INTRODUCTION
Utilities serve as the fundamental components for creating products and facilitating operations. The quality and management of these utilities – which include process, service, and product water, as well as air, gas and steam - have a significant impact on overall process efficiency and cost-effectiveness. Parker’s range of filtration and purification technologies can help manufacturers achieve the right quality for the intended use of their utility fluids ensuring a smooth, contamination-free process.
COMPRESSED AIR CONTAMINATION AND ITS SOURCES
For over 100 years, compressed air has been recognized as a safe and reliable power source and is widely used throughout industry. Known as the 4th utility, around 90% of all manufacturing companies use compressed air in some aspect of their operations.
Unlike other utilities such as gas, water and electricity which is supplied to site by a utility supplier and to strict tolerances and quality specifications, compressed air is generated on-site. The quality of the compressed air and the cost of producing this powerful utility is therefore the responsibility of the user.
Unknown to many compressed air users, the compressed air system contains a large array of both visible and invisible contamination which can significantly contribute to the performance and reliability of the compressed air system as well as various manufacturing quality concerns.
To provide clean, dry, oil-free compressed air there are a minimum of TEN contaminants originating from FOUR different sources that must be treated.
CONTAMINANTS IN DETAIL
Microorganisms
Ambient air can contain up to 100 million microorganisms per cubic metre. Due to their small size, bacteria, viruses, fungi, yeasts, moulds and spores will pass through the intake filter and into the compressed air system. Tests carried out by the Danish Technological Institute proved that microorganisms can survive in compressed air systems up to 400 bar, where the warm moist environment inside the air receiver and distribution piping provides an ideal environment for their rapid growth.
Water Vapour
Water enters the compressed air system as a vapour (gas). The ability of air to hold water vapour is dependent upon its pressure and its temperature. The higher the temperature, the more water vapour that can be held by the air, the higher the pressure, a greater amount of water vapour is squeezed out.
As ambient air is compressed, the temperature of the air increases significantly allowing the heated air to easily retain all of the water vapour entering the compressor.
Oil Vapour
Vehicle emissions and inefficient industrial processes lead to oil vapour contamination in the ambient air. Typical concentrations in ambient air can seem low but values measured in compressed air increase significantly when contaminants become concentrated. Once in a compressed air system, oil vapour can taint ingredients, finished products and packaging with an oily smell. Cooling also causes oil vapour to condense into liquid oil and form oil aerosols.
Atmospheric Particulate
Ambient air in industrial and urban environments will typically contain between 140 and 150 million dirt particles in every cubic metre. As 80% of these particles are less than 2 microns in size, they are therefore too small to be captured by the compressor air intake filter and will travel unrestricted into the compressed air system.
Once in the compressed air system, many of the hazards found in ambient air change phase, leading to the creation of additional contaminants. The air compressor, air receiver and distribution also add to the problem.
Liquid Water and Water Aerosols
After compression, compressed air is cooled to a usable temperature by an aftercooler. This cooling reduces the air’s ability to retain water vapour, resulting in condensation of water vapour into liquid water. The presence of liquid water also causes aerosols to be formed.
Aftercoolers typically incorporate a water separator to reduce the amount of liquid entering the compressed air system (these do not remove 100% of the condensed liquid and have no effect on aerosols).
The air leaving the aftercooler and entering the compressed air system is now 100% saturated with water vapour. Any further cooling of the compressed air will result in more water vapour condensing into liquid water and the generation of more aerosols.
Condensation occurs at various stages throughout the system as the air is cooled further by the air receiver, the distribution piping and the expansion of air in valves, cylinders and production equipment.
Liquid Oil and Oil Aerosols
As with water, oil vapour drawn in with the ambient air is cooled and condensed within the after-cooler leading to the formation of liquid oil and oil aerosols (even with oil-free compressors) which carry downstream.
The majority of air compressors in use today use oil in their compression stage for sealing, lubrication and cooling. Even though the oil is in direct contact with the air as it is compressed, due to the efficiency of modern air/oil separators built into the compressor, only a small proportion of this lubricating oil is carried over into the compressed air system as a liquid or aerosol (typically no more than 5mg/m³ for a well-maintained screw compressor) or as oil vapour.
Rust and Pipescale
Rust and pipescale can be directly attributed to the presence of water in the compressed air system and is usually found in air receivers and distribution piping. Over time, the rust and pipescale breaks away to cause damage or blockage in production equipment which can also contaminate final product and processes. Rust and pipescale problems often increase for a period of time after the installation of dryers into older piping systems which were previously operated with inadequate or no purification equipment.
ISO 8573-1:2010
ISO8573-1 is the primary document used from the nine parts of the ISO8573 standard. Importantly, ISO8573-1 contains air purity classification tables which can be used in one of three ways.
1.Compressed air users can use the air purity classifications it contains to specify the amount of contamination allowed in each cubic metre of compressed air
2. Compressed air purification equipment manufacturers can use the air purity classifications to specify the purity (quality) of compressed air delivered downstream of their purification equipment
3. It can be used to classify the purity (quality) of compressed air at a specific point in the compressed air system (based upon the contaminants found following testing at that sample point)
ISO8573-1 Air Purity Classifications Tables
It should be noted that within the ISO8573-1 standard document there are three individual classification tables, one for solid particulate, one for water and one for total oil. However, for many years the compressed air industry (compressor manufacturers and air treatment manufacturers) have combined the three tables into a single table for ease of use (see below).
Reference Materials:
FOOD AND BEVERAGE GRADE COMPRESSED AIR
In a food manufacturing facility, compressed air is used in a wide range of applications often coming into direct or indirect contact with production equipment, ingredients and finished product.
However, untreated compressed air contains harmful contaminants that may affect consumer safety. To ensure a safe and cost-effective production facility, it’s crucial to reduce these contaminants to acceptable levels.
Learn more about Food Grade Compressed AirCONTAMINATION REMOVAL TECHNOLOGIES
Ensuring effective control of compressed air contamination requires a number of purification technologies. The table below highlights the individual filtration and drying technologies that are required to treat each contaminant.
Liquid separators
Liquid separators reduce the content of all liquids at the point of installation. Liquid in a compressed air system is usually a mixture of oil and water (even when using an oil free compressor).
Recommended products:
Coalescing filters
A purification system will normally consist of two coalescing filters installed in series to remove water aerosols, oil aerosols, atmospheric particulate, microorganisms, rust and pipescale.
Recommended products:
FBP Treatment Systems Food / Beverage / Pharmaceutical Grade Compressed Air
Parker FBP treatment systems are supplied as a complete purification solution, designed to meet and exceed the compressed air purity requirements for Direct Contact and In-direct Contact applications within the food, beverage and pharmaceutical industries.
Recommended products:
Adsorption filters
To ensure ‘technically oil free’ compressed air, adsorption filters are employed. These utilise a large bed of activated carbon adsorbent for the effective reduction of oil vapour.
Recommended products:
Dry particulate filters
Dry particulate filters provide identical particulate reduction performance to the equivalent grade coalescing filter. Relying on mechanical filtration techniques, high efficiency dry particulate filters can provide particle reduction down to 0.01 micron with a removal efficiency of 99.9999%.
Recommended products:
Sterile filters
Absolute (100%) removal of solid particulates and microorganisms is performed by a sieve retention or membrane filter. They are often referred to as sterile air filters as they also provide sterilised compressed air.
Recommended products:
NITROGEN
NITROSource PSA and NITROSource Compact nitrogen gas generators from Parker produce a totally on-demand nitrogen gas supply from a standard factory compressed air supply; a safe and reliable alternative to delivered gas options. The compact and lightweight modular design provides a consistent and easy to maintain solution for small, medium and large flow rate on-site gas requirements.
When maintained in-line with Parker’s recommendations, NITROSource nitrogen generators will offer in excess of 10 years’ service life from the Carbon Molecular Sieve (CMS), the material that is used to separate nitrogen from compressed air.
The NITROSource range has been designed to meet multiple industry compliance including CU TR (EAC), CE, UL, CRN and has third party verified FDA Article 21 and European Food and Pharmaceutical approval. NITROSource is also exempt from annual PED pressure vessel inspection resulting in minimum disruption to production.
NITROSource generators are the ideal replacement to delivered nitrogen gas, eliminating the issues of administration, logistics and the potential risk of running out of gas associated with high pressure cylinders, liquid mini tanks or bulk storage vessels.
Related products:
CO2
PCO2 Carbon Dioxide Quality Incident Protection Systems from Parker offer a comprehensive solution to preserve and guarantee the quality of gaseous carbon dioxide used in sparkling beverage bottling.
Using multi-layer adsorbant technology, the PCO2 range is suitable for flow rates between 181 to 4354 Kg/h @ 24 bar g (400 to 9600 Lb/h @ 350 psi g) for plant scale protection.
Operating as a quality incident protection, removing a wide range of potential carbon dioxide impurities, the system guarantees the gas quality so it remains within industry and company guidelines, preventing detrimental consequences to the finished end beverage, producers reputation and their bottom-line.
Approved and recommended by the major global brand leaders, the Parker PCO2 is the beverage industry preferred choice and is installed in over 150 countries worldwide.
Find detailed information on quality incident protection in beverage processing hereRelated product:
STEAM
Steam filtration is often neglected or regarded as an add on to liquid or gas filtration application. It is, however, a specific application and should be treated with the same level of importance as air, gas and liquid systems if longer filter lifetimes and overall system cost-effectiveness are to be achieved.
Process vs “culinary grade” steam
Process steam, such as that used for general heating, steam jackets and bio waste kill systems, does not come into direct contact with the product being manufactured. Conversely, culinary grade steam is used in direct contact with food or food processing equipment and as such, must comply with 3A standard 609-03.
Parker’s range of pleated and sintered steam filters are designed to provide high quality particulate removal in process steam and are also available in 1 micron with compliance to 3A standard 609-03 for culinary applications. The robust, all welded 316L stainless steel construction offers long service life under extreme conditions for reduced operational costs.
Related product:
PROCESS COOLING
Process cooling is applied when an accurate and constant control of temperature within a process is required. Precision water chillers are commonly used due to their ability to provide cooling capacity regardless of changes to the ambient temperature, heat load and flow requirements of the application.
What is process cooling
In its most simplistic form, process cooling can be defined as follows:
- Process Cooling is the removal of unwanted heat from a process.
- Removal of the unwanted heat is often necessary to ensure the process continues in a safe, efficient & reliable manner.
Why process cooling?
In many industrial processes the heat load must be carefully managed. Different aspects of the overall application may require cooling.
Key cooling areas are as follows:
Direct cooling of a product
- Plastic during the moulding process
- Metal products during machining
Cooling a specific process
- Fermentation of beer & lager
- Chemical reaction vessels
Machine Cooling
- Hydraulic circuit & gearbox cooling
- Welding and laser cutting machinery
- Treatment ovens
WHY WATER CHILLERS FOR PROCESS COOLING?
Precision water chillers can be integrated with ease into most applications. The water chiller utilizes a refrigeration circuit to remove the heat load passed onto the cooling fluid (water or glycol mix) returning from the application.
The ability of a precision water chiller to operate across a range of ambient conditions at variable loads make them ideal for delivering efficient process cooling.
Advantages of using water chillers for process cooling include the following:
- Improve the efficiency of a process
- Enhance the quality of the finished product
- Prevent product spoilage caused by over heating
- Increase the speed of production (reduce cooling lag time/prevent over heating)
- Reduce wear and damage to machinery/reduce maintenance costs
- Improved process safety
Maintain constant and precise control of the process temperature
Cooling fluid can be delivered direct to the application heat source
Cooling is independent of the ambient conditions
Minimise potential contamination of the process through closed loop water circuit
Cooling fluid is recirculated reducing waste and cost
Modular design offering expansion options
High heat exchange capacity
Water is a readily available & low-cost resource in most industries
Potential to integrate into existing free cooling systems
WATER
Maintaining the necessary quality of water required for use throughout a manufacturing site is crucial for ensuring both operational continuity and consistent product quality. Parker clarification filters protect manufacturing and water treatment equipment from damage due to high levels of particulate present in ground/municipal source feed water while membrane filters remove waterborne spoilage organisms and pathogens.