with minimal incline and areas 7 b with large incline are present areas with identical or different incline 7 a 7 b can be furthermore spatially spaced from one another fig9 shows a separating member 50 in the form of a two start helix 70 that can be inserted into a channel the incoming flow of the tempering medium can be guided within a channel portion formed by one of the helix strands and the return flow of the tempering medium can be guided in the other channel portion defined by the other helix strand in this connection the supply and return of the medium can be provided within a single channel however there is also the possibility that the supply of the tempering medium is realized in one coil of one channel and the return of this tempering medium in another coil of another channel there is also the possibility to supply both helix strands of one channel with inflowing tempering medium wherein even different tempering media i e of different inconsistency and or temperature and or speed can be supplied fig9 shows that the inclination angle of the helix strands which are both used for supplying the tempering medium is continuously reduced in the flow direction this means that the travel path of the tempering medium is longer the residence time is increased and the speed must be correspondingly increased so that an improved heat transfer is possible fig1 shows a separating body 50 which at the same time has deflecting members as a unitary part thereof they are arranged within a partial area of the channel at any desired location in the second partial area the deflecting members with a continuously changing incline are provided with a computer controlled simulation an optimization of such deflecting members and.