Energy saving and environmental protection VPSA Oxygen Generation Equipment｜VPSA Oxygen Generators
- Product Scale
- Oxygen Purity
- Oxygen Pressure
- ≤20MPa (able to be pressurized)
- Annual Operation Rate
VPSA oxygen generation system is mainly composed of the blower, vacuum pump, switch valve, adsorber, and oxygen balance tank. The raw material air enters the adsorber with the oxygen molecular sieve after being pressurized by Roots blower. Water, carbon dioxide and nitrogen in the air are adsorbed so as to generate oxygen. When the adsorption capacity reaches a certain degree, the vacuum pump is used to carry out vacuuming. Adsorbed water, carbon dioxide and a small amount of other gas are pumped out and discharged to the atmosphere, so that the adsorbent is regenerated. The above-mentioned process is automatically controlled by the PLC & switch valve system.
Product Scale: 100~10000Nm3/h
Oxygen Purity: ≥70〜94%
Oxygen Pressure: ≤20MPa (able to be pressurized)
Annual Operation Rate: ≥95%
The pressure swing adsorption air separation oxygen generation equipment* s adsorption bed must contain two operation steps like adsorption and desorption. In order to continuously obtain the product gas, the oxygen generation equipment usually has over two adsorption beds. In addition, considering energy consumption and stability, some necessary auxiliary steps are set. Every adsorption bed undergoes adsorption, pressure release, vacuuming or pressure reduction & regeneration, washing & replacement, pressure balancing & pressure increase, and other steps, periodically and repeatedly operated. At the same time, every adsorption bed respectively undergoes different operation steps. Under the PCL control, they are regularly switched so that several adsorption beds may carry out the coordinated operation, staggered in the aspect of time, in order that the pressure swing adsorption equipment can be steadily operated to continuously obtain the product gas. For the actual separation process, it is required to consider other tiny components in the air. The adsorption capacity of carbon dioxide and water on the general adsorbent is much stronger than that of nitrogen and oxygen. The proper adsorbent may be added to the adsorption bed (or the adsorbent for oxygen generation is utilized) so as to carry out adsorption and elimination.
The number of adsorption towers required by the oxygen generation equipment is subject to oxygen generation scale, adsorbent performance, and process design concept. When the multi-tower operation is carried out, the operation stability is relatively better, but the equipment investment is higher. The current tendency is to use the high-efficiency oxygen generation adsorbent to try to reduce the number of adsorption towers, and adopt the short operation period, so as to improve the equipment efficiency and save the investment as much as possible.
VPSA Oxygen Generation Equipment's Application in the Smelting Industry
The open-hearth furnace process with oxygen blowing is to support the combustion. Its purpose is to strengthen the smelting process, shorten the smelting time and improve the steel output of the open-hearth furnace. The practice has proved that, if the open-hearth furnace process with oxygen blowing is adopted, the steel output of the open hearth furnace may be increased by over 100%, and the fuel consumption may be reduced by 33%〜50%. According to the calculation, the consumption per ton of steel is 30~40m3.
The electric furnace process with oxygen blowing may accelerate the furnace burden fusion and impurity oxidation, which means that the electric furnace process with oxygen blowing can improve the production capacity and enhance the quality. The electric furnace* s consumption per ton of steel varies with smelting steel types. For example, when the carbon structural steel is smelted, the oxygen consumption per ton of steel is 20~25mm3; however, the oxygen consumption per ton of high-alloy steel is 25〜30 m3. The required oxygen concentration is 90%〜94% enriched oxygen.
The blast furnace process with enriched oxygen blowing may observably reduce the coking and improve the output. According to the statistical information, if the oxygen concentration is enhanced by 1%, the iron output may be increased by 4%〜6% and the coking may be reduced by 5%〜6%. Especially, when the coal injection rate of coal-based iron-making water reaches 300kg, the corresponding oxygen consumption per ton of iron is 300m3.
In the smelting process of non-ferrous metals, if the oxygen is added, the sulfur may fully burn, so as to maintain the smelting temperature and improve the smelting speed. Taking copper as an example, using enriched oxygen to smelt the copper may save 50% energy. In other words, under the same fuel consumption condition, the copper output may be increased by 100%.
Deep-cooling Air Separation Oxygen Generation Equipment
VPSA Oxygen Generation Equipment
Liquefy the air and carry out the separation according to the boiling point difference between oxygen and nitrogen
Pressurization & adsorption and vacuumizing & desorption utilize the adsorption capacity deference between oxygen and nitrogen to achieve the separation.
The process is complicated. It is required to undergo the compression, cooling/refrigeration, pretreatment, expansion, liquefaction, fractionation, etc., and the operating temperature is less than -180.
The process is very simple, and it only needs compression and vacuumizing to achieve the separation; the operating temperature is the normal temperature.
Main Characteristics of the Equipment
More moving parts, complicated structure, more control elements of supporting instruments; centrifugal air compressor (or no-oil air compressor), steam-water separator, air purifier, heat exchanger, piston expansion device, separation tower for filters
Fewer moving parts, simple equipment, fewer control elements of supporting instruments. Blower, adsorption tower, vacuum pump, oxygen storage tank
With complicated operation, the equipment may not be used at any time. As the equipment shall be operated under the ultralow-temperature condition, therefore, it is required to have the process of pre-cooling startup and ineffective energy consumption (low-temperature liquid accumulation and heating purge). If the running & stop time is much longer and the number of times is much more, the finished product gas* s unit consumption is correspondingly increased. There are many complicated operating control & monitoring points. It is required to regularly stop the equipment for overhaul and maintenance. The operation personnel need to accept the long-term professional technical training and have rich practical operation experience.
With simple operation, the equipment may be used at any time. The operating control and monitoring are realized by the PLC. The time to start and stop the equipment is very short, less than 5 minutes. Short-term or long-term continuous operation or stop doesn't affect the operating conditions. Do not regularly stop the equipment for overhaul and maintenance. After accepting the short-term technical training, the operating personnel may operate the equipment.
Need oxygen, nitrogen, hydrogen and other gas products; the oxygen purity is 99.5%
Obtain the single gas, with the purity of 90-95%
Due to high precision & requirement of the centrifugal air compressor, condensation steamer and expansion device, the overhaul for the heat exchanger in the fractionation tower shall be completed by the personnel who have accepted the professional technical training with rich experience.
The maintenance for the blower, vacuum pump and program control valve belongs to conventional maintenance, and it may be completed by the general maintenance personnel.
Civil Engineering & Installation Features
With complicated unit and large covering area, need special workshop, fractionation tower and anti-freezing foundation, and have high engineering construction cost. The equipment shall be installed by the installation team with rich air separation equipment installation experience, and have long installation period, high difficulty (fractionation tower) and expensive installation cost.
The equipment has small outline dimension, and small covering area, with conventional installation, short installation period and low cost.
Automatic Program Safety
The number of units is much more. Especially, when the high-speed turbine expansion device is adopted, it is easy to affect the normal operation of the equipment due to faults. In addition, the skilled operating personnel are required to stay on the site. If the equipment is operated under the over lOP and high-pressure conditions, this will bring explosion risks and the related cases have occurred up to now.
After being started, the equipment may carry out the full-automatic program control to achieve the unmanned operation. As the equipment is operated under the normal temperature & low pressure, there are no unsafe factors, explosion risks or cases.
Inconvenient purity adjustment, high oxygen generation cost
Convenient purity adjustment, low oxygen generation cost
Oxygen Generation Cost
Energy consumption: -1.25kwhm³/h
Energy Consumption: Less than 0.35kwhm³/h