Honeywell Ecomax Series Technical Information page 18

Function
Housing
Gas insert
Combustion gas
Influence of the furnace temperature
The higher the furnace temperature, the greater the
pressure loss in combustion air and flue gas in the re-
cuperator.
When the furnace temperature is increased (at a
constant air supply pressure), the air mass flow rate
(= standard air flow rate) drops while the gas flow rate
remains virtually unchanged. In a system with air/gas
ratio control or without pneumatic air/gas ratio control,
temperature-dependent pressure losses in the burner
are not compensated for. The air index lambda drops
with increasing furnace temperature.
ECOMAX · Edition 10.17
Flue gas
Air guide tube
Combustion air
Radiant tube or
flue gas guide tube
Combustion chamber
In direct heating systems with flue gas eductor EJEK,
the quantity of flue gas extracted from the furnace
chamber via the burner decreases as the furnace tem-
perature increases. If flue gas extraction at maximum
furnace temperature is 80 – 90%, negative furnace
pressure is generally avoided even if the furnace tem-
perature is reduced by 400 – 500°C.
Ignition and flame control
The burner is directly ignited.
Ignition and flame control are provided by a combined
spark electrode/flame rod (single-electrode operation).
Flame control with UV sensor is required if a furnace
temperature of 1150°C (2102°F) for direct heating or
1050°C (1922°F) for indirect heating is exceeded.
Recuperator
18