Compactability measurement method and apparatus for sand casting

摘要

A compactability system measures the compactability of granular material such as sand as used in a sand casting foundry system. The compactability is displayed on a meter, recorded by a chart recorder, and used for controlling plows to insure that unacceptable sand is not fed into molding machines. The compactability is determined by initially determining density by passing gamma radiation through the granular material as it moves on a conveyor belt. The attenuation of the gamma radiation is dependent upon the density of the granular material and the depth of the granular material. A plow is used to insure that the depth of the granular material is controlled such that the radiation and attenuation will be an accurate indication of the sand density of the loose or uncompacted sand. This sand density is subtracted from an empirical value representative of the density of the compacted sand, and the difference is thereby divided by the empirical value, thereby deriving a compactability signal.