| In recent years,noise has become the one of main environmental pollution of Hangzhou Cigarette Factory(especially making and packing workshop).According to data collection from 2008 to 2011,the noise intensity ranged from 77 dB(A)to 91 dB(A)in Hangzhou Cigarette Factory,part of monitoring spots reach to health limitation,more than 85 dB(A).Noise has already a negative influence on employees’ health and surroundings of enterprises,however,there is no systematic and particular research to noise control.In this paper,we will measure and analyze the noise from making and packing workshop by using LMS Tset.lab vibration and noise test system,to study noise reduction of its main production machines.The application of sound field simulation software RAYNOISE,to simulate the sound environment of making and packing workshop,and finally verify noise reduction both in equipment and new workshop.According to measurement and analysis data from making and packing workshop,the sound average values of cigarette maker area and filter rod forming area,are 86.9 dB(A)and 86.1 dB(A)respectively.The energy is mainly concentrated in low and intermediate frequency scope;The average sound of major equipment cigarette maker PROTOS 70 is 85.3 dB(A),energy is mainly concentrated in the low and intermediate frequency scope,and a maximum noise 91.2 dB(a)appear in 125 Hz frequency domain.The noise spectrum presents a multi harmonic frequency characteristic with 59 Hz as the fundamental frequency.The average sound 85.0 dB(a)for KDF4 filter rod maker,the energy focus on low frequency range,maximum noise 89.9 d B(A)located at 100 Hz frequency domain,the multi harmonic noise spectrum at 97 Hz fundamental frequency.Noise reduction of machine is researched on the basis of sound characteristics of equipment.The design of insulation sliding door follows noise source of cigarette maker PROTOS 70(non symmetrical pentagon);The design of insulation double door aims to noise source of KDF4 filter rod maker(rectangular).Using 3.5 mm C type steel as support structure of sound insulation cover,the Polyvinyl Butyral(PVB)is adopted to units of sound insulation which effectively reduce noise more than 6 dB(A),and especially in the low and intermediate frequency.Applying RAYNOISE software to simulate the original schemes(which use the same design with old workshop)of new making and packing workshop and five kinds of noise control scheme,to obtain the stimulated voice value of workshop environment and equipment.The results show,the best way is to use the efficient sound absorption material(NCR ≥ 0.95)for walls and ceiling,the intermediate-acting sound absorption material(NCR ≥0.8)for cylinder and lamp,which will realize the noise reduction of 3.3-3.8 db(A).To verify the noise reduction effect of present machine and whole workshop,PROTOS 70 cigarette maker realize noise reduction by 4.8-6.7 dB(A),and 4.9-6.1 dB(A)for KDF filter rod maker;The noise reduction of the whole workshop attain to 5.2dB(A).In addition,the new introduced equipment PROTOS M8 cigarette maker,GD H1000 cigarette packer which reduce respectively 7.7 dB(A)and 4.9 dB(A)compared to old machines.ZJ 112 cigarette maker and ZB 47 cigarette packer have respectively 5.5 dB(A)and 3.7 dB(A)diminution compared to the original models.KDF 10 filter rod maker reduce 7.4 dB(A)compared to old one.The research shows,PVB sound insulation,high and intermediate efficiency mat erial are expected to an effective means of noise control in cigarette factory. |
