A method for the preparation of a dried powder in a facility, wherein the facility comprises i) a first drying chamber with a first upper end section, an opposing first lower end section and at least one first chamber side wall, the first drying chamber being a back-mixing drying chamber comprising one or more first heating elements, one or more first powder inlets, a first powder outlet, one or more first gas inlets and a first gas outlet, ii) a second drying chamber with a second upper end section, an opposing second lower end section and at least one second chamber side wall, the second drying chamber comprising one or more second heating elements, a second powder inlet, a second powder outlet, one or more second gas inlets and a second gas outlet, iii) a first powder passage for transfer of powder from the first drying chamber into the second drying chamber, which is provided by way of the first powder outlet that is connected to or identical with the second powder inlet, iv) a conveyor device and optionally a second powder passage for transfer of powder from the second drying chamber into the first drying chamber, wherein a mixture of powder and diluent, having a first average concentration by weight of diluent, is introduced through the one or more first powder inlets into the first drying chamber and a pre-dried powder, having a second average concentration by weight of diluent, is transferred from the first drying chamber into the second drying chamber through the first powder passage, wherein the diluent is for the most part or entirely removed from the mixture of powder and diluent after passage through the first and second drying chamber (100, 101) forming in the second drying chamber a dried powder, having a third average concentration by weight of diluent, wherein the first average concentration of diluent is higher than the second average concentration of diluent and the second average concentration of diluent is higher than the third average concentration of diluent, wherein a recirculation portion of the dried powder is transferred from the second drying chamber into the first drying chamber using the conveyor device and optionally the second powder passage, and wherein a discharge portion of the dried powder is discharged from the second drying chamber. i) a first drying chamber with a first upper end section, an opposing first lower end section and at least one first chamber side wall, the first drying chamber being a back-mixing drying chamber comprising one or more first heating elements, one or more first powder inlets, a first powder outlet, one or more first gas inlets and a first gas outlet, ii) a second drying chamber with a second upper end section, an opposing second lower end section and at least one second chamber side wall, the second drying chamber comprising one or more second heating elements, a second powder inlet, a second powder outlet, one or more second gas inlets and a second gas outlet, iii) a first powder passage for transfer of powder from the first drying chamber into the second drying chamber, which is provided by way of the first powder outlet that is connected to or identical with the second powder inlet, iv) a conveyor device and optionally a second powder passage for transfer of powder from the second drying chamber into the first drying chamber,