Apparatus for drying bulk goods, in particular of wood fibers and/or wood chips, comprising at least one dryer , in particular a drum dryer, at least one hot gas generator and at least one heat exchanger , which is provided to indirectly heat a vapor gas mixture for drying the bulk goods in the dryer , said at least one heat exchanger is heated by exhaust gases produced by said at least one hot gas generator , at least one branch line , upstream, downstream and/or within the at least one heat exchanger to the at least one hot gas generator to branch off a partial flow of the vapor gas mixture, and at least one line for the remaining partial flow to the dryer , wherein at least one multi-fuel burner and at least one solid fired hot gas generator are comprised, which are arranged to operated independent or in parallel, said at least one multi-fuel burner comprises a combustion chamber with a muffle in which a fuel/combustion air mixture is ignited and burned and a combustion chamber ceiling, said combustion chamber ceiling comprising - at least one inlet for combustion air into the muffle , - an outer nozzle ring forming an inlet for a cooling gas surrounding the muffle and - an inner nozzle ring forming an inlet for a cooling gas inside the muffle providing a laminar flow of cooling gas along the muffle , said inner and outer nozzle ring being separately controllable and said inner nozzle ring being fed with gas exhausted by the at least one solid fired hot gas generator , with ambient air and/or with gases resulting from external production processes . at least one dryer , in particular a drum dryer, at least one hot gas generator and at least one heat exchanger , which is provided to indirectly heat a vapor gas mixture for drying the bulk goods in the dryer , said at least one heat exchanger is heated by exhaust gases produced by said at least one hot gas generator , at least one branch line , upstream, downstream and/or within the at least one heat exchanger to the at least one hot gas generator to branch off a partial flow of the vapor gas mixture, and at least one line for the remaining partial flow to the dryer , wherein at least one multi-fuel burner and at least one solid fired hot gas generator are comprised, which are arranged to operated independent or in parallel, said at least one multi-fuel burner comprises a combustion chamber with a muffle in which a fuel/combustion air mixture is ignited and burned and a combustion chamber ceiling, said combustion chamber ceiling comprising - at least one inlet for combustion air into the muffle , - an outer nozzle ring forming an inlet for a cooling gas surrounding the muffle and - an inner nozzle ring forming an inlet for a cooling gas inside the muffle providing a laminar flow of cooling gas along the muffle , - at least one inlet for combustion air into the muffle , - an outer nozzle ring forming an inlet for a cooling gas surrounding the muffle and - an inner nozzle ring forming an inlet for a cooling gas inside the muffle providing a laminar flow of cooling gas along the muffle , said inner and outer nozzle ring being separately controllable and said inner nozzle ring being fed with gas exhausted by the at least one solid fired hot gas generator , with ambient air and/or with gases resulting from external production processes . <EOS>