Device for introducing a reducing agent into an exhaust pipe segment of an internal combustion engine

• US 6,382,600 B1
• Filed: 08/31/2000
• Issued: 05/07/2002
• Est. Priority Date: 12/01/1998
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Mahr, Bernd
• Primary Examiner(s): Bushey, C. Scott
• Application Number:
  US09/601,354
• Time in Patent Office: 614 Days
• Field of Search: 261/115, 261/28, 261/78.2, 261/DIG.39, 423/239.1, 423/212
• US Class Current: 261/78.2
• CPC Class Codes: B01D 53/9431 Processes characterised by a specific device
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A device for introducing a reducing agent, such as a solution of water and urea, into an exhaust pipe segment of an internal combustion engine that leads to a reduction catalytic converter. The reducing agent is introduced into the exhaust pipe via a reducing agent line discharging into the exhaust pipe, and the orifice end of the reducing agent line is provided with a spray head, which has at least one spray opening and a tapering cross section.

Claims

1. An apparatus for introducing a reducing agent into a portion of an exhaust pipe of an internal combustion engine, which portion leads to a reducing catalytic converter, having a reducing agent line discharging into the exhaust pipe, characterized in that a gaseous carrier material is delivered to the reducing agent line (4) upstream of the exhaust pipe (2) in order to drive the reducing agent through the reducing agent line;

that inside the exhaust pipe at the discharge and of the reducing agent line (4), a spray head (6) that has a tapering cross section is disposed, having at least one spray opening, and the cross section of the spray head (6) tapers in accordance with a continuous smooth curve; and

that the at least one spray opening (8) together with an axis of the spray head (6) forms an angle of at least 5°

, so that if a wall film which has formed on the reducing agent line detaches, it is united with a film on the inner wall of the spray head, as a consequence of the tapering cross section, upstream of the spray opening, so that a continuous atomization can be attained by means of the at least one spray opening.

2. The apparatus of claim 1, characterized in that the cross section of the spray head (6) forms a spherical dome.

3. The apparatus of claim 1, characterized in that the cross section of the spray head (6) tapers linearly and forms a conical dome.

4. The apparatus of claim 1, characterized in that said angle is 50°

.

5. The apparatus of claim 2, characterized in that said angle is 50°

.

6. The apparatus of claim 3, characterized in that said angle is 50°

.

7. The apparatus of claim 1, characterized in that a plurality of spray openings (8) are provided, distributed circumferentially on the spray head (5).

8. The apparatus of claim 2, characterized in that a plurality of spray openings (8) are provided, distributed circumferentially on the spray head (5).

9. The apparatus of claim 3, characterized in that a plurality of spray openings (8) are provided, distributed circumferentially on the spray head (5).

10. The apparatus of claim 4, characterized in that a plurality of spray openings (8) are provided, distributed circumferentially on the spray head (5).

11. The apparatus of claim 5, characterized in that a plurality of spray openings (8) are provided, distributed circumferentially on the spray head (5).

12. The apparatus of claim 6, characterized in that a plurality of spray openings (8) are provided, distributed circumferentially on the spray head (5).

13. The apparatus of one of claim 1, characterized in that the reducing agent line (4) can be acted upon by pressure.

14. The apparatus of one of claim 2, characterized in that the reducing agent line (4) can be acted upon by pressure.

15. The apparatus of one of claim 3, characterized in that the reducing agent line (4) can be acted upon by pressure.

16. The apparatus of one of claim 4, characterized in that the reducing agent line (4) can be acted upon by pressure.

17. The apparatus of one of claim 5, characterized in that the reducing agent line (4) can be acted upon by pressure.

18. The apparatus of one of claim 6, characterized in that the reducing agent line (4) can be acted upon by pressure.

19. The apparatus of one of claim 7, characterized in that the reducing agent line (4) can be acted upon by pressure.

20. The apparatus of one of claim 12, characterized in that the reducing agent line (4) can be acted upon by pressure.