Customized wet surface heat exchangers systems
WSAC systems come in all sizes from small, packaged units to large field-erected systems.
The packaged systems are skidded, pre-piped and pre-wired units, complete with control cabinets. These factory-tested, plug-and-play units ensure a fast and easy installation, and keep the associated installation costs low.
Our modular systems are ideal where cooling capacity needs to be expanded simply and efficiently. These medium sized WSACs have casings made of heavy-gauge steel and are delivered in pre-fabricated modules that are easily assembled on site.
Our largest systems are field erected. The basin is made of concrete and the overlying structure can be made of either fibre reinforced plastics (FRP) or concrete. A field-erected system is comprised of custom-designed tube bundles, which provide optimum maintainability over the lifetime of the system. A field-erected WSAC system offers the lowest total cost of ownership for duties where high-capacity cooling/condensing is required.
Fully customized WSAC systems
Highly durable equipment
Alfa Laval WSACs are engineered to meet heavy-duty industrial requirements and standards. They can sustain pressures up to 2500 psi and be designed to meet ASME, TEMA, PED and API specifications. All materials in contact with the process stream can have full ASME material certification if required. The units are fireproof and can be constructed for use in Ex environments.
The tubes can be either straight or serpentine shaped. Straight tubes are the preferred choice for fouling process media and when a low pressure drop is required. The piping can be arranged and valved so that any tube bundle can be taken out of service for maintenance while the unit is in operation.
As standard, all components are made of hot-dip galvanized steel with excellent resistance to corrosion. For applications with corrosive media, the tube bundles can be delivered in a variety of materials, for example different grades of stainless steel, super duplex and titanium.
All Alfa Laval WSAC systems are unique and custom designed to fit the exact requirements of their intended duties. This includes inlet and outlet temperatures, ambient conditions, flow rate, presence of corrosive media, required pressure drop, etc.
Redundancy can be built into the units in order to minimize or eliminate downtime for maintenance. This can include components such as spare fans, spray pumps and even tube bundles. The units can also be designed to cool several separate process streams independently.
Comparison with other technologies
WSAC systems produce the coldest possible process outlet temperature compared to other technologies. Other WSAC advantages are shown in the following table.
In this example the air temperatures are:
Dry bulb T = 37.7°C (100°F)
Wet bulb T = 26.1°C (79°F)
|Wet Surface Air Cooler (WSAC)||Cooling tower plus heat exchanger||Traditional air-cooled heat exchanger (dry)|
|Practical approach temperature||5.6°C (10°F)||8.3°C (15°F) in total, 5.6°C (10°F) for CT and 2.7°C (5°F) for heat exchanger||8.3°C (15°F)|
|Coldest practical process temperature||31.7°C (89°F)||34.4°C (94°F)||46.1°C (115°F)|
|Water consumption||Low-medium||High||Not applicable|
|Total system cost||Low-medium||Medium||Medium-high|