Entrained flow calciner

The present invention relates to an entrained flow calciner 1 with a first combustion chamber 10, the first combustion chamber 10 having a first combustion device 12, the entrained flow calciner 1 having a material feed 14 into the first combustion chamber 10, characterized in that the entrained flow calciner 1 has a second combustion chamber 20 , wherein the second combustion chamber 20 is arranged below the first combustion chamber 10, wherein the second combustion chamber 20 has a second combustion device 22, wherein between the first combustion chamber 10 and the second combustion chamber 20 a constriction 30 is arranged.