Coalescing Oil Mist Collectors

ALWO coalescing collectors for oil mist and machining-fluid aerosols are designed to capture liquid aerosols generated by metalworking processes such as turning, milling, grinding and other operations using cooling or lubricating fluids.

Contaminated air is extracted directly from the machine enclosure, as close as practical to the point where mist is generated. This limits aerosol dispersion into the production area and may allow part of the separated liquid to be recovered, depending on contamination and process requirements.

How coalescence works

The contaminated air passes through several separation stages. Prefilters retain larger droplets and solid contamination, while coalescing media cause fine liquid droplets to merge into larger drops. The separated liquid then drains by gravity into the collector sump.

Depending on the application, a system may include:

• labyrinth prefilters for coarse droplet separation;
• washable, self-draining metallic coalescing media;
• self-draining glass-fibre media;
• a final HEPA stage where required by the application assessment;
• a drain valve or a system for returning collected liquid.

Local and centralised systems

A local unit can serve one machine and be installed next to or on the enclosure. A centralised system can serve multiple machine tools through an extraction network, collection tank and, where the process permits, a recovered-fluid distribution system.

Options may include filter-condition monitoring, automatic start/stop with the served machine, variable-speed airflow control and automated drainage. Electrostatic filtration is an alternative technology for certain oil-mist applications and is selected separately according to the process.

Selection and maintenance

Aerosol type, airflow, temperature, fluid composition, contaminant concentration and operating schedule determine the required filtration stages. Process compatibility must be verified before any recovered fluid is recirculated. Washable media and consumable filters require inspection and maintenance intervals suited to the actual operating conditions.