre-stage oxidation catalyst for carrying out a SOx purge of an absorption type NOx catalyst that is set downstream thereof by causing an oxidation reaction of the fuel injected from the injection nozzle and increasing the exhaust temperature.