For decades, dual tank drying systems have been the accepted standard in sulfonation/sulfation plants – two vessels cycling between adsorption and regeneration every four hours, with all the inherent switching shocks, dew point swings, and operator attention that come with them. WEIXIAN asked: Why cycle at all? Unit 22 (full name: Unit 22 Rotor Silica Gel Bed Air Drying) is our answer – a single, continuously rotating silica gel rotor that eliminates the switchover entirely. This is a world first technology, purpose built to replace the intermittent drying paradigm that the industry has long accepted as unavoidable.

The Upgrade in Brief

• 8,000 hours/year continuous operation – no 4 hour changeover cycles, no regeneration induced production stops or turndowns.

• Stable air flow and temperature – no switching transients to disturb the process.

• Constant dew point at –65 °C ± 3 °C – no drift, no spikes, no surprises.

•  Consistent product quality – fewer side reactions, less tar, tighter specifications batch after batch.

• Simpler operations – fewer valves, no complex timing logic, near zero daily intervention.

•  Lower power consumption – optimised regeneration profile and reduced pressure drop cut electrical costs.

Why It Matters for Your Plant

Uptime – Your reactor sees exactly the same dry air at 8 a.m. and 8 p.m.

Product purity – Especially critical for high grade LABSA and SLES.

Operations – Your team focuses on output, not dryer babysitting.

Energy – Directly improves your per tonne variable cost.

Retrofit Ready, Investment Smart – Unit 22 is engineered as a direct replacement for existing dual tank layouts, sharing a similar footprint and connection points to minimise civil work during revamps. For new plants, it simplifies the entire drying skid. The capital cost is competitive, and the payback – from energy savings, maintenance reduction, and yield improvements – is remarkably short.

The Bottom Line – Dual tank drying is mature, but mature doesn't mean optimal. Unit 22 takes air drying from intermittent to truly continuous – something no one in the industry has achieved before. If you're planning a new sulfonation line or upgrading an old one, let's talk about this genuine step change.