The partial condenser (vent condenser)

A partial condenser, also known as a vent condenser, is a specially designed heat exchanger for condensing steam streams that do not consist entirely of water vapour. In many industrial processes (such as evaporation, drying or waste-to-energy), steam also contains non-condensable gases. These gases have a significant impact on the condensation behaviour and, consequently, on the efficiency of the process.

Whereas pure steam condenses at a constant temperature, the presence of non-condensable gases results in what is known as a condensation profile: the temperature drops gradually during condensation. This is because these gases disrupt heat transfer and accumulate as the process progresses. The result is that part of the steam does not condense, and valuable energy is at risk of being lost.

The partial condenser has been specifically developed to address this issue. Thanks to an optimised thermal design, often implemented as a tube heat exchanger, the steam is effectively cooled, causing a large proportion of the water vapour to condense into reusable condensate. At the same time, the remaining non-condensable gases and vapour streams are discharged in a controlled manner via a separate outlet.

This technology makes it possible to recover heat and water from complex waste streams, which directly contributes to greater energy efficiency and lower emissions. In addition, a vent condenser prevents unwanted steam losses and improves process stability.

By extracting maximum value even from ‘impure’ steam, the partial condenser is an essential component in sustainable and cost-effective process plants.