Abstract: The invention relates to a chamber mixer (10) for an exhaust after-treatment system of a motor vehicle, wherein a first fluid (12) can flow through the internal volume (18) of the chamber mixer in a through-flow direction (26), said internal volume being delimited by a housing (16), wherein at least one housing side of the housing (16) is double-walled and has an outer wall (30) and an inner wall (32) which divides the internal volume (18) into an inner chamber (34) and an outer chamber (36), wherein the fluid flowing in through an inlet opening (22) can be separated into a main flow (38) flowing through the inner chamber (34) and an auxiliary flow (40) flowing through the outer chamber (36), wherein the main flow (38) can be acted upon by means of a flow device (48) with a double swirl (50) and with a fluid introduction device (56) with an introduction end (58) which is arranged in the outer chamber (36) and via which a second fluid (14) can be injected into the inner chamber (34) through an introduction ope

Abstract: An apparatus for introducing and distributing a flowable additive into an exhaust gas flow comprises an inlet to receive the exhaust gas flow from a first exhaust gas treatment device, an outlet to output the exhaust gas flow to a second exhaust gas treatment device, a flow conducting device to lead the exhaust gas flow from the inlet to the outlet, and an injector opening into the flow conducting device, wherein an at least substantially straight-line main flow direction of the apparatus is defined by the inlet and the outlet. A mixing section of the flow conducting device arranged downstream of the injector extends obliquely or transversely to the main flow direction.