Eclipse Engineering Guide
Eclipse Engineering Guide
Eclipse Engineering Guide
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Tech Notes<br />
Summary of Fuel-Air Ratio Control Systems<br />
for Nozzle Mixing Burners<br />
Control System<br />
System<br />
Cost*<br />
Required<br />
Gas<br />
Pressure**<br />
Control Mode<br />
Hi-Low Modulating Firing Rate?<br />
* I=Inexpensive, M= Moderate, E=Expensive<br />
** L= Low, M=Moderate, H= High<br />
*** Depends on air and gas pressures at burner. See sheets for individual systems.<br />
† If bleeder vent is connected to combustion chamber.<br />
If backpressure<br />
fluctuates, does system<br />
maintain constant:<br />
Fuel-Air<br />
Ratio?<br />
On multiple burner<br />
zones, if one is<br />
shut off, do the<br />
others hold their<br />
ratio?<br />
On-ratio, linked valve<br />
On-ratio,<br />
I L • No *** No<br />
characterized valve<br />
On-ratio, cross connected<br />
M L to M • • No *** No<br />
proportionator<br />
On-ratio, cross connected<br />
M H • • No Yes Yes<br />
proportionator & bleeder M L to M • • No Yes Yes<br />
On-ratio, electronic<br />
Excess air,<br />
E M • • Yes Yes No<br />
fuel-only control<br />
Excess air,<br />
I M • • No *** No<br />
biased proportionator<br />
Excess air,<br />
M H • • No No Yes<br />
throttled impulse M H • • No Yes† Yes<br />
84<br />
Section 2<br />
Sheet C-1
Change language