The utility model discloses a hot air circulating device of a
smelting furnace, which relates to the technical field of hot air circulating devices of
smelting furnaces and comprises a furnace body, an emission reduction unit for filtering
nitrogen oxides, an air blowing unit for improving the filtering effect and a circulating unit, a reaction box is installed on one side of the furnace body, a
temperature control assembly is arranged at the lower end of the reaction box, a stirring unit used for evenly mixing hot air is arranged at the upper end in the furnace body, and a circulation unit is installed on the furnace body. The emission reduction unit comprises a box inlet air
pipe mounted at the upper end in the reaction box, the air outlet end of the box inlet air
pipe is connected with a transverse
pipe, and air outlet holes are formed in the upper end of the transverse pipe at equal intervals; according to the utility model, by utilizing the Karman vortex street effect,
flue gas is ejected upwards in a swinging manner, so that the contact area with
ammonia, a catalyst and the like can be increased, and the comprehensiveness of catalytic reduction of
nitrogen oxides is improved;
ammonia is discharged from the
ammonia outlet hole, and can enter the
elliptic cylinder again from the ammonia collecting hole to circulate by utilizing the Bernoulli principle, so that the
utilization rate of the ammonia is improved, and more cost is saved.