Method to substitute the supporting liquid by compressed air in an hydro-shield

摘要

The support fluid is evacuated in an upper cross-sectional area of the work face with simultaneous replacement with compressed air. Then in the upper cross-sectional area a support material is applied to the work face and finally also in the lower cross-sectional area the support surface is replaced by compressed air. A work chamber (4) is formed in a shield cover (1) by a dip wall (2) and a pressure wall (3). A closed cutting wheel (5) is operated in the work chamber. The work chamber is normally filled with fluid supporting the work face, the pressure of which is controlled by a compressed air cushion (7) between the two walls.