A packed tower scrubber lives or dies on the internals installed inside it. Two of the most common options, structured tower packing and chevron vane mist eliminators, do fundamentally different jobs. Confusing the two during specification is a common and costly mistake: one is built to absorb soluble gas, the other to knock out coarse droplets, and neither substitutes fully for the other. Kimre™ Clean Air Technology engineers both types of internals, which makes the functional split between them a useful starting point before specifying either one.
Two Internals for Different Scrubbing Jobs
Structured tower packing and chevron vane mist eliminators often sit in the same vessel, but they solve separate problems. Packing exists to maximize gas-liquid contact for mass transfer, while vanes exist to physically separate liquid droplets from a moving gas stream before it exits. Treating either as an all-purpose internal is where scrubber performance issues usually start.
Structured Tower Packing for Mass Transfer
Kimre's KON-TANE® tower packing is a structured, interlaced monofilament material assembled into layered pads. As liquid cascades over the packing, it breaks apart and continuously renews its exposed surface, since a droplet leaving one layer almost immediately contacts the next. That renewal is what drives efficient mass transfer: Kimre states that a single 7-inch stage of KON-TANE® can deliver the equivalent of up to three mass transfer stages, with the highest liquid-to-gas ratio available among comparable packing.
Chevron Vanes for Coarse Droplet Knockout
Chevron-style vane separators work by mechanical redirection rather than surface renewal, forcing gas through a zig-zag channel so entrained droplets cannot follow the airflow around each bend. They perform best on coarse droplets, generally above 20 microns, and are limited on the fine mist that mesh pads or tower packing handle more effectively. Vanes do not absorb gas; they only remove liquid already present in the stream.
Gas Absorption and Soluble Contaminant Removal Compared
This is the clearest functional split between the two internals. Tower packing is a mass transfer device: its structure exists to bring gas and liquid into repeated contact so soluble contaminants transfer into the liquid phase. Chevron vanes have no absorption function at all. A scrubber relying on vanes alone will knock out coarse liquid but pass soluble gas straight through untouched.
Pressure Drop and Energy Considerations
Packed bed scrubbers using KON-TANE® packing are classified as medium-energy scrubbers, and the packing prevents the liquid holdup that wastes pumping energy. Chevron vanes typically run at a very low pressure drop of their own, especially at high flow rates, which is part of their appeal as a final knockout stage rather than a primary absorption device.
Handling Particulate and Fouling Tendencies
Vane separators use an open channel design that resists fouling well in cleaner streams, making them low-maintenance where particulate load is light. Tower packing can be more exposed to fouling in dirty service, but Kimre's KON-TANE® packing addresses this with removable cassettes that can be pressure washed, solvent cleaned, or worked loose without an extended shutdown. Mesh pads show fouling in similar ways, one of the six signs a demister pad needs replacing.
Selecting Internals for a Packed Tower Scrubber
| Factor | Structured Tower Packing | Chevron Vane Separators |
| Primary function | Mass transfer / gas absorption | Coarse droplet knockout |
| Droplet range handled | Fine mist generated during scrubbing | Coarse, generally above 20 microns |
| Pressure drop | 50-150 mm water gauge (medium-energy range) | Very low, even at high flow rates |
| Fouling behavior | More exposed in dirty service; cleanable cassettes | Fouling-resistant open channel design |
| Typical role in a scrubber | Primary absorption stage | Final liquid knockout stage |
Most effective packed tower scrubbers do not choose one internal over the other; they use tower packing to absorb the soluble contaminant and a downstream vane or mist eliminator stage to catch whatever liquid the absorption step generates. Read our guide to mist elimination and mass transfer equipment to see how both fit into plant emissions control.
Kimre, Inc. manufactures mist eliminators and air pollution control products for industrial plants across the power generation and chemical processing industries. Contact Kimre to discuss internals for your packed tower scrubber.
