Eclipse Combustion AIRHEAT AH-MA - Manual (Page 20)

Eclipse AH-MA Air Heat Burner v2, Design Guide 160, 8/1/05 20
Step 2: Control
Methodology
The simplest control method is fuel modulation at fixed air flow. If
required turndown is greater than the burner’s capabilities, there
are two options:
1. Air Modulation
To lower the minimum input of the burner, the air flow can be
decreased as long as the pressure drop across the burner does not
go outside of the operating limits given in the “Operating Ranges”
chart in Data Sheet No. 160. The air flow can be changed with a
two-speed air handling system or a modulated system. As an
example, the air flow could be turned down from a pressure drop
of 1"w.c. to 0.25"w.c., giving a total air turndown of 2:1. This could
extend the minimum input level from 20,000 to 13,000 Btu/hr/ft.
Figure 3.8 Staged Burners
Staging
Divider Plate
Part No. 76506
Stage 2
Main
Gas
Stage 1
Pilot Gas
Pipe
Union
Pipe
Union
Stage 1
Main
Gas
Pipe
Union
Pipe
Union
Pipe
Union