In a multi-burner cluster, secondary and tertiary nozzles are ignited by:

In a multi-burner cluster, the primary burner plays a critical role in the ignition sequence for secondary and tertiary nozzles. When the primary burner is ignited, it creates a stable flame that provides the necessary heat and conditions to ignite the secondary and tertiary burners. This process is essential because it ensures that the secondary and tertiary nozzles receive sufficient heat to achieve combustion.

The primary burner’s flame not only helps in the ignition of the additional burners but also assists in maintaining a safe and controlled environment during operation. Using the primary burner to ignite the others provides a reliable and efficient method for starting up the system, given that it is designed to operate first and ensure that there is a proper flame and temperature before the operation of the remaining burners.

The other options, while they may pertain to ignition or flame stabilization in certain contexts, do not serve the primary function as effectively in a multi-burner cluster scenario. The primary burner is specifically designed and positioned to quickly and reliably ignite other burners in the cluster setup.