Film-forming agent of an evaporating apparatus

The invention relates to nuclear power engineering, in particular to radiochemical plant evaporating apparatuses intended for vaporizing highly radioactive solutions, more specifically to devices for creating a thin film in heating chambers (evaporators), and can be used in chemical, petrochemical, and other branches of industry. The film-forming agent comprises an insert mounted in the upper part of a heat exchanger tube and connected to a spindle of a siphon unit mounted on the cover of the evaporator. The insert is equipped with a tip that is made of a radiation-resistant material that cannot be wetted by an evaporated liquid. The tip is made of two interconnected cones: an upper inverted cone and a lower upright cone, the lower cone being equipped with a cylindrical band having projections centering the conical tip along the interior surface of the heat exchanger tube. A cap having slots along the perimeter of its lower face is movably mounted on the insert. The insert, which is connected to the spindle of the siphon unit, is joined by ribs to adjacent inserts. The technical result consists in remote regulation of the thickness of the film of the liquid flowing along the heat exchanger pipes.