ARRANGEMENT FOR INTRODUCING A LIQUID MEDIUM INTO EXHAUST GASES FROM A COMBUSTION ENGINE

• US 20130152558A1
• Filed: 09/14/2011
• Published: 06/20/2013
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Loman, Peter
• Granted Patent: US 9,140,163 B2
• Time in Patent Office: Days
• US Class Current: 60/317
• CPC Class Codes: B01F 2025/931 Flow guiding elements surrounding feed openings, e.g. jet nozzles
• CPC Class Codes: B01F 23/2132 using nozzles
• CPC Class Codes: B01F 25/313 wherein additional components are introduced in the centre of the conduit
• CPC Class Codes: F01N 2240/02 a heat exchanger
• CPC Class Codes: F01N 2240/20 a flow director or deflector
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/08 with prior mixing of the substances with a gas, e.g. air
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 3/10 by thermal or catalytic conversion of noxious components of exhaust by using other chemical processes, chemical aspects of catalytic conversion, e.g. using specified catalysts, B01D53/34
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• 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

Arrangement for introducing a liquid medium into exhaust gases from a combustion engine: an injector for injecting the liquid medium into an injection chamber (3), a casing (8) which surrounds the injection chamber, a mixing duct (6), a gathering chamber (10) which surrounds the casing and is connected to the injection chamber via throughflow apertures of the casing, and a bypass duct (12) for leading exhaust gases into the mixing duct without passing through the gathering chamber and the injection chamber. The inlet (11) of the gathering chamber diverts a portion of the exhaust gases to flow into the gathering chamber, and then into the injection chamber via the throughflow apertures, and thereafter into the mixing duct, while the bypass duct leads another portion of the exhaust gases into the mixing duct in order to be mixed there with the diverted exhaust gases.

Claims

1. An arrangement for introducing a liquid medium, into exhaust gases from a combustion engine, the arrangement comprising:

a line configured for exhaust gases to flow through the line;

an injection chamber having an open forward end;

an injector configured for injecting the liquid medium into the injection chamber;

a casing which demarcates the injection chamber in radial directions and is provided with throughflow apertures distributed round the circumference of the casing;

a mixing duct which forms part of the line and to which the injection chamber is connected via its open forward end;

a gathering chamber which is situated upstream of the injection chamber, surrounds at least part of the casing, has an inlet to receive exhaust gases and is connected to the injection chamber via the apertures of the casing in order to allow the exhaust gases received in the gathering chamber to enter the injection chamber via these apertures;

a bypass duct which is situated in the line upstream of the mixing duct in order to lead exhaust gases into the mixing duct without passing through the gathering chamber and the injection chamber;

the inlet of the gathering chamber is configured for diverting a portion of the exhaust gases flowing through the line, in order to cause these diverted exhaust gases to flow into the gathering chamber, and then into the injection chamber via the apertures and thereafter into the mixing duct via the open forward end of the injection chamber, while the bypass duct is configured for leading another portion of the exhaust gases flowing through the line into the mixing duct in order to be mixed there with the diverted exhaust gases; and

the combined cross-sectional area of the apertures of the casing is smaller than the cross-sectional area of the inlet of the gathering chamber so that the exhaust gases diverted to the gathering chamber are subject to a pressure increase in the gathering chamber.

2. An arrangement according to claim 1, wherein the inlet of the gathering chamber is dimensioned to divert to the gathering chamber 5-50% of the exhaust gases flowing through the line.

3. An arrangement according to claim 1, wherein the inlet of the gathering chamber is dimensioned to divert to the gathering chamber 10-20% of the exhaust gases flowing through the line.

4. An arrangement according to claim 1, wherein the casing is a truncated cone which broadens from the rear end of the injection chamber towards the open forward end of the injection chamber.

5. An arrangement according to claim 1, wherein the throughflow apertures of the casing are distributed symmetrically about its centreline.

6. An arrangement according to claim 1, wherein the injector is situated at the centre of the rear end of the injection chamber and is configured for injecting the liquid medium towards the open forward end of the injection chamber.

7. An arrangement according to claim 1, wherein the bypass duct surrounds the gathering chamber and is demarcated from it by a cowl which is situated between the gathering chamber and the bypass duct.

8. An arrangement according to claim 7, further comprising a bulging portion which extends into the line and which has the casing protruding from its upper side;

and

the gathering chamber is formed between the protruding portion, the casing and the cowl which surrounds the casing.

9. An arrangement according to claim 8, wherein the inlet of the gathering chamber is annular and extends around the bulging portion.

10. An arrangement according to claim 7, wherein the cowl is a truncated cone which broadens from its forward end into the mixing duct upstream towards its rear end.