Page 18

NORA Oilheat Technicians Manual

Figure 1-9: Adjustable head burner The nozzle assembly The nozzle assembly also known as the “drawer” assembly, or firing assembly, consists of the oil feed pipe (called the nozzle line), the nozzle, nozzle adapter, electrodes, transformer connections, and on some burners, a flame retention ring. The entire assembly is located in the air tube of the burner. An opening at the rear, top or side of the burner housing permits access to and removal of the nozzle assembly. Combustion heads The combustion head (also referred to as the turbulator, fire ring, retention ring, and end cone) creates a specific pattern of air at the end of the air tube. The air is directed in such a way as to force oxygen into the 1-8 Introduction to Oil Burners oil spray so the oil can burn. In order to do so, the combustion head must have the right amount of air delivered to it down the air tube from the fan, and the fuel pump and nozzle must deliver the right amount of fuel at the proper pressure. Elements needed for combustion As we have discussed, the three elements we need for combustion are oil, air, and spark. If we examine these three elements one at a time we will see that: • The amount of oil is based on the flow rate in gallons per hour (GPH) that you wish to burn. The size of the nozzle orifice (in GPH) and the pressure setting of the fuel unit determine the flow rate. • The spark is the ignition source for the fuel oil. With new advanced control systems, the spark is only on for a short period of time (usually 25 seconds maximum) at the beginning of the running cycle of the burner. Once flame is established, the heat from the flame keeps combustion going. Continuing to have the spark on after ignition is accomplished will only detract from the performance of the burner. • The air is the key element and the final adjustment of a burner. Air is introduced into the air tube by the fan through the air intake controlled by adjustable shutters or bands. The flame retention head incorporates three basic air-directing elements: the center opening for primary air, the secondary slots, and the Chapter 1 Intro to Oil Burners


NORA Oilheat Technicians Manual
To see the actual publication please follow the link above