Chain grate-rotary kiln preheating section single-side air draft process

Abstract

The invention discloses a unilateral air draft process of kiln process chain grate preheating section for making oxidized pellet. The invention resolves the problems of windage resistance increase, high electricity consumption, bad strength of the preheating pellet and finished pellet which are caused by hot wind turbulence vortex formed by air draft on both-side of the preheating section. The change from both-side air draft to single side air draft can reduce power consumption for more than 44 %, if 1,200,000 ton pellet is produced in one year, 4,800,000 kwh can be saved, and cost of an air draft equipment and maintain can be saved, the strength of the preheating pellet and finished pellet can be improved.

Description

technical field [0001] The invention relates to the improvement of the ventilation process of the preheating section of the grate in the production of oxidized pellets by the grate-rotary kiln method. Changed from the two-side exhaust process of the bellows in the preheating section to the single-side exhaust process. It belongs to the production of oxidized pellets in iron and steel metallurgy iron ore artificial lump ore pelletizing method. technical background [0002] Grate machine—The drying and preheating of the oxidized pellets produced by the rotary kiln is completed by blasting and exhausting the waste heat of the rotary kiln on the chain grate machine. There are various types of chain grates at home and abroad. According to the furnace cover, it is divided into two-stage type, that is, one stage of drying and one stage of preheating; three-stage type, that is, one stage of blast drying, one stage of exhaust drying, one stage of exhaust preheating or four-stage ty...

AI Technical Summary

Problems solved by technology

Under this process configuration, two fans draw air in opposite directions at the same time. On the one hand, the hot air forms a turbulent vortex in the air box of the preheating section; on the other hand, the wind on both sides flows through two pipes and enters the drying section, and forms another turbulent flow in the hood of the drying section. Vortex, which causes increased draft resistance, large fan power configuration, high power consumption, the two fans are configured at a full pressure of 5500Pa, and the air volume is configured at 255000m 3 / h, the excess capacity of the air volume configuration increases more than 60% of the air volume in the working condition. Even in this way, the air flow speed of the preheating spherical layer does not meet the process requirements, so that the temperature of the hood in the preheating section is high, while the temperature of the bellows is low. The preheating bulb Low layer temperature causes low strength of preheated balls and finished balls

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