Exhaust treatment burner and mixer system

1. An exhaust aftertreatment system comprising:

a first housing including first and second chambers, the first chamber including an exhaust gas inlet receiving exhaust gas from an engine, the second chamber receiving exhaust gas from the first chamber and including an exhaust gas outlet;

a burner including a second housing and a combustion chamber disposed within the second housing, the second housing at least partially disposed within the first chamber, the burner supplying heated gas to the second chamber separately from the exhaust gas, the heated gas within the burner being fluidly isolated from exhaust gas in the first chamber, the second housing being in a heat transfer relationship with exhaust gas in the first chamber;

a first swirl-inducing diffuser disposed between the first and second chambers and surrounding thesecond housing;

a second swirl-inducing diffuser attached to the first housing at the exhaust gas outlet of the second chamber; and

a third swirl-inducing diffuser disposed at an outlet of the second housing.

2. The exhaust aftertreatment system of claim 1 , wherein an outlet of the second housing is disposed within the second chamber downstream of an outlet of the first chamber.

3. The exhaust aftertreatment system of claim 1 , wherein one of the first, second and third swirl-inducing diffusers causes fluid flowing therethrough to swirl in a first rotational direction and another of the first, second and third swirl-inducing diffusers causes fluid flowing therethrough to swirl in a second rotational direction that is opposite the first rotational direction.

4. The exhaust aftertreatment system of claim 1 , wherein the second chamber is at least partially defined by an annular insulation member.

5. The exhaust aftertreatment system of claim 1 , wherein the first chamber defines an annular space that surrounds the second housing.

6. The exhaust aftertreatment system of claim 5 , wherein the exhaust gas inlet of the first housing includes a laterally outwardly extending tube, the tube including a longitudinal axis that is perpendicular to a longitudinal axis of the annular space of the first housing, and wherein the longitudinal axis of the tube does not intersect the longitudinal axis of the annular space.

7. An exhaust aftertreatment system comprising:

a first housing including a tubular body defining first and second chambers, the first chamber including an inlet receiving exhaust gas from an engine, the second chamber in fluid communication with the first chamber and including an outlet discharging the exhaust gas upstream of an aftertreatment device;

a first diffuser disposed within the tubular body and defining an outlet of the first chamber and an inlet of the second chamber;

a burner including a second housing and a combustion chamber disposed within the second housing, the second housing at least partially disposed within the first chamber, the burner supplying heated gas to the second chamber separately from the exhaust gas, the second housing being in a heat transfer relationship with exhaust gas in the first chamber, the burner including a second diffuser disposed at an outlet of the second housing; and

a third diffuser attached to the first housing at the outlet.

8. The exhaust aftertreatment system of claim 7 , wherein the heated gas within the burner is fluidly isolated from exhaust gas in the first chamber.

9. The exhaust aftertreatment system of claim 7 , wherein an outlet of the second housing is disposed within the second chamber downstream of the first chamber.

10. The exhaust aftertreatment system of claim 7 , wherein the first chamber defines an annular space that surrounds the second housing.

11. The exhaust aftertreatment system of claim 7 , wherein the first diffuser causes fluid flowing therethrough to swirl in a first rotational direction and the second diffuser causes fluid flowing therethrough to swirl in a second rotational direction opposite the first rotational direction.

12. The exhaust aftertreatment system of claim 7 , wherein each of the first, second and third diffusers includes a plurality of vanes inducing a swirled flow.

13. The exhaust aftertreatment system of claim 7 , wherein the second chamber is at least partially defined by an annular insulation member.

14. The exhaust aftertreatment system of claim 7 , wherein the inlet of the first housing includes a laterally outwardly extending tube, the tube including a longitudinal axis that is perpendicular to a longitudinal axis of the body of the first housing, and wherein the longitudinal axis of the tube does not intersect the longitudinal axis of the body.

15. The exhaust aftertreatment system of claim 14 , wherein the second housing of the burner is concentric with the body of the first housing.

16. An exhaust aftertreatment system comprising:

a first housing including first and second chambers, the first chamber including an exhaust gas inlet receiving exhaust gas from an engine, the second chamber receiving exhaust gas from the first chamber and including an exhaust gas outlet;

a burner including a second housing and a combustion chamber disposed within the second housing, the second housing at least partially disposed within the first chamber, the burner supplying heated gas to the second chamber separately from the exhaust gas entering the second chamber from the first chamber, the heated gas within the burner being fluidly isolated from exhaust gas in the first chamber, the second housing being in a heat transfer relationship with exhaust gas in the first chamber;

a first swirl-inducing diffuser disposed between the first and second chambers and surrounding the second housing;

a second swirl-inducing diffuser attached to the first housing at the exhaust gas outlet of the second chamber; and

a third swirl-inducing diffuser disposed at an outlet of the second housing,

wherein each of the first, second and third swirl-inducing diffusers include a plurality of radially extending and spaced apart vanes.

17. The exhaust aftertreatment system of claim 16 , wherein the burner supplies heated gas to the second chamber separately from the exhaust gas.

18. An exhaust aftertreatment system comprising:

a first tubular body having a first longitudinal axis and defining a chamber receiving exhaust gas from an engine and discharging the exhaust gas upstream of an aftertreatment device;

a second tubular body extending outward from the first tubular body and defining an inlet to the chamber, the second tubular body having a second longitudinal axis that is angled relative to the first longitudinal axis and is non-intersecting with the first longitudinal axis;

a burner including a housing and a combustion chamber disposed within the housing, the housing at least partially disposed within the chamber, the burner supplying heated gas to the first tubular body, the housing being in a heat transfer relationship with exhaust gas in the chamber, wherein the heated gas within the burner is fluidly isolated from the exhaust gas; and

a first diffuser disposed within the first tubular body and surrounding the housing of the burner;

wherein an outlet of the housing of the burner includes a second diffuser, and

wherein an outlet of the first tubular body includes a third diffuser.

19. The exhaust aftertreatment system of claim 18 , wherein an angle between the first and second longitudinal axes is ninety degrees.

20. The exhaust aftertreatment system of claim 18 , wherein the housing of the burner is concentric with the first tubular body.

21. The exhaust aftertreatment system of claim 18 , wherein each of the first, second and third diffusers includes a plurality of vanes inducing a swirled flow.

22. The exhaust aftertreatment system of claim 21 , wherein one of the first, second and third diffusers causes fluid flowing therethrough to swirl in a first rotational direction and another of the first, second and third diffusers causes fluid flowing therethrough to swirl in a second rotational direction that is opposite the first rotational direction.