Annular groove heavy-duty graphite condensers

Detail of an annular groove heavy-duty graphite condenser

With their specific design our annular groove heavy-duty graphite condensers are especially adapted to the condensation of highly corrosive vapors. Annular groove heavy-duty graphite condensers transfer heat from a condensing vapor to a cooling medium. Graphite discs are machined to create annular grooves on the service side and large, banana-shaped channels on the process side. Heat is transferred by conduction through the impervious graphite left between the process and the service channels. Annular groove heavy-duty graphite condensers consist of a stack of discs that are fused together.


3D renderings

3D Animations


  • Impervious graphite: GAB GPX1, GPX1T or GPX2
  • Pressure plates and flanges: carbon steel or stainless steel (optional)
  • Tie rods, nuts, bolts, washers, springs: stainless steel


  • Totally modular design: number of discs, size of discs and number of passes can be adjusted
  • Graphite discs with annular grooves (spirals)
  • Maximum disc diameter: 900 mm
  • Different groove widths possible
  • Graphite nozzles on product and utility sides
  • Thermal expansion compensation ensured by tie rods and helical springs
  • Carbon-fiber reinforcement (optional)

Key Features:

  • Design pressure: -1 barg (full vacuum) to +10 barg
  • Design temperature: -60 to +200°C (-76 to 392°F)
  • Heat transfer area: 0,3 to 55 m2 (3 ft2 to 592 ft2)
  • Design: according to European PED, ASME code, Chinese Pressure Vessel code and other national pressure vessel codes on request

Key Benefits:

  • Outstanding corrosion resistance
  • Superior heat transfer performance thanks to adjustable cross sections on both sides that guaranty a high level of turbulence
  • Gasket-free design (fused discs)
  • Resin-free surfaces (impregnation before machining)
  • Dead-zone-free design
  • Self-cleaning design prevents fouling and clogging
  • High operational safety
  • Highly reliable equipment therefore low cost of ownership and low maintenance cost
  • Compact and robust design
  • Short lead time
  • Long lifetime

Optional features:

  • Sight glass
  • Very large channel widths for special applications such as e.g. sublimation or reverse supplication
  • Carbon fiber reinforcement
  • Cleaning in place

Main applications:

  • Vapor condensation
  • Sublimation and reverse sublimation
  • Suited for multi and single purpose units

Technical documentation


PIRN9-EN-US GMP Compliant Annular Groove Condenser - NB-GMP Series (SI and US units)

PIRN10-EN-US GMP Compliant Annular Groove Condenser - HB-GMP Series (SI and US units)

PIRN11-EN-US Graphite Annular Groove Condenser - NB Series (SI and US units)

PIRN18-EN-US Graphite Annular Groove Condenser - HB Series (SI and US units)

TI021-EN GMP compliant Annular Groove Condensers

TI041-EN Graphite Condensers - Annular Groove vs. Block Design

TI046-EN Desublimation Processes with Annular Groove Equipment

WS1041-EN Annular Groove Heat Exchanger - Vertical Installation - Extended Endplate

WS1042-EN Annular Groove Heat Exchanger - Vertical Installation - Support Collar Mounting

WS1048-EN Annular Groove Heat Exchanger - Horizontal Installation

WS1550-Form-EN Questionnaire for Graphite Heat Exchangers - detailed

WS1551-EN Questionnaire for Graphite Heat Exchangers

WS1052-EN Annular Groove Heat Exchanger - Vertical Installation - Base Plate

WS1562-EN Annular Groove Condensers for Multi-purpose Plants

GAB Neumann’s annular groove heavy-duty graphite condensers – NB and HB series

GAB Neumann’s annular groove heavy-duty graphite condensers are designed to condense ultra-corrosive vapors. Safety, reliability, and performance on the long-term are our heavy-duty considerations when we size, design and manufacture annular groove heavy-duty graphite condensers.

Our extended and highly customizable annular groove heavy-duty graphite condenser portfolio enables us to provide particularly adapted solutions to totally or partially condensable vapors. All our annular groove heavy-duty graphite condenser designs are totally modular to best fit with individual process specifications. The number and size of discs, the number and width of channels as well as the number of passes both on process and service sides can be adapted to best meet the velocities, pressure drops, and heat transfer requirements.

They can be fitted with optional features such as sight glasses, cleaning in place and GMP design if required.

All our annular groove heavy-duty graphite condensers are machined after phenolic resin impregnation thereby guarantying a heat transfer surface which is totally free of resin and there ensuring the highest possible heat transfer rate.

Annular groove heavy-duty condensers

Annular groove heavy-duty condensers transfer heat from a condensing vapor to a cooling medium, generally water, brine, or ethylene glycol, without direct contact between fluids. For material properties, cost and efficiency reasons, annular groove heat exchangers are not manufactured out of any material other than impervious graphite.

The thermal performance of annular groove heavy-duty graphite condensers can vary significantly. It is therefore essential to select the type and size of annular groove heavy-duty graphite condensers that are the most adapted to the specific application and industrial process. There are a number of considerations including flow rate, pressure drop, design pressure and temperature, material compatibility, fouling, and many more that should be taken in account.

Industrial processes:

  • Crop protection
  • Fine chemicals
  • Active pharmaceutical ingredients
  • Fire retardants
  • Flavors and fragrances
  • Vitamins
  • Treatment, purification and concentration of spent acids
  • and many more…

GAB Neumann GmbH

Alemannenstrasse 29

79689 Maulburg


Tel: +49 (7622) 6751 0

Fax: +49 (7622) 6751 20

GAB Neumann GmbH | Alemannenstrasse 29 | D-79689 Maulburg | Phone +49 (7622) 6751 0 | Fax +49 (7622) 6751 20 | E-Mail |