How to remove water and oil from compressed air

The water and oil in the compressed air should be treated separately because their sources are different and the methods of removal are different. The following is a clear explanation of how to remove each, and at the same time talk about the role of water lubricated air compressor in this.

Conclusion first

water is removed by condensation and drying, and oil is removed by separation and filtration. If the air compressor is lubricated with water at the beginning, there is no oil problem at all, only the water needs to be treated, saving more than half of the trouble.

First, how to get to the water.

Where does the water in the compressed air come from. Air originally contains water vapor, and after being compressed, the temperature rises, and the water vapor becomes invisible gaseous water mixed in. When the air cools down, the gaseous water becomes liquid water, or condensate. So go moisture two steps.

The first step is condensation separation. Compressed air first enters a large tank or elbow pipe, so that the airflow slows down and the temperature drops, and the water will condense itself into water droplets and sink to the bottom, and then automatically drain through the drain valve at the bottom. The air storage tank can also play this role. The air stays in the tank for a period of time, and the water sinks. Just open the drain valve regularly and let it go.

The second step is drying treatment. Condensation can only remove most of the water, and some water vapor will remain. Use a dryer to completely absorb the remaining water. There are two common dryers, one is to use desiccant to absorb water, and the other is to use part of the dried air to blow wet air to take away the moisture. According to the factory's requirements for the degree of air drying, choose a different drying method.

How to get oil.

The oil comes from an oil-lubricated air compressor. During the compression process, the lubricating oil will become a mixture of oil and gas and mix into the air. Although the machine has its own oil and gas separation device, it is impossible to separate it 100%, and there will always be a small amount of oil running out. Oil is also divided into several steps.

The first step is oil and gas separation. There is a special separation device inside the air compressor, which uses centrifugal force or collision to throw large particles of oil droplets out of the air and collect them to the bottom. This step can remove most of the oil, but there will be a very fine oil mist residue.

The second step is filtration. Let the compressed air pass through the filter element, which can block the residual oil mist and tiny particles. If the filter element is used for a long time, it will be blocked and should be replaced regularly, otherwise it will not only be too clean, but also increase resistance and waste electricity.

The third step is activated carbon adsorption. If the air cleanliness requirements are particularly high, such as food, electronics industry, filtration alone is not enough, but also let the air through the activated carbon layer. Activated carbon can suck the smallest oil molecules, and the air is very clean.

Why can water lubricated air compressor save oil this step

water lubricated air compressor with water instead of lubricating oil, there is no oil in the compression chamber, so the compressed air does not contain oil at all. Without oil, there is no need for oil and gas separation, no need for precision filtration, no need for activated carbon adsorption, these oil removal equipment and consumables can all be saved.

It only needs to treat the water. The compressed gas-water mixture passes through a gas-water separator to remove most of the water, and the dryer sucks the residual water vapor again, and the dry and clean compressed air comes out. The whole process is much simpler than the oil-lubricated air compressor, and the later maintenance is also easy, without changing the filter element or treating oily wastewater.

To sum up

the core of water removal is first condensation and then drying, and the core of oil removal is first separation and then filtration and adsorption. However, if the water-lubricated air compressor is replaced from the source, the oil problem will disappear directly, and you only need to concentrate on dealing with water. For factories with high environmental protection requirements or products that are afraid of oil pollution, the water-lubricated air compressor fundamentally simplifies the entire post-treatment process, saving money and worry after long-term use.