System for dispensing and recovering liquids and device comprising same

A system for dispensing and recovering liquids configured to be disposed in a rigid container, including a tank for dispensing liquid to be used and a tank for recovering liquid after use, each of said tanks including an envelope and an orifice through which liquid passes, wherein each of said envelopes includes a first wall and a second wall which are similar, the first wall of one of the two envelopes being separate and distinct from the first wall of the other of the two envelopes, and each of which includes an external surface and a peripheral rim, said walls of one of said envelopes being connected to each other by said peripheral rim, each of said envelopes being configured to have a contracted configuration in which said walls are close to each other and said external surface of said second wall is convex while said external surface of said first wall is concave, and an expanded configuration in which contact between said two walls is limited to said peripheral rims and said external surfaces of each of said walls are convex, at least one of said envelopes being configured, in its expanded configuration, to be nested in the other of said envelopes in its contracted configuration, said two first walls being in contact with each other, wherein the first wall and the second wall of the two envelopes are exclusively connected to each other exclusively by the peripheral rim.