CHAPTER 5 CORRECTIVE MEASURES

Transcription

1 75 CHAPTER 5 CORRECTIVE MEASURES As per the analysis of air sampling tests and comparison of the results with standards, the fumes concentration at 2 meter and 4 meter distances from the welding machines are more than the minimum prescribed TLV level of 5 mg/cu.m. This is because the fumes and gases generated from the panel welding machines are stagnant around the welding machines, where the welder is working in his shift time. The natural welding system existed was not enough to dilute the fumes and gases generated from the welding machines. Hence the following corrective measures are suggested and implemented for reducing the concentration of welding fumes and gases well below the prescribed TLV level of 5 mg/cu.m. Following are the corrective measures suggested and implemented for reducing the concentration of welding fumes and gases, and radiation. 5.1 LOCAL EXHAUST SYSTEMS To improve the Ventilation System, a local exhaust systems with air suction capacity of 2000 cu.m/hr has been designed, which are to be mounted on each of the Water Wall Welding Machine. The schematic diagram of the exhaust system is shown in Figure 5.1. Also Figure 5.2 shows the panel welding machine after installation of local exhaust system.

2 76 Figure 5.1 Schematic Diagram of the Local Exhaust System Installed Figure 5.2 Panel Welding Machine after Installation of Local Exhaust System

3 FUME EXHAUSTERS Fume Exhausters are installed at a height of 4m in all column structures (total 8 numbers for each machine) inside shop floor, each with a suction capacity of 4000 cu.m/hr. 5.3 EXHAUST HOSES To reduce the toxic contaminations of the Welding Slag Dust generated from Submerged Arc welding (SAW) process, 6 local exhaust flexible hoses are arranged over the weld beads just after the 6 sprocket wheels on the machine as shown in Figure 5.3. These hoses are connected to one ID fan for sucking the slag dusts formed. Figure 5.4 shows the welded panel coming out of the machine with slag dusts sucked through the 6 local exhaust flexible tubes installed in the machine. Figure 5.3 Panel Welding Machine after Installation of 6 Local Exhaust Flexible Hoses for Sucking the Slag Dusts

4 78 Figure 5.4 Welded Panel Coming Out of the Machine with Slag Dusts Sucked through the 6 Local Exhaust Flexible Tubes Installed in the Machine 5.4 OPENING OF SHOP BOUNDARY WALLS To improve the overall ventilation and to minimize the accumulation of fumes generated during welding, all the boundary walls of the shops are opened from the top by 2.50 meters. 5.5 CURTAIN OF SPECIAL FILTER GLASS To reduce the light radiation and also for clear visibility of the job being welded through naked eyes, a curtain of special colored glass of shade No:11 and size 1m x 1m is mounted on each machine.

5 PERSONAL PROTECTIVE EQUIPMENTS Fume Respirators All welders are issued with fume respirators as an additional safety against the hazard of fumes and they are insisted to wear them compulsorily. Figure 5.5 shows the variety of fume respirators issued to welders. (a) Dust respirator with filter (b) Welding helmet fed with cleaned air (c) Breathing apparatus Figure 5.5 Variety of Fume Respirators Issued to Welders Welding Helmets Welding helmets with correct shades of filter plates are recommended and used. For protection of exposed skin adequate gloves and clothing issued. Safety glasses with UV protective side shields in addition to a proper welding helmet with filter plates are issued to all welders. Figure 5.6 shows the welding helmet with filter glass and Figure 5.7 shows how the helmet protects welder s eyes from flying sparks and radiation.

6 80 Figure 5.6 Welding Helmet with Filter Glass Figure 5.7 Welder Helmet Protects Welder s Eyes from Flying Sparks and Radiation Full Body Protective Clothing All the welders are issued to wear full body protective clothing as shown in Figure 5.8. Now all the welders are working very happily without fear of welding hazards in the shop floors.

7 81 Figure 5.8 Welder Working with wearing the Full Body Protective Clothing PPE for Noise Control Though the noise level in the working areas is below the tolerance level of 90dB, all welders are issued with Ear Plugs and insisted them to wear, so that the hazard due to noise is reduced.