| 摘要 |
Scouring is as in BE. 738254. The material is subjected below the bath level, to a series of pressures and reduced pressures, each time over a length of its path. Pref. the two metal sheets are placed in contact before the lower has reached its upper position, and the rise and fall movement of the lower plate has to be followed in the same direction during a time interval by the upper plate. Apparatus is described. |
