Flue gas self-circulation type low-nitrogen and non-oxidation nozzle

Abstract

The invention relates to a flue gas self-circulation type low-nitrogen and non-oxidation nozzle which comprises a nozzle housing, a flue gas pipe flange, an ignition electrode, a flame monitoring device, a cyclone, flue gas spray pipes and a flue gas distribution ring. The flue gas spray pipes and the flue gas distribution ring are arranged in a refractory material of an inner cavity in the nozzlehousing; a flue gas return passage is arranged in the outermost refractory material layer with a combustion air output passage in the inner cavity of the nozzle housing as the center; the flue gas return passage communicates with an inner cavity in the rear part of the combustion air output passage; the combustion air output passage comprises a laval spray pipe, a combustion air spray pipe arranged in a cavity in the rear part of the laval spray pipe, or a combustion air spray pipe with an auxiliary nozzle flue gas spray pipe; the flue gas return passage communicates with the tail of the laval spray pipe positioned in the center of a nozzle body, and forms a negative-pressure conduction state with a cavity in the front part of the flue gas return passage; the flue gas return passage is arranged between the nozzle housing and the flue gas spray pipes; and the flue gas return passage communicates with a flue gas passage through a restriction orifice and the flue gas distribution ring, thus an external ignition nozzle or an internal sublance combustion type nozzle body is formed.

Description

technical field [0001] The invention relates to a low-nitrogen and oxide-free combustion technology, in particular to a flue gas self-circulating low-nitrogen and non-oxidation burner and a heat medium heating furnace including the burner; it belongs to the technical field of metal thermal processing and heat treatment . Background technique [0002] Oxidation burning loss has always been a difficult problem in the thermal processing of metal materials. Large oxidation burning loss not only reduces the metal yield, but also affects the processing accuracy (in order to ensure the final size of the thermally processed product, a margin must be reserved before the workpiece is heated), And seriously affect the surface quality of the heated metal material. Uneven oxidation burning will lead to the formation of pits on the surface of the material, or an oxide layer that is difficult to remove, resulting in severe chromatic aberration. How to reduce or eliminate oxidative burnin...

AI Technical Summary

Problems solved by technology

Although this patent can reduce the amount of (NOx) produced, each of the divided small burners in the burner independently configures the air-fuel ratio through its own mechanical structure for independent combustion, and it is difficult to achieve the long flame requirements of the heating furnace in the steel industry

In addition, when the thermal load of the burner changes, it is difficult to effectively control the change of the air-fuel ratio of each small burner

The flue gas circulation of the burner requires additional installation of pipes and fans, the system is complex and difficult to implement effectively on site

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