什么是双级（两级）压缩？其压缩过程为自然空气通过空气过滤器进入第一级压缩，在压缩腔与少量润滑油混合，同时将混合气体压缩到级间压力。
What is two-stage (two-stage) compression? The compression process is that natural air enters the first stage of compression through an air filter, mixes with a small amount of lubricating oil in the compression chamber, and compresses the mixed gas to the inter-stage pressure at the same time.
压缩后的气体进入冷却通道，与大量油雾接触，从而大大降低了温度。降温后的压缩气体进入第二级转子，进行二级压缩，被压缩到最终排气压力。最后通过排气法兰排出压缩机，完成整个压缩过程。
The compressed gas enters the cooling passage and contacts with a large amount of oil mist, thus greatly reducing the temperature. After cooling, the compressed gas enters the second stage rotor and is compressed to the final exhaust pressure. Finally, the compressor is discharged through the exhaust flange to complete the whole compression process.