The invention concerns an apparatus (10) for separation of components with different volatility in a mixed fluid, said apparatus (10) comprising: a first heat exchanging unit (100) provided with first and second flow path structures (131, 132) forming separate flow paths for a first and a second fluid flow through the first heat-exchanging unit (100); an inlet (118) for feeding the mixed fluid to the apparatus (10); an inlet (119) for feeding steam to the apparatus (10); an arrangement for feeding a cooling medium through the apparatus (10), wherein said arrangement comprises at least one cooling medium inlet (105, 106, 107, 108). The invention is characterized in that the apparatus (10) comprises a second heat-exchanging unit (200) provided with third and fourth flow path structures (233, 234) forming separate flow paths for a first and a second fluid flow through the second heat-exchanging unit (200), wherein the cooling medium arrangement comprises at least one cooling medium inlet (205, 206, 207, 208) arranged in fluid communication with the fourth flow path structure (234) and wherein the first and third flow path structures (131, 233) are arranged in fluid communication with each other.