Eclipse ThermJet TJ0015 Design Manual page 15

Step 2:
Control Methodology
(continued)
Multiple burners
Automatic shut-off at the burner
Multiple burners
Automatic shut-off by zone
High/low gas with fixed-air control
(Can also be used for pulse firing.)
A burner system with high/low control gives a high or a low
input to the process. NO input between high and low fire is
possible.
1. Air
The amount of air to the burner is fixed.
2. Gas
a. Low fire:
A control input closes the solenoid valve 1.
Low fire gas passes through the butterfly valve 3 .
b. High fire:
A control input opens the solenoid valve 1 .
High fire gas passes through the open solenoid valve 1 .
Note:
Use of a ratio regulator 2 in a fixed-air system is optional
on a single burner system only. However, eliminating the
ratio regulator will adversely affect the ignition reliability at
inputs greater than 40% of maximum.
Figure 3.:
to other Zones
P
Main gas
shut-off
valve train
P
Main gas
shut-off
valve train
Single burner
P
Main gas
shut-off
valve train
Eclipse ThermJet Design Guide No. 205, 3/5/07
High/Low gas with fixed-air control
(Can also be used for pulse firing.)
➊
to other Zones
➋
to other Burners
➌
to other Zones
Automatic
shut-off by
➊
to other Zones
NC
➋
➌
➋
(optional)
to other Burners
NC
Automatic
shut-off at
the burner
to other Burners
zone
to other Burners
➊
➌
15