Air or steam feed appts. for concrete pan mixer - has feed element with hard rubber corner piece esp. wedge with self closing outlets

摘要

Appts. has a feed element which leads into a pan, located in the corners between the pan base and the vertical inner or outer wall, or in the discharge slide or on the wall of the pan. Each feed element is of elastic, hard-wearing material having an internal cavity; the steam, air, etc. is fed into this cavity and escapes from it through a release gap or bores under the applied pressure to enter the internal chamber of the mixer. The closure pressure causing the lips of the gap or the bores to close is provided by the in-built stresses in the feed element and/or in-built closure springs. In the case of an annular pan-type concrete mixer the feed elements may consist of components screwed to the outer wall and/or the base and constituting corner profiles. These tend to prevent accumulation of concrete in the corner and their elasticity makes them self-cleaning. With this arrangement, the height and the horizontal width of the corner elements is pref. 4-7 cm and flat springs are pref. used. The difficulties associated with valves, etc. are eliminated. The forming of a concrete crust in the corner is considerably reduced or eliminated. Wear on the blades of the mixer is reduced.