Abstract: An apparatus is provided wherein, in a static condition a lower phase liquid is covered by an upper phase liquid which is non-miscible with the lower phase liquid. In operation, the upper phase liquid is removed from a selected area of the lower phase liquid by raising the upper phase liquid to pass over a weir into a second chamber. Simultaneously a portion of the lower phase liquid is circulated over a second weir and caused to pass through a portion of the upper phase liquid to provide a scrubbing or cleansing action. When operation ceases the liquids automatically return to the static condition levels wherein the lower phase liquid is completely covered by the upper phase liquid. During operation articles or materials may be caused to enter and exit the lower phase liquid in the selected area, for treatment therein without contacting the upper phase liquid. The apparatus is useful in cleaning, degreasing, plating, pre-plating treatments and the like.

Abstract: A tank is provided in which a lower solution is covered by an upper solution which is non-miscible with the lower solution. In the operating condition the apparatus automatically uncovers a small area of lower solution by raising the level of lower solution in that area and having the upper solution pass over a weir into a holding chamber. When the operating condition ceases, the solution automatically returns to the same levels as in the static condition.