1. Dry oil-free screw air compressor is a twin-screw air compressor. Oil-free screw compression chamber is not lubricated, only in the gear box with lubricating oil which can be said to be dried. The surface of the rotor is a special coating, and the yin and yang rotor does not really touch. Due to non-contact, the first compression pressure of no oil dry screw is not very high. To improve the pressure, we usually use the two compression. The best compression effect is isothermal compression, but actually we can not achieve isothermal compression. The pressure of the first stage compression is probably the root number 2, and then the pressure enters the second stage of compression. The speed is very quick and the temperature of machine head is very high. The head housing is completely separated from the rotor. If the air is cold, the shell will be oil cooled; if it is water-cooled, the shell is water. Dry oil-free screw air compressor has high maintenance costs.
2. Water lubrication Oil-free air compressor is generally a single screw air compressor. The compressor lubrication medium is characterized by water. It’s sealed by water, with completely oil-free, producing pure oil-free compressed air and completely changing the production environment in some industries. Because it is sprayed into the compression chamber and the temperature is only about 40-50 degrees with constant temperature compression, the volume efficiency is 15% higher than the dry oil-free screw air compressor efficiency . The maintenance costs about no oil and water lubrication screw air compressor is low, and just need to replace the water, water filters, and air filters.