Burner for an exhaust-gas aftertreatment system, exhaust-gas aftertreatment system for an internal combustion engine

An exhaust-gas aftertreatment system for an internal combustion engine, comprising:

• a burner, including:
• a housing forming a combustion chamber, the housing having an outlet which is or can be connected to an exhaust-gas line of the exhaust-gas aftertreatment system,
• a fuel feed device configured to feed fuel into the combustion chamber,
• a fresh-air feed device configured to feed fresh air into the combustion chamber, and
• an ignition element configured to ignite a fresh-air/fuel mixture located in the combustion chamber,
• wherein the housing is configured such that the combustion chamber has a cylindrical main portion and a bulge protruding radially outward from the main portion, and the ignition element is arranged in the bulge,
• wherein the combustion chamber is configured such that a fresh-air/fuel mixture introduced into the cylindrical main portion flows in a swirl flow, and the bulge is configured to generate a recirculation flow that rotates in the opposite direction relative to the swirl flow.