Material returning device and boiler

The invention discloses a material returning device and a boiler, and belongs to the technical field of coal-fired boilers. The material returning device comprises a first material conveying section, a second material conveying section, a third material conveying section and a fourth material conveying section which are sequentially communicated, the second material conveying section is provided with a first end and a second end, one end of the first material conveying section is connected with the first end, and one end of the third material conveying section is connected with the second end. The first material conveying section is opposite to the third material conveying section, one end of the fourth material conveying section is connected with the other end of the third material conveying section, and the fourth material conveying section obliquely extends in the direction away from the third material conveying section; the material returning device further comprises a heat exchange pipeline used for bein