Patent ID: 8894822

Claim:
A method for evaporating a material to be distilled, comprising: inserting the material to be distilled ( 3 ) by at least partial evaporation into a distilling flask ( 4 ), the distilling flask being supported rotationally around an axis ( 2 ), heating the distilling flask ( 4 ) with the material to be distilled ( 3 ) via a heater ( 11 ), and rotating the distilling flask ( 4 ) during the heating process around the axis ( 2 ) by a drive ( 12 ), guiding vapor ( 13 ) forming due to the heating process via a vapor tube ( 5 ) encompassing the axis ( 2 ) into a cooler ( 6 ), the cooler ( 6 ) comprising a cooling spiral ( 8 ) connected to a cooling circuit to form a flow path ( 7 ) for a coolant and with said coolant flowing through it, and condensing the vapor ( 13 ) at the cooling spiral ( 8 ) and collecting distillate in a distillate flask ( 9 ), determining a difference between temperatures of the coolant continuously or in repeated intervals between two positions ( 14 , 16 ) in the flow path ( 7 ) of the coolant, spaced apart from each other by a section ( 18 ) of the flow path ( 7 ) of the coolant, determining a flow rate, using a flow meter ( 19 ), of the coolant from said section ( 18 ) continuously or in repeated intervals, wherein a control signal is deduced for the rotary evaporator ( 1 ) from a temporal progression of the determined temperature difference and a temporal progression of a determined flow rate, and determining an amount distilled and collected in the distillate flask ( 9 ) from the temporal progression of the determined temperature difference and the temporal progression of the determined flow rate and the control signal initiates an output of a value determined for the distilled amount.