For oil-free water-lubricated machines, please note a few points: 1. The lubricating part is water, and it is pure water, preferably pure water; 2. It does not contain oil, but contains water; 3. Water lubrication All of them are single-screw air compressors, which are not half cheaper than dry oil-free air compressors. 4. If it exceeds 90kw, it is best to use water-cooling. Water-cooled air compressors, whether oil-free or oil-based, need to build a simple water tower for cooling. Of course, the cooling effect must be strictly better than that of air-cooling. .
The dry oil-free machine is a twin-screw air compressor. There is no lubrication in the compression chamber of the oil-free screw machine. There is only lubricating oil in the gear box, which can be said to be dry. The surface of the rotor is specially coated, and the male and female rotors do not really contact. Since there is no contact, the first compression pressure is not very high. To increase the pressure, use two-stage compression. The best compression effect is isothermal compression. In fact, isothermal compression is not possible, so there is an intercooler and a trap (cooling, drainage) after the first stage of compression, and there is also a rear cooler after the second stage of compression. The pressure of the first stage of compression is approximately square root 2, and then this pressure enters the second stage of compression. Due to the high speed and high temperature inside the machine head, the machine head shell adopts one-time lost foam technology for cooling. The head housing and rotor are completely separated. If it is air-cooled, the shell is oil-cooled; if it is water-cooled, the shell is water-cooled.