Feedwater quality has a direct effect on steam boiler efficiency, equipment life, and operating cost. Two important parts of that feedwater system are condensate return equipment, which recovers hot condensate for reuse, and deaerators, which remove dissolved gases before the water reaches the boiler. Neither gets nearly the attention the boiler itself does, but poor feedwater system design can show up later as corrosion, shortened equipment life, and higher treatment costs.
Why returning condensate matters
When steam gives up its heat at a coil, heat exchanger, or process load, it condenses back into hot water. That condensate still carries useful sensible heat and much of the chemical treatment already added to the feedwater. Returning it to the boiler rather than sending it to a drain cuts two costs at once: less raw makeup water needs to be treated and heated from scratch, and less chemical treatment is needed overall, since the returned condensate has already been conditioned. Fabtek’s stainless steel condensate return units collect and return hot condensate to the boiler room, while its boiler feed systems combine condensate with makeup water and supply the boiler as demand requires. Fabtek uses stainless steel construction to reduce corrosion concerns in a demanding boiler room environment, and backs its receivers with a 20-year corrosion warranty.
Why the water still needs treating even when it’s returned
Even well-managed condensate return doesn’t solve the whole feedwater problem, because makeup water still has to fill the gap between what’s returned and what the boiler actually uses, and that makeup water carries dissolved oxygen and carbon dioxide. Left in the feedwater, dissolved oxygen drives pitting corrosion in the boiler and piping, while dissolved CO2 forms carbonic acid that attacks condensate lines. This is where deaeration comes in. A deaerator uses steam to physically strip dissolved gases from the feedwater, heating it toward saturation temperature and releasing dissolved oxygen, carbon dioxide, and other noncondensable gases before the water reaches the boiler. Sellers Manufacturing’s mechanical deaerators, engineered across a 100 to 4,500 HP range, remove dissolved oxygen and other noncondensable gases through this physical process rather than relying solely on chemical treatment, which can reduce chemical use and lower treatment costs.
Getting both pieces right, together
Condensate return and deaeration aren’t competing solutions to the same problem; they’re sequential steps in the same feedwater train. A boiler feed system without adequate deaeration still lets dissolved gases into the boiler; a deaerator with a poorly designed condensate return path just means the plant is doing more work heating and treating water that could have been reused. For anyone specifying or troubleshooting a steam plant, the useful question isn’t just “what boiler” but “what happens to the water on its way there.”
Specifying steam boiler room equipment in the Midwest and Rockies?
Blackmore and Glunt provides sales and specification support, technical training, local inventory, and post-sale startup and warranty service for the manufacturers we represent, including Fabtek and Sellers Manufacturing. Contact Blackmore and Glunt to talk through a project.
