Influence of DMM addition in light fuel oil on the flame emission in a domestic hot water boiler

In order to investigate the soot reduction potentialities of DMM (called also methylal) addition in an overall lean diffusion flame, tests have been carried out on our experimental fuel oil boiler whose burner is equipped with a spill-return atomizer.
The tests have been performed in steady state regime without and with addition of DMM. During all the tests, the oxygen at the chimney was kept constant (around 3%) by adjusting the position of the burner air damper and thus the air combustion mass flow rate. The combustion chamber has two quartz windows through which the flame emission was registered by using a photodiode sensible in visible range. Classical gas analysers were used to measure the CO and NOx concentrations at the chimney. DMM percentages up to 15% (by mass) have been tested.