CBN Grinding

Background

This global manufacturer produces a range of automotive valves and had been using external scrubbing units to pull the oil mist smoke from the various CBN grinding machines, and then discharging outside.

The low efficiency of this method resulted in environmental damage externally and created further problems internally with high levels of oil mist and smoke, drawing accompanying complaints from the workforce.

Problem

Due to the sheer number of CBN grinders and the quantity of oil mist and smoke being created (in excess of 200 mg/m³), the external scrubbing filtration units simply could not cope. Overloaded with oil mist, the scrubbing system continued to spill smoke and mist internally, and cause ecological damage externally.

Solution

Vokes Air engineers were asked to provide a long-lasting solution to resolve the problems. A full ScandMist survey was conducted, and accompanying report and recommendations produced.

One ScandMist MA 350R unit was installed along with a separate prefilter, connected by ducting to three CBN grinders. The ScandMist unit would discharge back into the facility.

Outcome

Post-installation testing showed that the Scandmist MA 350R and prefilter combination worked exceptionally well:

• Inlet concentrations of 200 - 250 mg/m³
• Discharge readings of 0.000 - 0.010 mg/m³
• External air readings of 0.020 - 0.030 mg/m³

Several more Scandmist MA 350R units and prefilters have since been installed, reducing the strain on the external scrubber filtration system and eliminating the enviromental damage. The internal air quality has also vastly improved.

Moreover, the oil retained by the ScandMist units is now returned directly to the oil sump reservoirs for reuse, instead of been discharged to outside enviroment.