Closed transport fluid system for furnace-internal heat exchange between annealing gases

A furnace for heat treating an annealing material, wherein the furnace comprises:

• a sealable first furnace chamber that is designed for accommodating and heat treating annealing material by means of a thermal interaction of the annealing material with a heatable or coolable first annealing gas in the first furnace chamber;
• a first heat exchanger that is arranged in the first furnace chamber, which first heat exchanger is designed for exchanging heat between the first annealing gas and a transport fluid, wherein the first heat exchanger is arranged within a housing section within a full flow of a fan, of the first furnace chamber, which housing section confines the first annealing gas in the interior of the first furnace chamber, and which housing section is in direct contact with the first annealing gas;
• a sealable second furnace chamber that is designed for accommodating and heat treating annealing material by means of a thermal interaction of the annealing material with a heatable or coolable second annealing gas in the second furnace chamber;
• a second heat exchanger that is arranged in the second furnace chamber, which second heat exchanger is designed for exchanging heat between the second annealing gas and the transport fluid, wherein the second heat exchanger is arranged within a housing section within a full flow of a fan, of the second furnace chamber, wherein the housing section confines the second annealing gas in the interior of the second furnace chamber;
• and
• a closed transport fluid path that is functionally connected to the first heat exchanger and the second heat exchanger in such a way that thermal energy can be transferred between the first annealing gas and the second annealing gas in a contactless manner by means of the transport fluid.