Air curtain feeding device and biomass gasification reaction system using same

The invention discloses an air curtain feeding device, comprising a motor, a speed reducing device, a rotating shaft, a spiral blade, a feeding pipe, a sealing cover and an air blowing device, wherein the speed reducing device is connected with the motor; the rotating shaft is driven by the motor and the speed reducing device and extends toward a feeding port of a gasification reactor of a fluidized bed gasifying reactor; the spiral blade is fixedly sheathed on the rotating shaft; the feeding pipe is sheathed outside the spiral blade, is provided with the feeding port and a discharging port, the feeding port of the feeding pipe is positioned below the discharging port of a stokehole storage device, and the discharging port of the feeding pipe is connected with a feeding port of the fluidized bed gasifying reactor; an air hole area is arranged between the feeding port and the discharging port of the feeding pipe and is internally provided with a plurality of air holes; the sealing cover is sheathed outside the air hole area of the feeding pipe and is sealed with a combined part of the feeding pipe; the sealing cover is provided with an air inlet; and the air blowing device is connected with the air inlet on the sealing cover. The purpose of the invention is as follows: as for broken sawdust (unformed) which can not be transmitted is conveyed by the spiral blade, the air cushionfeeding mode is used for assisting to blow the part of broken sawdust to the discharging port by adopting an air curtain mode, and therefore, the problems that due to long-term overstocking and scaling of the broken sawdust, the service life of the equipment is easy to shorten, even the whole feeding device is blocked and the like are solved.