Corner windbox overfire air compartment for a fossil fuel-fired furnace

The invention claims fossil fuel gas furnace tangential feeding system (10) and air box (16A, 16B, 16C and 16D) and injection chamber (18TE), is made (14) is coated the auxiliary air to the air furnace. The gas chamber (18TE) comprises a passage part (24), the passage part (24) is provided with a air-out pipeline (26) is entry end (30) and a (34) and air furnace opening (28) is communicated with the outlet end of the air outlet device (32). The air outlet device (34) comprises a guide airflow at least one guide plate (36) and rack (42), the rack (42) of the guide plate (36) supporting the passage part (24), is convenient for guiding the air flow to flow through the passage part (24) and (28) which is connected with the air furnace with a furnace (14) in. The guide plate (36) comprises a horizontal plane angle of are is an acute angle surface (38) and a pair of a transverse side (40A and) 40B. The guide plate (36) and rack (42) arranged in the passage part (24); the guide plate (36) front hub (52) of the air furnace opening (28) is configured.