Heat ExchangersDanfossSONDEX®SONDEX spiral heat exchanger


SONDEX spiral heat exchanger

The SONDEX spiral heat exchanger is the best solution for applications that require treatment of challenging fluids. The spiral heat exchanger is well-suited for waste water, sludges, slurries, fouling, liquids with fibers and solids, and liquids with high viscosity. The design allows for counterflow, which allows for a very precise approach to the correct temperature. The use of coiled metal plates instead of tubes, allows us to achieve a very high heat output, without losing the channel gab that allows the media to flow unhindered.

The spiral coil contributes also to the turbulent flow. This single-channel design helps alleviate fouling with the “self-cleaning” mechanism. SONDEX spiral heat exchangers operate without maintenance or cleaning in very long sessions. In some cases, the heat exchanger requires to be more frequent taken maintenance and cleaning. With our designed hinged covers, we’ve created a swing door that is very easy to open and close. The hinged covers are sealed with C-clamps and will let you access the coil for inspection and cleaning.

Features and benefits

  • Single-channel design that generates high shear rates which contributes to a self-cleaning effect, preventing clogging of the unit. Spiral heat exchangers are the perfect solution for challenging, high-viscosity media.
  • The channel size is selected to fit the flow and qualities of the media. The many variations in diameters and widths of the spiral coil allow for many different combinations, which mean that we can create the optimal solution for every duty.
  • Designed to handle a very aggressive temperature program and with a wide range of materials and plate thicknesses available, we customize each spiral heat exchanger to match the requirements of any application.
  • Limited need for maintenance and cleaning ensures extended operational uptime. If the need for cleaning arises due to particularly difficult media, the hinged covers provide easy access to the entire heat transfer surface.
  • Very compact solutions, our spiral heat exchangers have minimal space requirements. Despite their small stature, the long, curved flow paths allow for very high heat transfer coefficients up to twice as high as their shell and tube counterparts.

Technical specifications

  • Connections from DN32 to DN300 (1 1/4″ to 12″)
  • (Frames designed according to FEA and PED 2014/68/EU (EN13445) and ASME sec VIII, Div. 1 construction standards)
  • Shell materials: Carbon steel, stainless steel
  • Spiral materials: Carbon steel, stainless steel
  • Working pressure up to 16 bar (145 psi)*
  • Working temperatures from -20 °C to 200 °C (-4 °F to 392 °F)

*Higher pressure available upon request.


  • Dairy/food/beverage industry
  • Biogas industry
  • Wastewater industry
  • Pulp and paper industry
  • Heavy industry
  • Petrochemical industry
  • Chemical industry