“LIQUID OR PULP AERATION DEVICE” that projects liquid or pulp (P) through a spreading nozzle on a chain curtain (C) and captures air bubbles from the liquid or pulp (P) while the fluid outflows through the curtain links (C) by gravity forming films by virtue of an interaction of the surface strain and wettability between the three surfaces in question. As far as the outflow is concerned, these films end up interacting between themselves capturing the remaining air between them, thus forming profuse bubbles, resulting in the formation of liquid or foaming pulp (P) by virtue of the chain discharge (C).