A method for cleaning a nozzle arrangement of a spray drying apparatus during operation, comprising the steps of: providing a spray drying apparatus with a drying chamber , providing at least two pressure nozzle arrangements inserted into the drying chamber and having a feed inlet and a feed outlet, providing a feed conduit for supplying liquid feed to the feed inlet of each nozzle arrangement at a predefined pressure for atomization of the liquid feed, providing a system for cleaning of at least one nozzle arrangement , halting the feed supply for the nozzle arrangement(s) to be cleaned during operation, removing the nozzle arrangement(s) to be cleaned from the drying chamber while the operation of the spray drying apparatus is continued with atomization through the remaining nozzle arrangement(s) present in the drying chamber cleaning the nozzle arrangement(s) in the cleaning system , wherein after the feed supply is halted and before the nozzle arrangement(s) is/are removed from the drying chamber , the nozzle arrangement(s) is/are emptied for feed by a method step selected from i) supplying a liquid at substantially the same pressure as the predefined pressure of the feed supply to the feed inlet of the nozzle arrangement. ii) supplying pressurized air or gas at a pressure of at least 16 bar (1.6 MPa) to the feed inlet of the nozzle arrangement, iii) applying a suction from the feed inlet of the nozzle arrangement, and iv) applying an additional stream of pressurized air or gas concentrically of the feed outlet of the nozzle arrangement. providing a spray drying apparatus with a drying chamber , providing at least two pressure nozzle arrangements inserted into the drying chamber and having a feed inlet and a feed outlet, providing a feed conduit for supplying liquid feed to the feed inlet of each nozzle arrangement at a predefined pressure for atomization of the liquid feed, providing a system for cleaning of at least one nozzle arrangement , halting the feed supply for the nozzle arrangement(s) to be cleaned during operation, removing the nozzle arrangement(s) to be cleaned from the drying chamber while the operation of the spray drying apparatus is continued with atomization through the remaining nozzle arrangement(s) present in the drying chamber cleaning the nozzle arrangement(s) in the cleaning system , wherein after the feed supply is halted and before the nozzle arrangement(s) is/are removed from the drying chamber , the nozzle arrangement(s) is/are emptied for feed by a method step selected from i) supplying a liquid at substantially the same pressure as the predefined pressure of the feed supply to the feed inlet of the nozzle arrangement. ii) supplying pressurized air or gas at a pressure of at least 16 bar (1.6 MPa) to the feed inlet of the nozzle arrangement, iii) applying a suction from the feed inlet of the nozzle arrangement, and iv) applying an additional stream of pressurized air or gas concentrically of the feed outlet of the nozzle arrangement. i) supplying a liquid at substantially the same pressure as the predefined pressure of the feed supply to the feed inlet of the nozzle arrangement. ii) supplying pressurized air or gas at a pressure of at least 16 bar (1.6 MPa) to the feed inlet of the nozzle arrangement, iii) applying a suction from the feed inlet of the nozzle arrangement, and iv) applying an additional stream of pressurized air or gas concentrically of the feed outlet of the nozzle arrangement. <EOS>