Machine for heating an article or product by vapor condensation

A machine of the in-line type for heating articles or products at an elevated temperature by condensing vapor thereon, which comprises

• a tunnel having an entry and an exit;
• means for moving articles or products to be heated through said tunnel from said entry to said exit, and
• first, second, third, fourth, and fifth chambers distinct from each other and having a cross-section greater than that of said tunnel distributed along said tunnel and in the stated order and being connected to each other by sections of said tunnel, said third chamber being adapted to be filled with vapors of a primary liquid having a boiling point which is at least equal to the elevated temperature at which said articles or products have to be heated, said second and fourth chambers being provided with means for establishing therein a body of vapors of a secondary liquid having a boiling point lower than that of said primary liquid so as to condense any primary vapors coming from said third chamber, said first and fifth chambers being provided with cooling means for condensing any secondary vapors coming from said second and fourth chambers, respectively, and
• boiler means having heating means for boiling a primary liquid in said boiler, and means for feeding said third chamber with said vapors of primary liquid;
• means for collecting the condensates of primary vapors formed in said second and fourth chambers and for recycling them to said boiler means, and
• means for collecting the condensates of secondary vapors formed in said first and fifth chambers and for recycling them to said means for establishing the body of secondary vapors.