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 (5, 31, 31') 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 (5, 31, 31'), at least one branch line, upstream, downstream and/or within the at least one heat exchanger to the at least one hot gas generator (5, 31, 31') 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 (31, 31') 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 (31, 31'), with ambient air (13, 25) and/or with gases resulting from external production processes (16, 17, 27). at least one dryer, in particular a drum dryer, at least one hot gas generator (5, 31, 31') 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 (5, 31, 31'), at least one branch line, upstream, downstream and/or within the at least one heat exchanger to the at least one hot gas generator (5, 31, 31') 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 (31, 31') 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 (31, 31'), with ambient air (13, 25) and/or with gases resulting from external production processes (16, 17, 27).