Ecomax For Direct Heating Systems; Flow Rate Control - Honeywell Ecomax Series Technical Information

Application > ECOMAX for direct heating systems Application

1 .4 ECOMAX for direct heating systems

In direct heating systems, the burner ECOMAX is com-
bined with a flue gas guide tube FGT Set..D for routing
the flue gases through the furnace lining and a flue gas
eductor EJEK.
EJEK
ECOMAX
FGT-SET..D
Eductor EJEK generates a negative pressure by forc-
ing air through a centrally positioned nozzle and thus
draws the flue gases out of the furnace chamber
through the burner's heat exchanger. The motive air
flow is adjusted on the basis of the negative pressure
measured on the pressure tap between the burner and
the motive air nozzle. A flue gas valve AGK on the educ-
tor, which closes due to its own weight, minimizes back-
flow of hot flue gas from the furnace into the burner or
infiltrated air being sucked into the furnace when the
burner is switched off.
ECOMAX · Edition 10.17
AGK

1 .4 .1 Flow rate control

For direct heating, flow rate control should be inte-
grated in the system. The pressure loss in the recu-
perator depends on the furnace temperature. When
the furnace temperature is increased (at a constant air
supply pressure), the air flow rate drops. This change in
the air flow rate is measured by the orifice and the VAH
changes the gas volume accordingly to ensure that the
air index (lambda) on the burner is not dependent on
the furnace temperature.
VAS..N
AKT
BCU
BZA
BVHM + MB7..L
The ECOMAX is equipped with an integrated air orifice.
This can be used for recording the air flow rate as a
reference variable for the VAH. A separate upstream air
orifice is then no longer required. The impulse line p
for gas is connected to the burner downstream of the
integrated orifice so that the minimum gas pressure is
sufficient.
Prozess-Steuerung/
Process Control (PCC)
VAH
VMV EKO
p
d-
p
sa-
p
sa
LEH
ECOMAX
d-
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