NOX CONTROLLED SMALL SIZED CONDENSATION TYPE GAS BOILER AND ITS COMBUSTION METHOD BY EXHAUST GAS RECYCLING METHOD

摘要

PURPOSE: A gas boiler and its combustion method minimizes heat NOx generation, maximizes heat efficiency. CONSTITUTION: A gas boiler includes a recycling pipe(13), a blast fan(1), a mixer(5), a premixing gas burner(6), a chimney(10) and a separating board(12). The recycling pipe(13) recycles emission. The blast fan(1) supplies air for combustion. The mixer(5) and the premixing gas burner(6) mix emission with air. The chimney(10) is placed to the direction same with the boiler main body. The separating board(12) is placed on the emission side of a heat exchanger for double passes. A part of emission discharged through the chimney(10) is recycled to be reburnt with air and gas fuel to decrease density of NOx in the emission of the boiler.