There are two major environmental factors that may impact oil-free air: ambient air and the temperature of the ambient air.
Ambient Air
Ambient air has been shown to contain very small traces of oil from vehicles and other industrial sources. Tests performed by the Technische Überwachungs Verein (TÜV), an independent, international organization specializing in evaluating the safety and quality of technology and recognized worldwide for its independence, neutrality, professional expertise and strict standards, revealed that even in contaminated areas, oil content does not normally exceed 0.003 mg/m3.
When this oil is aspirated by an ISO 8573-1 CLASS 0 oil-free air compressor, the extremely low level of atmospheric oil is almost completely washed away by the condensate, which is normally discharged externally through the compressor’s condensate drains – an integral part of the intercooler and after-cooler assembly. This process results in relatively pure oil-free air. If a process requires further purity, then additional filtration can be applied, but is seldom required.
Ambient Temperature
Ambient temperature can have a profound effect on filter efficiency and the purity of air. When using oil-injected air compressors with oil removal filters, oil carryover through filter media increases exponentially according to the temperature at the filtration interface.
Filter performance is often specified at 68°F (20°C). If the ambient temperature in the compressor room increases to 86°F (30°C) – based on a standard after-cooler approach temperature – the compressor outlet temperature could be 104°F (40°C) and the oil carryover could be as much as 20 times the specified value. Such temperatures are not unusual even during cooler times of the year where the compressor room temperature can be substantially higher than other areas within that same facility.
Increased temperatures also increase the vapor content of the air, which can carry through to the end product. Moreover, high temperatures shorten the lifetime of in-line compressed air filters. For example, an increase in temperature from 68°F to 104°F can reduce an activated carbon filter’s lifetime by up to 90 percent. Even worse, the activated carbon filter does not warn the user when it is saturated. It will simply allow oil to pass through to the product or process.
Protect Your Product/Process from Environmental Influences
The air quality of Atlas Copco’s oil-free air compressors is relatively independent of temperature and its inherent design helps combat even the smallest traces of most impurities ingested from the ambient air. For these reasons, manufacturers in critical applications industries choose ISO 8573-1 Class Zero oil-free compressors that provide clean, 100 percent oil-free air. ISO 8573-1 standards define air quality levels and methods for determining contaminants in the air system. Class Zero is the industry standard for processes that require 100 percent oil-free air.
Learn more about Atlas Copco’s oil-free air compressors, or fill out our request a quote form and an Atlas Copco representative will be in touch with you shortly.
