Burners

What is a burner in the context of gas appliances?

• A device that controls the temperature of the appliance

• The part of the appliance where the flame stabilises

• A safety mechanism to prevent gas leaks

• The switch that turns the appliance on or off

What is the purpose of small ports incorporated into the burner when burning natural gas?

• To increase the temperature of the flame

• To mix the gas with air

• To prevent 'flame lift'

• To control the flow of gas

What is the function of the primary air in the atmospheric burner's operation?

• It is pre-mixed with the gas before combustion

• It is used to cool down the appliance after use

• It acts as a backup in case of gas supply failure

• It is the only air supply for the combustion process

What causes the flame to 'lift' off the burner and extinguish in a gas burner arrangement?

• Low flame velocity associated with natural gas

• High flame velocity associated with natural gas

• Stable retention flame

• Retention burner mixture velocity being too high

What is the function of the metering orifices in a bar burner associated with atmospheric boilers?

• To cool down the retention flames

• To supply water to the boiler

• To supply gas to the retention flames

• To ignite the gas automatically

What is indicated by a yellow tip in the flame of a bar burner?

• Complete combustion of gas

• Presence of unburned gas

• Optimal secondary air supply

• Efficient cooling of the retention flame

What is the role of secondary air in the combustion process of a bar burner?

• It is used to extinguish the flame.

• It diffuses into flames to support combustion.

• It cools down the retention flames.

• It is a byproduct of the combustion process.

What is the function of the component labeled 'f' in the diagram of a pre-aerated gas burner?

• Injector

• Primary air inlet

• Burner port

• Throat resistor (alternative primary air adjustment)

According to the text, what is the significance of the velocity of the gas leaving the injector in a bar burner?

• It relies on the venturi principle to operate the burner.

• It is the energy in this velocity that contributes to the whole process.

• It determines the color of the flame.

• It is regulated by the aeration control shutter.

What is the maximum velocity of the gas leaving the injector in the described bar burner?

• 25m/second

• 35m/second

• 45m/second

• 55m/second