Sand-blast cleaning process - directs blast at surface under water

摘要

The surface to be cleaned is sand-blasted under water, and the jets aimed at it can be at least partly enclosed by a funnel or cowl, from which the first impulse from the pressure source expels the water, after which it drives the grains against the surface. The funnels or cowl can be used to bridge the gap between jet nozzles and surface to be cleaned. The process is particularly for cleaning the surfaces of underwater concrete columns etc. where a break has occurred, before cement is applied to repair it.