PURPOSE: To prevent the decrease in the sprinkling efficiency and to improve the heat exchange efficiency by receiving heating medium discharged from a downward distributor by a dispersing plate inclined downward to the upper part side of a heat exchange panel, and dispersing to be sprinkled from the gap of a predetermined interval provided between the lower end face of the plate and the panel in a horizontal direction of the panel.

CONSTITUTION: The heating medium branched by a main distributor 21 disposed horizontally above a heat exchange panel 10 and discharged downward from many distributors 22 disposed at a predetermined interval is received by dispersing plates 23 inclined downward to the upper part side of the panel 10, and dispersed down in the horizontal direction of the panel 10 from the gap of the predetermined interval provided between the lower end faces of the plates 23 and the panel 10. Thus, after it is discharged down from the distributors 22, it is dispersed down to the upper part side of the panel 10 by the plates 23, and hence dusts are not stayed on the plates 23 and between the lower ends of the plate 23 and the panel, and sewage uniformly flows down on the entire surface of the panel 10.