Qi Yanyong: To achieve the goal of high yield and low consumption, it is necessary to improve the heat recovery efficiency of the grate cooler

On July 6, the "2023 China Cement Energy Conservation and New Energy Development Conference" sponsored by China Cement Network was held in Chongqing, a mountain city. Qi Yanyong, an associate professor of

Southwest University of Science and Technology, gave a brilliant speech on the theme of "Ways and Operational Ideas for Reducing Coal Consumption in Firing System". He pointed out that the high temperature of secondary and tertiary air is the core of coal saving in the kiln system, and the high air volume into the kiln is the key to the high yield of the kiln system. To achieve the goal of high yield and low consumption, it is necessary to improve the heat recovery efficiency of the grate cooler, avoid the phenomenon of "air short circuit" and improve the air volume into the kiln. In addition, the secondary and tertiary air temperature of the grate cooler in good operation can reach 1200 ℃ and 1050 ℃, and the standard coal consumption is only 98 kg/t. Cl, while the secondary and tertiary air temperature of the grate cooler in poor operation is only about 1000 ℃ and 800 ℃, and the standard coal consumption is as high as 110 kg/t. Cl.

Qi Yanyong believes that the main factor affecting the heat exchange efficiency of grate cooler is "wind short circuit". When the temperature of secondary and tertiary air is increased, the recovered heat of grate cooler is increased, the consumption of pulverized coal is reduced, and the theoretical air volume is reduced.

Qi Yanyong said that the concentration of rotary kiln firepower is the core of improving the temperature of the firing zone. The heat of pulverized coal should be brought into play in the firing zone as much as possible. The combustion efficiency of pulverized coal is the key to the concentration of rotary kiln firepower. The factors affecting the combustion efficiency of pulverized coal include: quality and fineness of pulverized coal; burner; temperature of secondary air; air speed in the kiln and combustion air volume of pulverized coal; under the condition that the equipment and pulverized coal are unchanged, the temperature of secondary air should be increased as much as possible, the combustion speed of pulverized coal should be increased, and the air speed in the kiln should be reduced as much as possible while meeting the ventilation in the kiln.