Compressed clean air for the food industry

Safety and hygiene are essential prerequisites for the food industry, from small artisanal workshops to large processing plants.

The food industry needs to manage quality very carefully to ensure that strict standards are adhered to at every stage of the production process.

A very important but often underestimated source of contamination is compressed air. A plant in which compressed air is not adequately treated may contain harmful or dangerous contaminants, which must be eliminated in order to protect the products, processes, plants, and—above all—the consumer.

During processing, compressed air comes into direct contact with the food when it is used as an integral part of the process for:

  • moving/positioning food
  • transporting food powders ordense fluids
  • forming aerosols
  • mechanical mixing
  • selecting materials
Compressed air for the food industry

These contaminants, which are usually grouped into the three families described in ISO 8573-1:2010 (dust, water, oil), can cause serious problems for the plants and equipment, which always entail significantly lower efficiency and higher production costs:

  • Corrosion and rusting of the tanks and distribution system
  • Blockages in and damage to valves, tools and machinery
  • Bad smells and unhealthy working environments
  • Oil condensates that are difficult and expensive to dispose of
  • Higher operating costs and plant maintenance costs

There are also serious risks with regard to the food product:

  • Product loss
  • Deterioration of characteristics (flavor, smell, color)
  • Shorter shelf life

Protection is therefore needed on two levels:

  • An adequate treatment system that is the right size to ensure effectiveprotection of products and processes.
  • Constant monitoring of air quality using suitable instruments.
Compressed air meat industry

Legislation on Compressed Air in Food Preparation

With regard to food hygiene and safety, Regulation (EC) 852/2004 clearly states that primary responsibility for food safety rests with the food business operator; it also defines the principles of the Hazard Analysis and Critical Control Points (HACCP) system.

Unlike in breathable or medical-grade air applications, however, there are no harmonized standards that establish the minimum acceptable purity levels for compressed air used in the food industry.

To make up for this, companies follow the guidelines issued by the British Compressed Air Society (BCAS) — currently the most authoritative source used as a reference for food-grade compressed air — which distinguish between two use cases in food processing:

  • Direct contact: Quality class 1.2.1 (ISO 8573-1:2010) is required, which necessitates the use of an adsorption dryer, as well as forced filtration for dust and oil.
  • Indirect contact: Quality class 1.4.1 is required, for which a refrigerated dryer is considered sufficient.
Air quality recommendations Impurities (solid particles) Moisture (water vapor) Total oil (aerosols + vapor) ISO 8573-1:2001 equivalent
Direct contact 0.01 µ  - 40°C PDP <0.01 mg/m3 Class 1.2.1
Indirect contact 0.01 µ +3°C PDP <0.01 mg/m3 Class 1.4.1

The possibility of microbiological contamination, by contrast, must be  examined according to a risk assessment based on the HACCP principles depending on the processing concerned.

Possible compressed air contaminants

Solid residues Liquids Gasses
Dirt Microorganisms Liquids Aerosols Vapor Gasses
Dust

Viruses

Oil

Oil

Oil

NO2

Rust

Bacteria

Water

Water

Water

CO

Deposits

Molds

 

 

 

CO2

Carbon residues

Yeasts

 

 

 

SO2

 

Spores

      O2

Various actions must be taken to protect food against the contaminants described, because each type of contaminant can be blocked or limited with devices that use different available technologies.

Contaminant reduction/removal
    Intake air Compressor Distribution system
Filtration technologies Water Dust and particulate Microorganisms Liquid oil and aerosols Oil vapor Rust and salt deposits
Liquid condensate Aerosols Vapor
Condensate separator
x
             
Filters Coalescing  
x
 
x
x
x
 
x
Adsorption (activated carbon)            
x
 
Dust      
x
x
   
x
Sterile/microbiological          
x
   
Dryers Adsorption (activated carbon)    
x
         
Membrane    
x
         
Refrigeration cycle    
x
         

You would like to know more? Download our food brochure now

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