2023-06-15 13:52:09

What is a dry oil-free screw air compressor?

What is a dry oil-free screw air compressor?

Grade 0 is oil-free, that is, the total oil content (oil brought in during compression + oil vapor in the air) reaches ≤0.01mg/m.

"Oil-free" means that the gas does not come into contact with oil at all during the compression process, that is, there is no oil lubrication between the compression chamber or the rotor of the compressor, but the bearings, gears and other parts in the compressor are still used Ordinary lubricating methods are used to lubricate, but an effective isolation shaft seal is adopted between these lubricating parts and the compression chamber.


Comparison of dry oil-free and water lubrication

Common ground

Air quality: all are oil-free units, and the compressed air can reach class0


1. The structure of the main engine is different (water lubrication is single screw + star wheel, dry oil-free is double screw)

2. Different lubrication methods (the lubricating medium of water lubricated is water, and the dry type is oil-free and non-lubricating medium)

3. Different cooling methods (direct cooling by cooling water, cooling by cooling jacket)

4. The exhaust temperature is different (the exhaust temperature of the dry oil-free main engine is high, and the built-in after-cooler of the unit is cooled)

5. The exhaust pressure range is different (the dry oil-free 8bar unit can be adjusted between 3.5 and 8,)

Oil-free air compressor selection suggestions:

1. ≤7m³/min (8bar) it is recommended to lubricate the oil-free screw compressor with water

2. It is recommended to use a dry oil-free screw compressor for >7m³/min (8bar)


Dry oil-free application industry

Dry oil-free screw air compressors are used in textile, electronics, metallurgy, food, chemical industry, medicine, petroleum and air separation and other places that require pure oil-free compressed air. It is also commonly used in bulk cement tank trucks, and in dry material transportation (such as grain, cement, coal powder, lime, sand and other industries.