Apparatus and method for separation of phases in a multiphase flow

Method for phase separation and coalescence of one or more of oil hydrocarbons, gas bubbles, light particles and mixtures thereof, in a water stream, in, after, or before one or more of a cyclone tank and a flotation tank, comprising the steps of generating, in a continuous stream in an outlet of a separation device, a vortex under a vortex breaker which cannot escape against the direction of a liquid stream passing the vortex breaker, so that saturation of the vortex arises from one or more of gas and pollution dragged into the vortex, wherein under the vortex breaker in a conical outlet there is brought forth a saturated second vortex column wherein a pulsating pressure in the separation device causes a pulsating output of large drops of coalesced matter selected from oil, gas, particulates and mixtures thereof, from the second saturated vortex column under the vortex breaker.