I. 1...... 1991 784.,. 14.1%, 57.3%, 42.7% (. 1993).,....... 2.,.,... 1.,. - 2 -
..,,., 1,,,. 4. 2. ( ),... 1998 6 1999 9 1 3.,.,. (descriptive statistics), (network analysis) (path distance) (multidimensional scaling), Krackplot (graph analysis).. 3. 1. 4.,,,.,,,. 112,,,,,. 1,000 52% 300 33%. 100 11%.. - 3 -
T able 1. Regional and scale distribution of respondents Region Scale Region and scale Cases Percent(% ) Pusan Inchon T aejon Kw angju T aeku Ulsan Kyongki Chungnam Chungbuk Jonnam Jonbuk Kyoungnam Kyoungbuk T otal 99 100 299 300 499 500 999 1,000 T otal 7 4 2 8 3 8 25 9 3 9 1 16 17 112 12 25 6 11 58 112 6.3 3.6 1.8 7.1 2.7 7.1 22.3 8.0 2.7 8.0 0.9 14.3 15.2 100.0 10.7 22.3 5.4 9.8 51.8 100.0 T able 2. Industrial classification distribution of respondents Industrial classification Cases Percent(%) Manufacture of textile 4 3.6 Manufacture of w ood and of products of w ood and cork, except furniture; 2 1.8 manufacture of articles of straw and plaiting materials Manufacture of pulp, paper and paper products 1 0.9 Manufacture of chemicals and chemical products 11 10.0 Manufacture of rubber and plastics products 1 0.9 Manufacture of other non- metallic mineral products 5 4.5 Manufacture of basic metals 20 18.2 Manufacture of fabricated metal products, except machinery and equipment 1 0.9 Manufacture of machinery and equipment n.e.c. 1 0.9 Manufacture of office, accounting and computing machinery 1 0.9 Manufacture of electrical machinery and apparatus n.e.c. 24 21.8 Manufacture of radio, television and communication equipment and apparatus 11 10.0 Manufacture of medical, precision and optical instruments, watches and clocks 1 0.9 Manufacture of motor vehicles, trailers and semi- trailers 20 18.2 Manufacture of other transport equipment 4 3.6 Manufacture of furniture; manufacturing n.e.c. 1 0.9 Electricity, gas, s team and hot w ater s upply 1 0.9 W ater transport 1 0.9 T otal 110 100.0-4 -
21.8%, 1 18.2%,, 10.0%. 2. 3 5 24%, 100 12%. 60 90 80 32%, 90 31%.., 68%, 69%( 67%). T able 3. Distributions of local exhaust system and operation year No. of facilities Cases Percent(% ) Operation year Cas es Percent(%) < 5 18 24.3 Sixties 3 3.5 5 9 14 18.9 Seventies 5 5.9 10 29 18 24.3 First half of eighties 11 12.5 30 49 9 12.2 Second half of eighties 27 31.8 50 99 6 8.1 F irst half of nineties 26 31.0 100 9 12.2 Second half of nineties 13 15.3 T otal 74 100.0 T otal 85 100.0 93%( 91%) 77%( 72%) 99 39%, 98 49%. 3.,,,, (ACGIH, 1998). ( 76.1%), 72.1%,, ( 39.5%). T able 4. Dissatisfaction of elements of local exhaust system Elements Diss atisfaction rate(%)* Hood 70.9 Duct system 76.1 Fan 62.1 Exhaust stack 39.5 Air cleaning device 72.1 * Percent of 112 respondents, 18.6%, - 5 -
18.3% 13.3%, 12.8%..... 27.1% 15.1% 10.6% 52.8%....,,,.. 32.2%, T able 5. Dissatisfaction of elements of local exhaust system Hood Duct sys tem Dis satis faction Cases Percent (%) Diss atisfaction Cases Percent (%) Shape 33 18.3 Dimension 12 4.2 Dimension 24 13.3 Shape 6 2.1 Performance 33 18.3 Corros ion, deformation 18 6.3 Location 36 20.0 Leakage 16 5.6 Corros ion 13 7.2 Static press ure opening 40 14.1 Deformation 6 3.3 Noise 16 5.6 Noise 23 12.8 Damper 23 8.1 No. of hoods 10 5.6 Accumulation in duct 30 10.6 Others 2 1.1 Cleaning duct 77 27.1 T otal 180 99.9 Cleaning hole 43 15.1 Others 3 1.1 T otal 284 100.0 Fan Exhaust stack Diss atisfaction Cases Percent (%) Dissatisfaction Cas es Percent (%) Lack of capacity 16 10.7 Corros ion 11 33. 3 Corros ion 8 5.4 Noise 21 63. 6 Noise 48 32.2 Air intake contamination 6 18. 2 Motors 9 6.0 Deformation 4 12. 1 Belts 18 12.1 Others 5 15. 2 Pulley 7 4.7 T otal 17 100.0 Improper RPM 7 4.7 Bearings 19 12.8 Impeller 11 7.4 Safety cover 5 3.4 Others 1 0.7 T otal 149 100.0-6 -
T able 6. Dissatisfaction of air cleaning devices Items Scrubber Adsorption tow er Bag filter Cyclone Electrostatic preciptator Combustors or Oxidizers Cases Percent(%) Cases Percent(%) Cas es Percent(%) Cas es Percent(%) Cases Percent(%) Cas es Percent(%) T ype 6 6.8 6 13.3 6 6.7 2 4.3 3 12.5 0 0.0 Lack of ca pacity 11 12.5 3 6.7 8 8.9 6 13.0 2 8.3 0 0.0 Corros ion 11 12.5 3 6.7 7 7.8 7 15.2 3 12.5 3 18.8 N oise 10 11.4 4 8.9 12 13.3 11 23.9 3 12.5 5 31.3 Increas ing P res sure loss 10 11.4 6 13.3 12 13.3 3 6.5 0 0.0 0 0.0 T roubles 10 11.4 1 2.2 9 10.0 3 6.5 3 12.5 1 6.3 Connectors 3 3.4 0 0.0 1 1.1 0 0.0 1 4.2 0 0.0 Window s 6 6.8 6 13.3 9 10.0 3 6.5 3 12.5 2 12.5 Low efficiency 13 14.8 4 8.9 9 10.0 10 21.7 2 8.3 2 12.5 Operation cost 6 6.8 10 22.2 11 12.2 1 2.2 3 12.5 3 18.8 Others 2 2.3 2 4.4 6 6.7 0 0.0 1 4.2 0 0.0 T otal 89 100.0 45 100.0 90 100.0 46 100.0 24 100.0 16 100.0 12.8%, 12.1%, 10.7%, 7.4%. 51.8 84.0%, 15.4 47.6%., ( ) ( ),,,,..,,,,,,,,,,,.. 4., 53.3%... 15.1%.. 78.3%. - 7 -
T able 7. T ype of Information suppliers T ype Cases Percent (%) Ministry of Labor 1 0.7 Korea Occupational Safety & Health Agency 81 53.3 Anti- pollution equipm ent businesses 81 53.3 Galvanized sheet w orks 23 15.1 Consultants 8 5.3 F actories of same kind 15 9.9 F actories of different kind 1 0.7 Others 13 8.6 T otal 152 100.0 24.4% 25 2. 1 64.6%,,. 44.2%, 35.7%. PC 4%,. 57.1% PC 76.8%.. 29.1% 26.8%, 22.2%, 21.8%. 4,,,.. 47.0%, ( ) 28.7%, 11.3%. 87%.... 44.7% 24.7%, 13.0%, 9.4%.. - 8 -
. 50% 23.4%, 15.6% 89.0%. 32.2%, 12.8%,,,,. 50%, 23.4%, 15.6% 89.0%,.. T able 8. Contact frequency per year and contact methods Items Cases Percent (% ) Contact frequency 1 8 6.8 per year 2 9 7.6 3 15 12.7 4 6 5.1 5 16 13.6 6 10 22 18.5 11 24 13 11.0 25 29 24.4 T otal 118 100.0 Contact methods Phone 92 35.7 FAX 30 11.6 Visit 114 44.2 Post 11 4.3 PC comm unication 8 3.1 Internet 2 0.8 Others 1 0.4 T otal 258 100.0 T able 9. Results of information search concerning elements of local exhaust system Elements Cases Percent (% ) Hood 70 26.8 Duct system 76 25.0 F an 57 50.0 Air cleaning device 58 75.0 T otal 261 100.0-9 -
T able 10. Detailed information of elements of local exhaust system Hood Duct s ystem Fan Air cleaning device Information Cases Percent Percent Percent Percent Information Cases Information Cases Information Cases (%) (%) (%) (%) T ype & Shape 54 47.0 Diameter 38 44.7 Capacity 32 50.0 T ype 32 50.0 Flow rate required* 33 28.7 Material** 21 24.7 T ype 10 15.6 Efficiency 10 15.6 Dimension 11 9.6 Head los s 8 9.4 Material*** 15 23.4 Material 15 23.4 Material 1 0.9 Accumulati on in duct, 3 3.5 W /A 2 3.1 Cost 2 3.1 clogging Location 13 11.3 Length, s hape 11 13.0 Efficiency 3 4.7 Capacity 3 4.7 Des ign Waste 3 2.6 Cleaning 3 3.5 Pow er 1 1.6 method treatment 1 1.6 T otal 115 100.0 Damper 1 1.2 Impeller 1 1.6 Safety 1 1.6 T otal 85 100.0 T otal 64 100.0 T otal 64 100.0 * Flow rate required and control velocity ** Including material, anti- acid, anti- corrosion, and manufacturing according to material *** Including anti- explosion, anti- acid, anti- corrosion Wheel alignment T o remove dust on impeller 46.9%, 14.7%.,. 39.9%, 9.8%. 38.5%, 50.4%..,,, 62%, 25%, 40%, (,,, ) 32%, 11%, 57%, 14%, 16%, 57%, 17%. - 10 -
T able 12. Distribution of path of information informants, its relationship, and period of contact Item s Cas es Percent (% ) Informants Ministry of Labor 3 2.2 Korea Occupation S afety & Health Agency 13 9.4 Friends or alum ni 11 8.0 Factories of s ame kind 54 39.1 Factories of different kind 13 9.4 Advertisement 5 3.6 Others 39 28.3 T otal 138 100.0 Relationship Business 108 87.8 Alumni 3 2.4 Others 12 9.8 T otal 123 100.0 Contact period < 1 year 3 3.2 1 2 34 35.8 3 4 15 15.8 5 9 29 30.7 10 years 14 14.8 T otal 95 100.0 5..,.,.,,,.,,..,,, 5 4. 1. 1., 2.,,,., - 12 -
.,, 5.,.,,.,., 3. 3.,..,... Fig 1. Information network for local exhaust system design - 13 -
,.,..,,.,, 4. 4,,,.,,...,, 5.,. Fig 4. Information network for local exhaust system - 15 -
.,.,,, 1998 6 1999 9., Krackplot. 1) 68%, 67%, 91%. 2),,,,,,,. 3), 1. 4) 3/4,,, FAX PC. 5). 6). 7),.. 8). 9),.,. - 16 -
.,...... RE FE RE NCE S.. ; 1993 American Conference of Industrial Hygienists. Industrial ventilation a manual of recommended practice. 23rd ed. Cincinnat: ACGIH; 1998, p. 1-2 - 17 -