STACK CAPACITIES, CORRECTION FACTORS FOR
ALTITUDES
_______________________________________________________________________
| | | | | |
| Altitude | | R | | R^{2/5} |
| Height in Feet | Normal | Ratio Barometer | | Ratio Increase |
| Above | Barometer | Reading | R² | in Stack |
| Sea Level | | Sea Level to | | Diameter |
| | | Altitude | | |
|________________|___________|_________________|_______|________________|
| | | | | |
| 0 | 30.00 | 1.000 | 1.000 | 1.000 |
| 1000 | 28.88 | 1.039 | 1.079 | 1.015 |
| 2000 | 27.80 | 1.079 | 1.064 | 1.030 |
| 3000 | 26.76 | 1.121 | 1.257 | 1.047 |
| 4000 | 25.76 | 1.165 | 1.356 | 1.063 |
| 5000 | 24.79 | 1.210 | 1.464 | 1.079 |
| 6000 | 23.87 | 1.257 | 1.580 | 1.096 |
| 7000 | 22.97 | 1.306 | 1.706 | 1.113 |
| 8000 | 22.11 | 1.357 | 1.841 | 1.130 |
| 9000 | 21.28 | 1.410 | 1.988 | 1.147 |
| 10000 | 20.49 | 1.464 | 2.144 | 1.165 |
|________________|___________|_________________|_______|________________|
These figures show that the altitude affects the height to a much
greater extent than the diameter and that practically no increase in
diameter is necessary for altitudes up to 3000 feet.
For high altitudes the increase in stack height necessary is, in some
cases, such as to make the proportion of height to diameter
impracticable. The method to be recommended in overcoming, at least
partially, the great increase in height necessary at high altitudes is
an increase in the grate surface of the boilers which the stack serves,
in this way reducing the combustion rate necessary to develop a given
power and hence the draft required for such combustion rate.