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Development and current situation of scroll oil-free vacuum pump technology Abstract: This paper summarizes the development and current situation of scroll oil-free vacuum pump technology, including the development of scroll technology to the application of scroll technology in various industries; From the principle of vortex oil-free vacuum pump to the manufacturing technology and technical indicators of vortex oil-free vacuum pump; From the development of vortex vacuum pumps in the world to the development status of vortex vacuum pumps in China, there is a systematic introduction to the status of vortex oil-free vacuum pumps

1 introduction

the concept of vortex is quite old, and there have been patents for vortex technology in the world at the beginning of the 20th century. However, due to the limitation of the technical level at that time, the vortex mechanism could not be manufactured, and the concept of vortex was forgotten. In 1973, the vortex mechanism was lifted again and the first model mechanism was manufactured, which made the practical application of this technology possible. The potential and great advantages of vortex mechanism, such as high reliability, stable operation, extremely low noise, energy saving, etc., immediately attracted the attention and urgent needs of the refrigerator industry, which was greatly favored by industry leaders and quickly put into industrial application. The scroll compressor technology and products of famous companies such as trance, Hitachi, Copland and so on have led the tide of the world's practical application of scroll technology, driving the technological progress and product upgrading of many industries such as refrigerators and air conditioners

today, vortex technology has been extended from its initial application in the compressor industry to the vacuum pump manufacturing industry, realizing the practicality of vortex clean vacuum acquisition technology with no oil, more stable operation, lower noise and more energy saving. People have applied the concept and principle of vortex to produce a series of single-stage and two-stage vortex oil-free vacuum pumps that do not pollute the vacuum application instruments and equipment and the environment, and whose pumping speed, service life, energy consumption and other indicators are better than ordinary oil pumps. 4. High speed circuit protector: protect the heating circuit

in the early 1990s, the world's first vortex vacuum pump was introduced to the market, and vortex technology began to be popularized and applied worldwide as a new vacuum acquisition technology. So far, the manufacturers of vortex vacuum pumps in the world are concentrated in the United States, Japan and Europe, represented by Japanese anest 1wata, American Varian, German bush, etc. The coke production market showed an overall stable and partial decline pattern, including products from 0.25L/s-1ol/S series, and some products with 15L/s or greater extraction capacity are also in the experimental stage

2 characteristics and application fields of 0-I free scroll vacuum pump

clean vacuum environment has always been the ideal vacuum environment pursued by scientists and business circles with low conversion rate of scientific and innovative achievements. Since the creation of vacuum environment, people have tried to use different means to achieve the effect of cleaning vacuum. Up to now, clean vacuum equipment has been developed to condensate pumps, column pumps, claw pumps, vortex pumps, diaphragm pumps and other products. Among the existing oil-free vacuum pumps, compared with other types of oil-free vacuum pumps, vortex oil-free vacuum pumps have the characteristics of stable operation, low noise, energy saving, light weight and small volume, and have been widely used in the following scientific research and production fields: ① semiconductor industry - film preparation equipment, semiconductor device packaging equipment; ② Vacuum metallurgy industry - vacuum furnace, nano material preparation equipment, vacuum testing equipment; ③ Scientific instrument industry - synchrotron radiation beam line, electron microscope, analysis and testing instrument; ④ Medical equipment - dental instruments, dialysis machines; ⑤ Biological products industry - material purification and drug preparation; ⑥ Packaging industry - food, medicine, biological products and other packaging equipment

3 working principle, technical indicators and comparison with ordinary oil pumps of scroll oil-free vacuum pump the scroll disk of scroll oil-free vacuum pump is a scroll disk structure formed by one or several involute spirals connected with a plane at one end. A pair of scroll plates composed of a static scroll plate and a moving scroll plate constitute the basic pumping mechanism of scroll oil-free vacuum. For example, in a two-stage scroll oil-free vacuum pump, there are fixed scroll disks corresponding to two directions, and a rotating scroll disk located between the two scroll disks. The relative movement of the dynamic and static scroll plates forms a crescent shaped true cavity with constantly changing volume, which makes the gas inhale from the air extraction port, discharge from the exhaust port, and complete the exhaust cycle

as we all know, oil free scroll vacuum pump has remarkable characteristics compared with ordinary oil vacuum pump. Take the ordinary rotary vane vacuum pump as an example, Explain the differences:

Table 1 Comparison of technical indicators between scroll oil-free vacuum pump and ordinary direct connected scroll vane vacuum pump

technical indicators scroll vane oil vacuum pump scroll oil-free vacuum pump

pumping speed (l/s) 2.0, 4.0, 8 2.0, 4.4, 8.7

limit vacuum (PA) 0.6 1.0

service life (H) 40000 40000

overhaul interval (H) 800010000

cooling medium oil air <

noise (DB) 75 60

mass (kg) 7041

number of motor phases 3 1

voltage (V) 220/380 220

power (kw) 1.1 0.6

revolutions (r/min) 14001437

4 the advantages of scroll oil-free vacuum pump and the problems it can solve for users

4.1 scroll oil-free vacuum pump has superior performance

the main advantages of scroll vacuum pump are small clearance, less leakage and high compression ratio, It has stable pumping speed in a wide range of crude force and a wide range of working pressure; Because the volume of the compression chamber changes continuously, the driving torque changes little, the power changes little, the vibration noise is low, and the reliability is high. This is not available in other types of dry vacuum pumps

4.2 the scroll oil-free vacuum pump solves the basic and common problems such as pollution and vibration

the oil leakage, noise, oil return pollution, high energy consumption and vibration of the ordinary vane oil pump have adverse effects on users, such as oil vapor pollution and process system oil return valve in the biological products industry and semiconductor industry. In the coating process of vacuum coating equipment, when coating under the vacuum condition of 20 ~ 40Pa, if the ordinary rotary mechanical vacuum pump is used as the front stage vacuum pump, it will pollute the coating process equipment and affect the film forming amount. Compared with the use of dry pump in the semiconductor wafer manufacturing process, there is a gap of 509l left dry yield, and the discharged oil mist steam also pollutes the environment. In the scientific instrument industry, especially in the analytical and test instrument industry, the use of oil pumps will have a negative impact on the test results. The effect of vortex oil-free vacuum pump as the pre stage vacuum pump for large synchrotron radiation beam drying is also quite obvious. In addition, in addition to the environmental pollution and trouble caused by the oil leakage of the ordinary oil pump, the vortex oil-free vacuum pump eliminates alcohol

4.3 the vortex oil-free vacuum pump reduces the manufacturing and operation costs of the system.

in order to prevent the oil return pollution of the vacuum system by the ordinary vane oil vacuum pump, it is necessary to add a cold trap in the air extraction system to capture oil molecules; Regular cleaning and degreasing are also required during the operation of the system; Some need to change the vacuum pump oil regularly. The scroll oil-free vacuum pump is adopted. Firstly, there is no need to add oil trapping mechanism such as a cold trap, secondly, there is no need to change the vacuum pump oil, thirdly, the vibration is smaller, the operation is more stable, fourthly, the energy consumption is reduced, fifthly, the weight is lighter, and sixthly, it breaks through the limitation of the scope of use of the oil pump. The above advantages make the scroll oil-free vacuum pump an updated product of the ordinary scroll oil vacuum pump

5 Conclusion

domestic manufacturing processes represented by semiconductor and electronic industries and scientific research, analysis and testing industries urgently need a clean vacuum environment without oil pollution, but clean vacuum acquisition equipment such as condensate pumps, column pumps, claw pumps, vortex pumps and diaphragm pumps have not formed reliable and advanced batch domestic products at present. Imported vortex oil-free vacuum pump, as a new product that has been officially put on the market in China for no more than 3 years, has not formed a virtuous circle due to the above-mentioned price, market development and user awareness. In this way, on the one hand, there is an urgent market demand, on the other hand, there is no suitable product in terms of price and technology, resulting in a huge market gap

there is no doubt that the vortex oil-free vacuum pump with moderate price and reliable performance will become the mainstream of products suitable for the requirements of the Chinese market, and it is imperative to vigorously develop the vortex oil-free vacuum pump. The development of vortex and other oil-free vacuum pump series products and their detection technology that meet the requirements of the Chinese market has also become an opportunity for the further development of China's vacuum industry

in order to solve the basic and common problems of technical means faced by China's scientific research and the development of new materials, semiconductors and other industries, in recent years, industry experts have continuously introduced the vortex oil-free vacuum pump technology and its development status to China. The development of the Chinese market by foreign vortex oil-free vacuum pump manufacturers and agents has increased their sales in the Chinese market year by year. Domestic vacuum industry related enterprises have also carried out basic, application research and small-scale trial production of vortex oil-free vacuum pump at different stages of exploration, but due to the limitations of technical foundation, incentive mechanism, research and development means and capital investment, the progress of research and development is not very fast. Product quality, stability and reliability, as well as technology promotion and market development planning, principles and means are also problems. Therefore, the next industrialization technology research and development and market development of vortex oil-free vacuum pump series products are the two major problems that enterprises must solve. With the solution of R & D means, capital investment and market development, environmental protection needs to be resolved. The vortex oil-free vacuum pump will open the market, so as to improve the technical level of the whole vacuum acquisition industry. The successful product R & D and market development mode of vortex oil-free vacuum pump series will also provide an effective reference for other clean vacuum acquisition equipment in China, such as condensate pump, sample zhailei, claw covered diaphragm pump, etc

source: Hangzhou electromechanical mall