Heated dosing mixer

Patent metadata

Field	Value
Publication number	US-2020088081-A1
Application number	US-201816135211-A
Country	US
Kind code	A1
Filing date	Sep 19, 2018
Priority date	Sep 19, 2018
Publication date	Mar 19, 2020
Grant date	—

Abstract

A vehicle exhaust system includes a mixer housing that has a doser opening and defines an internal mixing chamber. A doser injects fluid into the mixer housing through the doser opening. A flow passage has an inlet end positioned adjacent the doser opening and an outlet end open to the mixing chamber. At least one heating device associated with the flow passage.

First claim

1 . A vehicle exhaust system comprising:
a mixer housing defining an internal mixing chamber, wherein the mixer housing includes a doser opening; a doser to inject fluid into the mixer housing through the doser opening; a flow passage having an inlet end positioned adjacent the doser opening and an outlet end open to the mixing chamber; and at least one heating device associated with the flow passage.

2 . The vehicle exhaust system according to claim 1 wherein the heating device is an electric coil that heats a surface of the flow passage.

3 . The vehicle exhaust system according to claim 1 wherein the heating device is a heated plate that heats a surface of the flow passage.

4 . The vehicle exhaust system according to claim 1 wherein the heating device is positioned at the outlet end of the flow passage.

5 . The vehicle exhaust system according to claim 4 wherein the heating device surrounds an outer surface of the flow passage.

6 . The vehicle exhaust system according to claim 4 wherein an inner surface of the flow passage surrounds the heating device.

7 . The vehicle exhaust system according to claim 1 including a control that selectively activates the heating device when a temperature of the exhaust gas is below a predetermined temperature.

8 . The vehicle exhaust system according to claim 7 including at least one temperature sensor that measures exhaust gas temperature prior to entering the mixing chamber.

9 . The vehicle exhaust system according to claim 7 wherein the heating device heats the flow passage such that all fluid injected by the doser evaporates prior to entering the mixing chamber.

10 . The vehicle exhaust system according to claim 7 wherein an amount of energy required to heat the flow passage is determined based on an amount of injected fluid and the temperature of the exhaust gas.

11 . The vehicle exhaust system according to claim 1 wherein the flow passage comprises a solid or porous body , and wherein the flow passage comprises a cylindrical tube or cone.

12 . The vehicle exhaust system according to claim 11 wherein the base end of the flow passage is positioned adjacent the dose opening such that a gap is formed within the mixer housing between the base end of the flow passage and an inner surface of the mixer housing that surrounds the doser opening.

13 . The vehicle exhaust system according to claim 12 wherein exhaust gas is directed into the base end of the flow passage to mix with fluid sprayed into the base end of the flow passage such that a mixture of evaporated fluid and exhaust gas exits the outlet end of the flow passage.

14 . A vehicle exhaust system comprising:
a mixer housing defining an internal mixing chamber, wherein the mixer housing includes a doser opening; a doser to inject fluid into the mixer housing through the doser opening; a flow passage comprising a solid or porous body that has an inlet end positioned adjacent the doser opening and an outlet end open to the mixing chamber; at least one heating device positioned at the outlet end of the flow passage to heat the flow passage such that all fluid injected by the doser evaporates prior to entering the mixing chamber; and a control that selectively activates the heating device when a temperature of the exhaust gas is below a predetermined temperature.

15 . The vehicle exhaust system according to claim 14 wherein the heating device comprises an electric coil or heated plate, and wherein the flow passage comprises a cylindrical tube or cone.

16 . A method for injecting a reducing agent into an exhaust component comprising the steps of:
providing a mixer housing that defines an internal mixing chamber; providing a doser opening in the mixer housing; positioning a doser to inject fluid into the mixer housing through the doser opening; positioning a flow passage in the mixer housing such that an inlet end of the flow passage is positioned adjacent the doser opening and an outlet end of the flow passage is open to the mixing chamber; and using at least one heating device to heat the flow passage.

17 . The method according to claim 16 including heating the flow passage such that all fluid injected by the doser evaporates prior to entering the mixing chamber

18 . The method according to claim 17 including selectively activating the heating device when a temperature of the exhaust gas is below a predetermined temperature.

Assignees

• Faurecia Emissions Control Technologies Usa Llc

Inventors

• Rohde John G
• Gandikota Madhuri

Classifications

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title

• F01N2610/1453

  Sprayers or atomisers; Arrangement thereof in the exhaust apparatus · CPC title

• F01N2610/102

  after addition to exhaust gases, e.g. by a passively or actively heated surface in the exhaust conduit · CPC title

• F01N3/2013

  using electric or magnetic heating means · CPC title

• F01N2240/20

  a flow director or deflector · CPC title