Device for absorption of at least one component chosen among gas and vapor in a liquid based on an ejector principle, comprising a mixing zone in the form of a substantially straight tube (5) immediately downstream of the ejector (1). The device comprises an ejector (1) with central liquid passage (2) and a substantially annular, sectioned aperture (4) for gas/vapor. The gas aperture (4) generally surrounds the central liquid passage (2) and the annular, sectioned aperture (4) for gas/vapor is designed in a manner to cause the gas/vapor to enter the mixing zone with a velocity component that is inclined to the periphery surface of the tube to thereby provide a helical flow (6) downstream of the ejector (1).