Return feeder and circulating fluidized bed boiler

The utility model relates to the technical field of boiler equipment, in particular to a return feeder and a circulating fluidized bed boiler. The return feeder comprises a compensator body and an expansion joint, and medium flow exists on the inner side of the compensator body, so that in the construction process of the return feeder for the internal wear-resisting and fire-resisting plastic refractory, the medium flow such as smoke can flow through the inner side of the compensator body. The expansion gap penetrates through the compensator body, and one port of the expansion gap is located on the surface, facing the medium flow, of the compensator body. In order to avoid insufficient compensation amount of a compensator body and even failure of an expansion joint due to the fact that dust and impurities enter an expansion gap when medium flow flows through. The end, facing the medium flow, of the expansion gap is located on the downstream side of the medium flow, the end, back on tothe medium flow, of the e