Table 13-4. Example of fuel savings possible through reduction in blowdown (basis: one day).
| Evaporation (steam) | 2,000,000 | lb/day |
| Present blowdown: | 128,000 | lb/day (6%) |
| Reduced blowdown: | - 41,000 | lb/day (2%) |
| Reduction in blowdown : | 87,000 | lb/day |
| Feedwater (steam plus blowdown): | 2,041,000 | lb |
| Boiler Pressure | 200 | psig |
| Feedwater temperature: | 215 | °F |
| Makeup water temperature: | 60 | °F |
| Fuel (oil): | 145,000 | Btu/gal |
|
(@ 80% boiler efficiency) |
X .80 |
|
| Available fuel heat: | 116,000 | Btu/gal |
| (heat reduction) | 17,144,238 | Btu/day |
| Heat of liquid at boiler pressure: | 362 | Btu/lb |
| Heat of liquid at 60°F: | -28 | Btu/lb |
| Heat required: | 334 | Btu/lb |
| (reduction in blowdown) | 87,000 | lb/day |
| X 334 | Btu/lb | |
| Total Heat Saving: | 29,058,000 | Btu/day |
| +116,000 | ||
| Fuel savings
(@ $ 0.80/gal) |
250
X 0.80 |
|
| Daily savings: | $ 200 | |
| X 365 | days/yr | |
| Annual savings: | $72,000 |