An apparatus for drying material for an asphalt mixing facility includes a rotary kiln rotatably drivable about an axis of rotation, in which the material is dried, wherein the rotary kiln has a material inlet and a material outlet, a heating unit coupled to the rotary kiln for feeding heat to the rotary kiln, wherein the heating unit is designed with a burner which has a burner housing having a longitudinal axis, an air duct arranged at the burner housing for feeding air, a swirling element for swirling the air in the burner housing relative to the longitudinal axis, a hydrogen gas line connected to the burner for feeding hydrogen gas into the burner, wherein a hydrogen gas nozzle is connected to the hydrogen gas line for discharging the hydrogen gas, a burner head arranged at the burner housing for generating a burner flame.

The invention provides a burner apparatus comprising: a combustion chamber (8); a fuel dispenser (15, 16) arranged to direct a flow of fuel into the combustion chamber (8), the fuel dispenser (15, 16) being located at an upstream end of the combustion chamber and being connected or connectable to a fuel supply; an airflow modifier device (10), located at an upstream end of the combustion chamber, for controlling a primary air flow into the combustion chamber (8), the airflow modifier device (10) being configured to facilitate mixing of the air with the fuel to give a mixture for combustion; and one or more secondary air channels (24) for directing a cooling secondary air flow onto a stream of combustion products (e.g. flame) as the stream of combustion products emerges from a downstream end of the combustion chamber.

Also provided are a dryer apparatus comprising a burner apparatus as described herein and a method of drying aggregates using a burner apparatus as described herein.

A method of drying hemp plants using a rotary drying system that dries the plants without damaging the cannabidiol in the plants.