THE COMPARISON OF SINGLE SCREW AND TWIN SCREW AIR COMPRESSOR

2020/07/21

In the contemporary world,resource and environment problem is the common challenge for human beings, Green and low-carbon development is becoming the trend of international development. Especially in the background of coping with the international financial crisis and climate change, it is the common choice for major economies to promote green growth and implement green new policies. It has become an important national strategy to develop green economy and seize the commanding heights of global economic competition in the future. Especially since the beginning of the new century, the concepts of green economy, low-carbon economy and circular economy have been put forward and put into practice. Innovation and reform are always accompanied by social development. With the improvement of the social consciousness of environmental protection, energy saving, social requirement for the compressor energy consumption is higher and higher, single screw structure has good balance of bearing stress, high volume efficiency, water lubrication may be used for work, and so on.Double screw compressor is incommensurable with it. In my opinion, how to turn these advantages to the maximum level is a problem of single screw manufacturing enterprises have to think about.

Because the bearing force of single screw compressor structure is balanced, it can use water to replace the expensive and polluting oil for lubrication and cooling, which can greatly reduce the exhaust temperature and unit operating temperature, and achieve isothermal compression. In the field of oil-free compressor, water lubrication has a great advantage over dry oil-free compression. Such as high efficiency, large gas production volume under the same power(specific power is 10%-20% lowerless than dry oil-free), maintenance costs are very low, the unit operating temperature is low, do not use any lubricating oil,etc. It can be seen from the following table that the specific power of our company’s water lubricated screw compressor reaches and exceeds the standard of oil injection screw compressor.

CMN water lubricated oil free machine and micro oil screw air compressor specific power comparison sheet

Machine model

Motor power

kW

Exhaust air volume

M³/min

Air inlet pressure

Mpa

Specific power

kW/(m³/min)

Inspection report No.

Corresponding micro oil unit international demand specific power

kW/(m³/min)

CM22BF-8

22

3.51

0.9(Absolute Pressure)

7.44

2012YS223

7.5

CM37B-8

37

6.1

0.9(Absolute Pressure)

6.73

2012YS224

7.1

CM55B-8

55

9.6

0.9(Absolute Pressure)

6.4

2012YS225

6.9

CM75B-8

75

12.5

0.9(Absolute Pressure)

6.34

2012YS226

6.9

CM110B-8

110

19.4

0.9(Absolute Pressure)

6.5

2012YS227

6.7

CM130B-10

132

20.38

1.1(Absolute Pressure)

7.55

2012YS228

7.8

CM160B-12.5

160

22.17

13.5(绝)

9.14

2012YS229

9.2

Note:

    1.The above specific power data was extracted from the test report of hefei general mechanical and electrical products testing institute in 2012, and the specific power data so far is better than the above data.

    2.Specific power data of micro oil screw air compressor extracted from JN/ t6430-2002 micro oil screw air compressor

Because of the effect that water-lubricated oil-free air compressor one-stage compression can achieve the effect of dry oil-free compressor two-stage compression effect, the manufacturing cost is lower than dry oil-free type. When CMN water lubrication oil-free air compressor  obtains a certain share and get a high user evaluation in the market, there are a lot of single screw manufacturers produce water lubrication compressor, of course it’s a good phenomenon, it is the beginning of the competition between domestic oil-free machine and oil-free machine of foreign brands, also the beginning of product replacement. But there are a lot of manufacturers manufacturing products with major problems, they’re eager for quick success and quick profits on operating, take ultra-low price sales and so on,as a result,a lot of users are not satisfied with the product.

Most manufacturer who buys oil-free machine is more normative, strengthen the environmental protection consciousness,care about the stability of products use. Product quality is always the basis for the survival and development of enterprises, as a result of some manufacturers’ desire for quick success and quick profits, a lot of bad products are leaded into the market, which will seriously affect the reputation and development prospects of water lubrication oil-free machine industry. Therefore,we appeal don’t allowing low quality products come into the market,we cherish and nurture the water lubrication oil-free machine market, do not make a good product bad and make the product that customers do not trust. Our company is responsible for drafting the national industry standard JB/t1182-2014 “general used water spraying single screw air compressor” has been issued and implemented by the National Ministry of Industry and Information in October 2014. We hope that we can strictly implement the standard and do a good job in product quality. Products without quality are not qualified for development.

It’s the same that because the bearing force on the structure of the single screw compressor is more balanced,it is made into a medium and high pressure compressor with the advantages that the twin screw compressor can not compare. CMN two-stage compression medium pressure single screw oil injection compressor was put on the market in 2011. According to the test report of hefei general mechanical and electrical products testing institute 2013YS904,when the CMN two-stage compression oil injection screw compressor 22g-4.0 unit is at 4.0mpa,the volume flow is 1.59m/min, the shaft power is 23.6kw, and the unit specific power is 14.84kw/(m/min). Now the pressure range is 2.0Mpa to 4.0Mpa, the medium pressure machine whose power is 18.5kw to 250kw is popular among users and widely used in bottle blowing, pressure test, aviation, drilling, mining and all kinds of other fields. Especially in the energy saving aspect,compared with the piston type medium pressure machine,energy saving effect is up to 30%.Single screw is also a very good development direction in the field of medium  pressure machine.The industrial standard JB/t12655-2015 “medium pressure single screw air compressor” drafted by our company (EPCMN Compression Equipment co., LTD.) was issued and implemented by the ministry of industry and information technology, PRC on March 1st, 2016, providing a basis and guarantee for everyone’s work in this field.

In the field of oil-free medium pressure compressor, several foreign manufacturers of piston compressor have occupied more than 90% market share in the world. CMN two-stage compression medium pressure oil-free single screw air compressor has finished type test last year and is already used on the market. The performance parameters of CM110G-4.0 is working pressure 4.0mpa, motor power 110kW, volume flow rate 10.2m /min, noise 76dB(A), weight 2630kg, cooling water 24T/h, contour size: 3000×1350×1540mm, compressed air outlet pipe diameter DN32.

Single screw compressor has a lot of advantages that twin-screw compressor can’t compare, we should give full play to the advantages of the single screw type and circumvent weaknesses, through continuous improvement and innovation,do a good job in the field of water lubrication oil-free and medium pressure machine field,make a characteristic, make energy saving products with high quality, take a place in the international market.