Superheated-steam heating nozzle

A superheated-steam heating nozzle in which saturated vapor at 100° C. taken from a steam-intake tube provided at the inlet side of the nozzle is heated and then sprayed from a blow-out nozzle provided at the outlet side of said superheated-steam heating nozzle, with said superheated-steam heating nozzle comprising:

• a first steam pipe, a second steam pipe, a third steam pipe, and a fourth steam pipe that are concentrically disposed from inside to outside;
• a temperature-rise-prevention section that peripherally spreads steam from a steam-intake tube to the center of said inlet side, sending said steam to the gap between the third steam pipe and the fourth steam pipe;
• an outlet connection that is provided to said outlet side and that receives steam from the first steam pipe;
• a blow-out nozzle that is connected to the outlet connection;
• multiple electric heaters that are disposed in the gap between the second steam pipe and the third steam pipe and whose sealed sections at the tips traverse the aforementioned temperature-rise-prevention section and protrude toward the outside of said superheated-steam heating nozzle;
• a first loop-back section that is provided on said outlet side and that connects the gap between the third steam pipe and the fourth steam pipe with the gap between the first steam pipe and the second steam pipe;
• and
• a second loop-back section that is provided on said inlet side and that connects the gap between the first steam pipe and the second steam pipe with the inside of the first steam pipe.