Abstract: A wet deasher arrangement in which a trough is filled with quenched water and is arranged underneath an ash hopper of a boiler. The trough is provided with a quench water feed as well as an overflow and ash conveying equipment. The quench water is permanently circulated through a cooling unit with the aid of a pump, and the cooling unit is arranged between the overflow and the quench water feed. Oblique parallel plates are arranged within the trough before the overflow. The cooling unit has heat exchanger tubes divided into sections which are swept successively by quench water. They are accommodated in a pump upstream tank which precedes the pump. The upstream tank is obliquely arranged and converges to an outlet opening. The sections of the cooling unit may be arranged above each other within the pump upstream tank.