Sealed air device with coal drop pipe

The utility model provides a sealed air device with a coal drop pipe, which belongs to equipment of circulating fluidized bed boilers. The sealed air device comprises the coal drop pipe, an expansion joint and the like, wherein the expansion joint is mounted in the middle of the coal drop pipe; a coal drop inclined pipe is mounted at the lower end of the coal drop pipe and arranged with the coal drop pipe in a crossed manner; the left end of the coal drop inclined pipe is higher than the right end; a coal spraying air pipe is mounted at the left end of the coal drop inclined pipe; inner chambers of the coal drop pipe, the coal drop inclined pipe and the coal spraying pipe are communicated with one another; a first sealed air pipe and a second sealed air pipe are symmetrically mounted on the upper wall and the lower wall of the coal drop inclined pipe; and both of free ends of the first sealed air pipe and the second sealed air pipe incline to the left end of the coal drop inclined pipe. The sealed air device with the coal drop pipe has the advantages that since the first sealed air pipe and the second sealed air pipe are additionally arranged on the coal drop inclined pipe, and incline to the coal drop inclined pipe with angles smaller than 90 degrees, the wind pressure of sealed air entering the coal drop inclined pipe can prevent high-temperature and high-pressure fuel gas from flowing back, and the sealed air can improve the coal spraying effect and accordingly improve the boiler combustion efficiency.