What's the difference between an oil-free screw compressor and an oil screw compressor?
The oil-free screw compressor rotor do not contact each other, and the medium of gas and oil seal are separated, there is no direct contact, so the oil-free screw compressor is widely used in exhaust gas recycling, recycling of coke oven gas and coal seam gas pressure, medium pressure swing adsorption gas containing dust with liquid, gas composition changes in the larger places. The oil free screw compressor can meet the requirement of long time continuous operation of industrial production. The continuous running time is 24000 hours. But the volume efficiency of oil-free screw compressor is lower than that of fuel injection screw compressor, and the general single-stage pressure ratio is not more than 10.Fuel injection screw compressor rotor direct meshing drive, volume efficiency is high, single stage pressure ratio can achieve more than 10. However, because the lubricant and the process of direct contact with the media, so the medium gas requirements are relatively clean, and can not carry a large number of impurities and moisture, otherwise it will affect the lubrication effect of lubricating oil. In addition, the selection of lubricants in the selection of media and gas does not react, are generally dedicated synthetic oil. Therefore, the fuel injection screw is generally used for medium, gas, single work conditions, such as air compressors, refrigeration compressors, etc..
A) no oil screw compressor rotor clearance, do not contact each other, with a synchronous gear structure, the rotor based on synchronous gear transmission torque and positioning, oil injected screw compressor without synchronous gear structure, rotor direct engagement.B) an oil-free screw compressor has a shaft seal structure at the intake and exhaust end of the positive and negative rotor, separating the medium gas from the bearing lubricant. The fuel injection screw compressor has a shaft seal structure only at the end of the shaft connected with the driving machine to prevent the leakage of lubricating oil, and the medium gas is in contact with the lubricating oil.
No direct contact with the rotor oil free screw compressor, there is a certain gap between the rotor synchronous gear driven by Yang, Yin rotor, synchronous gears in the transmission of power, but also to ensure that the rotor clearance. The so-called "oil", refers to the gas during compression without contact with oil, but the compressor bearing, synchronous gear and other components, still need to adopt lubricating oil lubrication, the lubrication and the compression chamber is the effective seal between the segregatedThe injection screw compressor, gas lubricating oil is injected into the large amount of compression, play lubrication, sealing and cooling and reducing the noise, no oil injected screw compressor synchronous gear, the rotor directly drives the rotation of the rotor of Yin Yang, in addition to lubricating oil to reduce the exhaust gas temperature effect, but also to the bearing mechanical seals, valve friction etc.
