6
Eclipse ThermJet Self-Recuperative, V5, Design Guide 208, 9/16/2011
Design
When selecting a ThermJet Self-Recuperative burner,
choices are available to define a burner that will be safe
and reliable for the system in which it will be installed. The
design process is divided into the following steps:
1. Burner Model Selection Including:
• Burner Model / Size Selection
• Desired Efficiency
• Fuel Type and Pressure
2. Control Methodology
3. Ignition System
4. Flame Monitoring System
5. Combustion Air System:
• Blower Motor Type
• Air Pressure Switch
6. Main Gas Shut-Off Valve Train Selection
Step 1: Burner Model Selection
Burner Model / Size Selection
Select the size and number of burners based on the heat
balance. For heat balance calculations, refer to the
Combustion Engineering Guide (EFE 825).
Performance data, dimensions, and specifications are
given for each ThermJet Self-Recuperative model in
datasheet series 208.
Desired Efficiency
Smaller capacity burners are more efficient than larger
models. Firing at lower inputs also result in higher
efficiency.
Fuel Type and Fuel Pressure
The standard fuel is Natural Gas.
For other fuels contact Eclipse with an accurate
breakdown of the fuel contents.
The minimum required gas pressure at the burner can be
found in the ThermJet Self-Recuperative datasheets
series 208.
Step 2: Control Methodology
The control methodology is the basis for the rest of the
design process. Once the system is designed, the
components can be selected. The control methodology
chosen depends on the requirements of the process.
NOTE:
The stated operational characteristics only apply if
the described control circuits are followed. Use of different
control methods will result in unknown operational
performance characteristics. Use the control circuits
contained within this section or contact Eclipse for written,
approved alternatives.
Control Method
Eclipse recommends the high/low pulse method to control
the input of a ThermJet Self-Recuperative burner system.
The high/low control method is high/low air and gas
biased control with excess air at low fire (pulse firing). A
related control method, high/low/off, may also be
employed where additional turndown is required. These
methods may be applied to single burner as well as
multiple burner systems.
In the pages that follow you will find schematics of these
control methods. The symbols in the schematic are
explained in the “Key to System Schematics”, see
Appendix.
Modulating control may also be accommodated, contact
Eclipse with details for your application.
NOTE:
The following control method does not illustrate
flame safety. Flame safety is discussed in Step 4 on page
9 of this guide. Any decisions regarding the use and/or
type of flame safety should be made in accordance with
local safety and/or insurance requirements.
NOTE:
Eclipse recommends using a Dungs FRG Ratio
Regulator on all applications. All settings given in the
Installation Guide are based on use of the Dungs Ratio
Regulator. Use of a different ratio regulator may result in
improper burner operation.
3
System Design