The compression of the oil-free screw air compressor is oil-free, and the gas is not polluted. On the contrary, the impurities and liquid components that are already in the gas do not cause much interference to the screw compressor. Changes in gas composition, molecular weight, or pressure ratio will hardly affect the actual gas flow rate. Suitable for the injection of water or liquid materials for cooling, washing and preventing polymerization and other undesirable premature reactions.
Oil-free screw compressors can handle most gases:
Small molecular weight gas, such as hydrogen;
Inert gas, such as nitrogen;
steam;
oxygen;
Corrosive gases, such as hydrogen chloride and hydrogen sulfide;
Dirty or dusty gas, such as blast furnace gas, coke oven gas;
Toxic gases, such as phosgene and carbon monoxide;
Hydrocarbons and their mixtures, such as natural gas, vinyl chloride, propylene, etc.
Especially suitable for the following complicated working conditions:
Dirty gas or dust
There is polymer formation
Liquid entrainment
Contains corrosive ingredients
Changes in gas composition and/or molecular weight
Flow fluctuation
Changes in pressure or pressure ratio
Centrifugal air compressors may be affected by polymer adhesion to the impeller. When the polymer adhering to the impeller reaches a certain amount, the vibration value will be too high due to the imbalance; at the same time, the performance of the machine will decrease due to the reduction of the fluid passage. Under the above-mentioned complex working conditions, the piston air compressor needs frequent overhaul, and even a spare machine needs to be installed to enable the device to operate continuously.
The oil-free screw air compressor adopts a rigid rotor design and runs below the first critical speed. It is not sensitive to vibration caused by unbalance, so it can not be affected by the polymer generated on the surface of the rotor and the shell. In a sense, the foreign matter sticking to the rotor reduces the gap between the rotor and the gap between the rotor and the casing, but increases the volumetric efficiency. In some cases, in order to prevent the polymer from hardening and affecting the operation of the machine or process, water or liquid solvent can be injected to soften or dissolve the polymer.
Typical application examples are:
1. Petrochemical
Exhaust gas compressor of styrene plant: polymer generation, water injection or ethylbenzene.
Recycle gas compressor for butadiene plant: polymer is formed. Circulating gas compressor for linear alkylbenzene unit: large flow rate, low molecular weight, and varying composition.
Compression of cycle C4 in a high-density polyethylene device: containing polymer particles.
Compression of hydrogen-containing mixtures in various petrochemical plants: Oil-free screw compressors are mostly used for the compression of hydrogen-containing waste gas in styrene plants.
2. Refining
Refinery waste gas recovery: changes in composition and flow rate, which are corrosive due to the presence of hydrogen sulfide or chlorine.
Chemical industry
Lime Kiln Gas Compression in Soda Ash Plant
Compression of phosgene and chlorine in TDI/MDI device
Compression of hydrogen chloride gas
Compression of carbon monoxide gas
Polysilicon project tail gas compression
3. Energy Industry
Coke oven gas compression
Gas compression for steel mills)
Gas turbine or furnace fuel pressurization
Compression of gas containing acetylene
4. Oil and gas
Offshore oil and gas recovery (especially suitable for fluctuating conditions of gas composition, inlet pressure and flow) · Compression during oil and gas collection
5. Other
Air and clean gas: The compressed air of the instrument air system on industrial installations must be oil-free. The use of oil-free screw compressors has proven to be very reliable.
In an air separation plant, oxygen requires absolutely no oil compression, and nitrogen must also be completely clean.
It can be used in natural gas, ethylene, propylene, hydrocarbon gas, carbon dioxide, ammonia, vacuum pump, steam and other occasions.