Apparatus for additively manufacturing three-dimensional objects by means of successive layerwise selective irradiation and consolidation of layers of a build material which can be consolidated by means of an energy beam , the apparatus comprising: - at least one process chamber ; - a stream generating device allocated to the at least one process chamber , the stream generating device being adapted to generate at least one gas stream streaming through the process chamber during operation of the apparatus ; - a connecting line connecting the stream generating device with the process chamber ; - the connecting line being branched into at least two connecting line branches (11b1 - 11b3) at at least one branching point (BP), thereby, defining an unbranched section of the connecting line and a branched section of the connecting line , wherein - a first stream generating unit of the stream generating device is allocated to the unbranched section of the connecting line , and - at least one further stream generating unit of the stream generating device is allocated to the branched section of the connecting line ; wherein a first connecting line branch (11b1) is connectable or connected with the process chamber at a first connecting site of the process chamber and a further connecting line branch (11b2, 11b3) is connectable or connected with the process chamber at a further connecting site of the process chamber , the further connecting site being spaced apart from the first connecting site; and wherein the first connecting site is provided at an upper vertical position, particularly with respect to a reference plane, e.g. the build plane (E) of the apparatus , of the process chamber or a process chamber wall at least partly delimiting the process chamber , and the at least one further connecting site is provided at a lower vertical position, particularly with respect to a reference plane, e.g. the build plane (E) of the apparatus , of the process chamber or a process chamber wall at least partly delimiting the process chamber ; further comprising a control unit adapted to, particularly individually, control operation of the first stream generating unit and the at least one further stream generating unit on basis of at least one control criterion such that a sub-stream being introduced into the process chamber via the at least one further connecting site and streaming along a bottom wall of the process chamber and above the build plane (E) in which fume particles and/or smoke particles which are to be removed from the process chamber via the gas stream are generated has a higher streaming velocity than other sub-streams. - at least one process chamber ; - a stream generating device allocated to the at least one process chamber , the stream generating device being adapted to generate at least one gas stream streaming through the process chamber during operation of the apparatus ; - a connecting line connecting the stream generating device with the process chamber ; - the connecting line being branched into at least two connecting line branches (11b1 - 11b3) at at least one branching point (BP), thereby, defining an unbranched section of the connecting line and a branched section of the connecting line , wherein - a first stream generating unit of the stream generating device is allocated to the unbranched section of the connecting line , and - at least one further stream generating unit of the stream generating device is allocated to the branched section of the connecting line ; wherein <EOS>