| 摘要 |
PROBLEM TO BE SOLVED: To improve adhesion of a sprayed material, by feeding a blended refractory composition prepared by mixing short organic fibers in a mixture of a refractory aggregate and a binder at a specific ratio and, after the composition is adjusted to an earth-like state by kneading the composition, feeding the composition to a nozzle with pressure, and adding a powdery accelerating agent to the composition in a force- feeding pipe. SOLUTION: A blended refractory composition is prepared by mixing short organic fibers composed of synthetic organic fibers of PVA (including vinylon), polypropylene, etc., in a mixture of a refractory aggregate composed of sintered alumina, electro- melted alumina, etc., containing zirconia, etc., as needed, and a binder composed of alumina cement, magnesia cement, etc. The lengths of the short organic fibers are adjusted to 0.5-2.0 mm and the mixing ratio of the fibers is adjusted to 0.01-1 pts.wt. against 100 pts.wt. of the mixture of the refractory aggregate and binder. At the time of spraying the refractory composition, the composition is adjusted to an earth- like state by adding 3-15 wt.% water to the composition from the outside and fed to a nozzle under pressure. While the composition is fed to the nozzle through a force- feeding pipe, a powdery accelerating agent such as the silicate of soda, slaked lime, etc., having an average particle diameter of 1-50 μm is added to the composition in the force-feeding pipe. |
