Step 3: Control Methodology - Eclipse AirHeat AH series Design Manual

Motor Orientation
All AirHeat burners are assembled with a right-hand
blower motor orientation.
Remote Blower Sizing
For remote blower applications, the blower should be
sized to supply sufficient flow and pressure to the burner
to ensure proper burner performance.
Example:
Fire an AirHeat0200 burner on natural gas at 800,000
BTU/hr/ lineal ft. resulting in maximum input of 1,600,000
BTU/hr at an air pressure drop of 1" w.c. In the chart,
locate 800,000 Btu/hr/LF and read up to the 1" w.c. P
curve and then left to determine the excess air
percentage. In this case, 44% excess air.
Control and Operational Zone
10000
1000
0.6" w.c.
0.6"w.c.
1.5mbar
100 1.5 mbar
2.0 mbar
10
0 200
Input x 1000 BTU/hr/lineal ft.
0
200
Input (kW/lineal meter)
1. Determine Air Factor (1+ excess air %) = 1.44
2. Determine Fuel Flow (Input/Gros Heating Value*)
= (1,600,000/1000) = 1,600 scfh
3. Determine Air Flow (Air Factor x Stoichiometric Air
Requirement* x Fuel Flow) = 1.44 x 10 x 1,600
= 23,040 scfh air flow
* See Fuel Type Table

Step 3: Control Methodology

Input is normally controled by a motorized butterfly valve
in the gas line to the burner.
8
Typical Fixed
Air Control
1" w.c. (2.5 mbar)
1.2" w.c.
3.0 mbar
0.8" w.c.
400 600 800
400 600 800
Combustion
Air
Blower
• A control signal is sent from a process temperature
controller (sold separately) to the control motor.
(Refer to Bulletin 818C or contact Eclipse
Combustion for further information on temperature
controllers.)
Set Point
1000
1000
• The control motor modulates the gas butterfly valve
(BV) which controls the fuel flow to the burner.
• Air pressure and flow in the burner body remain
fixed throught the operating range.
• Modulation of fuel flow only, provides turndowns of
40:1.
Do not use other control methods without prior
approval from Eclipse.
Eclipse AirHeat Burner, V2, Design Guide 135, 6/16/2010
Gas Flow
BV Valve
Process
Control
Controller
Signal
Gas Flow
Process
WARNING
Control
Motor
Gas Flow
Control
Motor
Gas
BV