A trough-type liquid distributor uses troughs with lateral notches or orifices to evenly distribute liquid over the packing material in a packed column, ensuring efficient mass transfer in processes like distillation and absorption. It is a gravity-fed distributor that collects liquid from a parting box and directs it into narrow troughs, from which it flows through the orifices onto the packing bed below. Trough distributors are versatile, widely used, and can handle high liquid loads and varying flow rates, with designs available for different applications such as single-stage and two-stage configurations.