Combustion furnaces

Claim 1

IN A FURNACE PROVIDED WITH A VERTICAL CYCLONE ACTION COMBUSTION CHAMBER HAVING A BOTTOM STRUCTURE FRO SEPARATING SAID CHAMBER FROM A SPACE THEREBELOW AND MEANS FOR FEEDING FUEL INTO THE FURNACE A TENT SHAPED GRATE PROVIDED WITH AIR PASSAGE IN ITS SLOPS PARTS, SAID TENT-SHAPED GRATE FORMING THE CENTRAL PART OF SAID BOTTOM STRUCTURE, SAID GRATE HAVING A BASE AREA SMALLER THAN THE CROSS SECTION OF THE COMBUSTION CHAMBER BUT WITH SUFFICIENT AREA TO ENSURE COMBUSTION OF THE FUEL SUPPLIED WHILE THE SAME IS SLIDING DOWN THE GRATE A PARTIALLY PERFORATED ASH AND SLAG COLLECTING BELT SURROUDING THE BASE OF THE GRATE AND EXTENDING FROM THE GRATE TO THE WALL OF THE COMBUSTION CHAMBER SAID PERFORATIONS BEING SPACED FROM THE BASE LINE OF THE GRATE WALLS FOR SUBDIVIDING THE SPACE BELOW THE BOTTOM STRUCTURE INTO A FIRST COMPARTMENT BELOW THE GRATE AND A SECOND COMPARTMENT BELOW THE COLLECTING BELT MEANS TO SUPPLY COMBUSTION AIR TO THE FIRST COMPARTMENT ONLY AND FURTHER MEANS TO REMOVE ASH AND SLAG FROM THE SECOND COMPARTMENT WITHOUT CONTACT WITH THE COMBUSTION AIR, THE AIR PASSAGES IN THE GRATE BEING ARRANGED IN A MANNER TO AUGMENT THE TRANSPORTATION OF ASH AND SLAG FROM THE GRATE TO THE PERFORATIONS IN THE BELT.