Steam generator with flue gas return

Claim 1

A STEAM GENERATOR COMPRISING A COMBUSTION CHAMBER, A PLURALITY OF TUBES FORMING A WALL OF SAID COMBUSTION CHAMBER, SAID WALL HAVING A PLURALITY OF HORIZONTALLY ELONGATED APERTURES UNIFORMLY DISPOSED LONGITUDINALLY AND CIRCUMFERENTIALLY THEREOF AND SAID TUBES CONDUCTING OPERATING MEDIUM OF THE STEAM GENERATOR, MEANS FOR HEATIG SAID TUBES IN SAID COMBUSTION CHAMBER, SAID HEATING MEANS INCLUDING A HOT COMBUSTION GAS, A GAS-TIGHT WALL PLACED OUTSIDE OF AND IN SPACED RELATION TO SAID TUBES FOR FORMING A SPACE THEREBETWEEN, A FLUE CONNECTED TO SAID COMBUSTION CHAMBER FOR CONDUTING FLUE GAS PRODUCED BY SAID COMBUSTION GAS IN SAID COMBUSTION CHAMBER, AND CONDUIT MEANS CONNECTING AN INTERMEDIATE PART OF SAID FLUE AND THE SPACE BETWEEN SAID TUBES AND GAS-TIGHT WALL, SAID CONDUIT MEANS INCLUDING A BLOWER FOR RETURNING FLUE GAS FROM SAID FLUE THROUGH THE SPACE BETWEEN SAID TUBES AND GAS-TIGHT WALL TO SAID COMBUSTION CHAMBER AT A PRESSURE HIGHER THAN THE PRESSURE IN SAID COMBUSTION CHAMBER WHEREBY THE RETURNING FLUE GAS PASSING THROUGH THE APERTURES IN SAID COMBUSTION CHAMBER WALL PREVENTS CONTACT OF SAID HOT COMBUSTION GAS AND SAID COMBUSTION CHAMBER WALL.