Construction Tools Preparation:
Compulsory mixer, vibrating rod, iron wire, template, 2 electric welding machines, brick trowels, mud buckets, shovels, levels, etc.
1. Welding of anchors.
In the construction of rotary kiln lining, first clean the inner wall of the cylinder, including removing the old lining adhered to the inner wall of the cylinder, under the condition of ensuring the cleanliness of the inner wall of the cylinder, weld the anchor made of heat-resistant alloy steel (310 material), the shape of the anchor is Y-shaped, the length is 150mm, and the diameter is 10mm. The arrangement and spacing of the anchors is 250mm, the pouring thickness of the liner is 180mm, the temperature and conditions of use (1100). Anchors are generally in two columns per strip, and the rows are staggered from row to row. The surface of the metal anchor is coated with asphalt because the coefficient of thermal expansion of the metal is greater than that of refractory materials. The welding of anchors should be firmly welded and the distribution should be regular, and the distribution and welding strength should be carried out after welding.
Second, pouring. The castable adopts a powerful mixer, and then uses a vibrating rod to vibrate and pour, and the pouring process is divided into four steps: dry mixing, wet mixing, transportation and vibration molding of the castable. In order to fully mix the various particle size materials and various additives of the castable, so as to obtain the maximum accumulation specific gravity and the maximum application strength, the stirring time is required to be not less than 3min, and the amount of water added is strictly controlled, and the amount of water should not be too large, because with the increase of the amount of water used in the castable, its strength decreases and the apparent porosity increases.
After the castable is mixed evenly, it is transported to the construction site, and the pouring is generally vibrated while feeding, and the vibration time should not be too long until the surface of the castable is slurry without overflowing and there is no large number of bubbles discharged, so as to avoid segregation of each particle size material in the castable. It must be noted that the stirred material should be used up within 30 minutes, and the material that has begun to set is prohibited.
3. Requirements for expansion joints for lining construction.
In the construction, every 2000mm in the annular length direction, an expansion joint with a width of about 3-5mm should be opened to adapt to the volume expansion of the surface of the lining during the heating process.
Fourth, the baking of the lining.
After 24 hours of castable construction, a certain strength has been formed, and the formwork can be removed for natural maintenance. The curing time is 3 days or more, and heat preservation measures should be taken at low temperatures.
Baking time and keep.
Normal temperature -150, 15 per hour, 10 hours, 150 constant temperature for 24 hours;
150 -350, 15 per hour, 13 hours, 350 constant temperature 30 hours;
350 -600, 15 per hour, 17 hours, 600 constant temperature 24 hours;
Fifth, the lining material selection.
Corundum mullite castable, the main component raw material is corundum mullite, and the binding agent is aluminate cement and other materials. The product does not contain heavy metals and has good thermal shock stability.
Physical and chemical indicators:
Zhengzhou Kairuide kiln refractory.