Food-grade compressed air delivery solutions

The core goal of the food-grade compressed air delivery plan is one: to make the air in contact with food absolutely clean, free of oil, water and impurities.

Let's talk about where the air is. The use of compressed air in food factories is roughly divided into three levels. The first layer directly touches the food, such as mixing raw materials, fermenting, drying surface moisture, and aerating the package. Once the air in these links carries oil or bacteria, the food will be directly contaminated. The second layer touches the food indirectly, such as washing bottles and cans. Although the air does not touch the food itself, it will touch the container in contact with the food, which is also very demanding. The third layer does not touch the food at all, such as driving the cylinder to push the conveyor belt and controlling the valve switch, which requires relatively low air quality, but there can be no sludge blocking the pipeline.

Another very common use is to transport powdery raw materials, such as flour, sugar and starch, which are pushed in the pipeline by compressed air. If there is oil and water in the air, the raw materials will agglomerate and deteriorate.

What does that complete delivery plan look like. Starting from the air source, an air compressor compresses the air, then enters the air storage tank to buffer the pressure fluctuation, then removes the moisture through drying equipment, filters the oil mist, dust and bacteria layer by layer through multiple filters, and finally sends them to each gas consumption point through food-grade pipelines.

The most critical part of this is the air compressor. Food plants must use oil-free air compressors, and water-lubricated oil-free screw air compressors are currently the mainstream choice. Its working principle is well understood: when the screw inside the machine rotates compressed air, it does not use oil to reduce friction, but water. The water inside lubricates the screw while taking away the heat generated by compression, so there is no oil in the air. Because there is no need to change oil or filter element in the later period, maintenance is much easier. Moreover, the water-lubricated machine has small vibration and low noise during operation, which is more friendly to the workshop environment.

The pipeline is also exquisite. In the food grade transportation scheme, the rear pipe is generally made of stainless steel, the inner wall is smooth and not easy to accumulate dust, and impurities will not be precipitated into the air. The connection mode is quick-connect as far as possible to avoid the pollution risk caused by welding, and the later transformation is also convenient.

The filtration process is usually equipped with multi-stage filtration. First, large particles and moisture are blocked, then activated carbon is used to adsorb peculiar smell, and finally a sterilization filter element is passed to ensure that the air sent to the food is really clean.

To sum up, the idea of the food-grade compressed air transportation scheme is: water-lubricated oil-free screw air compressor ensures that the air is oil-free from the source, then dry and multi-stage filtration is used to remove water and impurities, and finally food-grade stainless steel pipes are used to cleanly deliver it to each gas point. As long as there is a problem in one link in the whole chain, the air quality will be discounted, so every link cannot be saved.