| 摘要 |
Techniques are disclosed for renovating sliding gate valve plates or for adapting conventional plates for use with problem-beset metals. Stationary plates (1) have their orifices (2) bored out to downwardly-tapering form and correspondingly tapered prefabricated refractory insert rings (3) are then cemented in place, the rings having axial depths equal to the plate thicknesses. An orificed plate (7) furnished with an integral depending nozzle (12) has its flow passage (13) bored out such that an upper bore portion extending through the plate (7) and part way along the nozzle (12) is transversely larger than the following downstream bore portion. A prefabricated refractory insert ring (9) is cemented into the upper bore portion, ring (9) being substantially as deep axially as the said bore portion. The downstream bore portion is lined with cementitious, metal-reinforced material (14). Materials for the insert rings (3, 9) and cementitious lining (14) are chosen to suit the pouring conditions and metals to be poured. |
