Tubular Heat Exchangers

CORTEX® Core Tubular Heat Exchangers

Heat Exchanger Operating in Corrosive Environments

APEX Group develops, fabricates and supplies a range of proprietary non-pressurized tubular heat exchangers. The heat transfer elements are made of bare cylindrical or oval tubes, arranged in triangular, square or rectangular pattern.

Our CORTEX Heat Exchangers are upgraded with A-CORREX® Technology to operate with flue gasses below the acid dew point to further decrease the exhaust flue gas temperature.

Key Features


  • Constructed from metallic (glass-enameled or polymer lined) or polymer composite tubes
  • Suitable for working with corrosive (condensing) fluids (with A-CORREX® Technology)
  • Easy replacement of the heat transfer elements
  • Easy to wash due to smooth Glass enameled or polymeric surface
  • Simple and cost effective construction
  • Good response to thermal cycles and thermal shocks
  • Relatively higher pressure drop and lower thermal effectiveness is achieved comparing to CORPEX® or V-FLEX® heat exchanger of the same size.

Fluids Handled:

  • Combustion Air
  • Flue gas from combustion of: gaseous fuels, liquid fuels, coal, wood, waste, biomass
  • Vapor, condensing or non-condensing
  • Industrial exhaust streams

Typical Services:

  • Combustion Air Preheater
  • Gas-Gas Heater
  • Flue Gas Cooler/ Condenser

Typical Technical Specifications:

  • Design Temperature: Up to 260 °C (possible higher)
  • Design Differential Pressure: Up to 0.5 barg
  • Duty Range: Unlimited
  • Thermal Effectiveness: ~70%
  • Pressure Drop Rates: 0-0.1 barg (max. 0.5 barg)
  • Leakage Rate: Less than 0.1%
Applicable Technologies:
Corrosion Resistant Materials

1. Glass-Enameled Carbon Steel

  • Made from carbon/stainless steel enameled with borosilicate glass
  • Resistant to Sulfuric Acid
  • High thermal conductivity of carbon steel
  • Extremely smooth, effectively repelling fouling and easily cleanable with water or steam
  • Operating temperature up to 260°C (up to 450°C possible)
  • Good resistance to heat cycles and thermal shocks
  • Easily replaceable heat transfer elements (tubes)
  • Mechanical strength of the metallic substrate
  • Extremely smooth, effectively repelling fouling and easily cleanable with water or steam.

2. Polymer Composite

  • Made from a special type of Polymer, featuring a higher thermal conductivity compared to pure polymers
  • Resistant to virtually any chemical attack below Acid Dew Point and Water Dew Point
  • Operating temperature up to 200 °C (short term peaks 220 °C)
  • Good resistance to heat cycles
  • Easy replaceable heat transfer elements (tubes)
  • Light weight

Photo Gallery