How to Read and Compare a Mist Eliminator Datasheet Without Being Misled

Mist eliminator quotations can look easy to compare.

Two suppliers may provide tables containing:

• diameter;
• thickness;
• material;
• mesh density;
• efficiency;
• pressure drop.

The buyer then places the two datasheets side by side.

The difficulty is that identical-looking headings do not always describe identical technical assumptions.

One supplier may quote a nominal efficiency based on a particular droplet size.

Another may refer to a different test basis.

One pressure-drop value may be dry.

Another may represent wet operation.

A low price can therefore appear technically equivalent when the engineering basis is actually different.

A good technical comparison should evaluate what each datasheet number means, not only the number itself.

Start With the Process Design Basis

Before comparing products, confirm whether both suppliers used the same:

• gas flow;
• temperature;
• pressure;
• gas density;
• liquid properties;
• vessel diameter.

If the inputs are different, the outputs are not directly comparable.

A supplier using actual gas flow may calculate a different face velocity from one using normalized flow incorrectly.

Always compare the calculation basis before comparing performance.

Check Whether Gas Flow Is Actual or Normalized

This is one of the most important details.

Mist eliminator velocity should be based on actual volumetric flow at operating conditions.

If one datasheet uses Nm³/h directly while another converts to actual m³/h, the calculated velocity can differ substantially.

The table may still show the same unit label.

Flow basis must therefore be explicit.

Look Beyond “Efficiency: 99%”

An efficiency percentage without context is incomplete.

Ask:

• 99% of what droplet size?
• At what gas velocity?
• At what liquid loading?
• Under what test conditions?

“99% efficiency” and “99% removal for droplets ≥10 μm under stated conditions” are very different levels of technical information.

The second is much more useful.

A strong datasheet should define the performance basis.

Check Whether Pressure Drop Is Dry or Wet

A clean dry separator has one pressure drop.

A wetted operating separator can have another.

If one supplier gives dry-shop resistance and another provides expected wet operating pressure drop, the two values cannot be compared directly.

The datasheet should ideally indicate:

• condition;
• gas velocity;
• separator geometry.

A suspiciously low pressure-drop number may simply use a different basis.

Confirm Active Mesh Thickness

Datasheets sometimes state:

“Demister thickness: 150 mm.”

But is that:

• active mesh thickness;
• total assembly height including grids?

This distinction matters in both process performance and physical installation.

A supplier quoting 150 mm active mesh plus support grids is not necessarily offering the same separator as another supplier quoting 150 mm overall assembly height.

The scope should be clarified.

Mesh Density Does Not Define the Complete Mesh

For wire mesh demisters, compare:

• wire diameter;
• density;
• specific surface area;
• void fraction

where available.

Two pads with the same density may not have the same internal geometry.

If the quotation provides only kg/m³, do not assume hydraulic equivalence.

This becomes especially important for replacement projects.

Vane Packs Need Profile Information

For vane separators, outside dimensions are not enough.

Review:

• blade spacing;
• profile depth;
• number of turns;
• hooks or pockets;
• flow direction.

Two vane packs can have the same:

• length;
• width;
• material

while producing different separation efficiency and pressure drop.

The blade profile is part of the product specification.

Material Grade Must Be Exact

A quotation stating only:

“stainless steel”

is incomplete for many projects.

Confirm whether the material is:

• SS304;
• SS316L;
• another alloy.

For plastics, confirm:

• PP;
• PVDF;
• another polymer.

Also check whether the stated material applies to:

• active separator;
• frames;
• grids;
• fasteners.

A corrosion-resistant mesh mounted on lower-grade supports may not provide equivalent service life.

Check the Scope of Support Components

One supplier may quote:

• mesh pad only.

Another may include:

• lower grid;
• upper hold-down;
• frame;
• clips.

The total price is therefore not directly comparable.

Datasheets and quotations should define the supply boundary clearly.

This prevents surprises during installation.

Segmentation Should Be Included

For large separators, check:

• number of sections;
• maximum segment size;
• manway compatibility.

A lower-cost quotation may assume fewer large sections that cannot actually enter the vessel.

The practical installation design belongs in technical evaluation.

Be Careful With “Maximum Gas Velocity”

A datasheet may list a maximum velocity.

Ask for the basis.

The actual acceptable velocity depends on:

• gas density;
• liquid density;
• liquid loading;
• geometry;
• re-entrainment criterion.

A universal-looking maximum value should not be applied blindly to every process.

Review the Missing Information

Missing fields can be as important as the values provided.

If the datasheet does not mention:

• liquid loading;
• droplet-size basis;
• fouling;
• gas density,

then performance may not have been evaluated against the complete process duty.

The best technical quotation is not necessarily the one with the longest table.

It is the one that connects the product specification to the actual operating conditions.

Build a Comparison on Equal Basis

A useful comparison table should align:

• process inputs;
• separator type;
• active area;
• material;
• internal geometry;
• thickness;
• expected DP;
• performance basis;
• support scope;
• segmentation;
• delivery scope.

Only then should price be compared.

This avoids selecting the lowest-cost product that actually represents a smaller technical scope.

Final Engineering Perspective

Mist eliminator datasheets contain many apparently precise numbers.

Those numbers are useful only when their assumptions are understood.

Efficiency, pressure drop, maximum velocity, density, thickness, and material should all be evaluated on the same engineering basis.

A reliable comparison asks:

“Are these two suppliers actually quoting the same duty and scope?”

before asking:

“Which number is lower?”