Centrifugal vs ElectroStatic Precipitator (ESP) Mist Collectors

They are widely applied for CNC machine oil mist, quenching fumes, commercial kitchen cooking fumes and industrial thermalprocessing oil mist. Overseas customers often need to choose between these two technologies.

Working Principle

Centrifugal mist collector It works on physical mechanical separation. Highspeed rotating impellers generate centrifugal force. Oilmist droplets are thrown onto the inner housing wall, merge into liquid oil and drain down for recovery. No high voltage electric field is involved.

ElectroStatic Precipitator (ESP) Oil mist particles get charged inside a highvoltage electric field and adhere onto collecting plates. Contaminated oil flows down along plates for collection. Separation is achieved by electrostatic adsorption.

Performance & characteristics

Centrifugal mist collector It delivers moderate removal efficiency at 7085%. It handles large oil droplets well but performs poorly on fine 0.52 μm mist particles. Faint white mist may still be visible at exhaust outlets. Power consumption is moderate, driven by rotating motors. Maintenance is straightforward: users only need to clean impellers and housings with no delicate plate assemblies. Mechanical failure rate is low, without highvoltage components. Normal wear mainly occurs on impellers and bearings. Fire risk is minimal thanks to its purely mechanical construction. It creates relatively high pressure drop and produces noticeable noise from spinning impellers. Initial purchase cost is lower. It cannot be used for standalone lowaltitude direct discharge; extra filter stages are usually required downstream.

ESP (ElectroStatic Precipitator) mist collector It achieves high separation efficiency from 85 % to 98 %, handling both fine and coarse oil mist. Exhaust gas is nearly invisible, which permits lowaltitude direct discharge. It consumes less electricity under the same air volume, with power draw mainly from fans and highvoltage power supplies. Regular maintenance is critical. Collecting plates must be dismantled and cleaned periodically. Efficiency drops sharply once plates are covered with sticky oil sludge. Highvoltage power units and insulators are vulnerable to contamination, causing sparking under heavyoil or humid conditions. Accumulated grease may bring potential fire hazard if maintenance is neglected. Pressure drop is low, and unitgenerated noise is slight (noise mostly comes from matching fans). Capital cost is higher. Major spareparts include collecting cells, highvoltage power supplies and insulators.

Suitable application scenarios

Choose centrifugal collectors for these cases:

• CNC workshops with heavyconcentration oil mist and large liquid droplets.
• Sites where frequent thorough cleaning cannot be guaranteed.
• Explosionproof environments where electric spark risks must be eliminated.
• Tightbudget projects with additional secondary filtration arranged downstream.

Choose ESP collectors for these cases:

• Strict emission requirements requiring invisible exhaust and lowaltitude direct discharge.
• Thermal quenching processes and commercial kitchen fume treatment with fine oil mist.
• Facilities where scheduled disassemblyandcleaning can be performed every 730 days.
• Projects with strict environmental assessment standards.

Important notes for export projects

• A standalone centrifugal unit cannot meet lowaltitude directdischarge requirements. White mist may remain at exhaust, so downstream filters are normally necessary. This point shall be clearly communicated to endusers.
• ESP performance will degrade drastically within 36 months without scheduled cleaning. Mandatory maintenance intervals must be stated clearly in operation manuals.
• Centrifugal type is preferred for explosionhazardous locations. Explosionproof modified ESP comes with significant cost increase.
• Sparepart preparation: ESP projects need stock for collecting cells, highvoltage power supplies and insulators; centrifugal units mainly require impellers and bearings.

Combined solution widely adopted in turn key overseas projects

Centrifugal preseparator + downstream ESP finetreatment The centrifugal stage removes most large oil droplets in advance. It reduces contamination load on ESP cells and extends cleaning cycles, balancing high efficiency and service life.

DR. AIRE Oil mist collector comes with CE, RoHS, ASHRAE 52.2-2017 certificates.  We help our clients/agents all over the world to set up business! Contact us for free quote now!

If you have same problem,  please contact DR. AIRE Electrostatic Filter Manufacturer for trouble shooting!