Drying apparatus and dryer for a textile web comprising an improved device for introducing heat

A drying apparatus, comprising:

• a dryer for a textile web, the dryer including a drying chamber and at least one air-permeable drum arranged to rotate in the drying chamber, wherein the textile web is guidable over a partial section of a circumference of the drum and heated drying air from the drying chamber is flowable through the textile web;
• a device to introduce heat for heating up the drying air, the device comprising an internal hot gas source and an external hot gas source, wherein the internal hot gas source is a component of the dryer and the external hot gas source is arranged peripherally to the dryer and includes a hot gas line connected at least indirectly to the dryer;
• a first heat exchanger adapted to release heat to the drying air;
• and
• a preheat exchanger and a fluid line coupling the preheat exchanger to the first heat exchanger, wherein the hot gas line of the external hot gas source extends into the preheat exchanger and transfers heat to a heating fluid in the fluid line.