We all know that many food industries use oil-free air compressors, but for many food companies, they still don’t know why they should choose oil-free air compressors. Here are some introductions on why the food industry should choose oil-free air compressors.
1. Compressed air used in food production is divided into 3 categories
Direct contact: that is, "compressed air is used as part of production and processing", compressed air that is in direct contact with food or ingredients.
For example: mixing food raw materials, conveying, fermenting, cooling, and spraying of powdered raw materials all require completely pure compressed air.
Indirect contact: gas that does not directly contact food and is used in packaging, transportation, storage and other processes.
For example: using compressed air to blow PET bottles or prepare and open bags before pouring food; used to control the use of valves and brakes in filling, packaging and bottling automated production lines.
Non-contact: There are also a small number of compressed air that does not need to contact food, and there are different quality requirements according to its use scenario.
For example: instrument air, some pneumatic equipment, and component air.
2. Compressed air standards for food production
For compressed air with direct or indirect contact, ISO 8573 proposes corresponding quality standards, stipulating that its pollutant content and particle size should be less than 1mg/m3, 1μm, oil mist content should be less than 0.01mg/m3, and pressure dew point should be less than -40℃td, that is, oil-free, dust-free and water-free standards.
If water impurities are not properly handled, they will enter the food raw materials and cause chemical reactions, causing harm to consumers and ultimately causing unnecessary losses to the company.
However, the compressed air used by most domestic food factories is dust-free and oil-free, but it is difficult to be water-free.
Excessive moisture (pressure dew point higher than -26°C) is often accompanied by the growth of rust and bacteria in the pipeline, which will pollute the food raw materials and increase the defect rate.
Therefore, when choosing an air compressor, in order to ensure product quality, many food companies choose oil-free air compressors; then the filter should generally choose 3-4 levels of filtration to ensure sufficient isolation of solid impurities and oil; finally, when choosing a dryer, in order to achieve a pressure dew point below -40℃td, a core adsorption dryer must be configured. If the inlet temperature is too high, it is sometimes necessary to use a refrigerated dryer or a cold dry filter.