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: A method for operating a reducing agent supply system for supplying an exhaust aftertreatment system of a motor vehicle is provided. In normal metering operation of the reducing agent supply system an at least approximately continuous air stream and a pulsed reducing agent stream are produced and are released at least partially via the nozzle into the exhaust line. In a cleaning operation for cleaning the reducing agent supply system an air stream formed from a number of air stream pulses and a reducing agent stream formed from a number of reducing agent stream pulses are produced and supplied to the nozzle means. The method can be used in particular in supply systems in which aqueous urea solution is used as reducing agent.