Views: 0 Author: Site Editor Publish Time: 2022-05-25 Origin: Site
We will introduce the equipment one by one according to the process of air separation system:
There are self-cleaning air filters, steam turbines, air compressors, superchargers, instrument compressors, etc.
(1) The self-cleaning filter generally increases with the increase of gas volume, the number of filter cartridges increases and the number of layers is higher. Generally, it is arranged in two layers above 25000 and three layers above 60000; Generally, a single compressor needs to be arranged with a filter separately and at the upper air outlet at the same time.
(2) Steam turbine is a type of high-pressure steam to expand and do work and drive the coaxial impeller to rotate, so as to do work to the working medium. There are three commonly used forms of steam turbine: full condensation, full back pressure and extraction condensation, and the more commonly used is extraction condensation.
(3) Generally, the investment of large-scale air separation unit of air compressor is single shaft isothermal centrifugal compressor. The energy consumption of imported is about 2% lower than that of domestic, and the investment is 80% higher; The air compressor adopts outlet venting without return pipeline. Generally, there are requirements for minimum suction flow and anti surge. The inlet guide vane is used for flow regulation. The imported domestic units are four-stage compression and three-stage cooling (the last stage is not cooled). The main air compressor is equipped with a set of water washing system to wash the surface sediments of impellers and volutes at all levels. The system is complete with the host.
(4) Generally, the investment of large-scale air separation unit of booster adopts single shaft isothermal centrifugal compressor and gear centrifugal compressor. Among them, gear compressor has great advantages in energy consumption, especially under the condition of large pressure ratio.
(5) There are generally three types of instrument Compressors: oil-free screw machine, piston type and centrifugal type. Since the piston type and centrifugal type are naturally oil-free, there is no need for oil removal device, only supporting drying device (water removal) and precision filter (solid particles removal); Screw machines generally have two types: oil and oil-free and then oil removal. Oil injection screw machines need to be equipped with oil removal devices and oil removal filters with very high precision to meet the process requirements. The advantage of this model is that the price is relatively cheap; The oil-free screw adopts dry rotor or water lubrication. The advantage of this model is that it is absolutely oil-free, but the disadvantage is that the price is expensive. The air volume below 500nm / h is suitable for piston type; The air volume below 2000Nm / h is suitable for screw machine or piston machine; The gas volume is more than 2000Nm / h, that is, the three models can be selected. When the gas volume is large, the centrifugal compressor has advantages, less vulnerable parts, easy maintenance and high cost performance.
The instrument compressor is used during start-up. After normal operation, it is extracted by Molecular Sieve Purifier.