Sludge Heat Exchanger

(Klean-Wall ™️ Heat Exchanger)

The sludge heat exchanger, or Komax Klean-Wall® Heat Exchanger, is mainly utilized for heating municipal sludge, FOG  (Fats/Oils/Grease), or manure for aerobic/anaerobic digestion purposes.  It is typically installed in a recirculation loop with a digester. The sludge heat exchanger can specifically be used to heat sludge using hot water OR to reclaim heat from hot outgoing digested sludge to heat the cold incoming sludge, enhancing biogas production and assisting in producing Class A biosolids.

Heating sludge to harness energy by capturing the biogas is a green practice utilized around the world in sustainable farming to capture methane gases. The biogas can be used to recover energy and generate power using a generator, and this energy can be used to power the other plant operations.

The Komax Hi-pass mixing technology of the heat exchanger eliminates the boundary layer, increasing the heat transfer efficiency. The turbulence created by the patented non-clogging Hi-pass mixing elements, set in a dual series of angles with a larger opening than the standard triple action static mixer, allows for sludge and debris to pass through the tube side and shell side piping, scavenges the pipe walls, resulting in low to no maintenance or production downtime. This technology keeps the pipe walls clean, by eliminating fouling or caking of sludge on the pipe wall, resulting in more consistent heating performance over time.  This makes the sludge heat exchanger more thermally efficient than a standard shell and tube heat exchanger. Due to the heat transfer improvement, Komax shell and tube heat exchangers can be up to 50% smaller than a standard ‘tube in tube’ heat exchanger for the same heating application.



  • Municipal Waste Water Treatment Plants
  • Dairy Farms
  • Breweries
  • Landfills
  • Biofuels


  • Municipal Sludge Mixing
  • FOG
  • Reclaiming heat from outgoing sludge/deliver to cold incoming sludge
  • Heat sludge to deliver re-circulation of anaerobic digestion

End Connections & Available Custom Options

Flanged Ends: Flanged end connections allow for easy mounting of the static mixer into the process pipeline. As a general standard, metal static mixers have raised face flanges per ASME B16.5 or ASME B16.47 (for sizes larger than 24”) standards. Komax can also fabricate mixers to contain DIN (metric) flanges as well.

Victaulic style Quick Disconnect couplings: These connections help in quick assembly and disassembly of piping connections to the heat exchanger. These can also be useful to quickly put together or break down the heat exchanger into individual passes for cleaning or maintenance.

Materials & Sizing

Diameter: Customer Specifications

Standard Metals: Carbon Steel & Stainless Steel

Pipe Schedule: Schedule 10-40

Mixing Elements

Non-clogging Mixing Elements (Hi-Pass)

Set of mixing elements placed on opposite side to allow wall-to-wall radial transfer of sludge and debris with no clogging or build up as it offers a wider opening in the center of the static mixer, allowing bigger particles to pass through. The jacketed heat exchanger transfers heat from one media to another by utilizing hot water or hot sludge. The internal hi-pass non-clogging mixing elements create high turbulence at the pipe wall, removing the internal film coefficient that prevents high efficiency heat transfer.

Downloadable Information:

Sludge Heating Brochure

Sludge Brochure

Sludge Mixer Brochure