Types Of Burners; Blue Flame Burners; Infrared Burners - Wolf OG36-LP Technical & Service Manual

Theory of Operation

Types of Burners

Blue Flame Burners - The U-shaped burners in the
Outdoor Grill are blue flame burners (See Figure 3-1).
With this type of burner, primary air is mixed with the
fuel gas before the gas reaches the burner ports. An
orifice is used to regulate gas flow to the burner. A
shutter and venturi are used to regulate the primary air.
The gas and air mix in the mixing tube, then exits the
burner ports where it is ignited. Secondary air is air
around the flames. The flame produced has several
zones, each represents a stage in burning of the gas.
The burner tip has a thin dark blue cone called the
inner or primary cone. A lighter cone called the outer
cone, surrounds the inner cone. Air around the flame
diffuses into the flame to burn at the outer cone. If con-
ditions are perfect, products from the inner cone burn
here. The final products of burning are carbon dioxide
and water vapor. An outer mantle surrounds the outer
cone where burning is usually completed. It is nearly
invisible and glows only because of the high tempera-
ture of the final combustion.
Infrared Burners - The sear burner and the rotisserie
burner in the OG models are commonly referred to as
infrared (IR) burners (See Figure 3-2). The under-fired
application for these burners uses a porous refractory
ceramic tile burner. With this type of burner, a substan-
tial amount of energy output is in the form of infrared
radiant energy. With infrared heat, thermal energy is
transmitted through space without heating the medium
through which it travels.
An orifice is used to regulate gas flow to the burner, but
the under-fired refractory infrared burner design
requires 100 percent primary air, so no shutter or ven-
turi is used. Gas and air mix in the mixing tube and
burner body, then exits the burner ports where it is ignit-
ed, producing a hot glowing burner surface. The flame
burns close to the burner surface at a high temperature.
Infrared energy is usually not affected by air flowing
between the burners and heated surfaces because of
the burner's numerous and tiny flames. This type of
heat is very efficient and compact.
NOTE: There is no shutter on infrared burners for
adjusting the primary air and as of this writing there is
no change in orifice size for differing altitude.
#814144 - Revision A - July, 2009
Outdoor Grill (OG) Series
Burner Body with Burner Ports
Mixing Tube
Shutter
Valve
Figure 3-1. Blue Flame (U-Shaped) Burner
Burner Body
Valve
Figure 3-2. Infrared (Sear) Burner
3-4
Venturi
Orifice
Mixing Tube
Orifice