Design And NVH Analysis Of Oil-free Twin-screw Blower

The blower is a general fluid machinery in the industrial field.Traditional blowers have many problems such as low efficiency,large energy consumption,large vibration,high noise,which do not meet the requirements of building a "two-oriented society".In Particular,General Secretary Xi Jinping proposed the "carbon peak" and "carbon neutral" node,and the demand for energy saving and environmental protection blowers is more and more vigorous.In addition,with the rapid development of food,pharmaceutical and other industries,the air cleanliness of the blower has put forward higher requirements,oil-free blower market share is growing.In order to further improve the power density of the equipment,the blower develops rapidly towards the direction of high speed,high efficiency and high reliability,which also brings a series of problems such as vibration and noise.The research on the above problems has important theoretical significance and engineering application value.This article closely follows the market demand and focuses on the above mentioned problems.The key technology of high-speed and high-efficiency oil-free twin-screw blower is specially researched.Taking Hui feng Fluid HF170 as the research object,the design of the whole machine system,rotor system design,transmission system and supporting system as well as the design of the lubrication system,the development of high-speed and high-efficiency oil-free twin-screw blower is completed through prototype trial production,experimentation and optimization design.During this period,strength analysis and modal analysis are carried out on the key Parts based on Solidworks simulation and Ansys,and vibration test is conducted to find the vibration point and excitation source of the equipment.At the same time,the noise test of high speed and high efficiency oil-free twin-screw blower is carried out to identify the main frequency of noise.Finally,the performance test of the whole machine is carried out.When the screw speed is 10000 rpm,the efficiency of the whole machine reached 75.73%,which is more than 25% higher than that of the Roots blower in the same state.According to the results of vibration and noise test,the vibration control and noise control measures of the whole machine are studied.The vibration speed is controlled below 2.4mm/s,and the noise of the whole machine is controlled below 84 d B.The main research contents of this Paper are as follows:(1)From the relevant design principles,extract the relevant HF170 oil-free twin-screw blower to extract guidance and basis.The key Parameters of the blower are designed and calculated,and the Solidworks software is used to design the entire system of the blower.Including rotor system design,transmission system design,support system design and lubrication system design.(2)Based on the static stress analysis of the HF170 oil-free twin-screw blower based on Solidworks Simulation,it is judged whether the design of the support system is reasonable.The modal analysis of the male and female spiral structure is carried out,and the first eight natural frequencies and vibration modes of the female spiral structure and the male spiral structure are obtained,which provides a theoretical basis for the vibration test and subsequent optimization of the whole machine.(3)The vibration test of the HF170 oil-free twin-screw blower is carried out using vibration sensors,8-channel data acquisition equipment,DEWESoft software,etc.,and it is obtained that the blower resonance was caused by the excitation of the male screw.The noise test is carried out to measure the noise of each speed and the corresponding frequency,and it is found that the noise frequency is consistent with the rotation frequency of the male screw,which lay the foundation for subsequent vibration control and noise control.Use pressure difference sensor,clamp flow meter and other measuring devices to measure input power,atmospheric temperature,exhaust gas temperature,volume flow and other related data,and calculate the performance of HF170 oil-free twin-screw blower.(4)Vibration control of the whole machine according to the results of vibration test analysis,including vibration isolation,damping and vibration reduction,adjustment of quality and stiffness.According to the results of noise test analysis,low-noise design is carried out on the intake channel,exhaust channel and the whole machine,including noise absorption design,noise elimination design,and noise blocking design.The improved effect was verified by the test again.The vibration speed was successfully controlled below 2.4mm/s and the noise was controlled below85 d B,which solved the vibration and noise problems.