FOOD 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. It can also be used to automate processes, assist packaging of products, and generate modified atmosphere gases on-site.
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.
DIRECT AND IN-DIRECT CONTACT APPLICATIONS
To determine the required air purity specification for each application, each compressed air usage point should be classified as either:
- Direct contact
- In-direct contact
- Non-food contact
Direct contact
Compressed air that directly contacts manufacturing equipment, production surfaces, ingredients, finished product, or packaging materials.
Examples: Sparging, air knives, spraying/coating, conveying, direct cooling, packaging, and drying.
In-direct contact
Compressed air that should not come into contact with manufacturing equipment, production surfaces, ingredients, finished product or packaging materials, but may inadvertently.
Examples: valves, cylinders and pneumatics operating in the manufacturing environment where contaminated exhaust air can then inadvertently contact manufacturing equipment, production surfaces, ingredients, finished product or packaging materials.
Non-food contact
Non-food contact is a recommended specification for compressed air used on a food manufacturing site that does not have the potential to come into direct contact or in-direct contact with manufacturing equipment, ingredients, finished products or packaging.
Examples: workshop air.
COMPRESSED AIR CONTAMINATION
Compressed air contains biological, chemical and physical hazards (referred to as contamination). When it comes to producing food and beverage grade compressed air, all of the ten contaminants identified below must be treated and reduced to acceptable levels.
Some contaminants, however, pose a greater risk than others and require specific attention, these are water and microorganisms.
Water (Liquid / Aerosols / Vapour)
For general industrial manufacturing, the treatment of water vapour to prevent corrosion is the primary concern. If no free water is visible, then the air is considered “dry”. However, for food and beverage grade compressed air, the major concern is around the combination of wet compressed air and how this promotes the growth of microorganisms.
Microorganisms
Ambient air contains viable and non-viable particles. A non-viable particle is a particle that does not contain a living microorganism but acts as transportation for viable particles, a viable particle is a particle that contains one or more living microorganisms. There can be up to 100 million microorganisms per cubic metre of ambient air.
Examples of microorganisms found in ambient air and typical size in microns
Due to their small size, they will pass directly through the compressor panel and intake filters. The warm moist air in the compressed air system provides an ideal environment for the growth of these microorganisms. The air receiver and distribution piping store and distribute their ever-expanding growth.
THE COST OF NON-COMPLIANCE
Poor compressed air quality and failure to control contamination can cause numerous problems for food and beverage manufacturers, many of which are not immediately associated with contaminated compressed air.
01
Product
- Contaminated ingredients
- Contaminated food or beverages
- Contaminated packaging
02
Consumer
- Potentially unwell / seriously ill consumers
03
Manufacturer
- Brand damage
- Legal actions
- Financial loss
- Potential imprisonment
04
Manufacturing Process
- Inefficient production processes
- Reduced production efficiency
- Increased manufacturing costs
- Failed quality audits
05
Compressed Air System
- Growth, storage and distribution of micro-biological contamination
- Corrosion within storage vessels and the distribution system
- Contaminated / damaged production equipment
- Blocked or frozen valves and cylinders
FOOD GRADE COMPRESSED AIR PURITY SPECIFICATIONS
Air purity (quality) is specified using ISO 8573-1, the international standard for compressed air purity. The standard contains classification tables for solid particulate, water and oil that can be used by compressed users to:
- Specify the amount of contamination allowed in each cubic metre of compressed air.
- Specify the purity (quality) of compressed air delivered downstream of their purification equipment.
- Classify the purity (quality) of compressed air at a specific point in the compressed air system.
Parker recommends Class 1:2:1 for direct contact and in-direct contact applications. This specification also directly matches the requirements of the British Compressed Air Society (BCAS) Best Practice Guideline 102-1, Food and Beverage Grade Compressed Air.
Reference Materials:
COMPRESSED AIR TREATMENT TECHNOLOGIES
Ensuring effective control of compressed air contamination requires a number of purification technologies.
COMPRESSED AIR TREATMENT SYSTEM
PARKER COMPRESSED AIR TREATMENT PRODUCTS
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:
FOOD GRADE NITROGEN
Food grade nitrogen is used for multiple applications to increase shelf life. Safety and quality regulations that are in place across the globe ensure a minimum standard of gas to protect human health.
Within Europe, EIGA – the European Industrial Gases Association - is instrumental in providing guidance on industrial gases legislation to the European Commission, which is then made into law by the European Parliament and implemented by member states.
The main food and beverage spoilage mechanisms are:
Oxidation
When fats and oils within food encounter atmospheric oxygen, oxidative rancidity can occur. This results in the food taking on an objectionable and unpleasant taste and/or odour.
Moisture gain
Atmospheric air contains moisture in the form of water vapour or humidity. If packed in ambient conditions, certain dry food products can absorb the moisture from the air trapped in the pack and become soggy and spoilt.
Microorganisms
Bacteria, moulds, and yeasts come under the general description of microorganisms and can be categorized by how their oxygen interaction facilitates metabolic and reproduction processes.
Often nitrogen and carbon dioxide are combined to retard anaerobic spoilage mechanism, with nitrogen used as a filler gas to prevent pack collapse caused by the highly dissolvable nature of CO2.
There are 3 main areas where nitrogen is used in the food production process:
BULK VESSEL BLANKETING
Blanketing is a process that involves the exclusion of ambient air by displacement with nitrogen gas. The introduction of nitrogen to the headspace of food processing and storage tanks - such as edible oil vessels - is a highly effective way of preventing oxidation and protecting against spoilage by yeast and bacteria. Nitrogen can also be used to back fill the void in vessels as the product is discharged.
PRODUCT TRANSFER, BLENDING AND SPARGING
Example of Nitrogen Being Used for Sparging
Nitrogen gas, at pressure, is used to push product through pipework and in doing so, keeps the process inert by excluding ambient air. It is also used to bubble through liquids in a process called “sparging”.
Sparging with nitrogen is a gentle way to “roll” or mix storage tanks. Nitrogen removes oxygen introduced during handling, helping to preserve ingredients. An on-demand nitrogen generator supplies a continuous stream of nitrogen to fill the voids within a package, preserving taste and freshness and extending shelf life.
MODIFIED ATMOSPHERE PACKAGING (MAP)
Most food products start to deteriorate from the moment they are harvested or prepared for packaging, being under attack from a multitude of spoilage mechanisms. By flushing, storing and/or packing with nitrogen, oxygen - that many of these micro-organisms need in order to survive and multiply - is removed and the spoilage process is significantly reduced.
Prepared salads and vegetables, fresh chilled ready meals, meat, poultry, fish, dairy produce (including cheese), breads, coffee as well as snack foods such as potato chips and nuts can all benefit from ‘modified atmosphere packaging’ (or MAP as it is often referred to). By using nitrogen gas from a Parker generator, the product shelf life is increased and the appearance and quite often taste, is also improved.
Typical vertical form fill and sealing (VFFS) machine
Vertical form fill and seal technology is widely used to package dry food products such as potato chips and extruded snack food, nuts, milk powder, coffee, grated cheese and spices. Nitrogen is injected into the bag, via a tube or partitioned section of the hopper, displacing ambient air.
System Installation
MAP gas requirements
TYPICAL NITROGEN SUPPLY METHODS
Obtaining a ready supply of nitrogen gas can be problematic and expensive. Typical gas supply methods include high pressure cylinders, liquid mini tanks or bulk storage vessels. However, each of these options introduces a range of problems that needs to be solved.
A reliable vendor is required, and valuable space on-site needs to be assigned for gas storage. Procedures must be established to monitor and manage the gas supply, and safety and handling concerns must be considered. The cost of addressing these logistical issues can be high and difficult to budget for, while the price of gas and supplier rates change continually. The environmental impact of truck-based deliveries is another important consideration for carbon footprint reduction.
In addition, liquid ‘boil-off’ vents expensive gas into the atmosphere, and approximately 10% of the gas in every cylinder is typically returned to the supplier unused.
PARKER PSA NITROGEN GAS GENERATORS
Parker’s range of modular, compact NITROSource PSA nitrogen generators produce food and beverage grade nitrogen gas from standard factory compressed air at a fraction of the cost.
Compressed ambient air using a standard oil-lubricated compressor between 6-13 barg is typically cleaned and dried to ISO8273-1-2010 class 1.2.1 using a Parker food, beverage and pharmaceutical (FBP) pre-treatment package. The Parker NITROSource PSA or NITROSource Compact nitrogen gas generator utilizes PSA (pressure swing adsorption) and CMS (carbon molecular sieve) technologies to selectively adsorb oxygen from the compressed inlet air.
This produces a constant stream of food and beverage grade nitrogen gas outlet.
Typical NITROSource layout for food and beverage applications
Reference Materials / White Paper:
PROCESS COOLING
The food and beverage industry is the largest manufacturing sector to use chilled water systems. Applications within the industry are very diverse due to the wide range of product types and how they are produced. Applied to most food applications through to packaging, cooling is a way of speeding up the throughput of produce, as it reduces the time from cooking or baking.
Precision cooling is a key factor in meeting some industry standards and ensuring consistently safe production methods are used. In addition to the regulatory requirements, precision cooling is also used to speed up the process, so that manufacturers can reduce lead-times and save money.
Parker Hyperchill and Hyperchill Plus chillers offer a robust and cost-effective solution ideally suited to the exacting cooling demands in this industry.
Related Products:
Reference Materials / White Paper:
COOLING IN THE FOOD PRODUCTION PROCESS
Chillers are prevalent in most types of food production. Broadly speaking, if a food is heated for cooking or baking, then it is likely to require cooling down prior to finishing and packaging. In some instances, it is necessary to cool specific ingredients during the process. In a bakery, the dough is typically mixed with cooled water, as this controls the yeast rising and allows consistency.
Some key methods of cooling product applied during production are as follows:
- Jacketed vessels
- Scraped surface heat exchanger
- Cooling tunnels
- Gasketed plate heat exchangers
Some typical illustrations opposite:
SPECIFIC MACHINE COOLING FOR PACKAGING MACHINES
At the end of production, almost all food and drink needs to be packaged. Most companies install machines specifically designed to pack the produce using an automated system. Some of these machines are manufactured by global OEM companies and others are bespoke systems, designed and installed by specialists in the field.
Irrespective of their origins, most of these machines adopt the same principle whereby they hermetically seal the food within a container to preserve shelf life.
The sealing process uses a heated tool to apply the seal and chilled water to set and free the package from the tool. These machines can sometimes be supplied from a central cooling system, or more commonly, will have a dedicated process chiller located at the point of use.
CENTRALISED COOLING SYSTEMS VS DEDICATED PROCESS CHILLERS
Centralised cooling systems have some benefits but also limitations. If well designed, they can be more efficient than small, single, point-of-use chillers, and combining multiple chillers in a modular system provides a robust solution. Hyperchill units are designed to be installed into a combined modular system, with the ability to add further chillers to increase capacity to customers’ needs.
Individual point-of-use chillers are generally used where numerous applications within a food factory have different operating criteria for water temperature and pressure. Hyperchill and Hyperchill Plus units are designed to be fully configurable to meet the specification of these applications.
POTABLE WATER
Potable water is widely used both as a food ingredient and in food preparation. A town’s mains water supply is inconsistent, with temperature values increasing in summer and decreasing through winter. The solution is to combine a chiller with external heat exchanger and tank, packaged with a control system to deliver a metered volume of water at the specified water temperature.
The system package size is based on batch size, cycle time and water temperature. The chiller water circuit and process potable water circuit must be independent, as food standard regulations do not allow potable water to be directly cooled by a chiller, due to risk of refrigerant contamination. Hyperchill and Hyperchill Plus are ideally suited to potable water packaged systems.
FOOD GRADE STEAM
Culinary steam (3A Standard 609-03)
This is an American standard laid down for the dairy industry and is defined as: “Steam that is free of entrained contaminants, is relatively free of water in liquid form and is suitable for use in direct contact with milk or milk products or product contact surfaces”.
The filtration requirements are applicable to the food and beverage industry as a whole and are being recognized far more outside of the USA. Its growing acceptance is mainly due to a lack of recognized standards for steam outside of the USA.
The Parker range has been specifically developed to target this area.
WHY IS IT NEEDED?
Steam is an often-neglected part of a process, regarded as an add-on to a customer’s liquid or gas filtration needs. It can, however, have large specific applications in its own right. The quality of steam used within the food and dairy industries has been raised higher on the agenda in an ever-increasing number of companies.
Culinary steam is standard across most food plants and is used across a multitude of applications, covering cleaning, and disinfecting of processing equipment with high temperatures, minimizing microbiological risks and cooking, curing, and drying.
Minimum accepted standards are now being quoted on a more regular basis with reference to ‘culinary grade’ steam. There is also a growing tendency to install central steam filtration systems that are of high capacity. This requires a specific design of filter to optimize the flow characteristics of the filter medium.
Our range of steam filters is geared to provide a solution for all applications.
HOW IS IT ACHIEVED
For culinary grade steam, 95% removal of particulate greater than 2µm in size is required. This can be achieved using a Parker 1 micron sintered or pleated stainless steel filter.
Related Products:
DAIRY PROCESSING
Extending shelf-life and ensuring food safety
Dairy plants with their warm, humid environment, provide the ideal conditions, as well as the nutrients, for the proliferation of bacteria which can result in ruined products.
Parker offers a range of filtration and separation technologies with proven sterile performance to protect dairy production and packaging processes from airborne spoilage organisms. Manufacturers can reach distant customers by increasing the shelf life of their product and reducing overall dairy waste from bacterial contamination.
Sterile gas applications in dairy processing include:
ASEPTIC PACKAGING
Aseptic packaging ensures that there is no microbial contamination of dairy products post processing, which fundamentally increases the lifetime of the product and protects against worst-case scenarios such as large-scale product recalls. Sterile air and gas filter cartridges provide an aseptic environment in which dairy products may be packaged to avoid microbial contamination.
TANK VENTING
During storage, dairy products may come into contact with airborne bacteria transmitted via vents on storage tanks. In order to reduce and eliminate the possibility of product contamination, vents on storage tanks can be fitted with sterile filters which inhibit any spoilage organism from entering the tank.
PRODUCT PURGE
During the production process, dairy products can remain in the pipes. This product is often pushed along by ‘flushing’ the pipes with air, forcing the product downstream. The introduction of unfiltered compressed air into the process may introduce micro-organisms into the product. To avoid contamination and maintain food safety, this compressed air can be sterile filtered before use within the production process, maintaining the stability of the final product.
PRODUCT MOBILITY
Sterile gas for product mobility is important at aseptic packaging where product delivery to the packaging process can be via an aseptic IBC. In many cases the IBC is top loaded with compressed gas to provide the motive force to drive through process lines and into the aseptic packaging machinery. To protect from product contamination and spoilage from airborne microorganisms, compressed gas used for product mobility should be sterile filtered close to the point-of-use.
PRODUCT AERATION / FOAMING
Product aeration allows dairies to be creative and innovative with the textures and mouthfeel of mousses, yogurts and cream cheeses. Aeration is being used to produce lighter products with a smooth mouth feel and reduces sugar and fat contents. The compressed air used in the process poses a significant threat of product spoilage through contamination from airborne microorganisms. Parker provides products which can help eliminate this problem.
STERILE GAS FILTRATION TECHNOLOGY
Parker offers a range of sterile gas filters and integrity test solutions to protect dairy processing and packaging from contamination:
HIGH FLOW BIO-X Sterile Gas Filters
Recommended products:
HIGH FLOW TETPOR II Sterilizing Grade Filters
Recommended products:
ASEPT-X Sterilising Grade Filter with Reverse Steaming and Condensate Management
Recommended products:
STERILE GAS FILTER INTEGRITY TESTING
The performance of sterile gas filter systems is critical to a dairy facility’s quality assurance objective of protecting their product from contamination during production and packaging. The ongoing performance of a plant’s sterilizing grade gas filters can be checked by routine integrity testing as part of their HACCP plan. The aerosol challenge test, performed by Parker’s Valairdata 4 provides a number of process advantages by being capable of testing both depth and membrane sterile gas filters in situ, quickly and easily.