Chain grate machine exhausting drying section and preheating section flue gas recycling and exhausting system

Abstract

The invention relates to a chain grate machine exhausting drying section and preheating section flue gas recycling and exhausting system which comprises a chain grate machine, a chain grate upper cover, a chain grate machine air tank, a ring cold machine, a ring cold machine upper cover, a ring cold machine air tank, a chain grate machine hot air return system, a ring cold machine hot air return system and a flue gas exhausting treatment system; and the chain grate machine upper cover is divided into a forced air drying section, an exhausting drying section, a first preheating section and a second preheating section. The chain grate machine exhausting drying section and preheating section flue gas recycling and exhausting system is characterized in that the chain grate machine air tank isdivided into three groups, an air tank I corresponds to the forced air drying section, an air tank II corresponds to the exhausting drying section and the front half section of the first preheating section, and an air tank III corresponds to the rear half section of the first preheating section and the second preheating section; and the air tank II and the air tank III are connected with the chaingrate machine hot air return system, the ring cold machine hot air return system and the flue gas exhausting system through flue gas branch pipes respectively. The chain grate machine exhausting drying section and preheating section flue gas recycling and exhausting system has the advantages that a temperature of return air of the chain grate machine can be adjusted; and a part of flue gas of each preheating section is used as cooling air for recycling, so that the quantity of the exhausted flue gas is lowered, and conditions are created for accurate control, energy conservation and emissionreduction of the pellet production process.

Description

technical field [0001] The invention belongs to the technical field of pellet production in the iron and steel metallurgical industry, and in particular relates to a flue gas recovery and utilization and discharge system in a chain grate machine exhausting drying section and a preheating section. Background technique [0002] At present, the chain grate machine-rotary kiln-circular cooler process is one of the main production processes for iron ore pellet production. The commonly used hot air process is to divide the chain grate machine into three chambers (three groups) and four sections. According to the temperature of the hot air flow and The upper cover of the chain grate machine is divided into four sections by passing through the material layer: blast drying section, exhaust air drying section, preheating section one, and preheating second section; according to the direction of hot air flow, the chain grate machine corresponding to the four sections The machine bellows...

AI Technical Summary

Problems solved by technology

When the temperature of the flue gas in the second stage of preheating is too high, in order to meet the needs of ventilation and drying, it is generally cooled by adding a certain amount of ambient air, which will increase the burden on the return hot air system; in the second stage of preheating When the flue gas temperature is low, it cannot meet the needs of ventilation and drying, and cannot achieve the expected dehydration effect of green pellets, which will affect the preheating process on the chain grate machine, resulting in the backward movement of the process on the chain grate machine, which will affect the output in mild cases, and in severe cases. The preheating ball index will be low, resulting in increased dust, rotary kiln rings and other consequences, affecting production stability and pellet quality

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