METHOD FOR TWO-STAGE FUEL COMBUSTION IN HORIZONTAL CYCLONE FURNACE FOR SECOND COMBUSTION STAGE Russian patent published in 1998 - IPC

FIELD: energy processing plants such as those used for sulfuric acid production lines. SUBSTANCE: method for two-stage combustion of fuel such as sulfur or hydrogen sulfide for production processes involves fuel combustion in two furnaces installed in tandem with combustion products cooled down after each of them in waste- heat boilers; novelty is that first-stage furnace functions to burn 40-60% of fuel with 80-90% of air used for burning all fuel admitted to it, combustion products are cooled down in waste-heat boiler to temperature 50-100 C higher than fuel ignition point and conveyed to second-stage furnace which is supplied with remaining portions of fuel and air. Horizontal cyclone furnace for second combustion stage has ball-shaped precombustion chamber and cylindrical afterburner intercommunicating through outlet channels made in partition between precombustion chamber and afterburner over helical lines oriented towards direction of gas swirling in precombustion chamber. The latter is provided with pipe connection for tangential admission of combustion products from first combustion stage, sulfur injectors, and lighting-up burner. Pipe connection is shifted along furnace longitudinal axis through up to 0.5 ball diameter from center of precombustion chamber in opposite direction from outlet channels. Secondary-air admission pipes are placed immediately after partition tangentially to swirling of jet of gases escaping channels concurrently with this swirling which is formed earlier. Afterburner has brick rack. Chamber and afterburner enclosure is made of brickwork. Furnace is surrounded by metal lining of spaced sheets. EFFECT: improved sulfur combustion. 4 cl, 10 dwg