Page 144 - Boiler plant and distribution system optimization manual

Over 100 Ways to Improve Efficiency 129

Advantages/disadvantages and smoking and soot formation prevented, the
It may be expensive to install a completely linkage should be precise with no play. Some-
new control system just to have cross limiting. times pins are lost and threaded bolts are substi-
However, if this condition is not corrected, the tuted instead and over time, these sharp threads
price in unburned combustibles and higher stack cause elongated holes and a tremendous amount
temperatures will surely be taking an undesirable of play. Also, non-precision parts are used to sub-
share of your fuel budget. stitute for lost or damaged parts. Control linkag-
es also bind, warp, shear pins and otherwise lose
their precision over the years and the only solu-
8. IMPROVE CONTROL SYSTEM ACCURACY tion is to restore it to a precision system.
WITH STRONG PRECISION PARTS
Advantages/Disadvantages
Cost You may have a burner and control system
Low that can’t be adjusted to maintain low excess air
levels and high efficiency. If so, some custom re-
Potential Savings building may be necessary. It’s a cheap enough
Moderate (2% to 12%) solution but you may have to be innovative and
use aircraft grade precision parts as shown in Fig-
Description ure 10.27.
If your control system is flimsy and does not
have strongly built precision parts, the chances
are that you can’t get a good tuneup or repeatabil- 9. STACK DAMPERS
ity. If control system linkage has any play at all,
precise excess-air levels cannot be maintained. Cost
For example, only 1/100 of an inch play in control Low
system linkage can cause the need for a 5% excess
air buffer zone. Potential Savings
If low excess air levels are to be maintained Moderate (5% to 20%)

Figure 10.27