De-aeration Column
De-aerated water in the beverage and brewing industry refers to process water treated to remove dissolved gases, primarily dissolved oxygen.
Dissolved oxygen reacts with beverage ingredients, generating off-flavour, stale notes, colour browning and degradation of other compounds.
On the other hand, minimizing residual oxygen inside the package prevents chemical oxidation and restricts the growth of aerobic microorganisms, greatly improving product stability and extending shelf life.
SKE adopts stripping-column-based de-aeration technology. With our distinctive column design, we can achieve a standard dissolved oxygen level below 20 PPB, and under specific operating conditions, as low as 10 PPB.
The system operates on the principle of counter-current mass transfer: liquid flows downwards by gravity while stripping gas flows upwards. Dissolved oxygen is removed from the liquid phase in accordance with Henry’s Law.
Inside the column is our proprietary stainless steel distribution packing cartridge. It spreads the water into a thin, steady and uniform falling film with an extensive contact surface, enabling sufficient mass transfer between the stripping gas and oxygen contained in the water.
Working Principle
Filtered water is pumped into the column at controlled flow, pressure and temperature of 10–25°C. For hot-column systems, raw process water first passes through a heat exchanger to reach 72–82°C. Heating drastically reduces oxygen solubility even before the water enters the column, facilitating ultra-low DO levels below 10 PPB.
Water enters the top of the column and flows through distribution nozzles. The spray plates break the liquid into micro-droplets and distribute it evenly across structured packing.
High-purity stripping gas (typically CO₂ or N₂ with purity ≥99.95%) is continuously injected at the column bottom. The upward-flowing stripping gas contains virtually no oxygen, bringing the oxygen partial pressure in the gas phase close to zero. As water trickles down the packing countercurrently against the rising gas stream, dissolved oxygen molecules naturally migrate into the CO₂/N₂ gas phase to reach equilibrium. Oxygen is effectively stripped out of the water droplets.
Oxygen-enriched gas reaching the column top is continuously vented to atmosphere. De-aerated water collects in the bottom sump of the column before being transferred to the DA-water storage tank. Level sensors monitor the water level inside the sump to automatically adjust the transfer pump output.
The DA-water storage tank is equally critical as the stripping column system. Prior to receiving de-aerated water, the tank must undergo gas purging to avoid re-oxygenation of treated water.
Features:
- Full CIP coverage with zero contamination risks
- Low maintenance demand: no moving or wearable parts to replace apart from routine CIP and chemical soaking
- Stable effluent quality: packed columns deliver massive gas-liquid contact area, achieving single-digit or low PPB dissolved oxygen levels unattainable by simple vacuum tanks or basic spray systems
- Ideal for sensitive premium products: craft beer, premium lager and vitamin-fortified juices. Even 50 PPB dissolved oxygen can trigger premature staling, off-flavours and colour shifts
- Industrial-scale capability: continuous operation for high flow rates ranging from 2,000 L/h to over 20,000 L/h
