The Wet Surface Air Cooler (WSAC®) is a closed loop cooling system that is an alternative to a Cooling Tower / Heat Exchanger system. The fluid being cooled (or condensed) does not come into contact with the atmosphere.
The WSAC® cooler or condenser operates with induced draft co-current flow, which means that the air and spray water are both traveling in a downward direction across the tube bundle. This configuration ensures that spray water is evenly distributed over the entire tube surface and essentially minimizes the risk for fouling.
As the cascading spray water mixes with the air, an equilibrium temperature forms as the water evaporates to the air, thus the warmed air and water mix together in the plenum/basin area providing inherent freeze protection during operation. Heaters can be included for non-operational cycles.
WSAC® systems are best applied for operations that will benefit from a leaving temperature of the process stream that is lower than can be reached economically by a cooling tower system. WSAC® systems generally use significantly less water and chemical treatment than conventional cooling towers applied to the same duty.
In a WSAC® system, warm process fluids or vapors are cooled in a closed-loop tube bundle (the process fluid being cooled never comes in contact with the outside air). Open loop water is sprayed and air is induced over the tube bundle resulting in the cooling effect.
Smaller Wet Surface Air Coolers can be factory assembled and larger units are field erected.
Prepackaged Niagara units, like the one pictured above, is designed as a single skid with no field assembly required. These units can be shipped directly to the job site for easy and immediate installation.
Field erected units like the one pictured above are the largest design type Niagara offers. Constructed using either concrete or FRP (Fiberglass Reinforced Plastic), field erected Niagara units offer the ability to cool high volumes of process fluid in a smaller plot area (footprint) than a traditional cooling tower. Observation and maintenance of the spray water distribution system can be accomplished without structure entry, fan shut down, or pump shutdown, providing 24 hour operation. Access doors and hatches also allow for cleaning and inspection of the lower water basin.
Power Industry
Chemical/Petrochemical Processing Industry
Steel Industry
Other Industrial Applications
With the growing concern of water usage, Niagara WSAC® systems can use poor quality water as spray to reduce fresh water consumption. Typical examples of water sources include blowdown from existing cooling towers, wastewater, river water, pond water, etc. Wide tube spacing in conjunction with low pressure/high volume nozzles allows spray water to be run at high cycles of concentration, up to 50 cycles in some cases, thereby reducing water consumption up to 70% annually.