Contact Us

Power Plant Applications

Power Plant Applications

Power Plant Applications

There are many areas at a coal fired power plant where treatment through thermal evaporation is a good decision. Among these are flue gas desulfurization, combustion residual leachate and bottom ash transport water. The US Environmental Protection Agency (EPA) is taking charge in these areas through the promulgating of new Effluent Limit Guidelines (ELGs) which necessitate that electric steam (coal fired) power plants meet new discharge limits to stay in operation. The new discharge limits are deemed necessary to protect our nation’s vital water resources, agriculture, industry, recreation activities and thriving community activities. The new ELG’s indicate that thermal evaporation will now be considered “Best Available Technology” (BAT). In other words, the ELG’s will mandate treating wastewater to Zero Liquid Discharge (ZLD) standards.

Xylem’s Vacom technology is a unique evaporation / crystallization technology considered BAT by EPA standards. This technology is specifically designed for FGD blowdown management to concentrate high hardness wastewaters.

The Vacom System separates the wastewater into pure water for reuse and crystallized solids for more efficient and cost-effective disposal. Its pioneering design combines an evaporator and crystallizer into a single system, simplifying the process.
Compared to its competitors, The Vacom system presents impressive advantages:

Footprint is reduced

The treatment process is simplified

Problems common in other processes (principally scaling and fouling) are eliminated

Lower operational costs, less maintenance costs and an easier maintenance schedule

Vacom in Flue Gas Desulfurization Blowdown:

Xylem’s Vacom technology circulates at extremely high rates relative to the evaporation rate, which provides tremendous heat transfer in a turbulent flow regime resulting in smaller heat exchangers, no scaling or fouling of the heat exchanger plates, and concentrating past the salt saturation levels to precipitate crystals allowing for an efficient ZLD operation.
  • Coal Fired Power plants are under increasing regulations to utilize technologies that reduce salt levels from wastewater.
  • A Vacom system crystalizes and concentrates the FGD blowdown lower than other technologies.
  • A true ZLD solution is achievable when Vacom concentrate is managed through a filtration technology, which provides smaller volumes for landfill stabilization and reduces the usage of pacash, flyash, lime or other stabilization amendments needed to ensure the final concentrate passes landfill leachate requirements.
  • Additionally, a smaller concentrate volume means a higher overall distillate recovery that can be reused at the plant.

Xylem can also treat Power Plant Cooling Tower Blowdown:

  • Eliminate large on-site ponds for blowdown which slowly evaporate and create long-term maintenance problems.
  • Reuse the distillate as cooling tower feed water.
  • Provides minimal disposal volumes of the concentrated salts.