Comparison of twin-screw air compressorCompared with single-screw compressor
I. Force balance
Single-screw compressor: Radial sum of screw The axial gas force can be automatically balanced, and the star gear teeth are subjected to gas forces, requiring the star gear teeth to have sufficient strength and rigidity.
Twin-screw compressor: The screw rotor is subjected to large radial and axial gas forces, requiring the screw to have sufficient strength and rigidity.
Second, the manufacturing cost
single screw compressor: screw and star wheel bearings can be used with ordinary bearings, the manufacturing cost is lower.
Twin-screw compressor: Due to the relatively large load of the two-screw rotor, it is required to select a bearing with higher precision and the manufacturing cost is higher.
Third, the reliability aspect
Single screw compressor: The star wheel of the single screw compressor is a vulnerable part. In addition to the high requirements for the star wheel material, the star wheel needs to be replaced regularly.
Twin-screw compressor: There is no wearing parts in the twin-screw compressor, and the trouble-free running time can reach 4 to 80,000 hours.
Fourth, efficiency aspects
In the new machine state, the efficiency of the single screw compressor and the twin screw compressor are basically the same. As the run time increases, the star wheel wear of the single screw compressor will result in reduced air volume and reduced efficiency. V. Noise and vibration
The noise and vibration of the single-screw compressor and the twin-screw compressor are basically the same.
Six, processing equipment
single screw compressor: there is no mature special processing equipment, which leads to the product performance is not very stable.
Twin screw compressor: There are mature screw milling machines and grinding machines to ensure stable product performance.
VII, operation and maintenance
Single screw compressor and twin screw compressor are basically the same operation and maintenance.
Eight, applicability
Single screw compressor: suitable for high exhaust pressure applications, such as high pressure air compressors, refrigeration compressors and natural gas compressors.
Twin screw compressor: Due to the limitation of rotor stiffness and bearing load, twin-screw compressor can only be used in medium and low pressure range, such as power air compressor, refrigeration compressor and low pressure natural gas compressor. The exhaust pressure should generally not exceed 4.5 MPa.
From the design theory, the single screw is much more advanced than the twin screw machine. This is from the product design structure, mainly the balance mechanics. The single rod machine has the "induced air passage" ; the gas forces on both ends of the worm are balanced with each other. The worm is free from any axial or radial gas force to achieve its own balance [visible force analysis diagram], and the force on the star wheel is only about 1/30 of the force of the twin-screw worm, so the mechanical noise is small. In addition, the number of exhausts per minute, the number of exhausts per minute of the twin-screw machine is 14850 times, and the number of exhausts per minute of the single-screw machine is 35,640 times. The exhaust pulsation is extremely small and the air supply is stable. The main source of airflow noise is more visible: the fewer the number of exhausts per unit time, the more severe the airflow pulsation, and the greater the airflow noise, and vice versa. Regarding the star wheel, many people don't understand it. Many domestic manufacturers use the engineering plastic star wheel. The disadvantage is that the exhaust gas will decrease with the extension of time. The advantage is that the installation is easy and the cost is low. The manufacturers used are Feihe, Jialix and so on. Zhengli's star wheel adopts aviation-grade composite carbon fiber/tough epoxy resin matrix with imported self-lubricating properties from the UK [see the manufacturer's website product introduction, technical data]. Shanghai Inspur uses an imported metal-based wear-resistant composite cast iron body. The star wheel is easy to wear and has a short service life and a rapid gas volume drop is the biggest defect of the single screw machine. At present, the star wheel material and profile problems of single-screw machines have not been solved by good methods. Zhengli's patented product "non-equal width teeth, three contact line tooth shape" said that the life of the star wheel can be increased by 6 times to 100,000 hours, but the customer response is still not very good.
Label [Double-screw air compressor advantages and disadvantages][Single-screw air compressor advantages and disadvantages]Recommended products: 3 cubic screw air compressor 6 cubic screw air compressor 10 cubic screw air compressor