April 2019

Focus on: Compressed Air Process, Controls & Plant April 2019 www.pwemag.co.uk Plant & Works Engineering | 25 compressors require the same level of careful filtration as lubricated compressors to remain compliant and avoid significant downtime as well as waste. This negates the argument of lower overall cost of ownership. Typically, the purchase price of an oil-free compressor is 45 to 50% higher than that of an equivalent lubricated compressor. Maintenance of the air end is generally more frequent than lubricated equivalents, and in some models, complete replacement of the air end is required after only a short number of years, which actually increases the overall cost of ownership significantly. It is also worth noting that the higher the quality of the compressed air, the higher the cost of producing it. We often find factories using oil-free compressors to provide all of their air requirements, when actually only a small part of their process requires such high levels of purity. This requirement could be addressed by point of use filtration, or if absolutely required, a smaller local point of use oil-free compressor with filtration. Efficient alternatives Advances in oil filtration technology mean that lubricated compressors can sufficiently meet stringent air purity standards - as well as provide a more functional and cost-effective choice. Lubricated, rotary vane compressors are exceptionally durable and around 15% more energy efficient. Typically, oil-free machines will absorb more power than oil-lubricated compressors, making the latter more economical to operate. This is because oil retains heat during compression, which increases performance efficiency. Oil acts as a coolant, and in a lubricated compressor it removes around 80% of the heat produced during air compression. The myth we often hear is that if you don’t use oil you will be more environmentally friendly, but this is more than negated by the higher energy consumption required to run an oil free compressor compared to an oil-lubricated compressor. Despite the market for oil-free compressors continuing to expand, in many cases a compressed air system combining lubricated vane compressors with high quality dryers and filters offers the best value and performance. The myths surrounding oil-free compressors have created an inflated market when filtration will often suffice. For further information please visit: www.mattei.co.uk tion iltra ter f oil/wa the art of Tru - lasts longer • es mor v remo • market, many There are man e Blue extends filter life by 20% oil content to below 10ppm ev - will remo e of them blue. But only one can do this... te solutions on the ter condensa y oil/wa te Unit Sepura Condensa inlets to your nnect up to 8 a™ NEW from Sepur e: sales@mfeuk.co.uk 01978 855995 t: be purchased from our sole UK distributor only can products ™ Genuine Sepura t makes all of this happe tion media tha iltra f tors contain the superio separa a Only Sepur OEM products. - 3rd party service kits that out-perf e cost effectiv • Co n. r Silexa™ orm genuine