I would like to ask about instrument air compressors, oil-free and low-oil types: what are their advantages and disadvantages in terms of operation, maintenance, and cost efficiency?

1. There is no difference in the operating environment; it’s only the lubrication method of the compressor that differs. The oil-free version uses self-lubricating materials, and its greatest advantage is that there is no oil at the outlet. HG20510 requires an oil content of 8 ppm in the instrument air; therefore, it is not necessary to have absolutely no oil present. Several sets of precision filters can be installed at the inlet of the mild heat dryer to remove oil; otherwise, the molecular sieve is prone to failure. The reliability of self-lubricating materials is naturally inferior to that of oil-lubricated ones, and oil-free versions are more expensive than those with oil! I once checked the price; it was about 50% more expensive

What was said upstairs is very comprehensive. 1. In fields such as food/pharmaceuticals, electronics, printing, chemicals, semiconductors, and precision spraying, where 100% oil-free conditions are required, oil-free air compressors must be used. 2. Oil-free air compressors include dry oil-free air compressors, oil-free water-lubricated air compressors, and oil-free scroll air compressors. Among them, oil-free water lubrication is the most expensive, dry oil-free lubrication is the next most expensive, and oil-free vortex lubrication is the cheapest. 3. Water-lubricated oil-free air compressors produce clean air suitable for breathing; they are environmentally friendly, energy-efficient, and capable of generating large volumes of air. They require low maintenance costs (as there is no lubricating oil or oil filter), have a very long service life, and extremely low maintenance expenses. The processing technology is quite stringent, resulting in high costs. It is not necessary to choose one if the general requirements are not particularly high. 4. The oil content in the gas produced normally by the air compressor is less than 8 ppm, so it is generally suitable for use without any problems. However, if the air quality is too poor, with too much water vapor and dust present, compression causes the water vapor and oil contaminants in the air to condense into small droplets; these droplets mix with the dust to form acidic sludge, which damages and shortens the lifespan of terminal equipment and valves. Usually, by using post-treatment equipment such as cold dryers/dryers and filters, the requirements can be met at a relatively low cost.

I am using a microheat regenerative dryer here, which has a pre-filter and a post-filter; the former removes oil while the latter removes dust