Device for intermittent combustion

Claim 1

A FUEL COMBUSTION AND FLUID HEATING SYSTEM COMPRISING A HOT GAS GENERATOR AND A HEAT EXCHANGER FOR TRANSFERRING HEAT FROM HOT GASES PRODUCED BY SAID GENERATOR TO A FLUID TO BE HEATED, SAID GENERATOR INCLUDING A COMBUSTION CHAMBER HAVING AIR SUPPLY OPENINGS, NON-RETURN VALVE MEANS CONTROLLING SAID OPENINGS, AND CONTROLLABLE PUMP MEANS INTERMITTENTLY SUPPLYING FUEL DIRECTLY INTO SAID COMBUSTION CHAMBER AT A FREQUENCY LOWER THAN THE RESONANCE FREQUENCY OF THE SYSTEM AND LESS THAN 50 PERIODS PER SECOND, SAID HEAT EXCHANGER INCLUDING AT LEAST ONE DISCHARGE DUCT IN COMMUNICATION AT ONE END WITH SAID COMBUSTION CHAMBER, THE RATIO OF THE LENGTH TO THE DIAMETER OF SAID DUCT BEING AT LEAST 180:1 AND THE CROSS-SECTIONAL AREA OF SAID DUCT BEING SMALL RELATIVE TO THE VOLUME OF THE COMBUSTION CHAMBER TO ACHIEVE HIGH VELOCITY OF THE GASES FLOWING THROUGH THE DUCT, SAID DUCT INCLUDING AT LEAST TWO GENERALLY LINEAR PORTIONS WHICH ARE JOINED SUCCESSIVELY IN THE DIRECTION OF GAS FLOW BY A DIFFUSER FOLLOWED BY A DUCT BEND PORTION.