Burner ignition is normal, but exhaust smoke color is abnormal

The diesel injected into the burner is mixed and burned at the same time. When the air supply is appropriate, the atomized CO2 and steam exhaust are colorless. When the air supply is insufficient, it will cause the incomplete combustion of diesel oil to generate CO and carbon particles, which will lead to black smoke. However, if the intake air volume is too large and strong, the oil mist that is too late to burn may be blown away, forming a white smoke discharge.

The common reason for black smoke is that the opening of combustion air inlet valve is too small, and the common reason for white smoke is that the opening of air inlet valve is too large. In both cases, the air inlet valve should be readjusted. When adjusting, you can observe the exhaust smoke color and adjust the opening of the damper until the exhaust smoke color is close to colorless.

Another reason for the black smoke is the poor atomization of diesel oil, which contains large droplets and cannot be fully mixed with air, resulting in black smoke due to incomplete local combustion.

The causes of poor diesel atomization are as follows:

The atomization capacity of the nozzle decreases seriously due to aging or clogging;

The oil pump outlet pressure is too high or too low.

The atomization effect is poor due to the low oil pressure of the nozzle caused by low pressure of the oil pump. But if the pressure of the oil pump is too high, the injection pressure will also be low. Because, the oil delivery volume of the oil pump is inversely proportional to the oil delivery pressure. If the oil pressure is too high, the oil delivery volume must be reduced. Because, the orifice of the nozzle is constant, the pressure difference between the two ends of the nozzle will be reduced, resulting in black smoke. This is due to the poor atomization of the oil supply. The oil outlet pressure of the oil pump can be adjusted according to the exhaust smoke color. Turn the pressure regulating screw clockwise to increase the oil output and decrease it; otherwise, the oil output will increase when the pressure drops.