🔍 Key Concepts

• Combustion quality in boilers and how air and fuel must be balanced • Effects of air-fuel ratio on flame stability and vibration • How fuel temperature changes atomization and burner behavior

💭 Think About

• For each option, ask: could this condition make the flame unstable enough to cause pressure pulsations or vibration in the furnace or boiler? • Think about how poor atomization or poor mixing affects how smoothly fuel burns inside the furnace. • Consider whether changing fuel temperature can indirectly affect air needs or combustion stability.

✅ Before You Answer

• Verify which conditions can lead to uneven or pulsating combustion in the furnace. • Check whether each factor can cause flame instability or burner ‘rumble’ that would be felt as vibration. • Before picking a combined option, be sure every single listed condition can reasonably cause vibration or panting on its own.