Method and system for optimizing drying grate-rotary kiln oxidate pellet thermal regulation

Abstract

A method and a system for optimizing a drying grate-rotary kiln oxidate pellet thermal regulation are characterized in that a blower is adopted to pressurize the combustion air of a center burner; the pressure of the combustion air is increased to 18 to 25 KPa; the length of the flame of the center burner of a rotary kiln is controlled to be 15 to 17 m; a heat source point is added in a gas hood to increase the temperature of the preheating segment II of a drying grate by 100 to 150 DEG C; hot air of 500 to 1,000 DEG C are supplied to an air drying segment and a preheating segment I; and the system comprises a pressurizing device, the heat source point and a hot air supply device. The invention has the advantages that reasonable drying and preheating temperature gradient is formed, the drying and preheating effect is improved, energy is saved, the proportion of production of hematite is improved from the highest 40 percent to 100 percent, the hot air volume of the drying grate is sufficient, the hot air temperature is standard, the drying and preheating effect of fresh pellets is remarkably improved, the yield is increased, the consumption of coal gas is lowered, the powder entering the kiln is reduced, and the phenomenon that ring forming is liable to be caused by high-temperature powder feeding of the rotary kiln.

Description

technical field [0001] The invention relates to a method and system for optimizing the thermal system of the grate-rotary kiln oxidation pellets used in a large-scale grate-rotary kiln pelletization production line (above 2 million tons / year). Background technique [0002] In the traditional design of a large-scale grate-rotary kiln pelletizing production line (above 2 million tons / year), the length of the grate is generally greater than 55 meters, and the length of the rotary kiln is greater than 40 meters. The production heat source is provided by the central burner on the upper part of the discharge port of the rotary kiln, and the heat source is pumped by the heat recovery fan and the main exhaust fan to deliver hot air for recycling use by various parts such as the rotary kiln and the chain grate. During production, the roasting temperature of the rotary kiln and the preheating temperature of the chain grate increase with the increase in the proportion of hematite used ...

AI Technical Summary

Problems solved by technology

If we only increase the heat from the central burner of the rotary kiln and increase the roasting temperature to above 1300°C, and rely on increasing the roasting temperature of the rotary kiln to make up for the lack of heat in the grate, the rotary kiln will quickly form rings due to excessive temperature, and the heat will be wasted. The energy consumption is too high, and the reheating fan and refractory materials are damaged, which affects its life

Images