A gravity liquid distributor a having a lower plate provided with orifices via which a liquid leaves the distributor in order to irrigate a lower element. Parallel parallelepipedal chimneys dedicated to the passage of the ascending gas. The chimneys are distributed over an entire central portion with a circular cross section of the lower plate, which frees up a peripheral channel, which is fluidically connected to the troughs, over the perimeter of the lower plate. A plurality of hats that are able to guide the liquid collected above the troughs towards the peripheral channel, each hat having an elongate rectangular form with two ends, with just one hat per trough, the hat being closed off at just one end such that at least the majority of the liquid collected flows towards the peripheral channel. The hats are oriented at an acute or zero angle with respect to the horizontal.

Systems and methods utilize heated waste flue gas to treat water. The heated waste flue gas, which may come from a steam generator, bubbles through untreated water to vaporize the untreated water and separate out solids and other contaminants before subsequent condensing. The steam generator may receive resulting treated water to produce steam for injection.