Selection of Refractories for Tertiary Air Duct of Cement Rotary Kiln

　　The function of the tertiary air duct is to introduce the excess cooling air of the grate cooler into the preheater, which mainly bears the wear of high-speed high-temperature wind. The air temperature of the tertiary air duct can reach 1200 ° C, so it also bears part of the thermal stress. In order to keep warm, a layer of high-temperature calcium silicate board should be pasted on the tertiary air duct, and then refractory bricks should be laid.

　　Although the tertiary air duct is in a static state for a long time, the wind speed in the air duct can reach up to 20m/s, and the scouring effect of the cement clinker particles mixed in the refractory bricks cannot be ignored, so the tertiary air duct generally adopts high-strength alkali-resistant bricks or 1550 Silica bricks are used for masonry, and the service life is 2-3 years. The elbow of the tertiary air duct shall be built with steel fiber castables.

　　The steel fiber castable produced by Zhengzhou Zhenjin is added with heat-resistant stainless steel fibers to form a network frame structure inside the castable, and at the same time change the stress distribution inside the castable. On the basis of ensuring the original high temperature performance of the castable, the castable is enhanced. The toughness, mechanical shock resistance and wear resistance of the body improve the service life of the castable.