Tech Tip

Compressor Oil Purification

Compressed Air

Compressed air is often referred to as the “fourth utility”.  Just like electricity, water and natural gas, compressed air is critical to most all industrial facilities and manufacturing operations. The most widely employed type of air compressor used today is the oil-flooded rotary screw style. It is favored due to its lower initial capital cost, availability and ease of installation and operation. 

What are the issues with a rotary screw air compressor?

The total annual cost of operation of a rotary screw air compressor (energy cost, maintenance cost, labor and waste disposal) will typically exceed the initial cost of the air compressor itself.

Fluid contamination is the number one source of maintenance expenses involved in keeping a rotary screw air compressor up and running.  Contamination reduces the service life of the oil and all components it contacts causing accelerated wear, corrosion and fouling. Due to the design of rotary screw air compressors, they continually ingest solid and vapor contaminants, forcing these contaminants directly into the oil.  Inside the compressor, these contaminants chemically react with the oil, causing oxidation, producing acids and permanently changing the oil’s physical, chemical and performance properties.  The most destructive contaminants are the acids and ultra-fine or clearance-size solids that are not removed by the compressor’s standard, full-low oil filters. These contaminants continuously accumulate in the oil, deteriorating the oil’s ability to lubricate, cool and protect expensive compressor internals. The end result is wasted energy consumption stemming from higher pressure drops, increased maintenance and repair time, more compressor downtime and increased waste oil handling and disposal.

How Do We Solve These Issues?

The Compressor Oil Purifier (COP) is specifically designed for oil-flooded rotary screw air compressors. The COP is a proactive control system that combines proven ion exchange acid adsorption and ultra-fine filtration technologies to remove harmful acids and clearance-size solids that accumulate in compressor oils.

The COP is a dual-core cartridge that combines both mechanical and chemical separation technologies. As a small slip-stream of contaminated oil flows through the purifier’s cartridge, ultra-fine clearance-sized solids are removed down to three microns absolute. The pre-filtered oil then passes through the ion exchange media bed which adsorbs and neutralizes both weak and strong acids present in the oil.  By continuously removing these harmful contaminants, the purifier helps maintain the oil’s original physical, chemical and performance properties. The COP is suited for most synthetic compressor fluids including PAGs, PAOs, hydro-treated hydrocarbons and ester-based fluids.

Benefits of the Compressor Oil Purifier

Extended Oil Life:   The COP extends compressor fluid life up to five times the manufacturer’s rated oil life and reduces oil purchases by as much as 80%.

Extending Separator Life:  The COP extends compressor separator life up to three time the manufacturer’s rated life and reduces separator purchases by as much as 60%.

Reduced Energy Consumption:  The COP decreases compressor energy consumption by as much as 3% by reducing the fouling and energy-robbing pressure drop of compressor separators.

Reduced Maintenance Labor:   The COP reduces routine maintenance labor costs by as much as 50% by extending compressor fluid and separator change intervals.

Extended Airend Bearing Life:   The COP reduces the number of ultra-fine solids less than 15 microns by as much as 97%. Studies by SKF Bearing illustrate that by improving lubricant filtration from the standard compressor’s oil filter performance of 25 microns absolute down to three microns absolute, performance of the purifier can extend bearing life by a factor of four.

Reduced Waste Oil Handling and Disposal:  The COP lowers oil handling and disposal costs and reduces environmental impact by reducing the generated volume of hazardous waste oil and filters.

Note:  “Tech Tips” offered by Flodraulic Group or its companies are presented as a convenience to those who may wish to use them and are not presented as an alternative to formal fluid power education or professional system design assistance.

Experts in fluid power, electrical and mechanical technologies.