All workers exposed to a hot and sometimes also humid environment may run the risk of heat stress and especially so if the work is strenuous. Heat loads at 7 different potlines were measured and some of the results are presented here. The overall picture that these data represent is that the heat exposure in the potlines is high and sometimes above the recommended Threshold Limit Values (TLV). Especially work in the Soderberg potlines during manual pot skimming (carbon dust removal) and anode deformation removal imposes considerable ahead stress. It is not unusual that Vernon Globe Temperatures then are above 100 deg C. in the Soderberg potlines the heat stress measurements showed a positive correlation with potline amperage and an indication of a correlation was found with the ventilation of the potroom. In the prebake potrooms anode changing may cause heat-induced problems. The variation in heat load form one prebake potroom to another was low with no evidence for dependencies on potline amperage or ventilation. Improvements must be sought for by looking at possible work practices, which at frequent intervals should allow the operator to be in a low-level heat load zone or by introduction of mechanical equipment that entirely removes the need to work in the heat exposed zones. The WiBGeT equipment for heat stress measurements was easy to use and none of the participating operators found it troublesome to wear. The method presented here represents a first attempt to compare heat stress measurements in all Hydro Aluminium's smelters and to combine these with a risk assessment method based on TLV values for work in hot environments. A method based on use of similar equipment and evaluations for future heat stress analysis will be recommended for the Hydro Aluminium smelters and probably also for other Scandinavian smelters.
展开▼
