Some machine tool operations require flood coolant. Not only does the liquid remove heat of friction from the tool and the work piece, it also provides lubrication that the cutting of some materials require. For other machining operations, mist coolant removes heat, provides a measure of lubricity, and minimizes (to a degree) the volume of liquid used in a flood coolant application.
Whether you flood or mist liquid right onto a tool cutting metal, some of it’s going airborne. CNC machines are oftentimes equipped with collection systems for coolant mist, and it’s not unusual to see ambient mist collectors installed in machine shops to take care of the mist that escapes individual machines.
These mist collectors play an essential role in these facilities, as there are considerable health risks associated with exposure to these fluids, both oil- and water-based. In the U.S., the National Institutes of Health (NIH) compiles & analyzes risks associated with skin contact & inhalation of metalworking fluids. The National Institute for Occupational Safety and Health (NIOSH) has comprehensive recommendations of limitations on exposure to them. In England, the Health & Safety Executive agency likewise published a document geared toward helping machine shops and their employees work safely with them.
Speaking of NIOSH, they strategize a Hierarchy of Controls that can be applied to most any industrial process:
While mist collectors (Engineering Controls) are reasonably effective (and essential in the large number of applications where metalworking fluids are necessary), there are still a fair amount of applications where liquid coolant CAN be eliminated. For those applications, consider the EXAIR Cold Gun Aircoolant Systems.
Using Vortex Tube technology, EXAIR Cold Guns generate cold air flow from a supply of compressed air, instantly & on demand, with no moving parts to wear or electrical components to burn out. They’re safe, quiet, effective, and install in minutes, using a built-in bar magnet and 1/4 NPT compressed air connection.
We know we can’t replace liquid coolant in every machining application, but if you’d like to explore elimination of it in your processes, give me a call.
Russ Bowman, CCASS