Analysis and Troubleshooting of Common Problems in Burners - Asphalt Mixing Plant Burner

Analysis and Troubleshooting of Common Problems in Burners

Analysis and Troubleshooting of Common Problems in Burners

1. Burner can be ignited normally, but extinguishes after a few seconds This typical fault phenomenon is caused by the accumulation of soot on the flame sensor of the burner. The flame sensor is a type of light-sensitive resistor that reduces its resistance when exposed to light and increases its resistance when exposed to light. The control unit of the burner determines whether the combustion process continues based on the resistance value of the flame sensor. If the flame sensor has a high impedance, the fuel oil is immediately shut off to prevent unburned diesel fuel from accumulating. The flame sensor probe is located in the air intake channel of the burner, and its surface is easily dirty due to black smoke, backfire, and dust from the air intake. Check the sensor probe, and if necessary, clean the surface with alcohol or detergent.

2. Flame is normal, but exhaust smoke is abnormal Fuel oil injected into the burner is mixed and burned simultaneously. When the air supply is sufficient, CO2 fogging and steam exhaust are colorless. When the air supply is insufficient, incomplete diesel fuel combustion produces CO and carbon particles, resulting in black smoke emission. However, if the air intake is too large, strong wind may blow away the unburned oil mist, resulting in white smoke exhalation.

The common reasons for black smoke emission are:

1. The nozzle is worn or clogged, resulting in poor atomization ability;

2. The pump pressure of the fuel oil is too high or too low.

Of course, if the pump pressure is too low, the atomization effect is poor, but if the pump pressure is too high, the injection pressure will also be low. This is because the fuel oil amount in the pump is inversely proportional to the oil pressure. If the oil pressure is too high, the amount of fuel oil inevitably decreases. Since the nozzle hole diameter is constant, the pressure difference between the two ends of the nozzle will decrease, resulting in fuel injection, often accompanied by black smoke. According to the exhaust smoke color, the fuel oil pressure can be adjusted. On the contrary, pressure decreases, oil production increases. The normal range of oil pump pressure is 0.98~1.18mpa, and it cannot be adjusted arbitrarily.

3. Fluctuating flames often extinguish and automatically reignite after extinction This phenomenon is usually caused by insufficient fuel supply. If diesel fuel is not cut off in time during the operation of the burner, it will inevitably lead to extinction. After extinction, the flame sensor is in a high impedance state. The control unit indicates that fuel injection is stopped and preheating air is blown for about 10s. If fuel injection can be established after that, the burner can be reignited. If diesel fuel is still not supplied during fuel injection, ignition failure occurs, and the control unit will automatically take measures to stop fuel injection and ignition after a delay of about 10s, and the air supply motor will stop working and turn on the red warning light. Wait for 1-2min, and then the afterburning delay ends, the red light can be manually reset, and the next ignition process will automatically start.

When fuel supply is insufficient, combustion noise often occurs with fluctuating flames. At this time, the fluid in the supply pipeline may be accompanied by gas bubbles, making the injection pressure unstable, and combustion is unstable. In addition, when oil pipeline has gas, the running resistance of pump will suddenly increase and decrease, resulting in the "fluctuating, fluctuating sound" mentioned above. When combustion is unstable, it is often accompanied by black smoke, because insufficient fuel oil pressure cannot establish a good combustion condition, making diesel fuel atomization poor and unable to be completely burned.

The common reasons for combustion instability are:

1. External air enters the fuel pipeline and forms gas bubbles;

2. The intake pipe is narrow, blocked, or compressed, making the fuel supply channel unsmooth, and diesel fuel supply is insufficient;

3. The filter (including the intake air filter, diesel fuel filter, and fuel pump filter) in the fuel system is clogged. In winter, fuel system clogging is frequent because diesel fuel has poor fluidity at low temperatures, and wax particles tend to settle, blocking the pipeline, diesel fuel filter, and fuel pump filter, making the fuel supply channel unsmooth, resulting in combustion instability or extinction. If the workshop temperature is low, drying lights can be used to heat the fuel pipeline and important parts such as the fuel pump and filters. In the case of difficult ignition, heating the intake valve can preheat the intake air.