Why Does a Mist Eliminator Fail? Common Causes and Engineering Solutions

Why Does a Mist Eliminator Fail? Common Causes and Engineering Solutions

Introduction

A mist eliminator is designed to remove liquid droplets from gas streams and prevent liquid carryover from industrial towers.

However, some systems experience poor mist removal performance even when a demister has been installed.

Mist eliminator failure is usually caused by incorrect selection, improper installation, unsuitable operating conditions or material problems.

Understanding the causes of failure helps engineers improve gas-liquid separation performance and avoid repeated maintenance.

DAIER Separation provides wire mesh mist eliminators, vane mist eliminators and customized gas-liquid separation solutions for industrial applications.

How Does a Mist Eliminator Work?

A mist eliminator separates liquid droplets from gas flow through:

• Inertial collision

• Droplet coalescence

• Gravity drainage

Gas passes through the separator while liquid droplets are captured and returned to the tower.

The performance depends on:

• Droplet size

• Gas velocity

• Separator design

• Material selection

Common Causes of Mist Eliminator Failure

1. Gas Velocity Is Too High

Problem

When gas velocity exceeds the design limit, captured droplets may be carried away again.

This phenomenon is called:

Liquid re-entrainment

Effects

High gas velocity may cause:

• Increased outlet mist concentration

• Liquid carryover

• Reduced separation efficiency

Solution

Check:

• Gas flow rate

• Operating conditions

• Mist eliminator design capacity

Select a suitable separator based on actual hydraulic conditions.

2. Incorrect Mist Eliminator Type Selection

Different applications require different designs.

Wire Mesh Mist Eliminator

Suitable for:

• Fine droplets

• Cleaner gas streams

• High efficiency requirements

Vane Mist Eliminator

Suitable for:

• Large droplets

• High gas capacity

• Fouling conditions

Using the wrong type may result in poor performance.

3. Fouling and Blockage

Causes

Mist eliminators may become blocked by:

• Dust

• Solids

• Crystals

• Corrosion products

Effects

Fouling can cause:

• Increased pressure drop

• Reduced gas flow

• Lower separation efficiency

Solutions

Possible solutions:

• Select open-structure vane separators

• Improve upstream filtration

• Schedule regular inspection

4. Material Corrosion

Mist eliminators often operate in aggressive environments.

Possible causes:

• Acid gases

• High temperature

• Chemical attack

Effects

Corrosion may cause:

• Mesh damage

• Structural failure

• Reduced service life

Solution

Select suitable materials:

• SS316L

• PP

• PTFE

• Special alloys

5. Improper Installation

Installation problems can affect performance.

Common issues:

• Incorrect orientation

• Poor sealing

• Insufficient support

• Damaged sections

Solution

Confirm:

• Installation direction

• Support structure

• Segment connection

• Tower internal dimensions

6. Wrong Droplet Size Assumption

Mist eliminators are designed according to droplet characteristics.

If actual droplets are different from design assumptions:

• Efficiency may decrease

• Carryover may increase

How to Troubleshoot Mist Eliminator Problems?

Engineers should check:

Operating Data

• Gas flow rate

• Temperature

• Pressure

• Liquid loading

Equipment Condition

• Separator condition

• Fouling level

• Corrosion status

• Installation condition

Process Changes

Check whether:

• Gas load increased

• Liquid circulation changed

• Process composition changed

Information Required for Mist Eliminator Evaluation

Provide:

• Tower diameter

• Gas flow rate

• Gas composition

• Droplet size

• Operating temperature

• Operating pressure

• Mist eliminator type

• Material requirement

• Current performance issue

Conclusion

Mist eliminator failure is usually related to selection, operating conditions, fouling or installation problems.

A successful gas-liquid separation system requires matching the mist eliminator design with actual process conditions.

DAIER Separation provides engineering support and customized mist eliminator solutions for scrubbers, absorption towers and industrial separation equipment.

Related Products

• Wire Mesh Mist Eliminator

• Vane Mist Eliminator

• Plastic Mist Eliminator

• Tower Internals

• Gas Liquid Separator