Double-helix pneumatic nebulized micro-oil igniting and flame stabilizing device

The invention relates to a double-helix pneumatic nebulized micro-oil igniting and flame stabilizing device, which comprises a bumping coal dust concentrated and fractional combustion pulverized coal burner and a double-helix pneumatic nebulization micro-oil gun. Concentration of micro-oil employs a form combining bumping concentrating block and concentrating loop; a combustion chamber of the device comprises a combination of an inner combustion chamber and an outer combustion chamber; the bumping concentrating block is an annular lug boss with a triangular section; the bumping concentrating loop is an tapered circle structure; the inner combustion chamber and the outer combustion chamber are concentric and symmetric structures of different inner diameters .The double-helix pneumatic nebulized micro-oil gun and the pulverized coal burner employ a concentric assembly structure. 4 inner atomizing gas channels of the fuel nozzle of the micro-oil gun are spirally formed; 4 outer atomizing gas channels of the middle nozzle are also spirally formed; rotation directions of the inner atomizing channels are the same as rotation directions of the outer atomizing channels. The device of the invention is mainly applicable to start-up igniting and under-load flame stabilizing stages of pulverized coal fired boiler, thereby replacing presently used large-oil-gun igniting and flame stabilizing method. The method use coal to replace oil, so as to reach the goal of cost saving.