Maintaining high compressed air quality is important for the reputation and operation of your business. Not only does it impact your end product, but also pertains to the performance of your air compressor.
Using contaminated air can lead to health issues, and cause system shutdowns. This article covers various topics you'll come across when exploring air quality, including air purity classes, filter types, and dryers.
Read on below to learn more about how to improve air quality for your industry and application.
When evaluating air compressors, you'll come across the ISO 8573-1 standard. With this standard, the International Organization for Standardization (ISO) determines air purity for three types of possible contamination: oil, water, and particles.
These ratings are ranked into 10 classes, from 0-9. Class 0 is the cleanest and is only given to oil-free air compressors. For water content, class 1 has to have a dew point of -70 °C, while class 9 can contain between 5-10 g/m3 of water/water vapor.
Each class correlates with an application. For example, class 0 applies to sensitive industries like food and pharmaceutical/medical. It's important you meet your correlating ISO class to avoid quality control issues, and ensure your end product doesn't impact your customers.
In most cases, you'll need external equipment to reach the appropriate class level, including filters, dryers, and separators.
There are two types of filters you'll encounter, coalescent and particulate. A coalescent filter removes both oil vapor and dust, making them a good choice for oil-injected air compressors.
If you're only concerned with dry materials, a particulate filter is suitable for removing solid particles. However, it's worth mentioning that removing all traces of oil is recommended.
Our filters have deep plated hydrophobic & oleophobic media, along with a pleated element for high dust retention. You'll find that they're rated by micron size from 0.01 to 5. The smaller the rating, the tinier the particles the filter will collect.
When comparing filters, you'll notice they're evaluated by ISO 8573-1 standards. The latter pertains to the oil concentration upstream of the filter. Ceccato tests at 10 mg/m3.
Air compressor filters are no replacement for dryers for achieving clean, dry air. A proper air compressor setup incorporates various components, and typically includes a dryer to remove unwanted moisture. There's two main dryers you'll encounter, refrigerant and desiccant.
Suitable for most pneumatic applications, refrigerant dryers can achieve a pressure dew point (PDP) of around 4 °C.
You'll find the right PDP level for your application within the relevant ISO 8573-1 class.
These dryers work by first cooling hot compressed air with refrigerant, removing the condensate, and then heating the air back up for use. This occurs through an air-to-heat exchanger.
Refrigerant dryers can be both air-cooled and water-cooled, and come in non-cycling and cycling options. Non-cycling is the cheapest option to buy and means the dryer runs continuously.
As condensate is created, it's important that it's properly drained. There are intelligent drain discharge systems available for some refrigerant compressors. They ensure minimal air is wasted when condensate is removed.
If your ISO 8573-1 class requires a lower PDP, then you'll likely need a desiccant dryer.
Unlike refrigerant dryers, desiccant dryers don't use a cooling method to bring the temperature down. Instead, they attract water vapor with desiccant material, for example silica gel. Since this is finite, it needs to be regenerated for continual use.
The main benefit of a desiccant dryer is they can achieve a PDP of -40 °C or lower. This temperature makes this equipment suitable for extremely sensitive applications like food and medicine.
These machines typically have two towers, one for separating water vapour from air, and one for regenerating the desiccant. To maintain a constant flow, the dryer switches between the towers.
Due to their capabilities, desiccant dryers are more costly than refrigerant dryers. However, as mentioned, they're only needed for particular applications.
We hope this article covers how to improve your air quality and meet ISO standards. As you're exploring our website, and various options, we're here to help point you in the right direction. Feel free to get in touch and our team will create a custom solution for you.