NOVELTY - The method for increasing gas yield in a fermentation device such as a biogas plant or a fermenter, comprises exposing biomass before and/or after the fermentation in an operational chamber inertial forces due to short term extreme acceleration and directly subsequent delay of the carrier medium flowing in a closed flow channel. The inertial forces acting on the biomass are produced over a change of the aggregate condition in which the carrier medium is aligned in an inlet into the operational chamber for evaporating and in an outlet of the operational chamber for condensing.    USE - Method useful for increasing gas yield in a fermentation device such as a biogas plant or a fermenter.    ADVANTAGE - The method ensures effective and economical increasing gas yield in a fermentation device such as a biogas plant or a fermenter.    DETAILED DESCRIPTION - The method for increasing gas yield in a fermentation device such as a biogas plant or a fermenter, comprises exposing biomass before and/or after the fermentation in an operational chamber inertial forces due to short term extreme acceleration and directly subsequent delay of the carrier medium flowing in a closed flow channel. The inertial forces acting on the biomass are produced over a change of the aggregate condition in which the carrier medium is aligned in an inlet into the operational chamber for evaporating and in an outlet of the operational chamber for condensing. The change of the aggregate condition is carried out over the change of the flow velocity, where the change of the flow velocity is carried out over a constriction of the cross-section of the flow channel, and is carried out over a conical passing constriction of the operational chamber in which the diameter at the inlet point of the operational chamber and the diameter at the outlet point of the operational chamber are larger than the diameter at the narrowest point of the constriction, which acts itself around a nozzle. The diameter and length of the nozzle stand to each other in a ratio of 1:4-1:6. The flow velocity is 40 and 50 m/second. The biomass is repeatedly promoted by the same operational chamber. The disintegration of the biomass is carried out before the fermentation and after the secondary fermentation, and is carried out between the secondary fermentation and the cut off. The biomass is homogenized before the disintegration. An INDEPENDENT CLAIM is included for a fermentation device such as biogas plant or fermenter.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic representation of a method for increasing gas yield in a fermentation device such as a biogas plant or a fermenter (Drawing includes non-English language text).