The grill is used for toasting, grilling or browning previously cooked food. It works
by directing radiant heat that has been produced on the surface of a red-hot fret,
mesh or gauze surface, on to the food. There are two designs of grill.
First, those referred to as conventional grills, as they have been around the longest.
The grill consists of a pressed steel burner, fed via an injector at one end and located
beneath an expanded metal fret. The flames, on leaving the burner, heat the metal fret
and cause it to glow red-hot. The combustion products rise by convection through
holes in the canopy top. The biggest problem with this design is the problem of
uneven cooking, a result of the burner failing to heat the whole surface of the fret
uniformly.
In the second design of grill, known as a surface combustion grill, the injector feeds gas
into the primary air intake, this entails some 80–90% of that required for combustion.
The mixed gas and air now travels to the centre of a sealed chamber, which has a fine
metal mesh burner surface where the ignition probe is located and where combustion
takes place, the air/gas mixture clings to its face, producing an evenly heated radiant
surface across the entire burner.
