Chimney-Zone™ Design
In most separators, oil droplets and solids travel side-by-side through the plate pack. They collide, re-entrain, co, and create sludge.
Mercer designed Chimney-Zones™ to prevent that.
A Chimney-Zone™ is a 4-inch-wide quiescent chamber that runs the full length of the plate pack. These chambers are completely isolated from inlet flow velocities—zero turbulence, zero crosscurrents, and zero chance of being swept back into the flow path.
Inside these quiet chambers, droplets and solids move in one direction only:
This directional segregation is the key element inside the patented design. Segregating each constituent eliminates the commingling that causes sludge formation and prevents particles from interfering with droplet rise.
Mercer engineered these zones into every Multi-Pack™ coalescer because real industrial wastewater demands more than theoretical laminar flow—it demands a way to process oils and solids OUT of the coalescer, not trap them inside.
Most coalescing media force both phases (oil + solids) through turbulent corrugated paths with hidden pockets prone to fouling. Even in laminar flow, this creates unavoidable issues:
Short plate widths alone do nothing unless the coalescer has a way to remove oils and solids away from the rise lanes and into a stable, quiet environment.
Chimney-Zones™ solve the core mechanical problem every other geometry struggles with.
Here is what actually happens inside the Mercer Multi-Pack™ — taken directly from the company’s engineering and validated in the field for more than 40 years.
Each Chimney-Zone™ is a 4-inch-wide baffled corridor with no through-flow.
This means:
Once oil or solids enter these zones, they are removed from the process stream entirely.
Where the tops of the herring-bone plates meet, Mercer creates a dedicated oil-riser chimney.
In the adjacent trough,never more thaan 24” away, the geometry creates a dedicated solids settling shaft.
Oil moves up only.
Solids move down only.
They never share the same pathway, never collide, never interfere.
This segregation is what eliminates sludge creation inside the pack.
This is a signature Mercer advantage.
Inside the Multi-Pack™:
This dramatically improves separation speed and prevents the “highway” of laminar flow from becoming a place where particles linger or recirculate.
If laminar flow is the process highway, Chimney-Zones™ are the off-ramps.
Unlike add-on features or isolated pockets in other designs, Mercer’s zones:
This keeps the pack clean and hydraulically stable.
This is why Mercer coalescers keep operating efficiently long after other plate packs have failed.
Industrial operators consistently report:
The quiet, isolated nature of Chimney-Zones™ means droplets and particles can take “all the time in the world” to rise or settle—because nothing is flowing through their chamber to sweep them away.
If you want a separator that handles real-world solids and oil loads without constant plugging, Mercer’s testing and evaluation will show exactly how Chimney-Zones™ perform on your wastewater.
If testing shows Mercer’s solution will not deliver meaningful improvement, you will know before you commit. Free testing and evaluation are included.
A 4-inch-wide, baffled, zero-velocity chamber that isolates oil and solids from the flow and allows them to rise or settle without interference.
They prevent collisions between droplets and solids, reducing sludge creation and maintaining coalescence efficiency.
No more than 24 inches. After that, they enter a quiescent chimney where they can complete separation undisturbed.
Because solids are quickly removed from the plates instead of accumulating and plugging the pack.
Yes. They are a patented design element built into every Multi-Pack™ coalescer.
