Pressurized heater for producing hot process water in large quantities from scale-forming water

Claim 1

A DIRECT CONTACT HEAT EXCHANGER COMPRISING A CLOSED VESSEL WITH A LIQUID RESERVOIR FOR COLLECTING HEATED LIQUID ADJACENT THE BOTTOM THEREOF, A COMBUSTION CHAMBER FOR PRODUCING HOT GASES FOR SAID VESSEL, LIQUID FEED MEANS FOR INTRODUCING LIQUID INTO THE UPPER PART OF SAID VESSEL, A PLURALITY OF HEAT TRANSFER ZONES IN THE PATH OF SAID LIQUID AS IT PASSES TOWARD THE BOTTOM OF SAID VESSEL FROM SAID LIQUID FEED MEANS, THE ZONE ABOVE THE COMBUSTION CHAMBER HAVING RELATIVELY OPEN PACKING AND BEING ONE IN WHICH AT LEAST SOME OF THE WATER IS CONVERTED INTO VAPOR, ANOTHER ZONE LOCATED NEARER TO THE FEED MEANS HAVING FINER PACKING THAN THE FIRST MENTIONED ZONE AND BEING ONE IN WHICH THE LATENT HEAT OF THE WATER ADJACENT THE TOP OF SAID VESSEL FOR COMING LIQUID, MEANS ADJACENT THE TOP OF SAID VESSEL FOR EXHAUSTING FLUE GASES, AND MEANS MAINTAINING A PRESSURE IN SAID VESSEL SUCH THAT THE PARTIAL PRESSURE OF THE LIQUID VAPOR IS EQUIVALENT TO THE TEMPERATURE TO WHICH THE LIQUID IS TO BE HEATED.