PURPOSE: To reduce the space occupied by an entire device by a method wherein the space between heat transfer panels is narrowed while a smooth hot melt injection work or a cleaning work for each of heat transfer panels can be carried out.

CONSTITUTION: Heat transfer panels arranged side by side in a horizontal direction perpendicular to the arrangement direction of each of heat transfer pipes are divided into a first heat transfer panel 22A and a second heat transfer panel 22B. The second heat transfer panel 22B is constructed to be enabled to move in respect to the arrangement direction of the heat transfer pipes for the first heat transfer panel 22A.