Abstract: In a process for intermittently spraying a setting pasty composition mixed with a tempering liquid, in particular for building up refractory linings of metallurgical vessels, the composition is conveyed from a preparing station (6) at which it is prepared, to a delivery nozzle (11). In order to prevent the composition from thickening or hardening in the duct (15) leading to the delivery nozzle (11) when delivery is interrupted, it is conveyed during delivery stops in a circuit that includes the delivery nozzle (11).

Abstract: In an apparatus for building up and repairing a refractory lining of an industrial furnace, the material is centrifugally deposited by a wheel rotated by a vertical drive shaft passing through a hopper and a mixing chamber connected thereto. A shut-off bell member having a bevelled lower edge is slidably mounted on the mounting housing of the shaft for vertical movement into selected positions wherein the bevelled lower edge defines an annular gap between the hopper and the mixing chamber for permitting the granular refractory material to flow from the hopper into the chamber and the bevelled lower edge engages the conical inside wall surface of the hopper for completely closing the annular gap for interrupting the flow. The vertical movement is effected by a pneumatic motor attached to the bell member by means of a linkage and rods.

Abstract: Apparatus for building up and repairing a refractory lining of an industrial oven or like hot-running vessel comprises a disc rotatable in a horizontal plane in either direction for centrifugally depositing a granular refractory material on a portion of the lining to be built up or repaired, a conduit having an outlet opening above the disc for feeding the granular material thereto, and a drive shaft for the disc and for mixing and conveying elements for the granular material in the conduit, these elements being capable of conveying the granular material to the rotatable disc in either one of the selected directions of rotation of the disc.