Ash discharge system

An ash discharge system which discharges clinker ash from a furnace bottom of a boiler furnace, the ash discharge system comprising:

• a conveyor device which transports the clinker ash out of a region that is below the furnace bottom;
• and
• a separation device provided at a passage of the clinker ash from the furnace bottom to the conveyor device, the separation device including a separator which permits the clinker ash with a predetermined size or less to pass through the separator, and inhibits a large-mass clinker from passing through the separator, the large-mass clinker being the clinker ash with a size larger than the predetermined size.