The present invention is an ultra-low emissions dust-removal apparatus and an ash removal method thereof. According to the apparatus, a dust removal device is divided into a plurality of
filtration chambers, the upper portions of the
filtration chambers are communicated with a gas
inlet channel and are provided with gas inlet valves, the middle portions of the
filtration chambers are communicated with a gas outlet channel and are provided with gas outlet valves, a vertical filtration bag is arranged between two tubesheets, an ash hopper is arranged below the lower tubesheet, and the internal of the filtration bag is communicated with the ash hopper. The ash removal method of the apparatus comprises: closing the gas
inlet valve, maintaining the gas outlet valve at the opening state, closing the gas outlet valve after a few seconds, opening the gas
inlet valve after a few seconds, closing the gas
inlet valve for a few seconds after opening the gas inlet valve for a few seconds, and then opening the gas outlet valve so as to complete the one ash removal period. The apparatus has advantages of simple equipment, low maintenance
workload, low operation and maintenance cost, and long filtration bag service life. According to the ash removal process, the pressures on both sides of the filtration bag produce the fluctuation through the opening and the closing of the gas inlet valve and the gas outlet valve so as to make the filtration bag deform and shake to form the self-cleaning type ash removal way having the ash removal effect, such that the
operating energy consumption is substantially reduced.