Unit 12 Oil Heat Components

OBJECTIVES After studying this Unit, the reader should be able to

•List and describe the parts of a high pressure oil burner

• Describe service procedures for oil burner components

GUN-TYPE OIL BURNER• Oil and air forced into burner for mixing and ignition• Burner motor provides power for the fan and fuel pump • Burner fan or blower – Forces air into the chamber• Fuel oil pumps – delivers oil to the chamber• Nozzle – atomizes oil prior to ignition• Air tube – delivers air to the chamber• Electrodes – provides spark for ignition• Ignition transformer / electronic igniters• Primary control unit – controls burner operation

Transformer

Blower Housing

Air Inlet Collar

Flexible Coupler

Fuel Pump

Blower

Motor

Air Tube

Mounting Flange

Static Disc

End Cone

Nozzle

Electrodes

OIL BURNER COMPONENT PARTS

BURNER MOTOR

• Split-phase fraction horsepower motor• Facilitates motion of the blower and fuel pump• Flexible coupler connects motor to the pump• Normal motor speeds are 1750 and 3450 rpm• Pump should always match the pump’s rpm

BURNER FAN OR BLOWER

• Squirrel cage blower• Has an adjustable air inlet opening• Fan forces air through the air tube to the combustion chamber• The air is mixed with atomized fuel in preparation for

combustion

FUEL OIL PUMPS

• Can be either single or two-stage pumps• Pump has a built in pressure regulator• Pressure regulator can be adjusted• Oil pressures range from 100 psig to 140 psig• Single stage pumps are used when the oil tank is located above the

burner• Two-stage pumps are used when oilis stored below the burner

NOZZLES• Atomizes the fuel for combustion• Bore size determines the amount of oil used• Rated by spray pattern, flow rate and angle• Spray patterns: hollow, solid, or semi-solid cones• Flow rate is measured in gallons per hour• Spray angles range from 30 to 90 degrees• Always select the proper nozzle

THE NOZZLE

Brass Body

Sintered Filter

Screwpin

Stainless Steel Distributor

Stainless Steel Orifice Disc

Orifice

ELECTRODES

• Located within the air tube

• Metal rods insulated with ceramic insulators

• Electrode ends make contact with the transformer terminals

• Provide a high voltage spark for ignition

• Continuous or intermittent ignition

Static Disc

Nozzle

Electrodes

Ceramic Insulators

Air Tube

End Cone

IGNITION TRANSFORMERS & ELECTRONIC IGNITERS

• Step-up transformers with 120-volt primary• Secondary voltage is 10,000 volts or more• Provides the high voltage to the electrodes• Cannot be serviced in the field• Spark can be checked in the field

HEAT EXCHANGER• Exchangers transfer the heat from combustion to the air that is

circulated to heat the structure• Heat exchangers also separate flue gases from the air

circulated to heat the structure• Heat exchangers should be inspected during normal service for

cracks• Some states allow cracked heat exchangers to be welded, but

most do not• Correct airflow is important across the heat exchanger

Unit Summary• The typical oil burner contains a motor, blower, fuel pump, nozzle,

electrodes and primary control• Nozzles rated by flow rate, angle and spray pattern• Ignition transformers and electronic igniters provide the high voltage needed

for spark ignition