Danfoss Introduces Semi-Welded Heat Exchangers for Ammonia Refrigeration

Danish manufacturer Danfoss has introduced a series of semi-welded plate heat exchangers specifically designed for industrial ammonia (NH₃) refrigeration.

The heat exchangers can be used for applications such as condensers, flooded and pumped evaporators, sub-coolers, desuperheaters, superheaters, economizers and oil coolers. 

In a press release announcing the launch, Danfoss US claimed a safer, more energy-efficient design for the new SW19-59 series, with an improved thermal performance due to a “more compact design with optimized plate geometry, to support high turbulent flow and a lower charge.”

The SW19-59 series comes in five sizes, can handle temperatures from -40°F to 248°F (-40°C to 120°C), and pressures up to 300psi (20.7bar). The heat exchangers are characterized by “easy and fast service and maintenance,” Danfoss stated.

The SW19-59 exchangers feature a new glue-free gasket system and grove design, to ensure high gasket stability and “optimal” plate alignment. The new design gives technicians quick access to the plate pack, and the “non-corrosive nylon roller that makes it easy to slide the follower along the carrying bar,” Danfoss said. 

Apart from improved service and maintenance, the plate heat exchangers also have “fast and safe” assembly thanks to “fixed bolt heads and lock bushes that offer prevention against nut and bolt head rotation when opening and closing the unit.”

The new design has a double-gasket barrier, which reduces the risk of contamination by draining potential leakages outside the plate pack. The design also increases the sealing effect, and prevents gasket blow out, Danfoss said.

All assembled heat exchanger units are leak tested with helium before leaving the factory.